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Space News Update — October 20, 2015 —

Contents

In the News

Story 1:

Hubble’s Planetary Portrait Captures New Changes in Jupiter’s Great Red Spot

Story 2:

Closest Northern Views of Saturn's Moon Enceladus

Story 3:

Sierra Nevada on Watch for Critical Cargo Award

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. Hubble’s Planetary Portrait Captures New Changes in Jupiter’s Great Red

Spot

Credits: NASA/ESA/Goddard/UCBerkeley/JPL-Caltech/STScI

Scientists using NASA’s Hubble Space Telescope have produced new maps of Jupiter – the first in a series of

annual portraits of the solar system’s outer planets.

Collecting these yearly images – essentially the planetary version of annual school picture days for children –

will help current and future scientists see how these giant worlds change over time. The observations are

designed to capture a broad range of features, including winds, clouds, storms and atmospheric chemistry.

Already, the Jupiter images have revealed a rare wave just north of the planet’s equator and a unique

filamentary feature in the core of the Great Red Spot not seen previously.

“Every time we look at Jupiter, we get tantalizing hints that something really exciting is going on,” said Amy

Simon, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This time is no

exception.”

Simon and her colleagues produced two global maps of Jupiter from observations made using Hubble’s high-

performance Wide Field Camera 3. The two maps represent nearly back-to-back rotations of the planet,

making it possible to determine the speeds of Jupiter’s winds. The findings are described in an Astrophysical

Journal paper, available online.

The new images confirm that the Great Red Spot continues to shrink and become more circular, as it has been

doing for years. The long axis of this characteristic storm is about 150 miles (240 kilometers) shorter now than

it was in 2014. Recently, the storm had been shrinking at a faster-than-usual rate, but the latest change is

consistent with the long-term trend.

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The Great Red Spot remains more orange than red these days, and its core, which typically has more intense

color, is less distinct than it used to be. An unusual wispy filament is seen, spanning almost the entire width of

the vortex. This filamentary streamer rotates and twists throughout the 10-hour span of the Great Red Spot

image sequence, getting distorted by winds blowing at 330 miles per hour (150 meters per second) or even

greater speeds.

In Jupiter’s North Equatorial Belt, the researchers found an elusive wave that had been spotted on the planet

only once before, decades earlier, by Voyager 2. In those images, the wave is barely visible, and nothing like it

was seen again, until the current wave was found traveling at about 16 degrees north latitude, in a region

dotted with cyclones and anticyclones. Similar waves – called baroclinic waves – sometimes appear in Earth’s

atmosphere where cyclones are forming.

“Until now, we thought the wave seen by Voyager 2 might have been a fluke,” said co-author Glenn Orton of

NASA’s Jet Propulsion Laboratory in Pasadena, California. “As it turns out, it’s just rare!”

The wave may originate in a clear layer beneath the clouds, only becoming visible when it propagates up into

the cloud deck, according to the researchers. That idea is supported by the spacing between the wave crests.

In addition to Jupiter, the researchers have observed Neptune and Uranus, and maps of those planets also will

be placed in the public archive. Saturn will be added to the series later. Hubble will dedicate time each year to

this special set of observations, called the Outer Planet Atmospheres Legacy program.

“The long-term value of the Outer Planet Atmospheres Legacy program is really exciting,” said co-author

Michael H. Wong of the University of California, Berkeley. “The collection of maps that we will build up over

time will not only help scientists understand the atmospheres of our giant planets, but also the atmospheres of

planets being discovered around other stars, and Earth’s atmosphere and oceans, too.”

In Jupiter’s North Equatorial Belt, scientists spotted a rare wave that had been seen there only once before. It is similar to

a wave that sometimes occurs in Earth’s atmosphere when cyclones are forming. This false-color close-up of Jupiter

shows cyclones (arrows) and the wave (vertical lines). Credits: NASA/ESA/Goddard/UCBerkeley/JPL-Caltech/STScI

Source: NASA Return to Contents

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2. Closest Northern Views of Saturn's Moon Enceladus

NASA's Cassini spacecraft zoomed by Saturn's icy moon Enceladus on Oct. 14, 2015, capturing this stunning image of the

moon's north pole. A companion view from the wide-angle camera (PIA20010) shows a zoomed out view of the same

region for context. The view was acquired at a distance of approximately 4,000 miles (6,000 kilometers) from Enceladus

and at a Sun-Enceladus-spacecraft, or phase, angle of 9 degrees. Image scale is 115 feet (35 meters) per pixel.

