EYEPIECE Journal of the Amateur Astronomers Association of New York

May 2012 Volume 61 Number 5 ISSN 0146-7662

By TOM HAEBERLE

There is no question about the importance of the

transit of Venus. It has inspired early astronomers to accu-

rately measure the solar system by determining the value of the astronomical unit (AU). Measure it, they did, but its accu-

racy remained questionable for a long time.

The possibility that Venus may on rare occasions pass in

front of the sun was first given serious thought by Johannes Kepler years before he died in 1630. His predicted transit of

1631 was not observed due to uncertainty of observation local-

ity. He also failed to predict the 1639 transit.

Fortunately the young English astronomer Jeremiah Hor-rocks fined-tuned Kepler’s calculations and realized transits

occurred in pairs of eight years. Barely months before the

event, Horrocks contacted his friend William Crabtree to

watch the event on and around December 4, 1639. Both men

were successful and they became the first two human beings to

see the event.

Kepler’s third law of planetary motion predicted a

planet’s distance from the Sun in relation to its orbital period.

The exact distance in miles were completely unknown. Dis-

tances are measured in AU’s which is the Sun-Earth distance

being equal to one and an orbital period of one year; all the

other planets distances and periods are in relation to the Earth.

Edmond Halley realized that the Venus transits could be

the solution to determining the size and scale of our solar sys-

tem. In the next transit years of 1761 and 1769, international

scientific expeditions were assembled and disbursed to all

parts of the world. Observations were also made from Tahiti

on the first voyage of Captain Cook. But many of these transit

parties would not come home unscathed. Cook had lost promi-nent astronomer Charles Green to illness in 1769. The French

lost members to diseases at the Baja California post.

But despite successes, the accuracy of start and exit times

was to be foiled by the “black drop effect,” a dark elongated projection linking Venus with the sky when Venus entered or

left the sun’s disk. Other “new” technologies of the 19th

The History of Venus Transits continues on page 2

The History of Venus Transits

By DAN HARRISON

NASA took a hit in the fiscal 2013 federal budget re-

leased in March and the agency is reportedly reconsidering

whether it has the necessary funding for future missions to

Mars.

The budget proposal of $17.7 billion, a decrease of 0.3%

or $59 million from the fiscal 2012 budget, places NASA at its

lowest level of funding in four years. President Obama envi-

sions a flat budget through 2017, with no out-year growth even

for inflation, and reflects a series of cost-cutting measures put

forth by the administration.

Specifically, Mars exploration would be cut $226.2 mil-

lion in fiscal 2013, down from this year’s $587 million. The

remaining $360.8 million will go for the nuclear-powered Mars Science Laboratory (MSL) now en route to the planet,

and the upcoming Mars Atmosphere and Volatile Evolution

Mission (MAVEN) orbiter scheduled for launch in 2013 to

study Mars’ upper atmosphere.

The budget proposal would effectively end NASA’s co-

ordination with the European Space Agency. Asked whether

NASA would continue to send smaller-scale probes to the

planet, officials noted they remain in contact with ESA about a

2018 Mars mission.

The latest budget cuts could leave NASA with few op-

tions beyond eliminating future missions. The agency noted it

remains confident it can continue to fulfill its role in space

exploration.

“We’ll develop an integrated strategy to ensure the next

steps for Mars exploration will support science as well as hu-

man-exploration goals, and potentially take advantage of the

2018 to 2020 exploration window,” said administrator Charles

Bolden.

Some officials said the latest budget demonstrates a

downward trend, and that NASA is unlikely to launch any

major missions to Mars in the near future.

“We’re looking at a moderate mission, a partnership

seeking synergies between human spaceflight, science and the

need to demonstrate technologies that advance other missions

in the future,” an agency official said.

The administration noted the proposal didn’t reflect an

intention to eliminate key NASA endeavors, instead citing the

need for budget constraints in light of the projected deficit.

Some important, but currently unaffordable missions are de-

ferred, such as large-scale missions to study the expansion of

the universe and to return samples from Mars.

Downsizing NASA - Less is Not More continues on page 5

Downsizing NASA – Less is Not More

2004 Venus Transit

From Carl Schurz Park

(Stan Honda, 2004)

2

May’s Evening Planets: Jupiter has plunged towards the

Sun and soon will be gone. Look for it early in May and low

in the west. Venus is also beginning a precipitous fall and will be gone by the end of the month. It will be very close to the

bright second-magnitude star for several days centered on

May 6th. Moving into center stage are Mars and Saturn. Mars

is moving away from Earth and getting fainter. Saturn, close

to the first-magnitude star Spica, was at opposition to the Sun

last month and is still moving retrograde (east-to-west).

May’s Evening Stars: Auriga and Gemini can be seen in

the northwest as they begin to set. They are all that is left of

the great winter stars. Use Mars to pick out Leo the Lion and

its bright star Regulus. To the southeast of Leo is Virgo the

Virgin. Like Leo, Virgo is easily located by the planet Saturn

and the star Spica. The Big Dipper is high at this time of year.

Follow the arc of its handle to Arcturus, the brightest star of the spring sky. Arcturus’s constellation is Boötes the Herds-

man. Moving to the northeast, we can spot with some care the

constellation Hercules. Below Hercules is the bright star Vega

in Lyra the Lyre, one of the stars making up the Summer Tri-

angle which we’ll see more of next month. May’s Morning Planets: The only bright planet is Saturn,

low in the southwest. For the more adventurous, eighth-

magnitude Neptune is in Aquarius. Uranus, in Pisces, is very

low and will require quite an effort to spot. The two planets

will improve their position over the next few months. May’s Morning Stars: The glorious Summer Triangle domi-

nates the overhead sky. To the south are Scorpius the Scorpion

and Sagittarius the Archer. Spring constellations like Boötes

and Virgo (containing Saturn) are still visible in the west. To

the east are Pegasus and its Great Square. Extending it to the

northeast takes us to Andromeda.

May 4 The Moon, Saturn and Spica gather low in the

evening sky. Mars and Moon are 6½° apart,

Saturn and Moon are 8½° apart May 5 Eta (η) Aquarid meteors peak (full Moon at 10:35p.m. (EDT) will limit the number seen) May 6 Spica is closest to the Moon (5°) May 8 The Moon is 8° left of Antares May 12 Last Quarter Moon at 2:47 p.m. (EDT) May 13 Jupiter is in conjunction with the Sun May 15 Venus is stationary. It will begin falling back to-

wards the Sun at a faster rate

May 20 Solar eclipse; China to western US (not in NYC) New Moon at 4:47 p.m. (EDT)

May 22 Venus is 5½° from the Moon in the twilight sky

May 27 Mercury is in superior conjunction with the Sun,

in the evening sky; Regulus is 7° above the Moon May 28 First Quarter Moon at 3:16 p.m. (EDT) May 29 Mars is 8° north of the Moon.

For additional information visit: www.aaa.org/month1205

The History of Venus Transits (continued from page 1)

century would be employed to better capture and measure in-

gress and egress times, utilizing telegraph communication be-

tween scientists, maritime chronometers to accurately time events, and improvements made with astrophotography to su-

persede drawings.

Encouraged by English astronomer John Herschel, a

wealthy businessman named Warren De la Rue was to oversee

the development of the photoheliograph. The initial design by

De la Rue was to be built under his supervision by Andrew

Ross and Company who had enlisted the help of German opti-

cian John Henry Dallmeyer as science advisor.

This device would be used by astronomers to capture the 1860 eclipse in Spain. Larger images of the Sun were captured

in 1874 and 1882 with similar devices. In the latter year,

American astronomer David P. Todd went to California’s Mt.

Hamilton Observatory to view the transit. Using an ex-

panded photo-heliostat device and the observatory’s twelve-

inch refractor, he was able to obtain photographs of the event.

The photo plates were regarded as the best obtained from that

era.

Observers in the eastern United States had the advantage

of watching the transit in its entirety in 1882. Lewis M. Ruth-

erfurd is said to have observed the transit from Second Avenue

in New York City. Unfortunately all these attempts yielded no

better results despite all the care and effort to obtain an accu-

rate value of the astronomical unit.

In the end Venus would provide a meaningful measure-

ment of the AU, but not by the transit method. In March, 1961,

radio astronomers bounced signals off the planet and received

its echo in 6.5 minutes. Even this wasn’t considered accurate.

