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Space News Update — May 3, 2019 —

Contents

In the News

Story 1: Hubble Astronomers Assemble Wide View of the Evolving Universe

Story 2: LIGO and Virgo detect neutron star smash-ups

Story 3: SpaceX offers new details on Crew Dragon test anomaly

Departments

The Night Sky

ISS Sighting Opportunities

Space Calendar

NASA-TV Highlights

Food for Thought

Space Image of the Week

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1. Hubble Astronomers Assemble Wide View of the Evolving Universe

Astronomers have put together the largest and most comprehensive "history book" of galaxies into one single image, using 16 years' worth of observations from NASA's Hubble Space Telescope.

The deep-sky mosaic, created from nearly 7,500 individual exposures, provides a wide portrait of the distant universe, containing 265,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the big bang. The faintest and farthest galaxies are just one ten-billionth the brightness of what the human eye can see. The universe's evolutionary history is also chronicled in this one sweeping view. The portrait shows how galaxies change over time, building themselves up to become the giant galaxies seen in the nearby universe.

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This ambitious endeavor, called the Hubble Legacy Field, also combines observations taken by several Hubble deep-field surveys, including the eXtreme Deep Field (XDF), the deepest view of the universe. The wavelength range stretches from ultraviolet to near-infrared light, capturing the key features of galaxy assembly over time.

"Now that we have gone wider than in previous surveys, we are harvesting many more distant galaxies in the largest such dataset ever produced by Hubble," said Garth Illingworth of the University of California, Santa Cruz, leader of the team that assembled the image. "This one image contains the full history of the growth of galaxies in the universe, from their time as 'infants' to when they grew into fully fledged 'adults.'"

No image will surpass this one until future space telescopes are launched. "We've put together this mosaic as a tool to be used by us and by other astronomers," Illingworth added. "The expectation is that this survey will lead to an even more coherent, in-depth and greater understanding of the universe's evolution in the coming years."

The image yields a huge catalog of distant galaxies. "Such exquisite high-resolution measurements of the numerous galaxies in this catalog enable a wide swath of extragalactic study," said catalog lead researcher Katherine Whitaker of the University of Connecticut, in Storrs. "Often, these kinds of surveys have yielded unanticipated discoveries which have had the greatest impact on our understanding of galaxy evolution."

Galaxies are the "markers of space," as astronomer Edwin Hubble once described them a century ago. Galaxies allow astronomers to trace the expansion of the universe, offer clues to the underlying physics of the cosmos, show when the chemical elements originated, and enable the conditions that eventually led to the appearance of our solar system and life.

This wider view contains about 30 times as many galaxies as in the previous deep fields. The new portrait, a mosaic of multiple snapshots, covers almost the width of the full Moon. The XDF, which penetrated deeper into space than this wider view, lies in this region, but it covers less than one-tenth of the full Moon's diameter. The Legacy Field also uncovers a zoo of unusual objects. Many of them are the remnants of galactic "train wrecks," a time in the early universe when small, young galaxies collided and merged with other galaxies.

Assembling all of the observations was an immense task. The image comprises the collective work of 31 Hubble programs by different teams of astronomers. Hubble has spent more time on this tiny area than on any other region of the sky, totaling more than 250 days, representing nearly three-quarters of a year.

"Our goal was to assemble all 16 years of exposures into a legacy image," explained Dan Magee, of the University of California, Santa Cruz, the team's data processing lead. "Previously, most of these exposures had not been put together in a consistent way that can be used by any researcher. Astronomers can select the data in the Legacy Field they want and work with it immediately, as opposed to having to perform a huge amount of data reduction before conducting scientific analysis."

The image, along with the individual exposures that make up the new view, is available to the worldwide astronomical community through the Mikulski Archive for Space Telescopes (MAST). MAST, an online database of astronomical data from Hubble and other NASA missions, is located at the Space Telescope Science Institute in Baltimore, Maryland.

The Hubble Space Telescope has come a long way in taking ever deeper "core samples" of the distant universe. After Hubble's launch in 1990, astronomers debated if it was worth spending a chunk of the telescope's time to go on a "fishing expedition" to take a very long exposure of a small, seemingly blank piece of sky. The resulting Hubble Deep Field image in 1995 captured several thousand unseen galaxies in one pointing. The bold effort was a landmark demonstration and a defining proof-of-concept that set the stage for future deep field images. In 2002, Hubble's Advanced Camera for Surveys went even deeper to uncover

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10,000 galaxies in a single snapshot. Astronomers used exposures taken by Hubble's Wide Field Camera 3 (WFC3), installed in 2009, to assemble the eXtreme Deep Field snapshot in 2012. Unlike previous Hubble cameras, the telescope's WFC3 covers a broader wavelength range, from ultraviolet to near-infrared.

