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Space News Update — April 23, 2019 —

Contents

In the News

Story 1:

SpaceX Confirms Anomaly during Crew Dragon Abort Engine Test

Story 2:

Nearby Asteroids Reveal Sizes of Distant Stars

Story 3:

The Universe’s First Type of Molecule Is Found at Last

Departments

The Night Sky

ISS Sighting Opportunities

NASA-TV Highlights

Space Calendar

Food for Thought

Space Image of the Week

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1. SpaceX Confirms Anomaly during Crew Dragon Abort Engine Test

SuperDraco thrusters fire on a prototype of SpaceX’s Crew Dragon spacecraft at the company’s test site in Central Texas.

Credit: SpaceX

An accident Saturday during an abort engine test on a Crew Dragon test vehicle at Cape Canaveral sent a

reddish-orange plume into the sky visible for miles around, a setback for SpaceX and NASA as teams prepare

the capsule for its first mission with astronauts.

SpaceX is testing the Crew Dragon ahead of the capsule’s first test flight with astronauts later this year,

following a successful Crew Dragon demonstration mission to the International Space Station in early March.

SpaceX confirmed the accident, first reported by Florida Today, in a statement Saturday evening. No injuries

were reported.

“Earlier today, SpaceX conducted a series of engine tests on a Crew Dragon test vehicle on our test stand at

Landing Zone 1 in Cape Canaveral, Florida,” a company spokesperson said. “The initial tests completed

successfully but the final test resulted in an anomaly on the test stand.”

NASA Administrator Jim Bridenstine tweeted that the space agency was notified of the accident.

“The NASA and SpaceX teams are assessing the anomaly that occurred today during a part of the Dragon

Super Draco Static Fire Test at SpaceX Landing Zone 1 in Florida,” Bridenstine said in a written statement.

“This is why we test. We will learn, make the necessary adjustments and safely move forward with our

Commercial Crew Program.”

A photo captured by a Florida Today photographer from a local beach showed an orange plume visible on the

horizon in the direction of Cape Canaveral Air Force Station. Such plumes are usually associated with burning

or leaking toxic hypergolic propellants.

Florida Today reported that unconfirmed reports suggested the Crew Dragon test vehicle was nearly

destroyed, and workers in the area said they heard explosions.

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The Crew Dragon’s thrusters consume hygergolic hydrazine and nitrogen tetroxide propellants, which

chemically ignite when mixed together. The Crew Dragon’s Draco thrusters are used for in-orbit maneuvers

and pointing, while eight larger SuperDraco thrusters — packaged in pairs into four propulsion modules — are

used for aborts during a launch emergency.

“Ensuring that our systems meet rigorous safety standards and detecting anomalies like this prior to flight are

the main reasons why we test,” a SpaceX spokesperson said. “Our teams are investigating and working closely

with our NASA partners.”

A dispatcher at the Brevard County Emergency Operations Center said local officials were aware of the SpaceX

accident at Cape Canaveral, but were not aware of any risk to the public.

The SuperDraco thrusters are designed to push the Crew Dragon spacecraft away from a failing rocket during

launch. Each engine has a 3D-printed chamber and can produce up to 16,000 pounds of thrust, with the ability

to restart multiple times.

SpaceX did not specify which Crew Dragon vehicle was involved in Saturday’s accident on the test stand, but

people familiar with the company’s test plans said it was likely the same spacecraft that successfully flew to

the space station last month. Ground teams returned the Crew Dragon spaceship to Cape Canaveral following

its March 8 splashdown in the Atlantic Ocean.

Engineers planned to refurbish the capsule for an in-flight abort test as soon as June, in which the Crew

Dragon would activate its SuperDraco engines at high altitude about a minute after launching from the

Kennedy Space Center on a Falcon 9 rocket. Hotfire tests of the Crew Dragon’s abort propulsion system, like

the SuperDraco test conducted Saturday, were planned by SpaceX before the in-flight abort test.

The high-altitude abort test is intended to prove the Crew Dragon capsule can save astronauts from a

catastrophic explosion under the most extreme aerodynamic forces during launch. The test is one of the final

tests for the Crew Dragon program before NASA signs off on putting astronauts on the spacecraft.

SpaceX’s first Crew Dragon mission with astronauts, known as Demo-2, was scheduled no earlier than July 25.