Image Credit: NASA/JPL-Caltech/Space Science Institute

NASA's Cassini spacecraft has begun returning its best-ever views of the northern extremes of Saturn's icy,

ocean-bearing moon Enceladus. The spacecraft obtained the images during its Oct. 14 flyby, passing 1,142

miles (1,839 kilometers) above the moon's surface. Mission controllers say the spacecraft will continue

transmitting images and other data from the encounter for the next several days.

Scientists expected the north polar region of Enceladus to be heavily cratered, based on low-resolution images

from the Voyager mission, but the new high-resolution Cassini images show a landscape of stark contrasts.

"The northern regions are crisscrossed by a spidery network of gossamer-thin cracks that slice through the

craters," said Paul Helfenstein, a member of the Cassini imaging team at Cornell University, Ithaca, New York.

"These thin cracks are ubiquitous on Enceladus, and now we see that they extend across the northern terrains

as well."

In addition to the processed images, unprocessed, or "raw," images are posted on the Cassini mission website

at:

http://saturn.jpl.nasa.gov/mission/flybys/enceladus20151014

Cassini's next encounter with Enceladus is planned for Oct. 28, when the spacecraft will come within 30 miles

(49 kilometers) of the moon's south polar region. During the encounter, Cassini will make its deepest-ever dive

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through the moon's plume of icy spray, sampling the chemistry of the extraterrestrial ocean beneath the ice.

Mission scientists are hopeful data from that flyby will provide evidence of how much hydrothermal activity is

occurring in the moon's ocean, along with more detailed insights about the ocean's chemistry -- both of which

relate to the potential habitability of Enceladus.

Cassini's final close Enceladus flyby will take place on Dec. 19, when the spacecraft will measure the amount

of heat coming from the moon's interior. The flyby will be at an altitude of 3,106 miles (4,999 kilometers).

NASA's Cassini spacecraft spied this tight trio of craters as it approached Saturn's icy moon Enceladus for a close flyby on

Oct. 14, 2015. The craters, located at high northern latitudes, are sliced through by thin fractures -- part of a network of

similar cracks that wrap around the snow-white moon. The image was taken in visible light with the Cassini spacecraft

narrow-angle camera on Oct. 14, 2015 at a distance of approximately 6,000 miles (10,000 kilometers) from Enceladus.

Image scale is 197 feet (60 meters) per pixel. The image was taken with the Cassini spacecraft narrow-angle camera on

Oct. 14, 2015 using a spectral filter which preferentially admits wavelengths of ultraviolet light centered at 338

nanometers.

Source: NASA Return to Contents

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3. Sierra Nevada on Watch for Critical Cargo Award

Sierra Nevada Corp. technicians prepare the Dream Chaser engineering test article for another round of atmospheric flight

tests. Credit: Sierra Nevada

A prototype of Sierra Nevada’s Dream Chaser space plane is nearing shipment to California’s Mojave Desert to

resume runway landing tests as officials wait for word from NASA whether the company will win a competition

to ferry cargo to the International Space Station.

The announcement from NASA, expected in early November, bears additional significance for Sierra Nevada

after the space agency bypassed the Dream Chaser last year with its selection of Boeing and SpaceX to ferry

crews between Earth and the space station.

Sierra Nevada has agreements with the European Space Agency, Japan’s space agency and the German space

agency to study how the Dream Chaser could fare in the international marketplace.

But the scope of that work is a sliver of the value of a NASA cargo award.

Sierra Nevada is up against NASA’s incumbent space station cargo transportation providers, SpaceX and

Orbital ATK, and Boeing, which has proposed using its CST-100 crew capsule for supply runs. NASA originally

envisioned selecting multiple winners in May, but now the award is slated for around Nov. 5, according to the

agency’s website.

“Not having delays in the award would be a good thing,” said Mark Sirangelo, head of Sierra Nevada’s space

systems division. “It’s a rough thing, and we all know it’s a complicated process. The original award was

scheduled for May or June, and now it’s November, and in doing that it not only delays the ability for all of us

to move forward, but … this is a people industry. We’ve got lots and lots of people who are waiting to see

what happens, and they’ve got lives and families. That’s the most important thing from our perspective.”