Over time, the AU has become a “derived constant” with its value being equal to an ideal body and not the actual planet

Earth. Also, measurements made of positions of space probes

provided a more absolute value. So the mean distance between

the Earth and the Sun has yielded a modern value of

92,955,807 miles.

A few months after the 2004 transit, Dr. Jay Pasachoff

spoke at the American Museum of Natural History regarding

his research in to the black drop effect. His concluding re-

marks where that the “effect” came from both the blurring by

“older” terrestrial telescopes and solar limb darkening as Ve-

nus entered the disk. It is Earth’s atmosphere that pronounces

this effect from the ground and that the refraction through Ve-

nus's atmosphere wasn’t a factor in causing the effect.

The next transits of Venus will be in December, 2117 and

December, 2125. So we’ll have to wait at least 105 years for

the next one unless we can find a way to get to Mars sooner.

Venus transits happen more frequently there, roughly at 32

year intervals. But a transit of Venus from Mars is like seeing

a transit of Mercury from Earth; being the same apparent size

from their respective planets.

After 2012, one can only ponder worlds we will never

know and events unseen. But mark your calendar; there will be

a transit of Mercury on May 16, 2016. Then there is the great-est transit of all coming our way on August 21, 2017, a Total

Eclipse of the Sun is to cross the contiguous United States for

the first time in 38 years. ■

WHAT’S UP IN THE SKY

AAA Observer’s Guide for May 2012

By RICHARD ROSENBERG

EYEPIECE May 2012

May’s “Skylights”

3

Hello Members:

On this, my final message to you all as president, I want to thank those who have helped me along the way:

- Michael O’Gara and Lynn Darsh, my predecessors as president, who helped me get my feet wet

- Tom Haeberle, club treasurer and fellow NexStar 8 observer

- Joe Delfausse, who manages financials with Tom and makes the High Line a must-see for the public every week

- Jason Kendall, Inwood Hill Park’s intrepid version of Joe, representing the club on air, in class and in the field

- Marcelo Cabrera, AAA webmaster, who always found the problem when my computer acted flaky

- Dan Harrison and Evan Schneider, who have produced and perfected our terrific news journal, Eyepiece

- Gerceida Jones, who restored our AAA Seminar as a club event

- Edward Fox, whose accurate minutes guide us and who has developed our new AAA online store

- David Kraft, who does a terrific job each year finding speakers for our AAA Lecture Series

There are too many others to mention, but my thanks to all of you.

It’s been a lot of fun and nothing will change. I hope to remain a board member, and I’ll be at the High Line and the

Brooklyn Heights Promenade observing with you all.

See you at our annual meeting on May 16th!

Sincerely,

Rich Rosenberg, AAA President

A Message from AAA President Richard Rosenberg

EYEPIECE

Maybe yes, maybe no, but researchers this month wrote

in the International Journal of Aeronautic and Space Sciences

that one of the three experiments, which were known as the

“Labeled Release” (LR) experiment, hinted at the presence of

life on Mars, while the others did not.

In 1976, two Viking probes went to task seeking the pres-

ence of Martian life. As with other more recent missions, exo-

biologists observed heated soil samples, but in this instance

treated it with a radioactive aqueous solution. Gases given off

by the first of the three experiments hinted at signs of life.

With more knowledge over time, scientists have now

offered a new perspective, that perchlorates may have con-

taminated the other two experiments, which had originally

caused scientists to discount the first successful outcome. A

mathematical analysis of the samples found that salts in the soil on Mars “threw off” initial estimates, and that the soil

samples show strong evidence of microbial life.

The major issue with any experiment is that it must be

staged and proven before testing can occur on another world. “Ideally to use a technique on data from Mars one would want

to show that the technique has been well calibrated and well

established on Earth,” stated planetary scientist and astrobiolo-

gist Christopher McKay from NASA’s Ames Research Center.

“Finding organics is not evidence of life or evidence of past

life. It's just evidence for organics,” he clarified.

Despite NASA’s position, other scientists remain more

optimistic. “The ultimate proof is to take a video of a Martian

bacteria. They should send a microscope - watch the bacteria

move,” said Dr. Joseph Miller at USC's Keck School of Medi-

cine. “On the basis of what we've done so far, I'd say I'm 99%

sure there's life there.”

The answer may come soon, with NASA’s Curiosity

rover scheduled to land on Mars at Gale Crater near Mount

Sharp on August 6. Earth - please stand by. ■

Life on Mars? The Debate Continues as Viking 1 and 2 Data are Scrutinized

May 2012

NEBULA OF THE MONTH: STINGRAY

A nebula is born. In 1998, astronomers witnessed for the

first time the birth of a nebula (HEN-1357), as large as 130

solar systems, but 18,000 light-years from Earth. It appears

only as big as a dime viewed a mile away. Formed after an old

star swelled to become a red giant and ejecting its outer layers

into space, the bright central star is surrounded by a green ring

of gas. Its companion star is diagonally above at 10 o'clock.

“The Stingray nebula is, in

human terms, just an infant because only within the past 20 years did its central star rap-

idly heat up enough to make the nebula start to glow. It is extraordinary to catch a star in

this exceedingly brief phase of

its evolution.”

Photo and Quote:

NASA; Matt Bobrowsky

Orbital Sciences Corp.

What is your favorite nebula? Write eyepieceeditor@gmail.com to have your answer published!

Contacting AAA

Membership: members@aaa.org

Eyepiece: editor@aaa.org

General Club Matters and Observing: president@aaa.org

Telephone: 212-535-2922 Website - www.aaa.org

4

come with cheap telescopes, have all but disappeared. They’re

very dangerous, though, as they can crack when they heat up,

and should never be used.

Your telescope’s finder - which magnifies light and has a

larger aperture than your eye - should be covered or removed

when solar observing. You could cover it with a mini-cell

made of solar filter film.

Projection - The easiest way to project the Sun’s image

is with a pinhole projector: making a tiny hole like a pinprick

in a sheet of paper. An image of the Sun will appear behind it.

Projecting it on a white surface is best. In order to see Venus,

the projected image should be at least a yard away from the

pinhole.

One can use a telescope to project a brighter image. Care

must be taken that no one gets between the eyepiece and

screen and inadvertently looks directly at the Sun. Eyepiece projection should be used for limited time periods, as the Sun’s

heat can damage the eyepiece by softening the glue holding

the elements together. ■

I have used my 60mm refractor to observe Mars from

late February through early April 2012.

Mars displayed a large triangular dark region, Syrtis Ma-

jor, during the last week of February in the eyepiece of my

refractor at 100x. The region looked a dark gray as contrasted

with the otherwise coral pink Martian disk. Mars rotates slightly more slowly than does the Earth so that, as each eve-

ning passed, Syrtis Major was displaced an additional 9 de-

grees closer to the limb of the planet and eventually disap-

peared. Other dark regions rotated into place but were rather

vague and not distinct in the eyepiece of my refractor. Fi-

nally, in early April, Syrtis Major again began to reappear on

the Martian disk, but by then Mars had reached its closest ap-

proach to Earth in early March so that the apparent size or an-

gular extent of the disk shrunk from around 14 seconds of arc

to around 12 seconds of arc.

Mars will become hard to observe as the apparent angular

extent of the disk shrinks due the Earth's leaving it behind as

we orbit more rapidly around the Sun. Meanwhile Saturn was

rising earlier toward its mid-April opposition and Venus was

becoming an ever thinning and enlarging crescent as it ap-

proaches its transit of the Sun on June 5. ■

EYEPIECE May 2012

HOW TO SAFELY OBSERVE JUNE’S VENUS TRANSIT By TONY HOFFMAN

On June 5, for the second time this century and the

last until 2117, the planet Venus will transit the disk of the

Sun. This event will be visible from New York between 6:03

p.m. until sunset at 8:24 p.m. The AAA will be hosting an ob-

serving event, as will several other organizations, but you can

also view or photograph the transit on your own. In observing

the Sun, eye safety is paramount. Fortunately, there are per-

fectly safe ways to enjoy this event.

Solar Filters - Most solar filters block all infrared and

ultraviolet light while letting a greatly reduced amount of vis-

ual light through. They’re designed either for visual, including telescopic observation, or for use with a camera. Filters meant

for visual work must have an optical density of at least 5.