NASA said earlier this month that it would reevaluate the target launch date for the Demo-2 mission in the

next few weeks, and sources recently suggested — before Saturday’s accident — that the Demo-2 launch was

likely to be rescheduled for late September or early October.

Veteran shuttle astronauts Bob Behnken and Doug Hurley are assigned to the Demo-2 mission, which was

planned to use a new spacecraft.

NASA awarded SpaceX and Boeing multibillion-dollar contracts in 2014 to develop the Crew Dragon and CST-

100 Starliner spaceships to ferry astronauts to and from the International Space Station.

The first unpiloted flight of Boeing’s Starliner spacecraft to the space station is scheduled for August, followed

by a test flight with astronauts in November. Boeing delayed the Starliner test flights after a fuel leak during

an abort engine test on a test article last year forced engineers to redesign part of the craft’s propulsion

system.

Once the commercial crew spacecraft complete their test programs, NASA plans to rotate four-person crew to

and from the space station, ending the agency’s sole reliance on Russian Soyuz crew ferry ships. Soyuz

capsules have carried all NASA astronauts into orbit since the retirement of the space shuttle in 2011.

SpaceX has won a series of NASA contracts totaling more than $3.1 billion since 2010 to develop the human-

rated Crew Dragon spacecraft. A similar set of contracts were awarded to Boeing, worth more than $4.8

billion.

Source: SpaceflightNow.com Return to Contents

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2. Nearby Asteroids Reveal Sizes of Distant Stars

This artist's concept shows the (greatly exaggerated) diffraction pattern of starlight that occurs when an asteroid passes

in front of the star. The pattern of light allows astronomers to measure the star's size. Credit: DESY, Lucid Berlin

Stars in the night sky appear as tiny points of light because they are too far away for your eyes to resolve. But

even through powerful telescopes, stars still appear as mere points because they are too small to see their

true physical size at vast distances. Now, a group of astronomers from over 20 different institutions has found

a way to combine a unique telescope array with passing asteroids to measure the diameter of two distant

stars, including the smallest star directly measured to date at just over twice the size of our Sun.

Their work appeared April 15 in Nature Astronomy. And using this new information, astronomers can better

refine their picture of the properties and life cycles of stars, which are the building blocks that make up our

galaxy and every other galaxy in the universe.

How to measure a star

To measure the size of a star, the collaboration used events called occultations. An occultation occurs when

one object — such as an asteroid or planet in our own solar system — passes in front of a star. Occultations

can reveal a wealth of information about either the object passing in front of the star, or about the star itself.

An occultation in 1977 led astronomers to discover the rings of Uranus, while occultations of Pluto allowed

researchers to probe the dwarf planet’s tenuous atmosphere.

In this pilot study, the team went after even more difficult-to-see occultations — those caused by asteroids

passing in front of background stars. To catch the events, they used the Very Energetic Radiation Imaging

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Telescope Array System, or VERITAS, which contains four telescopes designed to detect gamma rays. Each

12-meter telescope is made up of 350 individual mirrors, which allow the array to detect the extremely faint,

fast flashes of light caused when gamma rays interact with our atmosphere. The array can also spot asteroids

in our solar system occulting distant stars; as an asteroid zips in front of a star at about 15 miles (24

kilometers) per second, the dip in starlight is extremely short-lived. But the way the star’s light behaves as it

diffracts around the asteroid during that time reveals the star’s size.

Occultations occur often, but the shadow cast by the event is tiny compared to the size of Earth. Shadows only

fall over a minuscule portion of the planet, so many astronomers who study occultations take to the road (or

sea, or sky) with mobile telescopes. VERITAS can’t move, however, so to study occulted stars, the team had to

wait for an occultation to occur that would be visible from the Fred Whipple Observatory in Arizona, where the

array is located.

A perfect lineup

The team’s first target was the star TYC 5517-227-1, which is 2,674 light-years away. It was briefly blotted out

by the 37-mile-wide (60 km) asteroid Imprinetta on February 22, 2018. “Nobody was sure the occultation

would even be visible from our location in the first place,” said co-author Tyler Williamson of the University of

Delaware in a

press release. “The most recent estimate we had going into the night was that there was about a 50 percent

chance that the shadow would be cast over our observatory — the asteroid is small, and there were

uncertainties in size and trajectory, making it impossible to say for sure where the shadow would fall.”