Engineers adapted the design of the Dream Chaser crew vehicle for exclusively cargo over the last 12 months,

introducing a new concept with more autonomy, an expendable cargo module with solar arrays, and foldable

wings to fit inside the nose cones of multiple types of boosters.

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Sierra Nevada intended the crew version of Dream Chaser to launch without an aerodynamic fairing.

Sirangelo updated reporters two weeks ago on preps for approach and landing tests of a Dream Chaser

engineering article at NASA’s Armstrong Flight Research Center at Edwards Air Force Base, California. The

descent demos come after the prototype Dream Chaser was damaged during an unpowered glide test in

October 2013, when one of the ship’s two main landing gears did not deploy.

He said the upcoming test series, expected to begin in the first quarter of 2016, will use the Dream Chaser’s

flight software program and include drop and tow tests at NASA Armstrong. The earlier tests featured a

temporary landing gear configuration borrowed from the F-5 fighter jet, and engineers have added

redundancy for the coming flights.

With stubby wings and a 30-foot length, the Dream Chaser is about one-fourth the size of a space shuttle

orbiter. Its cargo variant could haul up more than 12,000 pounds — 5,500 kilograms — of equipment and

experiments to the space station, according to Sierra Nevada.

The spaceship could dock or berth with the space station, and it would be outfitted to deliver pressurized

supplies and external cargo. At the end of each mission, the Dream Chaser space plane would return to Earth

with research specimens and other items designated for recovery, while the detachable cargo module would

burn up in Earth’s atmosphere, disposing of the space station’s rubbish.

The upcoming landing tests are part of a still-active funding agreement Sierra Nevada signed with NASA’s crew

transportation program in 2012. Under the terms of the arrangement, the federal government pays Sierra

Nevada as the company achieves pre-agreed milestones, and the atmospheric demo sequence is the final step

in the agreement.

NASA has committed approximately $350 million since 2010 to Sierra Nevada supporting the Dream Chaser

space plane’s development. Sierra Nevada has not disclosed how much internal funding it has routed toward

the program.

Sirangelo said Dream Chaser’s atmospheric test article will be shipped from Sierra Nevada’s Colorado facility to

NASA Armstrong in California by the end of the year or early next year and flight testing will start in the first

quarter of 2016.

A Sikorsky Skycrane helicopter will hoist the prototype spaceship — which weighs about three tons in its

current test configuration — over a runway at Edwards Air Force Base, then drop the craft for a computer-

guided approach.

“We’re thinking three to six (flights),” Sirangelo said. “That’s the glide tests from different altitudes. What

we’re looking to do is exceed the goals that we set out, and when we do that, we’ll be done with the flight

tests.”

The series will include tow tests that will pull the Dream Chaser along the ground and lift it airborne for further

demonstrations, Sirangelo said.

As for resolving the landing gear glitch that prematurely ended the 2013 test flights, Sirangelo said engineers

have added mechanical actuators to the hydraulic undercarriage deployment system.

“We’re expecting to have the vehicle completed and moved out, depending on the NASA and Air Force

regulations, within the next three to four months, and flight testing will start in the first quarter of 2016,”

Sirangelo said.

The Dream Chaser cargo carrier could be ready for space missions by late 2018 or early 2019, he said.

Source:SpaceflightNow.com Return to Contents

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The Night Sky

Credit: Astronomy Now.com

Source: Sky and Telescope Return to Contents

Tuesday, October 20

First-quarter Moon (exact at 4:31 p.m. Eastern Daylight Time). The Moon stands in the south at sunset. After dark,

look to the Moon's upper left for Alpha and Beta Capricorni, both 3rd magnitude. Alpha, the higher one, is a naked-

eye double star (separation 0.1°). Use binoculars to see that Beta is a closer, more unequal double.

The Orionid meteor shower should be active from midnight to dawn Wednesday and Thursday mornings. It's a

middling shower, with about 20 meteors per hour visible before the first light of dawn under ideal dark-sky

conditions. The shower's radiant is near the top of Orion's club.

Wednesday, October 21

• Alpha and Beta Cap are now to the Moon's right in early evening.