Filters for unmagnified viewing include eclipse glasses,

sheets of special film, and #14 or darker welder’s glasses. The trouble is that Venus’s disk is near the limit of naked-eye visi-

bility for most observers. I was unable to see Venus without

magnification during the 2004 transit.

Some filters intended for photographic use only (for ex-ample, Baader AstroSolar film, with an optical density of 3.8)

transmit more light than filters for visual use. They can be

used safely as long as the photographer avoids looking through

the camera’s optical viewfinder in framing the shot. Most re-

cent DSLRs incorporate Live View, a digital viewfinder,

which is totally safe to use.

Hydrogen-Alpha Filters - The two main types of solar

filters are white-light filters, which transmit much of the visual

light spectrum (at greatly reduced brightness), and hydrogen

alpha filters, which transmit a narrow bandwidth centered on

the hydrogen alpha spectral line (656.28 nm). Hydrogen alpha

filters are more expensive—one for a 4-inch scope costs about

$700, while an equivalent white-light filter costs barely a tenth

of that—but can show much more detail, including filaments,

prominences, and flares. A white-light filter shows mainly

sunspots.

Dedicated solar telescopes with hydrogen-alpha filters

are also available. The most well known is the Coronado PST

(personal solar telescope), which has a 40mm objective and sells for about $600. Coronado and other companies such as

Lunt Solar Systems also sell higher-end models.

White-Light Filters - White-light filters are available either as glass or a thin film similar to Mylar. Filter makers set

their filters in cells that fit most common scope or camera lens

diameters, so they can be placed over the front of the tube.

Manufacturers also sell film in sheets, so amateurs can build

their own cells. Be sure the cell fits snugly around the tube,

and is in no danger of being blown off. Also, be sure that thin-

film filters are not damaged or ripped before each use.

In a refractor, telescopic filters must totally cover the

objective. For reflectors, filters are generally off-axis, to pre-

vent the secondary mirror from blocking a portion of the light

path and introducing unwanted diffraction. The filter only cov-

ers a portion of the objective (the rest is masked), effectively

stopping down the telescope’s aperture. This usually produces

a more stable image in large reflectors.

Fortunately, eyepiece solar filters, which used to often

Mars Observations February-April 2012

By JOE FEDRICK ________________

Mars’ Syrtis Major Planetia

(at far right of planet image)

A 630-mile wide basaltic rock forma-

tion first discovered by Christiaan

Huygens in 1659.

Photo Credit: NASA.gov

5

EYEPIECE May 2012 Downsizing NASA - Less is Not More (continued from page 1) The budget proposal doesn’t imperil NASA’s $2.5 billion Mars Science Laboratory mission, which will deliver the Curi-osity rover this August to investigate if the planet can, or ever did, support microbial life. Nor does it affect the $485 million MAVEN mission, to launch in late 2013 to study Mars’ upper atmosphere and gather information about how the planet’s climate has changed over time. The proposed budget responds to diminished funding for robotic exploration. Obama allocated $1.2 billion to NASA's planetary-science programs, a 20% cut from current the allot-ment of $1.5 billion, with further reductions expected over several years. O cials indicate a “basic mission” to Mars might cost somewhere between the $485 million MAVEN and NASA’s $720 million Mars Reconnaissance Orbiter, which launched in 2005 and is still studying the planet. The scaled-back Mars strategy puts on hold plans for a sample-return mission. NASA is continuing to work on an astrophysics flagship mission, the James Webb Space Telescope. The huge instru-ment, billed as the successor to Hubble, is slated to cost $8.8 billion and launch in 2018 at the earliest. In addition to a sample-return mission, another probe on inde nite hold is one that would study Jupiter’s ocean-hosting moon Europa. Although potentially ripe with some sort of life given the abundant present of water ice, the mission is cur-rently too expensive. Potential funding cuts are deeply unsettling to some sci-entists and space-exploration advocates. “People know that Mars and Europa are the two most important places to search in our solar system for evidence of past or present life forms,” said Jim Bell, president of the Planetary Society. “Why, then, are missions to do those searches being cut in this proposed budget? If enacted, this would represent a major backwards step in exploration of our solar system.” Society CEO Bill Nye told SPACE.com: “We are on the verge of finding habitable environments on Mars and other worlds. These discoveries will change the world. Curtailing this work now will lead to spacecraft that don't work right, missions that crash and dissipation of the aerospace work-force.” NASA isn’t abandoning agships forever. Scientists and managers will keep laying the foundations necessary to enable ambitious missions, so they'll be ready to hit the ground run-ning should the fiscal environment improve.

________________________

Observing the AMNH/AAA Star Party By JASON KENDALL

The AAA continued its fine tradition of coordination and support of the AMNH Rose Center’s Hayden Planetarium on March 27. For years, dedicated club members have been collaborating to achieve a common goal: sharing our love of the night sky with the wondrous public. That night in the dome, JJ Rusher was giving a Celestial Highlights tour with the Zeiss projector. Across the dome ceiling was the night sky, just a week before the spectacular conjunction of Venus and

Jupiter. While the planetarium show unfolded, members of the AAA were busy setting up telescopes on the adjacent Ross Terrace. Ted Williams from the Franklin Institute brought his sound system to lead the evening. Brooklyn amateur astrono-mer Stephen Stromer brought a huge telescope to wow the crowd. But they weren't the only ones. The club was amply represented by our intrepid observers including Michael O'Gara, Bruce Kamiat, Jordan Kushner, Rori Baldari, Howard Fink, Rik Davis, John Delaney, Ed Fox, John Benfatti, Jason Kuperman and Sara Freizer, David Sena, Mark Tuthill, Hora-cio Dortona, Andy Lawler, Surayah Davis and Joseph White. On display that evening were telescopes of all sizes, but it was Jupiter, Venus and the Moon that graced the Ross Ter-race with their beauty. All of the observers set up and waited with anticipation for a mass exit of the 400-person planetarium audience to view the celestial objects above. While the observ-ers focused on their targets in the sky, Ted Williams gave an impromptu presentation over the sound system. The crowd was so large that, when called up to the microphone, I didn't even hear Ted’s voice. I was focused on teaching people wait-ing on observing lines how to navigate around the constella-tions using nothing but an outstretched hand. The evening came to a close promptly at 10 p.m. Suz-anne Morris, Senior Manager of Public Programs, called the evening “a complete success,” and said that she can't wait for the next exciting AMNH/AAA joint event together in June. Afterwards, as is often the case, many of our AAA ob-server team members visited a nearby pizzeria to discuss club events, public outreach, current science and the joys of sharing their varied interests in astronomy with others. The AAA and its dedicated members once again demon-strated that AAA and the AMNH working together can suc-cessfully create community, educate the public and offer an enjoyable outing of family fun.

Astronomical Fact of the Month

The Great Wall of the Universe Spanning 1.37 billion light years across and containing over 10,000 galaxies, the Sloan Great Wall stands almost two billion light years from Earth (or 613 Megaparsecs in astronomical terms). Its network of superclusters of galaxies are not gravita-tionally bound, yet they stand as part of this massive structure. ________________________

The Sloan Digital Sky Survey quantified this portion of our uni-verse utilizing a dedicated 2.5 meter telescope at Apache Point Observatory, New Mexico, and a 120-megapixel camera imaging 1.5 degrees of sky (about eight times the area of the Moon). A pair of spectrographs measured 600 galaxies and quasars in a single observation. The final dataset included 230 million celes-tial objects detected in 8,400 square degrees of imaging, and spectra of 930,000 galaxies, 120,000 quasars and 225,000 stars.

6

solar system. As our astronomy technology advanced, we’ve

even managed to discover planets in other solar systems.

Eventually, we will discover that some of those Earth-sized extrasolar planets have liquid water and oxygen. Then, we

have a planet with life that we will want to study more than

any other. Then we reach the limits of remote observing tech-

nology. The only way to study a planet for signs of life and

civilization is to go there. That is an enormous leap in technol-

ogy but also a foreseeable one.

In a few hundred years (or more) humans will improve

the propulsion methods of space probes and probably send a

probe to another star system in a reasonably short amount of

time. These extrasolar planets that we think have life on them

will probably be the first destination. Hopefully we will find

complex life walking or flying about or huddling around

campfires. Maybe we will find an intelligent species with

farmers, engineers, scientists and politicians.