This new image mosaic is the first in a series of Hubble Legacy Field images. The team is working on a second set of images, totaling more than 5,200 Hubble exposures, in another area of the sky. In the future, astronomers hope to broaden the multiwavelength range in the legacy images to include longer-wavelength infrared data and high-energy X-ray observations from two other NASA Great Observatories, the Spitzer Space Telescope and Chandra X-ray Observatory.

The vast number of galaxies in the Legacy Field image are also prime targets for future telescopes. "This will really set the stage for NASA's planned Wide Field Infrared Survey Telescope (WFIRST)," Illingworth said. "The Legacy Field is a pathfinder for WFIRST, which will capture an image that is 100 times larger than a typical Hubble photo. In just three weeks' worth of observations by WFIRST, astronomers will be able to assemble a field that is much deeper and more than twice as large as the Hubble Legacy Field."

In addition, NASA's upcoming James Webb Space Telescope will allow astronomers to push much deeper into the legacy field to reveal how the infant galaxies actually grew. Webb's infrared coverage will go beyond the limits of Hubble and Spitzer to help astronomers identify the first galaxies in the universe.

Source: NASA Return to Contents

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2. LIGO and Virgo detect neutron star smash-ups

On April 25, 2019, the National Science Foundation's Laser Interferometer Gravitational-Wave Observatory (LIGO) and the European-based Virgo detector registered gravitational waves from what appears likely to be a crash between two neutron stars—the dense remnants of massive stars that previously exploded. One day later, on April 26, the LIGO-Virgo network spotted another candidate source with a potentially interesting twist: it may in fact have resulted from the collision of a neutron star and black hole, an event never before witnessed.

"The universe is keeping us on our toes," says Patrick Brady, spokesperson for the LIGO Scientific Collaboration and a professor of physics at the University of Wisconsin-Milwaukee. "We're especially curious about the April 26 candidate. Unfortunately, the signal is rather weak. It's like listening to somebody whisper a word in a busy café; it can be difficult to make out the word or even to be sure that the person whispered at all. It will take some time to reach a conclusion about this candidate."

"NSF's LIGO, in collaboration with Virgo, has opened up the universe to future generations of scientists," says NSF Director France Cordova. "Once again, we have witnessed the remarkable phenomenon of a neutron star merger, followed up closely by another possible merger of collapsed stars. With these new discoveries, we see the LIGO-Virgo collaborations realizing their potential of regularly producing discoveries that were once impossible. The data from these discoveries, and others sure to follow, will help the scientific community revolutionize our understanding of the invisible universe."

The discoveries come just weeks after LIGO and Virgo turned back on. The twin detectors of LIGO—one in Washington and one in Louisiana—along with Virgo, located at the European Gravitational Observatory (EGO) in Italy, resumed operations April 1, after undergoing a series of upgrades to increase their sensitivities

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to gravitational waves—ripples in space and time. Each detector now surveys larger volumes of the universe than before, searching for extreme events such as smash-ups between black holes and neutron stars.

"Joining human forces and instruments across the LIGO and Virgo collaborations has been once again the recipe of an incomparable scientific month, and the current observing run will comprise 11 more months," says Giovanni Prodi, the Virgo Data Analysis Coordinator, at the University of Trento and the Istituto Nazionale di Fisica Nucleare (INFN) in Italy. "The Virgo detector works with the highest stability, covering the sky 90 percent of the time with useful data. This is helping in pointing to the sources, both when the network is in full operationand at times when only one of the LIGO detectors is operating. We have a lot of groundbreaking research work ahead."

In addition to the two new candidates involving neutron stars, the LIGO-Virgo network has, in this latest run, spotted three likely black hole mergers. In total, since making history with the first-ever direct detection of gravitational waves in 2015, the network has spotted evidence for two neutron star mergers; 13 black hole mergers; and one possible black hole-neutron star merger.