But the odds were in the team’s favor — VERITAS’ ability to take 300 images each second revealed that

Imprinetta did indeed pass in front of the star, allowing the researchers to study the starlight during the event

and determine the star is about 11 times the diameter of our Sun. That makes it a red giant star, which has

puffed up and cooled off in the later stages of its life.

A few months later, on May 22, 2018, the 55-mile-wide (88 km) asteroid Penelope crossed in front of TYC

278-748-1. At a distance of 700 light-years, TYC 278-748-1 is only about 2.17 times the diameter of our Sun,

classifying it as a G-dwarf star, like our own. This size also makes TYC 278-748-1 the smallest star ever

measured directly.

Seeing stars

Measuring the diameters of stars directly reveals a treasure trove of information, says study co-author Jamie

Holder, also at University of Delaware. “How big and how hot a star is tells you how it was born, how long it

will shine, and how it will eventually die,” he says.

The size of most stars is not measured directly, but instead estimated based on properties such as

temperature and brightness. Some stars have been directly measured

through similar methods, such as when the Moon passes in front of them or by using a technique called

interferometry, which combines the light from two or more telescopes to tease out details. But using VERITAS

to watch asteroid occultations, the team says, is 10 times better than lunar occultations and two times better

than interferometry, offering a clearer picture of more — and smaller — stars in the future.

Now that the technique is proven, the team plans to improve and increase their observations with VERITAS.

Ultimately, the technique will assist astronomers in “building data on a whole new population of stars,” Holder

says.

Source: Astronomy Return to Contents

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3. The Universe’s First Type of Molecule Is Found at Last

Image of planetary nebula NGC 7027 with illustration of helium hydride molecules. In this planetary nebula, SOFIA

detected helium hydride, a combination of helium (red) and hydrogen (blue), which was the first type of molecule to ever

form in the early universe. This is the first time helium hydride has been found in the modern universe. Credits:

NASA/ESA/Hubble Processing: Judy Schmidt

The first type of molecule that ever formed in the universe has been detected in space for the first time, after

decades of searching. Scientists discovered its signature in our own galaxy using the world’s largest airborne

observatory, NASA’s Stratospheric Observatory for Infrared Astronomy, or SOFIA, a Boeing 747SP jetliner

modified to carry a 106-inch diameter telescope.

When the universe was still very young, only a few kinds of atoms existed. Scientists believe that around

100,000 years after the big bang, helium and hydrogen combined to make a molecule called helium hydride

for the first time. Helium hydride should be present in some parts of the modern universe, but it has never

been detected in space — until now.

SOFIA found modern helium hydride in a planetary nebula, a remnant of what was once a Sun-like star.

Located 3,000 light-years away near the constellation Cygnus, this planetary nebula, called NGC 7027, has

conditions that allow this mystery molecule to form. The discovery serves as proof that helium hydride can, in

fact, exist in space. This confirms a key part of our basic understanding of the chemistry of the early universe

and how it evolved over billions of years into the complex chemistry of today. The results are published in this

week’s issue of Nature.

Credit: DLR (CC-BY 3.0)

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“This molecule was lurking out there, but we needed the right instruments making observations in the right

position — and SOFIA was able to do that perfectly,” said Harold Yorke, director of the SOFIA Science Center,

in California’s Silicon Valley.

Today, the universe is filled with large, complex structures such as planets, stars and galaxies. But more than

13 billion years ago, following the big bang, the early universe was hot, and all that existed were a few types

of atoms, mostly helium and hydrogen. As atoms combined to form the first molecules, the universe was

finally able to cool and began to take shape. Scientists have inferred that helium hydride was this first,

primordial molecule.

Once cooling began, hydrogen atoms could interact with helium hydride, leading to the creation of molecular

hydrogen — the molecule primarily responsible for the formation of the first stars. Stars went on to forge all

the elements that make up our rich, chemical cosmos of today. The problem, though, is that scientists could

not find helium hydride in space. This first step in the birth of chemistry was unproven, until now.

“The lack of evidence of the very existence of helium hydride in interstellar space was a dilemma for

astronomy for decades,” said Rolf Guesten of the Max Planck Institute for Radio Astronomy, in Bonn,

Germany, and lead author of the paper.