It stands to reason that if technologically advanced extraterrestrials do exist and are more advanced than humans,

then eventually they would have detected the rocky planets in

our solar system within the habitable zone. Eventually, they

would send a probe to observe us. So, if there are alien space

probes doing flybys of Earth right now, they would want to

study first before they talk to us. It would afford them a rare

opportunity to see a primitive civilization develop and give

them a better perspective on their own evolution. We can only

guess how they would judge us based on our struggles with

human conflict, limited resources and treatment of our natural

environment. At some point, they might decide that we have

matured enough as a species and decide to make contact.

So, if aliens decide to contact humans, who do they call?

Imagine an alien message in an email to the White House or to NASA. No one would understand it or take it seriously. This

is the irony of the situation. If an alien species tried to contact

anyone on Earth that was not specifically listening for them,

the call would not be seen as credible. Also, the signal itself

won’t be in a form that is easy to understand. The only organi-

zation capable of receiving and understanding a signal from an

alien civilization would be an organization designed specifi-

cally to listen for alien contact. It is for this reason that it is

important for humans to continue to support SETI’s efforts.

They are the only ones who will answer the phone. Let us

make sure they keep listening for Earth. ■

Richard Brounstein’s monthly column, “WHAT IF,” explores what today

seems improbable or impossible. Stay tuned for more fascinating concepts.

Carl Sagan once asked “Who speaks for Earth?” We

still don’t have an answer to this. In this article, I would like to

ask the question, “Who listens for Earth?”

In 1959, Frank Drake began an experiment (Project

Ozma) to search for extra-terrestrial intelligent life forms

(aliens) in other parts of the galaxy. He theorized that an alien

civilization, at least as advanced as humans would have radio

technology. Radio waves travel at the speed of light and could

be travelling throughout the cosmos. Humans have sent radio signals into space since the 1930s so why shouldn’t aliens be

sending us signals? All we have to do is listen. In 1984, the

SETI (Search for Extra Terrestrial Intelligence) Institute was

founded and ever more sophisticated experiments were con-

ducted to find evidence of artificial radio signals coming from

somewhere else in the galaxy.

Unfortunately, many people (including scientists) believe

that finding aliens is so unlikely that these searches are not

worth the effort. This translates into limited support. In April,

2011, the SETI Institute shut down the Allen Telescope Array

due to funding shortfalls. While funding was eventually found

and the array came back on line in December, 2011, for eight

months, the human race was not listening for any aliens that

might contact us.

Why are people so skeptical? That is easy to figure out. Consider that planets with liquid water (the only way known

way to create life) are extremely rare. Even less likely are

planets that actually formed microbial life in this water. Only

a small subset of those planets with microbes might have

evolved more complex life forms such as plants and animals.

Yet, just because a planet has complex life forms does not

mean it will have evolved intelligent beings like primates. We

can hope that if intelligent life evolves, it is only a matter of

time before they learn to build technology like wheels, com-

puters and spacecraft. Yet there is no guarantee. In other

words, probably the rarest thing to find in the universe is a

planet with an intelligent species who can build technology.

We should feel honored to know that human beings are

probably among the rarest things in the universe. Certainly, finding another civilization would be the most incredible dis-

covery history. But does that mean that aliens would bother

contacting us?

We can predict the behavior of aliens by looking at the

one example of a technologically advanced civilization…

humans. Humans have survived and thrived partially because

of our exploration of our planet and current exploration of the

EYEPIECE May 2012

WHAT IF??? WHO LISTENS FOR EARTH? By RICHARD BROUNSTEIN

Cartoon by Joshua M. Erich (www.pixelatedparchment.com)

7

Good Night, Moon(s)

Earth usually has more than one moon at any given

time, according to a new computer simulation. The familiar

Moon is joined by a rotating cast of captured asteroids that

often measure just a few feet across. The mini-moons typically

orbit Earth for less than a year before shooting back into space.

Scientists simulated movements of 10 million near-Earth aster-

oids as they passed by us. They then tracked trajectories of the

18,000 space rocks that Earth’s gravity captured in the simula-

tion. At least one asteroid with a diameter of 3 feet or more is

likely orbiting Earth at any one time.

Billions and Billions….and Billions

There should be billions of habitable, rocky planets

around the Milky Way’s red dwarfs, a new study suggests,

based on a survey of 102 of these stars. Astronomers found

nine planets slightly larger than Earth. They weigh 1-10 times

Earth’s mass, and two were discovered in their star’s habitable

zone. Extrapolating from these findings, researchers estimate

that tens of billions of these planets are in the Milky Way,

about 100 in the immediate neighborhood of the Sun. So,

about 40% of all red dwarfs have a super-Earth in the habitable

zone. Since red dwarfs are cooler than the Sun, their habitable zones are much closer in than ours. That puts planets there at

risk of being hit with stellar eruptions or flares, common on

red dwarfs. Such flares could release X-rays or ultraviolet ra-

diation that could harm or inhibit development of life.

Disko is Back

Stars with disks of debris around them might be good

targets to search for Earth-like planets, researchers say. Debris

disks consist of fields of planetesimals and dust encircling

stars. A few hundred stars have shown signs of a debris disk. It’s thought debris disks are replenished by collisions between

asteroid-sized bodies that are leftovers of rocky planet forma-

tion. If any disk is relatively large, its system might be calm

enough for rocky worlds to form. Stars with wider and more

massive outer disks are more likely to harbor rocky planets.

Systems with less massive Neptune-sized giant planets are also

likely to support terrestrial planets. Although stars with debris

disks should be good places to look for terrestrial planets, only

about one in six stars older than 1 billion years are observed to

have the disks.

Stars on the Orbital Runway

Some zones encircling baby stars are far more popu-

lar than others, drawing crowds of giant planets while the

other potential paths for orbits remain empty. Certain orbital

distances seem strangely attractive to gas giants. The apparent

explanation: high-energy radiation from these stars. Radiation

carves gaps in protoplanetary disks of gas and dust that swirl

around young stars and provide raw materials for worlds. This

process, photo-evaporation, is the result of ultraviolet light and

other high-energy photons from the star heating the disk mate-rial closest to the solar systems. When surveys aimed at dis-

covering extrasolar planet systems get better at spotting outer

giant planets, astronomers expect to find more evidence for a

pileup of giant planets at around 1 AU.

Gassing Up the Galaxy

Galaxies don’t seem to have enough matter inside

them to keep forming stars at the rates they do. But astrono-

mers have caught a galaxy in the act of recycling material it

previously threw out, which may explain the misconception.

Our Milky Way seems to turn about one solar mass’ worth of

matter into new stars every year. Yet it doesn’t have enough

raw materials, such as gas and dust, to continue for more than

a few billion years. Observations of multiple galaxies suggest

the Milky Way is typical in this regard, gathering mass previ-

ously lost to support star formations. Scientists suspect proc-

esses within galaxies, such as supernova explosions and the

force of radiation from bright stars, expel gas into space. Re-

searchers questioned whether gravity would be enough to pull it back in, especially where distant galaxies seem to push out

gas with great force. In a new study astronomers observed 100

galaxies, five to eight billion light-years away. For six, re-

searchers found expelled gas flowing back. But researchers

think recycling is occurring more often than those numbers

indicate, because the flow of gas is difficult to observe and

depends on visual orientation relative to Earth. Astronomers

suggest recycling processes could be occurring in up to 40% of

the cases.

Black Holes Just Fade Away

A relatively “ordinary” black hole has been discov-

ered in a distant galaxy, Centaurus A, 12 million light-years

away. This is the first time a low-mass black hole has been

found so far beyond the Milky Way. By observing its X-ray

emissions as it gobbles material from its environment, scien-

tists determined it to be a low-mass black hole, one likely in

the final stages of an outburst and locked in a binary system

with another star. Researchers used Chandra to make six

100,000-second long exposures of the galaxy. It revealed an

object with 50,000 times the X-ray brightness of our Sun, but a month later it had dimmed by more than a factor of 10. Later,

it dimmed by a factor of more than 100, to become undetect-

able. This is typical of similar black holes in the Milky Way.