Thursday, October 22

Vega is the brightest star very high in the west at nightfall. Arcturus, equally bright, is getting low in the west-

northwest. The brightest star in the vast region between them, about a third of the way from Arcturus back up

toward Vega, is Alphecca, magnitude 2.2 — the crown jewel of Corona Borealis.

Friday, October 23

Have you checked out Mercury, Jupiter, Mars, and Venus in early dawn? The last three of these are in a rapidly

evolving dance! Tomorrow morning Venus and Jupiter are 1.6° apart and closing.

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ISS Sighting Opportunities (from Denver)

Date Visible Max Height Appears Disappears

Tue Oct 20, 7:27 PM 4 min 43° 10° above NW 38° above ENE

Wed Oct 21, 6:35 PM 5 min 26° 10° above NNW 11° above E

Wed Oct 21, 8:13 PM < 1 min 32° 24° above W 32° above WSW

Thu Oct 22, 7:18 PM 5 min 77° 10° above NW 23° above SE

Fri Oct 23, 6:30 PM 2 min 30° 30° above E 11° above ESE

Fri Oct 23, 8:04 PM 2 min 15° 14° above WSW 12° above SSW

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

NASA-TV Highlights (all times Eastern Time Zone)

Tuesday, October 20

• 2:30 p.m. - In-Flight Interview with the Google Zeitgeist Conference (all channels)

Wednesday, October 21

1 p.m., - Smithsonian’s National Air and Space Museum Presents “STEM in 30” -- Mars: A Current Elementary or Middle School Student Will Most Likely be the First Human to Step Foot on Mars (NTV-1 (Public), NTV-2 (Education))

Thursday, October 22

8:30 a.m. - In-Flight Interviews with WNYC Radio and CNBC (Starts at 8:25am) (all channels)

2 p.m. - ISS Expedition 45 U.S. Spacewalk Preview Briefing (all channels)

Friday, October 23

10:30 a.m. - In-Flight Educational Event with the LBJ Library (Starts at 10:25am) (NTV-1 (Public), NTV-3 (Media))

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

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Space Calendar

Oct 20 - Asteroid 119000 (2000 YV55) Occults HIP 4932 (6.3 Magnitude Star)

Oct 20 - Apollo Asteroid 2015 TD144 Near-Earth Flyby (0.030 AU)

Oct 20 - Asteroid 39382 Opportunity Closest Approach To Earth (2.320 AU)

Oct 20 - Kuiper Belt Object 308379 (2005 RS43) At Opposition (42.210 AU)

Oct 20 - 20th Anniversary (1995), STS-73 Launch (Space Shuttle Columbia, Spacelab)

Oct 20 - 45th Anniversary (1970), Zond 8 Launch (USSR Moon Flyby)

Oct 21 - Orionids Meteor Shower Peak

Oct 21 - Comet C/2014 A4 (SONEAR) At Opposition (3.204 AU)

Oct 21 - Asteroid 4104 Alu Closest Approach To Earth (1.555 AU)

Oct 21 - Ron McNair's 65th Birthday (1950)

Oct 22 - Comet P/2015 T3 (PANSTARRS) At Opposition (1.780 AU)

Oct 22 - Comet P/2001 H5 (NEAT) Perihelion (2.436 AU)

Oct 22 - Comet 318P/McNaught-Hartley Perihelion (2.448 AU)

Oct 22 - Comet 26P/Grigg-Skjellerup At Opposition (3.899 AU)

Oct 22 - Apollo Asteroid 2015 TZ143 Near-Earth Flyby (0.011 AU)

Oct 22 - Aten Asteroid 2006 UY64 Near-Earth Flyby (0.061 AU)

Oct 22 - Asteroid 2343 Siding Spring Closest Approach To Earth (0.766 AU)

Oct 22 - Karl Jansky's 110th Birthday (1905)

Oct 23 - Comet 7P/Pons-Winnecke At Opposition (2.030 AU)

Oct 23 - Comet 326P/Hill Perihelion (2.780 AU)

Oct 23 - Asteroid 203 Pompeja Closest Approach To Earth (1.588 AU)

Oct 23 - Asteroid 2700 Baikonur Closest Approach To Earth (1.843 AU)