Helium hydride is a finicky molecule. Helium itself is a noble gas making it very unlikely to combine with any

other kind of atom. But in 1925, scientists were able to create the molecule in a laboratory by coaxing the

helium to share one of its electrons with a hydrogen ion.

Then, in the late 1970s, scientists studying the planetary nebula called NGC 7027 thought that this

environment might be just right to form helium hydride. Ultraviolet radiation and heat from the aging star

create conditions suitable for helium hydride to form. But their observations were inconclusive. Subsequent

efforts hinted it could be there, but the mystery molecule continued to elude detection. The space telescopes

used did not have the specific technology to pick out the signal of helium hydride from the medley of other

molecules in the nebula.

In 2016, scientists turned to SOFIA for help. Flying up to 45,000 feet, SOFIA makes observations above the

interfering layers of Earth’s atmosphere. But it has a benefit space telescopes don't— it returns after every

flight.

“We’re able to change instruments and install the latest technology,” said Naseem Rangwala SOFIA deputy

project scientist. “This flexibility allows us to improve observations and respond to the most pressing questions

that scientists want answered.”

A recent upgrade to one of SOFIA’s instruments called the German Receiver at Terahertz Frequencies, or

GREAT, added the specific channel for helium hydride that previous telescopes did not have. The instrument

works like a radio receiver. Scientists tune to the frequency of the molecule they’re searching for, similar to

tuning an FM radio to the right station. When SOFIA took to the night skies, eager scientists were onboard

reading the data from the instrument in real time. Helium hydride’s signal finally came through loud and clear.

“It was so exciting to be there, seeing helium hydride for the first time in the data,” said Guesten. “This brings

a long search to a happy ending and eliminates doubts about our understanding of the underlying chemistry of

the early universe.

Scientists on the airborne observatory SOFIA detected the first type of molecule that ever formed in the

universe. They found the combination of helium and hydrogen, called helium hydride, in a planetary nebula

near the constellation Cygnus. This discovery confirms a key part of our basic understanding of the early

universe and how it evolved over billions of years into the complex chemistry of today.

Sources: NASA Return to Contents

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The Night Sky

• With the Moon now gone from the evening sky, explore the Leo Triplet and more of the best springtime galaxies

with your sky atlas and the Deep-Sky Wonders column in the April Sky & Telescope, page 54.

Friday, April 26

• Last-quarter Moon (exact at 6:18 p.m. EDT). The Moon rises tonight around 3 a.m. daylight-saving time, right in

the center of the dim, boat-shape pattern of Capricornus. High above it is Altair. The brightest "stars" far to the

Moon's right or upper right are Saturn, then Jupiter.

Saturday, April 27

• As the last of twilight fades out, the dim Little Dipper extends to the right from Polaris. High above the Little

Dipper's bowl (marked by Kochab, Polaris's equal in brightness), you'll find the bowl of the Big Dipper.

Source: Sky and Telescope Return to Contents

Moon passes over the Sagittarius Teapot and pairs with Saturn. (For clarity, the Moon in these scenes is always

shown larger than its actual apparent size.

Tuesday, April 23

• Right after dark, the Sickle of Leo stands vertical

high in the south. Its bottom star is Regulus, the

brightest of Leo. Leo himself is walking

horizontally westward. The Sickle forms his front

leg, chest, mane, and part of his head. Denebola,

about two and a half fists left of Regulus, is his

tail-tip.

• As dawn begins to brighten on Wednesday

morning, the waning gibbous Moon shines almost

midway between Jupiter to its right and Saturn to

its left.

Wednesday, April 24

• As dawn begins on Thursday morning, the

waning Moon poses with Saturn.

Thursday, April 25

• Right after dark, find Procyon high over bright

Sirius in the southwest. Look upper left of Procyon

by 15° (about a fist and a half at arm's length) for

the dim head of Hydra, the enormous Sea

Serpent. His head is a group of 3rd- and 4th-

magnitude stars about the size of your thumb at

arm's length.

About a fist and a half lower left of Hydra's head

shines Alphard, his 2nd-magnitude, orange heart.

The rest of Hydra zigzags (faintly) from Alphard all

the way over and down almost to the southeast

horizon.