Venus Bubble Bath

Giant magnetic bubbles around Venus (which has no

magnetic field) and the auroras above Earth are caused by the

same magnetic phenomena. These findings could explain mys-

terious flashes of light from Venus, in addition to the way comet tails work. Scientists had seen magnetic reconnection

with planets only with intrinsic magnetic fields, such as Earth,

Mercury, Jupiter and Saturn. These magnetic fields deflect

charged particles in the solar wind streaming from the Sun into

a magnetosphere surrounding the planet. Despite having no

magnetic field, Venus does have a magnetotail, caused by the

solar wind interacting with its ionosphere, the upper part of its

atmosphere loaded with electrically charged ions. Scientists

have now discovered magnetic reconnection in the magneto-

tail. The result was a magnetic bubble of plasma 2,100 miles

wide that lasted for 94 seconds. Plasma dynamics of Venus

and Earth are surprisingly similar, despite their different mag-netic environments. These findings could help explain night

time lights on Venus.

EYEPIECE May 2012

AAA BRIEFS IN ASTRONOMY

8

The Mystery of Life

Organic molecules that were building blocks for life

on Earth could have formed in the dusty disk surrounding the

Sun before planets developed, a computer model shows. The study also suggests the process would be the same around

other stars that acquire planets, which means some yet undis-

covered worlds could be seeded as well. Orbiting dust that

provided raw material for planets, asteroids and comets could

have been exposed to ultraviolet light needed to develop or-

ganic molecules. The fact that organics could have formed in

the disk doesn’t explain how they got onto Earth. When Earth

formed, it was a molten mess, with temperatures high enough

to destroy any organics. Scientists say organic compounds

could have survived on asteroids and comets left behind in the

solar system after planets formed. As these pummeled Earth

over eons, they may have deposited building blocks for life.

Thirsty? Maybe Stop on Mercury

New MESSENGER evidence is building support for

the idea that Mercury may harbor water ice in some of its most

extreme terrain. Certain areas of Mercury’s poles were previ-

ously found to be bright in radio waves. Now, MESSENGER

has found those radar spots appear to be in permanent shadow.

Images show all radar-bright features near Mercury’s poles are

in shadowed areas, consistent with the water-ice hypothesis. But bright spots could represent another substance, and some

pieces of evidence don’t fit together perfectly. For example,

some craters are thought to have temperatures inhospitable to

water ice. Many locations would require a thin layer of insula-

tion to keep the ice colder than the surface, which is believed

slightly too warm. Meanwhile, two new studies suggest Mer-

cury has an interior unlike any other rocky planet in the solar

system and a surprisingly dynamic history. Mercury’s huge

iron core is larger than thought, and is likely overlain with a

shell of iron and sulfur, a layered structure not known on

Earth, Venus or Mars. Mercury also apparently remained geo-

logically active for a surprisingly long time. The northern hemisphere’s range of elevations is smaller than on Mars or

the Moon. Many craters’ floors have been tilted substantially.

Data suggest Mercury has an iron core comprising 85% per-

cent of its radius.

MESSENGER probes Mercury

Faster Than a Speeding Bullet

Planets in tight orbits around stars that get ejected

from the Milky Way may be tossed out at speeds of up to 30

million mph, a new study finds. In 2005, astronomers found

evidence of a star flying out of the Milky Way at 1.5 million

mph. It was part of a double-star system that wandered too

close to the our supermassive black hole. The strong gravita-

tional pull ripped the stars apart, sending one hurtling through

space, while capturing the other to orbit the black hole.

Here Come the Jets

The pull of Saturn’s gravity stretches and strains

huge cracks on Enceladus that spray icy, geyser-like jets, new

research finds. Cassini images have enabled scientists, for the

first time, to make a connection between Saturn’s gravity and

Enceladus’ jet-spewing fissures. Long fissures in the south polar region are nicknamed “tiger stripes” by researchers ex-

amining jets from the warmest regions. Scientists had previ-

ously suggested tidal pulls from Saturn’s gravity could explain

the jets, but until now, they’d been unable to make a connec-

tion between jets and stress on the fissures. Researchers found

the tiger stripes are strained most when Enceladus swings clos-

est to Saturn, but this type of deformation also occurred often

when the moon was far away. Findings also suggest Saturn’s

tidal movements generate much heat in the area.

Watching for the Big One

A NASA-sponsored program that scans the cosmos

for potentially dangerous asteroids is being upgraded. NASA

has allocated $4.1 million for the Catalina Sky Survey (CSS)

at the University of Arizona/Tucson, which seeks new comets and asteroids. In 2011, CSS uncovered 586 NEOs, 65% of

NEO discoveries that year. Money will be used to expand the

power of CSS’ largest telescope, develop more sensitive soft-

ware and conduct searches on more nights. To detect NEOs,

CSS uses two telescopes to take four images of selected por-

tions of the sky roughly10 minutes apart. Software then exam-

ines the data to look for faint objects that appear to be moving

across the sky in a straight line.

The Irony of Our Solar System

Shortly after Earth and Mars were born, they found

themselves in a lengthy bout of cosmic bumper cars with com-

ets and space rocks. A new study suggests asteroids of the in-

ner solar system were also subjected to such impacts. Astrono-

mers analyzed chemical compositions of Vesta and several other asteroids and found chemicals that bind tightly to iron,

not only in cores of the space rocks but their mantles. The

presence of the iron-loving elements outside the core suggests

they were deposited there by impacts with other bodies after

the asteroids had formed, but still early in the solar system’s

history. This late accretion is well-accepted for Earth, the

Moon and Mars, but it wasn’t clear if it was widespread. Since

certain elements bind tightly to iron, any present early in a

planet’s formation would have been pulled into its iron core.

So the presence of these iron-loving elements in the mantles of

Earth, the Moon and Mars must have been delivered after core

formation ceased.

EYEPIECE May 2012

AAA BRIEFS IN ASTRONOMY

9

What’s on the Galactic Menu?

Galaxies change their eating habits during adoles-

cence, becoming more cannibalistic, according to a new study.

Astronomers examined a band of galaxies 3 billion-5 billion

years after the Big Bang. They found at the start of this phase,

galaxies prefer to snack on smooth flows of gas, but as they

mature, they consume smaller galaxies. Two ways of growing

galaxies are competing: violent merging events when larger

galaxies eat smaller ones, or a smoother and continuous flow

of gas onto galaxies. Smooth flows of gas seem to have domi-

nated the growth of galaxies in the very young universe, while

galaxy mergers are more prevalent over time.

Milky Way Center is Not Nougat

The giant black hole at the center of the Milky Way

may be vaporizing and devouring asteroids, explaining fre-

quent flares. The flares last a few hours with brightness rang-

ing from a few to nearly 100 times the black hole’s output.

Scientists suggest there’s a cloud around Sgr A* containing

trillions of asteroids and comets, stripped from their parent

stars. Asteroids passing within 100 million miles of the black

hole are shredded by its tidal forces. These fragments would

then be vaporized by friction as they pass through the hot, thin

gas flowing onto the black hole. It would take asteroids larger

than an estimated six miles in radius to generate flares.

Mining on the Moon?

Far more of the Moon may be made of material from

Earth than previously thought. Scientists have suggested the

Moon was created when a Mars-sized object named Theia

collided with Earth 4.5 billion years ago, with more than 40%

of the Moon made up of debris from that body. But researchers

expected this alien world to be chemically different from

Earth, and past studies have revealed the Moon and Earth ap-

pear similar regarding isotopes, more than might be suggested

by the current model. New findings are further evidence the

Moon’s makeup is similar to Earth’s.

Dawn Has a Bright Idea

The Dawn spacecraft has found that some areas on

Vesta can be nearly twice as bright as others, revealing clues

about the asteroid’s history. Analysis finds this material has

undergone little change since forming four billion years ago.

Bright areas are predominant in and around craters. Rocks

impacting the surface have exposed and spread this material.

One surprise was that material isn’t randomly distributed, sug-

gesting underlying geology determines where it occurs. Dark

materials seem to be related to impacts and their aftermath.

Please Don’t Feed the Orionids

Jupiter’s powerful gravity can help supercharge a

meteor shower caused by the trailing debris of Halley’s

Comet, a new study suggests. Every October, the Orionids,

leftover bits of Halley’s Comet, burn up in our atmosphere.

This is generated by an orbital interplay between Jupiter, the

comet and the meteoroids, the study says. Halley’s has likely

been in resonance with Jupiter in the past, which in turn in-

creases the odds of populating the Orionid stream with reso-

nant meteoroids.