Oct 23 - Neptune Trojan 2001 QR322 At Opposition (29.035 AU)

Oct 23 - Kuiper Belt Object 55636 (2002 TX300) At Opposition (41.326 AU)

Oct 23 - 40th Anniversary (1975), Venera 10, Venus Orbit Insertion (USSR Venus Orbiter/Lander)

Oct 24 - Cassini, Orbital Trim Maneuver #427 (OTM-427)

Oct 24 - Comet 61P/Shajn-Schaldach Closest Approach To Earth (1.135 AU)

Oct 24 - Comet 202P/Scotti At Opposition (1.881 AU)

Oct 24 - Asteroid 2991 Bilbo Closest Approach To Earth (1.363 AU)

Oct 24 - Asteroid 12561 Howard Closest Approach To Earth (2.522 AU)

Oct 24 - 55th Anniversary (1960), Nedelin Disater - Launch Pad Explosion, Over 100 People Killed

Source: JPL Space Calendar Return to Contents

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Food for Thought

Mars Water Discovery Sparks Exploration Debate

NASA Mars Reconnaissance Orbiter's HiRISE image of Recurring Slope Lineae in Melas Chasma, Valles Marineris. Arrows

point out tops and bottoms of a few lineae.

Credit: NASA/JPL-Caltech/University of Arizona

The revelation that dark streaks flowing downhill on Mars are signs of present-day liquid water has sparked

debate on how best to investigate the Red Planet features.

These dark streaks, called Recurring Slope Lineae (RSL), flow down steep slopes during warm seasons and

fade when the weather is cooler. The streaks are caused by liquid water laden with salts, scientists announced

last month.

The new RSL findings may well bolster the odds that life exists today on Mars. Moreover, RSL might be a draw

for future human explorers, as those sites could lead to underground aquifers on the planet, NASA officials

have said. [Flowing Water on Mars: The Discovery in Pictures]

However, exploring RSL sites further is a matter of some controversy. One contentious issue has to do with

"planetary protection" — how best to safely survey RSL sites up close, without contaminating these features

with Earth-transported microbes.

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Red light on the Red Planet?

If there's a way to sample an RSL site with a Mars robot — say, NASA's car-size Curiosity rover— many

scientists would be eager to go for it. Life exists everywhere there's liquid water here on Earth, so RSL areas

are intriguing places to search for signs of Mars life.

But other researchers might want to put the brakes on such an operation, out of concern that Earth life could

take root at these sites. That worry is especially applicable to Curiosity, which carries contaminated drill bits.

Before Curiosity's launch, the rover's developers made an internal decision not to send the drill bits through a

final ultra-cleanliness step. Not doing so marked a deviation from the planetary protection plans scripted for

Curiosity's $2.5 billion mission, much to the dismay of NASA planetary protection authorities.

Round-the-clock monitoring

Curiosity is currently exploring the foothills of the 3.4-mile-high (5.5 kilometers) Mount Sharp, which lies in the

center of a big crater called Gale.

The powerful High Resolution Imaging Science Experiment (HiRISE) camera system aboard NASA's Mars

Reconnaissance Orbiter has spotted streaks near Mount Sharp's base that have characteristics similar to RSL.

However, none of those markings has been confirmed to be RSL as of yet.

"The bottom line is that there are no promising candidates near Curiosity, so diverting the rover to look at

poor candidates may not be justified," said HiRISE principal investigator Alfred McEwen, of the University of

Arizona in Tucson.

However, "If they [mission scientists] do get in range [of an RSL site], they should image over a range of

[different] times of day," McEwen told Space.com.

David Stillman, a scientist at the Southwest Research Institute in Boulder, Colorado, voiced similar sentiments.

"Round-the-clock monitoring of a dark RSL is just what we need," he told Space.com. "It would be wonderful if

Curiosity could sit below an RSL alcove and watch the incremental lengthening."

Stillman contends that RSL are the most accessible form of water on Mars — easier to get at than buried ice

and hydrated minerals. Therefore, astronauts should take advantage of RSL features "and use them as early

settlers used spring water," he said.

Special regions

Curiosity is not permitted to access "special regions" on Mars — areas where liquid water exists, or where

Curiosity's presence could cause liquid water to exist (say, by melting ice) — said Cassie Conley, NASA's

Planetary Protection Officer.