When two black holes collide, they warp the fabric of space and time, producing gravitational waves. When two neutron stars collide, they not only send out gravitational waves but also light. That means telescopes sensitive to light waves across the electromagnetic spectrum can witness these fiery impacts together with LIGO and Virgo. One such event occurred in August 2017: LIGO and Virgo initially spotted a neutron star merger in gravitational waves and then, in the days and months that followed, about 70 telescopes on the ground and in space witnessed the explosive aftermath in light waves, including everything from gamma rays to optical light to radio waves.

In the case of the two recent neutron star candidates, telescopes around the world once again raced to track the sources and pick up the light expected to arise from these mergers. Hundreds of astronomers eagerly pointed telescopes at patches of sky suspected to house the signal sources. However, at this time, neither of the sources has been pinpointed.

"The search for explosive counterparts of the gravitational-wave signal is challenging due to the amount of sky that must be covered and the rapid changes in brightness that are expected," says Brady. "The rate of neutron star merger candidates being found with LIGO and Virgo will give more opportunities to search for the explosions over the next year."

The April 25 neutron star smash-up, dubbed S190425z, is estimated to have occurred about 500 million light-years away from Earth. Only one of the twin LIGO facilities picked up its signal along with Virgo (LIGO Livingston witnessed the event but LIGO Hanford was offline.) Because only two of the three detectors registered the signal, estimates of the location in the sky from which it originated were not precise, leaving astronomers to survey nearly one-quarter of the sky for the source.

The possible April 26 neutron star-black hole collision (referred to as S190426c) is estimated to have taken place roughly 1.2 billion light-years away. It was seen by all three LIGO-Virgo facilities, which helped better narrow its location to regions covering about 1,100 square degrees, or about 3 percent of the total sky.

"The latest LIGO-Virgo observing run is proving to be the most exciting one so far," says David H. Reitze of Caltech, Executive Director of LIGO. "We're already seeing hints of the first observation of a black hole swallowing a neutron star. If it holds up, this would be a trifecta for LIGO and Virgo—in three years, we'll have observed every type of black hole and neutron star collision. But we've learned that claims of detections require a tremendous amount of painstaking work—checking and rechecking—so we'll have to see where the data takes us."

Source: Phys.org Return to Contents

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3. SpaceX offers new details on Crew Dragon test anomaly

A SpaceX executive May 2 provided new details about, but no cause of, an incident that destroyed a Crew Dragon spacecraft during a ground test last month.

Hans Koenigsmann, vice president of build and flight reliability at SpaceX, said at a NASA briefing about the upcoming launch of a cargo Dragon spacecraft to the International Space Station that the anomaly took place just before the ignition of the SuperDraco thrusters on the spacecraft during an April 20 test at the company’s Landing Zone 1 at Cape Canaveral Air Force Station in Florida.

Koenigsmann said that the spacecraft had, earlier in the day, completed other tests on the stand, including of its smaller Draco thrusters. “Just before we wanted to fire the SuperDracos, there was an anomaly and the vehicle was destroyed,” he said.

He declined to speculate on the cause of the accident. “It is too early to confirm any cause, whether probable or root,” he said. “The initial data indicates that the anomaly occurred during the activation of the SuperDraco system.” The activation of the thrusters takes place about a half a second before ignition. He added, though, that he didn’t think the problem was with the SuperDraco thrusters themselves, citing “about 600 tests” of the thrusters over the course of its development.

He later said it was unlikely that the incident had anything to do with composite-overwrapped pressure vessels, or COPVs, that are part of the propulsion system. The design of a COPV used on the Falcon 9’s second stage was blamed for an explosion during preparations for a static-fire test of the rocket in September 2016, leading to a redesign of that pressure vessel.

“The COPVs are different from Falcon 9. These are different in material, they have a different form,” he said. “I’m fairly confident that the COPVs are going to be fine.”

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Koenigsmann said the company is currently focused on the investigation into the mishap, and declined to estimate how much of an impact it will have on the schedule of upcoming test flights. SpaceX had planned to perform an in-flight abort test using the Crew Dragon spacecraft destroyed in the anomaly as soon as June, followed by a crewed test flight no earlier than July.

“Finishing the investigation and resolving this anomaly is actually our prime focus, certainly for me, right now,” he said. “I hope this is a relatively swift investigation at the end of the day, and I don’t want to completely preclude the current schedule.”