From Russia, With Astronauts

Russia plans to send cosmonauts to the Moon and

unmanned spacecraft to Mars, Venus and Jupiter by 2030. The

Russian space agency, Roscosmos, also wants a new rocket

called Angara to become the nation's workhorse launch vehicle

by 2020, replacing the Soyuz and Proton rockets that have

been carrying the load since the 1960s. Roscosmos also plans

to top Angara with a new six-seat spaceship, upgrading the

three-passenger Soyuz spacecraft that is the world’s only

means of transporting astronauts to and from the ISS. Russia’s

new space vision focuses heavily on the Moon. In addition to

the manned landing, Roscosmos is considering construction of

a space station in lunar orbit by 2030.

The Flux Capacitor, It’s Not, Marty

Giant unstable loops of plasma arcing from the Sun’s

surface may be behind explosive solar flares and other erup-

tions. Astronomers have long noticed enormous arches of

plasma emerging from the surface. Known as magnetic flux

ropes, they have spiraling magnetic field lines. Massive elec-

trical current typically runs through each tube’s core. Magnetic

flux ropes, also called coronal loops and solar prominences, sit

on the surface, with matter and energy flowing through them

for hours or days. Scientists thought these structures linked

with solar eruptions, but evidence has been elusive. One year ago, researchers witnessed formation and evolution of a mag-

netic flux rope on the surface before and during a solar erup-

tion. This suggests eruptions are triggered by instabilities in

these structures.

Earth Gets Slapped by the Sun

The recent spate of furious eruptions on the Sun

hurled the biggest amount of heat towards Earth in seven

years. The March 8-10 storm shot enough energy toward Earth

to power every home in New York City for two years. Al-

though the influx of solar energy puffed up the atmosphere,

increasing drag on low-orbiting satellites, it caused fewer dis-ruptions to electronic infrastructure than some expected. It also

sparked dazzling auroras. Solar eruptions began March 6, and

on March 8 a coronal mass ejection smashed into Earth’s mag-

netic field. For three days, the upper atmosphere absorbed 26

billion kilowatt-hours of energy. Infrared radiation from car-

bon dioxide and nitric oxide, the thermosphere’s two most

efficient coolants, radiated 95% of that back into space.

Bigger is Better

Radio telescopes in Australia and South Korea have

linked, forming a mega-instrument 5,000 miles across. The scope should have 100 times more resolving power than the

Hubble. Five telescopes were linked up, three in Australia and

two in South Korea. The dishes simultaneously observed a

galaxy 3.5 billion light-years away for five hours. The linkup

also demonstrated technologies that will be required to make

the Square Kilometer Array a reality. The SKA, a future mega-

scope with an estimated price tag of nearly $2 billion, will

connect 3,000 separate dishes, each about 50 feet wide.

EYEPIECE May 2012

AAA BRIEFS IN ASTRONOMY

VENUS TRANSIT IS COMING……..VENUS TRANSIT IS COMING

10

is used to determine the equivalent focal length. Usually it’s

about 1.5, meaning a 300mm becomes a 450mm lens.

Pictured here is the 2004 transit taken from Carl Schurz

Park where the AAA gathered as the sun rose. I used a Nikon

D2X, 300mm with a 2X teleconverter making a 600mm lens.

Factor in the 1.5 sensor conversion and it is equivalent to a

900mm lens.

I taped a black polymer protective film from Thousand

Oaks Optical over the front of the lens to reduce the bright-

ness, mandatory for solar photography. The inexpensive film

reduces the exposure by quite a bit, so you may have to shoot

at ISO 400 or 800, which shouldn’t be a problem.

Finding a suitable foreground object adds to the photo.

Plan out your location - visit a potential site 1 or 2 days before

the event and track the Sun’s angle. This will reveal how much

time you will have to shoot before the Sun (and Venus) disap-

pears behind any distant object in your view screen. Here in New York the transit will begin about 2 hours before sunset,

so one option would be to find a distinctive portion of the sky-

line to include in the frame. Please remember to always exer-

cise caution when looking at the Sun either through your lens

or directly. Approved eye protection and lens protection is

critical for safety.

Enjoy your photographic endeavors!

FOCUS ON THE UNIVERSE

It’s time to go out and shoot “star trails” and also pre-

pare to photograph the last-in-our-lifetime Transit of Venus.

One of the pictures that accompanies this column is the first

‘star trails’ photo I did with a digital camera. The stars appear

to be rotating around Polaris, the North Star, above the 4-meter dome at Kitt Peak National Observatory in southern Arizona.

This is a nearly one-hour exposure. The photo is actually com-

prised of 117 separate 30-second exposure frames assembled

in Photoshop.

To achieve a spectacular visual perspective, find an inter-

esting foreground object. Look towards Polaris if you want

stars circling a point; look to the east or west to produce

streaks going almost vertically. An intervalometer is very help-

ful for this process, as it automatically triggers exposures for a

time-lapse series. One setting you might try is a 1-minute ex-

posure, allowing 1 second between exposures for a total of 60

frames. That gives you the equivalent of a 1-hour exposure (1

minute x 60 frames = 60 minutes).

Longer exposures (2 or 3 minutes) are fine and you won’t

have to take as many frames. Forty-five minutes is often long

enough to make a nice set of streaks. It’s best to experiment

and see what you like. Make sure your tripod is anchored well

and won’t move for the 45-60 minutes required.

After the night’s shooting, go to your computer (now

considered the “digital darkroom”). Open the first shot in Pho-

toshop and remember the file number. This will be your base

image. Open up the next 5-6 frames in the sequence. Chose the

second frame, go to “Select All,” then “Copy.” Go back to the first frame (the base image) and select “Paste.” You’ll now see

the frame in the window. In the Layers window (visible if you

look at the pull-down menu under the tab Windows), choose

“Lighten” from the menu. The star streaks from two images

will now be joined in the sky while any foreground image will

stay the same.

Chose the third frame and repeat the process, copying

and pasting onto the base image (listed as “Background” in the

Layers window). As you add each successive frame, you will

see the streaks begin to grow and the full image will start to

appear.

Adding each layer adds to the size of the photo, so if the

program slows down, go to “Layer,” click on “Flatten Image.”

You’ll see all the layers in the Layers window collapse into

one. Continue adding frames until you are done. Flatten Image

one final time. At this point, go to “Save As” and chose

“Photoshop (PSD).” This will allow you to go back and make

slight alterations to the layers if necessary. Then “Save As”

again, and choose “Tiff file (TIF).” This will be a full, uncom-pressed file saved at the highest quality, which you can save as

smaller JPEGs.

Turning to daylight photography, this is a good time to

prepare for the June 5 Venus transit. I recommend shooting it

with a 200mm to 300mm lens at a minimum. Fortunately most

digital SLRs have smaller image sensors so a conversion factor

EYEPIECE May 2012

“Stars—Kitt Peak National Observatory, 2006” (by Stan Honda)

Stan Honda is an accomplished professional photographer and contributing

writer for Eyepiece. In this continuing series of articles, he shares his exten-

sive knowledge of photographic equipment and techniques. Visit

www.stanhonda.com or submit your questions to stanhonda@gmail.com.

Capturing Star Trails and Solar Transits

By STAN HONDA

“Transit 2004”

(Stan Honda, 2004)

11

Apparently, Chicken Little wasn’t all wrong. Al-

though the sky is not actually falling, thousands of meteorites,

nearly one million kilograms, do hit the Earth every day.

Those surviving atmospheric friction fall in sizes smaller than

a grain of rice. In some instances a larger object survives,

causing some degree of alarm. Now that over 8,000 asteroids

in near-Earth orbit have been identified, is there reason for serious concern? According to the AMNH presentation,

“Asteroids: Friends or Foes,” Professor Richard P. Binzel

from the MIT Department of Earth, Atmosphere, and Plane-

tary Science, believes they are “More likely friends.” While

Binzel’s conclusion is reassuring, his presentation focused

primarily on the dangerous side of the issue, a more compel-

ling subject to consider.