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ISS Sighting Opportunities (from Denver)

Date Visible Max Height Appears Disappears

Fri Apr 26, 5:15 AM 2 min 12° 10° above SSE 11° above ESE

Sun Apr 28, 5:07 AM 4 min 32° 10° above SSW 26° above E

Sighting information for other cities can be found at NASA’s Satellite Sighting Information

NASA-TV Highlights (all times Eastern Time Zone)

April 23, Tuesday

2 p.m. - The von Kármán Lecture Series 2019: Red Planet Rovers and Insights (All Channels)

April 24, Wednesday

10:55 a.m. - International Space Station In-Flight Interviews with Army News Service, KCTS-TV, Seattle

and KUOW Radio, Seattle and NASA astronaut Anne McClain (All Channels)

April 26, Friday

10 a.m. – SpaceCast Weekly (All Channels)

12:05 p.m. - International Space Station In-Flight Education Event for the Canadian Space Agency for the

Stonepark Intermediate School in Charlottetown, Prince Edward Island with astronaut David Saint-Jacques

of CSA (All Channels)

Watch NASA TV online by going to the NASA website. Return to Contents

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Space Calendar

Apr 23 - Apollo Asteroid 478784 (2012 UV136) Near-Earth Flyby (0.074 AU)

Apr 23 - Colloquium: From Microbes to Exoplanets - Ecological Remote Sensing of the McMurdo Dry Valleys of Antarctica and Beyond, Tucson, Arizona

Apr 23-24 - Outer Planets Assessment Group (OPAG) Steering Committee Meeting, Washington DC

Apr 23-25 - 4th Group on Earth Observations (GEO) Data Technology Workshop: The ERA of Big EO Data, Vienna, Austria

Apr 23-26 - 46th IOP Plasma Physics Conference, Leicestershire, United Kingdom

Apr 23-26 - Workshop: Precision Era in High Energy Physics, Portoroz, Slovenia

Apr 23-26 - Technical Meeting on Nuclear Data for Anti-neutrino Spectra and Their Applications, Vienna, Austria

Apr 24 - Asteroid 3192 A'Hearn Closest Approach To Earth (1.177 AU)

Apr 24 - Asteroid 69263 Big Ben Closest Approach To Earth (1.427 AU)

Apr 24 - Lecture: The NASA Archives - 60 Years in Space, London, United Kingdom

Apr 24 - Colloquium: The Star-Formation History of the Universe, Greenbelt, Maryland

Apr 24 - Lecture: Project Eden - The Search for Nearby Exo-Earths, Tucson, Arizona

Apr 24-26 - Global Conference on Space for Emerging Countries (GLEC 2019), Marrakech, Morocco

Apr 24-26 - 2019 Aerosols, Clouds, Precipitation and Climate (ACPC) Workshop, Nanjing, China

Apr 24-27 - United Nations/China Forum on Space Solutions: Realizing the Sustainable Development Goals, Changsha, China

Apr 25 - Moon Occults Saturn

Apr 25 - Moon Occults Dwarf Planet Pluto

Apr 25 - Asteroid 3414 Champollion Closest Approach To Earth (1.313 AU)

Apr 25 - European Space Tech Transfer Forum 2019, Warsaw, Poland

Apr 25 - Lecture: Polarization by Interstellar Dust -- What Does it Tell Us?, Ithaca, New York

Apr 25 - Seminar: Lie Algebra Expansions and Actions for Non-Relativistic Gravity, Barcelona, Spain

Apr 25 - Seminar: Understanding Oxidized Differentiation Through the Brachinites and Implications for the Oxidized Bodies in the Solar System, Houston, Texas

Apr 25 - Guglielmo Marconi's 145th Birthday (1874)

Apr 25-26 - Enabling Multi-Messenger Astrophysics in the Big Data Era Workshop, Baltimore, Maryland

Apr 26 - Teleconference: NASA Pre-Proposal Conference for the Discovery 2019 AO

Apr 25-26 - 4th International Conference on Advanced Spectroscopy, Crystallography, and Applications in Modern Chemistry, Rome, Italy

Apr 26 - Asteroid 263251 Pandabear Closest Approach To Earth (1.486 AU)

Apr 26 - Colloquium: The Impact Hazard from Small Near-Earth Objects - Lessons from Chelyabinsk, Greenbelt, Maryland