He didn’t say how the capsule lost in the test mishap, which flew on the Demo-1 mission to the station, would be replaced for the in-flight abort test. He noted SpaceX has “multiple spacecraft” in various stages of production, which he said should mitigate any effect the loss of this capsule will have on the test flight schedule.

Koenigsmann spoke at a briefing NASA held prior to the scheduled May 3 launch of a cargo Dragon spacecraft on a mission to the International Space Station. The launch was previously scheduled for May 1 but postponed because of a problem with a switching unit that routes power on the station. Kenny Todd, NASA’s space station operations and integration manager, said the faulty unit was swapped out by controllers using the station’s robotic arm, clearing the way for the launch to proceed.

Todd also said that NASA worked closely with SpaceX to confirm that there was no commonality between the systems involved in the Crew Dragon anomaly and those on the cargo Dragon. “We were able to get our arms around the common areas that we had to look at, that they had to look at,” he said. “At the end of the day, we didn’t see any change in our overall measurable risk in going into the mission.”

This cargo Dragon, flying a mission designated CRS-17, previously flew to the station on the CRS-12 mission in August 2017. The spacecraft will carry 2,482 kilograms of cargo, of which about 1,700 kilograms is in the form of science payloads, including those to be mounted on the station’s exterior.

Liftoff of the CRS-17 mission is scheduled for 3:11 a.m. Eastern May 3, but forecasts predict only a 40 percent change of acceptable weather because of an approaching system. Forecasts improve to 70 percent for a backup launch date May 4 at 2:48 a.m. Eastern. Todd said that, should the launch not take place in either instantaneous launch window, NASA and SpaceX would have to wait a week before the next attempt because of scheduled downtime on the Eastern Range.

Source: SpaceNews.com Return to Contents

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The Night Sky

Friday, May 3

• Three zero-magnitude stars shine after dark in May: Arcturus high in the southeast, Vega much lower in the northeast, and Capella in the northwest. They appear so bright because each is at least 60 times as luminous as the Sun, and because they're all relatively nearby: 37, 25, and 42 light-years from us, respectively.

Saturday, May 4

• Vega is the brightest star in the northeast late these evenings. Look 14° (about a fist and a half at arm's length) to Vega's upper left for Eltanin, the nose of Draco the Dragon. Closer above and upper left of Eltanin are the three fainter stars of Draco's stick-figure head, also called the Lozenge. Draco always points his nose to Vega no matter in what part of the sky we see them. He seems awfully curious about it. Do dragons eat jewels?

The faintest star of Draco's head, opposite Eltanin, is 4th-magnitude Nu Draconis. It's a lovely, equal-brightness double star for binoculars and small scopes (separation 61 arcseconds).

• New Moon (exact at 6:46 p.m. EDT).

Sunday, May 5

• As night descends, look high in the west for Pollux and Castor lined up almost horizontally (depending on your latitude). These two stars, the heads of the Gemini twins, form the top of the enormous Arch of Spring. To their lower left is Procyon, the left end of the Arch. Farther to their lower right is the other end, formed by Menkalinan (Beta Aurigae) and then brilliant Capella. The whole thing sinks lower through the evening.

• Before the Moon returns to brighten the evening sky, learn to find (once and for all!) the famous galaxies M81 and M82 by using the faint "Mini-Dipper" attached to the Big Dipper's lip. See Matt Wedel's Binocular Highlight column and chart in the May Sky & Telescope, page 43.

Monday, May 6

• As twilight fades, look low in the west-northwest for the thin crescent Moon a few degrees above Aldebaran as shown here.

Tuesday, May 7

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•The crescent Moon hangs in the west-northwest at dusk near Mars and Beta Tauri (which is to Mars's left), and very close to or even on top of 3rd-magnitude Zeta Tauri.

Will the Moon occult Zeta for your location? It will if you're in Florida or the deep south (where the Moon will be low in darkness), the mid-south (with the Moon higher in twilight), or much of Mexico and Central America. See map and timetables from IOTA. (The text there consists of three timetables: for the star's disappearance, its reappearance, and the locations of the cities and towns. Watch for the divisions between the tables as you scroll.)