Asteroids are small bodies that orbit the Sun, composed

of rock, carbon, or metal. They can be the size of small plan-

ets (asteroid Ceres is classified as a dwarf planet) and are

formed in the inner solar system, mostly within the asteroid

belt located between Jupiter and Mars. Perturbations from

Jupiter, perhaps nudged from their orbits by a close encounter

or collision with other asteroids, pushes some of these objects

in our direction. Most range in size from 50 meters to over 30 kilometers in diameter. Scientists estimate that 500 - 1,000

near-Earth asteroids are one kilometer in diameter or greater in

size. Impact on Earth by an asteroid this size would result in a

global disaster – luckily, the chances of an asteroid hit that size

is about once every one million years.

By compiling data on Moon craters, scientists extrapo-

lated the results and predicted the frequency of impacts on

Earth. Binzel noted that acknowledging the possibility of

large asteroid impacts here is a modern space age realization.

Current science has allowed us observe impact craters else-

where - on Mercury, Venus (by radar), Mars, and the Moon.

Such evidence is harder to find on Earth. Most craters here are

undetectable, either hidden under the ocean or erased by geo-

logical processes like plate tectonics. In 1960, geologist

Eugene M. Shoemaker developed a methodology to validate

large asteroid impacts on our planet. Having studied craters caused by atomic bomb tests, Shoemaker found shock quartz,

or coesite, a unique mineral created at instantaneous high pres-

sure and high temperature. He discovered a large presence of

coesite at the 50,000-year-old Barringer Crater in Arizona,

confirming that an impact event was responsible.

Shoemaker’s method has helped confirm about 100 aster-

oid impact craters on Earth, including the 180-kilometer-wide

Chicxulub crater buried under Mexico’s Yucatan Peninsula.

About 65 million years ago, a10 km asteroid impacted Earth at

this site and caused the mass extinction of plants, animals and dinosaurs. Physicist Luis Alvarez and his son, geologist Walter

Alvarez, proposed this theory based on evidence of a thin

layer of iridium-enriched clay within the K-Pg boundary,

which is the geologic demarcation point that separates the Cre-

taceous and Paleogene periods and signifies the mass extinc-

tion event. Iridium from meteorites is found in small quanti-

ties all over the Earth. The abnormally high concentration

found at the Chicxulub crater, which formed contemporane-

ously with the mass extinction event, led them to postulate that

the asteroid causing this impact eliminated the dinosaurs. The

chance of a repeat strike event is once in every 100 million

years, so only 35 million years to go.

If the odds are favorable that we will avoid a significant

impact event, should we have any future concern? The largest

recorded impact in recent history was in 1908 at Tunguska, Russia, an isolated part of Siberia. A few tens of meters across,

the meteoroid exploded in open air, 5-10 kilometers above the

Earth’s surface, with sufficient energy to equal a nuclear

weapon and potential to level any modern city. The chance of

an object this size hitting Earth is about one in 20,000 over the

next 50 years, which is the same probability of an airplane

crash. Other large impacts in modern history may have gone

unnoticed if they occurred in remote, ocean areas, although

any sizable ocean impact would cause a giant tsunami.

Smaller impacts have damaged cars and homes. The only re-

corded case of a person being hit by a meteoroid happened in

1954 when an Alabama woman sitting on her couch suffered

bruising from an incoming object.

Binzel is the creator of the Torino scale, used to catego-

rize the impact hazard of an object by measuring collision

probability versus destructive consequence. Torino levels are determined by MIT’s Lincoln Near Earth Asteroid Research

(LINEAR), a NASA program that detects and catalogues near-

Earth asteroids. Currently, deflection is believed to be the best

defense against a potential threat. Scientists have only discov-

ered one object that rated level 4, the highest on the Torino

scale, with a 1% or greater chance of collision capable of re-

gional devastation. Apophis 99942, with a diameter approxi-

mately 270 meters, has since been downgraded to 0; it will

pass us on April 13, 2029. In March, Torino scale level 1 as-

teroid 2011 AG5, missed the Earth. NASA’s Near Earth Ob-

jects Program Office predicts a 1 in 625 chance of future im-pact on February 5, 2040. With a diameter of 140 meters and

traveling at an average velocity of 14.67 km/s, 2011 AG5

would produce the equivalent of 100 megatons of TNT, about

twice the energy of Tsar Bomba, the most powerful nuclear

weapon ever detonated.

Asteroids Abound at AMNH (continued on page 12)

EYEPIECE May 2012

HIT ME WITH YOUR BEST SHOT: ASTEROIDS ABOUND AT AMNH By AMY WAGNER

Purdue University Impact Earth database of impact parameters

12

_______________________ AAA Lecture Takes Us “Searching

for Earthlike Worlds”

By TONY HOFFMAN

Carl Sagan’s model of the cosmic calendar was

evoked at the AMNH Kaufmann Theater on March 30 as

Debra Fischer, professor of astronomy at Yale University, in-troduced her topic for the evening: “Searching for Earthlike

Worlds.”

Compressing the age of the universe into a single year, in

which our galaxy would have formed in March, the Sun and its planets in August, the dinosaurs arisen on December 25 and

gone extinct on December 30, with all of human history occur-

ring in the last hour or so was the tenet of Carl Sagan’s time-

line. Fisher speculated what humanity might be able to accom-

plish if we have the same species longevity as a species like

the dinosaurs.

Early planet hunting techniques began with the radial

velocity method, detecting a planet’s wobble through analysis

of its star’s spectrum. This method led to identifying the first

exoplanet orbiting a Sun-like star, 51 Pegasi b. Fisher uses this

technique in her own work today. She discussed the Kepler

project, which uses the transit technique, highlighting Kepler-

11, a 6-planet system, and “Tatooine,”in which a Saturn-sized

world orbits a double star. In collaboration with her colleagues

at Yale and Oxford, the citizen science project Planet Hunters was formed, encouraging the public to search for exoplanets in

Kepler data. The project has already published papers an-

nouncing the finding by its volunteers of several planets that

EYEPIECE May 2012

had “…fallen through cracks in the Kepler data,” she ex-

plained.

Direct imaging has so far yielded only large gas giants,

but, Fischer says “We want to be at the point when we can

take a photograph of a star, null out the light from the star, and

see those pale blue dots (of Earthlike worlds), orbiting.”

Earthlike worlds - rocky worlds where water pools on the

surface - are the goal, and projects like Kepler and HARPS

have been zeroing in or near a star’s habitable zone. Not all

seemingly Earthlike worlds may be life-bearing, however.

“We want to find hundreds of Earths,” says Fischer.

Fischer runs a Yale lab that’s working to increase the

resolution of spectrographs so that smaller worlds can be

found via the wobble technique. Her team is using a spectro-

graph they developed to try to find low-mass planets in the

Alpha Centauri system.

How does our solar system compares with others, Fisher

queried. Kepler data indicates that most stars host multi-planet

systems, with approximately 1.6 planets per star as a lower

limit. Around 1% of stars have hot Jupiters, and more than 30% of stars have super-Earths, planets with masses up to 10

times that of Earth.

There are others looking for life from a different perspec-

tive. Astronomers are now partnering with biologists, working to understand origins of life on our planet, and geologists, who

are helping us to understand the geological processes that cre-

ate magnetic fields and that sequester water on planets. Many

of these scientists are the future astrobiologists and planetary

geologists who will join today’s exoplanet hunters in their

quest to locate new worlds.

In closing, Fischer noted that there are people who think

the money going to NASA would be better spent elsewhere.

“If you’re a business manager, you have to think about the day

-to-day running of your business, but to be really successful - a

Steve Jobs, a Bill Gates - you also need to have vision. That’s

where astronomy plays a key role. We have vision - we’re

looking out, then looking back, and understanding ourselves

better for that.” ■

Kepler Planet Candidate catalog histogram Credit: NASA.gov website

Asteroids Abound at AMNH (continued from page 11)

Near-Earth asteroids also bring potential benefits - they

could be mined for valuable mineral resources. The Origins

Spectral Interpretation Resource Identification Security Re-golith Explorer (OSIRIS-Rex) mission will launch a probe in

2016 to study and return samples from 1999 RQ36, a carbona-

ceous asteroid. Jim Green, Director of the Planetary Science

Division of NASA’s Science Mission Directorate, says that an

asteroid is a “time capsule from the birth of our solar system,”

and RQ36 possesses organic molecules necessary for life and

matter that pre-date the formation of Earth. While the scien-

tific implications are clear, other minerals and metals could

offer profitable commercial applications. Finally, asteroids

can become important in furthering our experience in space

exploration. In April, 2011, President Obama announced a goal to send “astronauts to an asteroid for the first time in his-

tory” by 2025. This mission could involve a six-month trip

into deep space; a crucial test for new spacecraft designed for

long journeys and, perhaps, important practice for a future

mission to Mars.