"So the question in regard to RSL access by Curiosity would be how far away the rover needs to stay," Conley

told Space.com. "Guidelines on 'how close is close enough' are certainly in work . We're in the process of

setting up detailed analyses to evaluate where Curiosity may go relative to dark slope streaks/RSL in Gale

Crater."

Shaping those guidelines depends on many factors that are currently poorly known, Conley said, so her office

will be having a detailed discussion with Curiosity team members to understand all available current data

about the specific locations and traverses in question before coming to any conclusions.

"These will be analogous in general to the proposed constraints on future human missions," Conley said,

"which involve estimation of the amount and type of Earth contamination that could be released, and also

consideration of possible transport mechanisms that might introduce contamination to special regions."

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Crème brûlée

John Rummel, a senior scientist at the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain

View, California and a former NASA Planetary Protection Officer, has his own bottom line when it comes to

Curiosity and RSL sites.

"Curiosity has nothing much that it can add to the picture with any of its stand-off capabilities, and quite a lot

to lose in trying," Rummel told Space.com.

From 65 feet (20 meters) away, "the rover can tell us pretty much the same things that we can already tell

from orbit," Rummel said. "What is the benefit from taking the risk?"

Furthermore, RSL sites may consist of a crusty layer atop soupy brine, akin to a crème brûlée dessert, Rummel

said. So exploring an RSL-harboring slope could be hazardous in multiple ways.

"That could give way and trap the rover or flip it over, downslope," Rummel said. "And for planetary protection

purposes, the potential to break it open has got to be considered as well."

Explore Mars responsibly

If such an incident did occur, the debate about ultraviolet sterilization of Curiosity's exterior would be moot,

Rummel said, because the "unaccounted" microbes on the machine's inside could come into contact with liquid

water.

"So if making a so-so measurement of an RSL kills both the rover and our chance to explore Mars responsibly,

I can't get too enthusiastic about the bet!" Rummel said. "But if someone wanted to make that bet, they

would have to demonstrate, through modeling and experimentation, that there would be no threat of letting

live Earth microbes into the potential special region at whatever distance they pick."

Furthermore, NASA's Planetary Protection Officer, along with the head of the space agency's Science Mission

Directorate, "would have to agree with that decision," Rummel concluded, "something I think extremely

unlikely with what we know today."

Source: Space.com Return to Contents

NASA's Curiosity rover is currently exploring the base of Mount Sharp. The Martian peak's base has features similar to Recurring Slope Lineae (RSL), which are caused by liquid water, but none are confirmed to be RSL. Sites 33, 36, 46, and 56 are closest to the rover. Credit: "Slope activity in Gale crater, Mars" by Colin Dundas, Alfred McEwen published in the scientific journal Icarus.

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Space Image of the Week

Flash floods in Mangala Valles

Image Credits: Copyright ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Explanation: The images were taken by the high-resolution stereo camera on ESA’s Mars Express on 12 July just

to the south of the mouth of Minio Vallis. The region is part of the Mangala Valles outflow channel system, and is

situated in the southwestern portion of the Tharsis bulge, home to several volcanoes, including the Solar System’s

largest: Olympus Mons.

The region’s proximity to these volcanic giants likely played an important role in creating the channels seen in these

images, which were carved by large volumes of flowing water. There, hot, molten rock could have reached the

surface in an episode of increased volcanic activity during the formation of the Tharsis bulge.

This activity may have triggered the melting of subsurface ice, and consequently the formation of the water-carved

channels.

Several basins and impact craters were also filled with water, with overflows flushing through multiple spillways and

towards Amazonis Planitia, the lowlands to the north. For example, a channel drains into the 28 km-wide impact

crater in the upper right of the image, breaching its crater wall.

The crater in the centre of the image has a somewhat different appearance: it was filled with water and sediments

and later eroded back again. ‘Chaotic terrain’ formed around it, characterised by isolated blocks of surface material

that have been chaotically arranged during the release of subsurface water and subsequent surface collapse.

Another example of an infilled and eroded crater lies to the southeast (bottom left in the main image) of this crater.

A deep channel carves through the landscape along the bottom edge of the image, its inner walls displaying layers,

terraces and streamlined islands eroded by the outflowing water.

Source: ESA Return to Contents