Source: Sky & Telescope Return to Contents

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ISS Sighting Opportunities

For Denver:

Date Visible Max Height Appears Disappears Fri May 3, 4:09 AM 2 min 63° 61° above WNW 29° above NE Sat May 4, 3:20 AM 1 min 28° 28° above ENE 15° above ENE Sat May 4, 4:53 AM 4 min 19° 10° above WNW 13° above NNE Sun May 5, 4:04 AM 2 min 28° 26° above NW 18° above NNE Mon May 6, 3:15 AM < 1 min 30° 30° above NNE 21° above NNE Mon May 6, 4:49 AM 3 min 13° 10° above NW 10° above NNE Tue May 7, 2:26 AM < 1 min 11° 11° above NE 11° above NE Tue May 7, 3:58 AM 3 min 17° 14° above NW 13° above N Sighting information for other cities can be found at NASA’s Satellite Sighting Information NASA-TV Highlights (all times Eastern Daylight Time) May 3, Friday 11 a.m. - SpaceCast Weekly (All Channels) 12 p.m. - NASA’s 3D-Printed Habitat Challenge (All Channels) 4 p.m. - NASA’s 3D-Printed Habitat Challenge (All Channels)

May 4, Saturday 2:30 a.m. – Coverage of the launch of the SpaceX CRS-17 Dragon Cargo Craft Mission to the International Space Station; launch is scheduled at 2:48 a.m. ET (All Channels) TBD - SpaceX CRS-17 post-launch news conference

May 6, Monday 5:30 a.m. - Coverage of the rendezvous and capture of the SpaceX CRS-17 Dragon Cargo Craft at the International Space Station; capture scheduled at 7 a.m. ET (All Channels) 9 a.m. - Coverage of the installation of the SpaceX CRS-17 Dragon Cargo Craft to the International Space Station (All Channels) Noon – International Space Station In-Flight Event for the Canadian Space Agency with the “Bring Space to Your School Contest” in Inuvik, Northwest Territories, and astronaut David Saint-Jacques of CSA (Public Channel with interpretation; Media Channel in native language)

Watch NASA TV on the Net by going to the NASA website. Return to Contents

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Space Calendar

• May 03 - [Apr 30] Dragon CRS-17/ OCO-3/ STP-H6 Falcon 9 Launch (International Space Station) • May 03 - Comet 138P/Shoemaker-Levy Perihelion (1.703 AU) • May 03 - [Apr 27] Amor Asteroid 2019 HP Near-Earth Flyby (0.024 AU) • May 03 - Amor Asteroid 4957 Brucemurray Closest Approach To Earth (1.066 AU) • May 03 - James Hey's 110th Birthday (1909)

• May 04 - [Apr 27] Star Wars Day • May 04 - [Apr 27] STP-27RD Electron Launch • May 04 - Comet 306P/LINEAR At Opposition (1.827 AU) • May 04 - Comet 3D/Biela Closest Approach To Earth (2.294 AU) • May 04 - [Apr 30] Aten Asteroid 2019 HV3 Near-Earth Flyby (0.032 AU) • May 04 - Asteroid 4103 Chahine Closest Approach To Earth (1.635 AU) • May 04 - Asteroid 160512 Franck-Hertz Closest Approach To Earth (2.027 AU) • May 04 - Centaur Object 471143 Dziewanna At Opposition (35.085 AU) • May 04 - 30th Anniversary (1989), Magellan Launch (Venus Orbiter) • May 04 - Fritz von Opel's 120th Birthday (1899)

• May 05 - [Apr 28] Space Day

• May 05 - [Apr 28] National Astronaut Day • May 05 - Eta Aquarids Meteor Shower Peak • May 05 - Comet 102P/Shoemaker At Opposition (3.461 AU) • May 05 - Comet 186P/Garradd Perihelion (4.389 AU) • May 05 - Amor Asteroid 2016 GF216 Near-Earth Flyby (0.092 AU) • May 05 - Amor Asteroid 1980 Tezcatlipoca Closest Approach To Earth (1.244 AU) • May 05 - Asteroid 84225 Verish Closest Approach To Earth (1.477 AU) • May 05 - 20th Anniversary (1999), Galileo, Callisto 20 Flyby • May 06 - Comet P/2019 A8 (PANSTARRS) Closest Approach To Earth (1.646 AU) • May 06 - Comet P/2012 O2 (McNaught) Perihelion (1.692 AU) • May 06 - Amor Asteroid 2009 MN8 Near-Earth Flyby (0.076 AU) • May 06 - Apollo Asteroid 1865 Cerberus Closest Approach To Earth (0.369 AU) • May 06 - Asteroid 2001 Einstein Closest Approach To Earth (0.859 AU) • May 06 - Asteroid 18610 Arthurdent Closest Approach To Earth (1.823 AU) • May 07 - Comet 222P/LINEAR Closest Approach To Earth (1.281 AU) • May 07 - Comet 312P/NEAT At Opposition (2.832 AU) • May 07 - Comet 184P/Lovas At Opposition (3.245 AU) • May 07 - Comet C/2018 F4 (PANSTARRS) Closest Approach To Earth (3.253 AU) • May 07 - [Apr 30] Apollo Asteroid 2019 HQ3 Near-Earth Flyby (0.040 AU) • May 07 - Asteroid 6758 Jesseowens Closest Approach To Earth (1.299 AU)