The usefulness of asteroids appears to outweigh the po-

tential threat. Given the steep odds for impact, a betting per-

son would certainly side with Binzel on this issue but, just the same, we are glad to have him and his team keeping an eye out

for the rest of us. ■

13

AAA Events on the Horizon

May 2012

Tuesdays, May 1, 8, 15, 22, 29, 8:30-10:30 p.m., P, T, C Observing on the High Line, Manhattan (Enter at 14th Street)

Next dates: Tuesdays in June

Wednesday, May 3, 6:30-8:30 p.m., M AAA NYU Seminar, Manhattan

5 Washington Place, Rm 101/Student Projects

Friday, May 4, 6:15 p.m., P AAA Lecture Series - Last of the 2011-22012 Season

Dr. Alex Wolszczan, “The Astronomical Future of Humankind”

Kaufmann Theater of the AMNH

Saturday, May 5, Dusk-Midnight, P, T, C Moon Appreciation Night at Custer Institute 1115 Main Bayview Road, Southold, New York

(Call 631-765-2626 to confirm observing conditions)

Saturday, May 12, 8:30-11 p.m., P, T, C Observing at Great Kills Gateway Nat’l Park, Staten Island At end of Montague Street

Next date: June 23 Wednesday, May 16, 6:30-8:30 p.m., M AAA Annual Meeting (including dinner)

120 Warren Street, Manhattan

(Board meeting follows: 8:30-9 p.m. to elect officers) Wednesday, May 23, Dusk-11 p.m., P, T, C Observing at Prospect Park, Brooklyn

Next date: June 20 Friday, May 25, Dusk-11 p.m., P, T, C Observing at Carl Schurz Park, Manhattan

Next date: June 29

Friday, May 25, 8-11 p.m., P, T, C Observing at Floyd Bennett Field, Brooklyn

Next date: June 8

Saturday, May 26, 10 a.m. - Noon, P,TC Solar Observing in Central Park At the Conservatory Water Next date, June 30

Tuesday, May 29, 6:30 p.m., P Astronomy Live-Around the World in 60 Minutes AMNH Hayden Planetarium Space Theater

Wednesday, May 30, Dusk-11 p.m., P, T, C Observing at Brooklyn Heights Promenade, Brooklyn

At the end of Montague Street

Next date: June 27

Legend for Events

M: Members T: Bring telescopes, binoculars, etc.

P: Open to the public C: Cancelled if cloudy

Final AAA Lecture on May 4

Contemplates Earth’s Demise

By DAN HARRISON

Dr. Alexander Wolszczan, an Evan Pugh Professor of

astronomy and astrophysics at Pennsylvania State University

and a director of its Center for Exoplanets and Habitable

Worlds, will wrap up the AAA’s 2011-12 lecture series Friday,

May 4 when he speaks on “The Astronomical Future of Hu-

mankind.” The free public lecture is at 6:15 p.m. in the Kauf-

mann Theater of the American Museum of Natural History.

“The fact that long-term survival of the human race is by

no means guaranteed shouldn’t prevent us from considering

the astronomical phenomena that may affect it,” Wolszczan

tells Eyepiece. “Such considerations are also important for

research related to life in the universe and its persistence in the

face of cosmic evolution.

“I will review the most relevant astrophysical phenomena

that may influence life on Earth, such as stellar evolution, mo-

tion of the solar system around the galaxy, stellar explosions,

galaxy collisions and asteroid strikes, and discuss our chances

to survive them.”

Wolszczan is an astrophysicist whose research interests

focus on exoplanets. He’s also worked on topics in relativistic

gravitation, pulsars, brown dwarfs and the physics of the inter-

stellar medium.

Wolszczan is best known for his discovery, in 1992, and the

subsequent confirmation, of the first planets orbiting a star

other than the Sun. He is also a discoverer and co-discoverer

of pulsars and several planets around giant stars.

Wolszczan received a doctorate in physics in 1975 from

the Nicolaus Copernicus University in Torun, Poland, and has

taught there. He also held positions at the Max Planck Institut

fur Radioastronomie in Bonn, Germany, Cornell University’s

National Astronomy and Ionosphere Center, and Princeton

University before coming to Penn State 20 years ago.

Wolszczan was the recipient of “The Best of What’s

New'” Grand Award of Popular Science magazine in 1994, the Penn State Faculty Scholar Medal for Outstanding Achieve-

ment in 1995 and the Beatrice M. Tinsley Prize of the Ameri-

can Astronomical Society in 2000. In 2001, he was awarded

the Marian Smoluchowski Medal by the Polish Physical Soci-

ety and received an Alexander von Humboldt Foundation Re-

search Award for senior U.S. scientists. He was elected a fel-

low of the American Association for the Advancement of Sci-

ence in 2011. Wolszczan was featured on one of the series of

16 postage stamps issued in Poland in 2001 to commemorate

the Polish millennium. ■

EYEPIECE May 2012

ATTENTION ALL AAA MEMBERS

JOIN US TO OBSERVE THE VENUS TRANSIT

JUNE 5 - Just Before Sunset

Check the AAA website and Facebook page

for all locations and upcoming details

AAA ONLINE STORE IS NOW OPEN

AAA Presents: A new and exciting wide selection of

logo merchandise

for our members to

purchase online

“Shop the Stars”

www.aaa.org/store

14

Amateur Astronomers Association

PO Box 150253

Brooklyn, NY 11215

ADDRESS SERVICE REQUESTED

First Class Mail

EYEPIECE May 2012

Amateur Astronomers are taking on new roles in the

scientific community. Today, they are sifting through Kepler

data looking for hidden exoplanets and monitoring the skies

for new supernovae and other celestial phenomena. On Jan

31, amateurs from around the world worked together to

chronicle the close approach of giant asteroid Eros, uploading

their images to a common website as the Earth passed between the asteroid and the Sun and using them to recalculate the dis-

tance and path Eros travels. Discovered in 1898, Eros is one of

the larger near-Earth asteroids, 20 miles wide. It was visited by

NASA’s Near Earth Asteroid Rendezvous in 2000.

This trend may seem recent, but there has always been a

role for amateur astronomers in the quest to contribute to the

constantly expanding database of our universe. Hundreds of

years ago, scientists were sent around the globe to observe

calculated astronomical events. Often, their treks ended in

frustration or tragedy due to perilous routes and unknown en-

vironments. Some were able to watch it all from home, though.

In the Netherlands, the 1761 transit of Venus was observed by

Johan Lulofs, a professor of mathematics and philosophy at

Leiden University. He made his observations from the simple

university observatory located on the roof of the Academy Building.

In 1931, the close approach of the asteroid Eros allowed

professional astronomers to calculate its distance and make

that era's most accurate measurement of the solar system. As-

tronomers in Germany, Algiers, Johannesburg, Tokyo and California captured photographs of the asteroid against the

background of stars. By comparing images taken at the same

time but from different locations, they could use trigonometry

to determine exactly how far away the asteroid passed. From

this, they could calculate the distance to other planets, taking

the best measurement of the bodies orbiting the Sun. As the

asteroid passed near Earth in early February, 2012, amateur

astronomers and students from around the world sought to

recreate this historical experience through modern technology.

Was Eros too close for comfort? How about 16.6 million

miles from annihilation of the Earth? That was our “comfort

zone” on Jan 31 as giant asteroid Eros sped past our planet at

54,492 mph. ■

NEXT MONTH IN EYEPIECE—Transits!

Our Look Ahead to June: Stan Honda continues his “Focus

on the Universe series; Sandra Wayne gives us a short history of Venus; Alan Rude reveals how dark matter transits pulsars;

Richard Brounstein amazes us once again in his “What If”

column; AAA Briefs in Astronomy continue to inform us;

Rich Rosenberg’s “What’s Up in the Sky”….and more special

surprise features have been planned!

VENUS TRANSIT IS COMING! 6/5/12 - 6:03 p.m.

EROS BRINGS AMATEUR ASTRONOMERS TOGETHER

By Evan Schneider