Apr 26 - Seminar: The Large D Membrane Paradigm for General Four-Derivative Theory of Gravity in the Presence of a Cosmological Constant, Barcelona, Spain

Apr 27 - Aten Asteroid 2019 GF1 Near-Earth Flyby (0.012 AU)

Apr 27 - Apollo Asteroid 3103 Eger Closest Approach To Earth (1.013 AU)

Apr 27-30 - 156th National Academy of Sciences Annual Meeting, Washington DC

Source: JPL Space Calendar Return to Contents

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Food for Thought

Travel Through Wormholes Is Possible, But Slow

Credit: CC0 Public Domain

Wormholes can exist -- but don't pack your bags just yet, said Harvard physicist presenting at the 2019 APS

April Meeting in Denver.

A Harvard physicist has shown that wormholes can exist: tunnels in curved space-time, connecting two distant

places, through which travel is possible.

But don't pack your bags for a trip to other side of the galaxy yet; although it's theoretically possible, it's not

useful for humans to travel through, said the author of the study, Daniel Jafferis, from Harvard University,

written in collaboration with Ping Gao, also from Harvard and Aron Wall from Stanford University.

"It takes longer to get through these wormholes than to go directly, so they are not very useful for space

travel," Jafferis said. He will present his findings at the 2019 American Physical Society April Meeting in

Denver.

Despite his pessimism for pan-galactic travel, he said that finding a way to construct a wormhole through

which light could travel was a boost in the quest to develop a theory of quantum gravity.

"The real import of this work is in its relation to the black hole information problem and the connections

between gravity and quantum mechanics," Jafferis said.

The new theory was inspired when Jafferis began thinking about two black holes that were entangled on a

quantum level, as formulated in the ER=EPR correspondence by Juan Maldacena from the Institute for

Advanced Study and Lenny Susskind from Stanford. Although this means the direct connection between the

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black holes is shorter than the wormhole connection -- and therefore the wormhole travel is not a shortcut --

the theory gives new insights into quantum mechanics.

"From the outside perspective, travel through the wormhole is equivalent to quantum teleportation using

entangled black holes," Jafferis said.

Jafferis based his theory on a setup first devised by Einstein and Rosen in 1935, consisting of a connection

between two black holes (the term wormhole was coined in 1957). Because the wormhole is traversable,

Jafferis said, it was a special case in which information could be extracted from a black hole.

"It gives a causal probe of regions that would otherwise have been behind a horizon, a window to the

experience of an observer inside a spacetime, that is accessible from the outside," said Jafferis.

To date, a major stumbling block in formulating traversable wormholes has been the need for negative

energy, which seemed to be inconsistent with quantum gravity. However, Jafferis has overcome this using

quantum field theory tools, calculating quantum effects similar to the Casimir effect.

"I think it will teach us deep things about the gauge/gravity correspondence, quantum gravity, and even

perhaps a new way to formulate quantum mechanics," Jafferis said.

Source: American Physical Society Return to Contents

A model of 'folded' space-time illustrates how a wormhole

bridge might form with at least two mouths that are connected

to a single throat or tube. Image: © edobric | Shutterstock

Credit: Space.com

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Space Image of the Week

Source: NASA APOD Return to Contents

Spiral Aurora over Icelandic Divide

Image Credit & Copyright: Juan Carlos Casado (TWAN,

StarryEarth)

Explanation: Admire the beauty but fear the beast. The beauty is the aurora overhead, here taking the form of great green spiral, seen between picturesque clouds with the bright Moon to the side and stars in the background. The beast is the wave of charged particles that creates the aurora but might, one day, impair civilization. In 1859, following notable auroras seen all across the globe, a pulse of charged particles from a coronal mass ejection (CME) associated with a solar flare impacted Earth's magnetosphere so forcefully that they created the Carrington Event. A relatively direct path between the Sun and the Earth might have been cleared by a preceding CME. What is sure is that the Carrington Event compressed the Earth's magnetic field so violently that currents were created in telegraph wires so great that many wires sparked and gave telegraph operators shocks. Were a Carrington-class event to impact the Earth today, speculation holds that damage might occur to global power grids and electronics on a scale never yet experienced. The featured aurora was imaged in 2016 over Thingvallavatn Lake in Iceland, a lake that partly fills a fault that divides Earth's large Eurasian and North American tectonic plates.