Source: JPL Space Calendar Return to Contents

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Food for Thought

What makes a planet habitable

Which of Earth's features were essential for the origin and sustenance of life? And how do scientists identify those features on other worlds?

A team of investigators with array of expertise ranging from geochemistry to planetary science to astronomy published this week an essay in Science urging the research community to recognize the vital importance of a planet's interior dynamics in creating an environment that's hospitable for life.

With our existing capabilities, observing an exoplanet's atmospheric composition will be the first way to search for signatures of life elsewhere. However, Carnegie's Anat Shahar, Peter Driscoll, Alycia Weinberger, and George Cody argue that a true picture of planetary habitability must consider how a planet's atmosphere is linked to and shaped by what's happening in its interior.

For example, on Earth, plate tectonics are crucial for maintaining a surface climate where life can thrive. What's more, without the cycling of material between its surface and interior, the convection that drives the Earth's magnetic field would not be possible and without a magnetic field, we would be bombarded by cosmic radiation.

"We need a better understanding of how a planet's composition and interior influence its habitability, starting with Earth," Shahar said. "This can be used to guide the search for exoplanets and star systems where life could thrive, signatures of which could be detected by telescopes."

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An artist's impression of the surface of the super-Earth Barnard's Star b. Credit: ESO/M. Kornmesser

It all starts with the formation process. Planets are born from the rotating ring of dust and gas that surrounds a young star. The elemental building blocks from which rocky planets form—silicon, magnesium, oxygen, carbon, iron, and hydrogen—are universal. But their abundances and the heating and cooling they experience in their youth will affect their interior chemistry and, in turn, things like ocean volume and atmospheric composition.

"One of the big questions we need to ask is whether the geologic and dynamic features that make our home planet habitable can be produced on planets with different compositions," Driscoll explained.

The Carnegie colleagues assert that the search for extraterrestrial life must be guided by an interdisciplinary approach that combines astronomical observations, laboratory experiments of planetary interior conditions, and mathematical modeling and simulations.

"Carnegie scientists are long-established world leaders in the fields of geochemistry, geophysics, planetary science, astrobiology, and astronomy," said Weinberger. "So, our institution is perfectly placed to tackle this cross-disciplinary challenge."

In the next decade as a new generation of telescopes come online, scientists will begin to search in earnest for biosignatures in the atmospheres of rocky exoplanets. But the colleagues say that these observations must be put in the context of a larger understanding of how a planet's total makeup and interior geochemistry determines the evolution of a stable and temperate surface where life could perhaps arise and thrive.

"The heart of habitability is in planetary interiors," concluded Cody.

Source: Phys.org Return to Contents

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Space Image of the Week

Hubble Spots Stunning Spiral Galaxy

Few of the universe’s residents are as iconic as the spiral galaxy. These limelight-hogging celestial objects combine whirling, pinwheeling arms with scatterings of sparkling stars, glowing bursts of gas, and dark, weaving lanes of cosmic dust, creating truly awesome scenes — especially when viewed through a telescope such as the NASA/ESA Hubble Space Telescope. In fact, this image from Hubble frames a perfect spiral specimen: the stunning NGC 2903.

NGC 2903 is located about 30 million light-years away in the constellation of Leo (the Lion), and was studied as part of a Hubble survey of the central regions of roughly 145 nearby disk galaxies. This study aimed to help astronomers better understand the relationship between the black holes that lurk at the cores of galaxies like these, and the rugby-ball-shaped bulge of stars, gas and dust at the galaxy’s center — such as that seen in this image.

Text credit: ESA (European Space Agency) Image credit: ESA/Hubble & NASA, L. Ho et al.

Source: NASA Return to Contents