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Space News Update — February 9, 2016 —

Contents

In the News

Story 1: Scientists discover hidden galaxies behind the Milky Way

Story 2: Dark Matter Makes Galaxy Clusters Clump

Story 3: New and Improved Orion Crew Module Arrives at Kennedy Space Center

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. Scientists discover hidden galaxies behind the Milky Way

Hundreds of hidden nearby galaxies have been studied for the first time, shedding light on a mysterious gravitational anomaly dubbed the Great Attractor.

Despite being just 250 million light years from Earth--very close in astronomical terms--the new galaxies had been hidden from view until now by our own galaxy, the Milky Way.

Using CSIRO's Parkes radio telescope equipped with an innovative receiver, an international team of scientists were able to see through the stars and dust of the Milky Way, into a previously unexplored region of space.

The discovery may help to explain the Great Attractor region, which appears to be drawing the Milky Way and hundreds of thousands of other galaxies towards it with a gravitational force equivalent to a million billion Suns.

Lead author Professor Lister Staveley-Smith, from The University of Western Australia node of the International Centre for Radio Astronomy Research (ICRAR), said the team found 883 galaxies, a third of which had never been seen before.

"The Milky Way is very beautiful of course and it's very interesting to study our own galaxy but it completely blocks out the view of the more distant galaxies behind it," he said.

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Professor Staveley-Smith said scientists have been trying to get to the bottom of the mysterious Great Attractor since major deviations from universal expansion were first discovered in the 1970s and 1980s.

"We don't actually understand what's causing this gravitational acceleration on the Milky Way or where it's coming from," he said.

"We know that in this region there are a few very large collections of galaxies we call clusters or superclusters, and our whole Milky Way is moving towards them at more than two million kilometres per hour."

The research identified several new structures that could help to explain the movement of the Milky Way, including three galaxy concentrations (named NW1, NW2 and NW3) and two new clusters (named CW1 and CW2).

University of Cape Town astronomer Professor Renée Kraan-Korteweg said astronomers have been trying to map the galaxy distribution hidden behind the Milky Way for decades.

"We've used a range of techniques but only radio observations have really succeeded in allowing us to see through the thickest foreground layer of dust and stars," she said.

"An average galaxy contains 100 billion stars, so finding hundreds of new galaxies hidden behind the Milky Way points to a lot of mass we didn't know about until now."

Dr. Bärbel Koribalski from CSIRO Astronomy and Space Science said innovative technologies on the Parkes Radio telescope had made it possible to survey large areas of the sky very quickly.

"With the 21-cm multibeam receiver on Parkes we're able to map the sky 13 times faster than we could before and make new discoveries at a much greater rate," she said.

The study involved researchers from Australia, South Africa, the US and the Netherlands, and was published today in the Astronomical Journal.

Source: EurekAlert Return to Contents

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2. Dark Matter Makes Galaxy Clusters Clump

The largest building blocks in the universe are galaxy clusters. Galaxy clusters are what they sound like: clusters of galaxies, linked by their mutual gravity. They’re big, maybe millions of light-years wide, and can contain thousands of galaxies.

Galaxy clusters are the lights that trace out the contours of cosmic structure. But they’re only the tip of the proverbial iceberg: dark matter forms the cosmic web’s skeleton. Clusters sit in big halos of dark matter, and the more massive the cluster, the more dark matter is there. We know there’s something like ten times more matter than what we see in these clusters because, if there weren’t, the galaxies zooming around a cluster would be able to escape — the cluster would fly apart.

Theorists fabulously recreate cosmic structure using simulations that contain only dark matter and gravity. But there’s a prediction of such simulations that astronomers have been having trouble finding evidence for in the real world. That prediction is called assembly bias. Instead of matter’s clustering behavior depending solely on mass, assembly bias says that clusters will form faster or slower depending on how dense the dark matter is in their surrounding environment.

This density isn’t the density of the dark matter halo in which the cluster sits. Rather, it’s on a larger scale: it’s the density of the environment in which the halo sits. This is a difficult concept to grasp, so as an analogy, think of an egg crate.

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The egg crate represents the density of dark matter in the cosmos. Places where the density is high are the peaks in the egg crate; places where the density is low are the troughs. These peaks and troughs are leftovers from the earliest days of the universe, inconsistencies that subsequently led to the formation of the cosmic web.

Unlike an egg crate, though, dark matter density peaks are not all equally “peaky.” Some have steep sides, where there’s a shear drop-off in density. Others have gentle slopes, where density falls off more gradually.

Halos sit on top of these density peaks. A cluster on a shear drop can have the same mass as a cluster on a gentle slope, but if assembly bias exists, a cluster on top of the steep peak will have formed slower than the cluster on the gentle slope. This is because massive structures tend to suck in material more rapidly as they grow if they’re surrounded by regions of higher density, where there’s a larger supply of mass.

If that’s true, then fast-formed clusters should lie closer together than slow-formed clusters. In other words, fast-formed clusters should cluster.

These predictions came from work done by Neal Dalal (now at University of Illinois at Urbana-Champaign) and others. But observers need clusters of exactly the same mass to test the theory in the real universe, and those have been hard to find: previous analyses have only revealed hints that assembly bias might exist.

Hironao Miyatake (Princeton, Kavli IPMU of University of Tokyo, and JPL) and colleagues set out to try again. They gathered 8,648 clusters from the Sloan Digital Sky Survey and divided them into two groups: fast-forming and slow-forming. Then they “weighed” the clusters by examining how the clusters’ masses gravitationally distorted background light from more distant galaxies. That way, they confirmed they were working with samples of equal masses.

When the team looked at how clustered the two types of clusters were, the researchers found that indeed, the fast-forming clusters were more touchy-feely with their neighbors — exactly what assembly bias predicts. The team reported the result January 25th in Physical Review Letters.

This result relies on a proxy to determine how fast a galaxy cluster formed, namely the distribution of galaxies within the clusters. The team is now working to more directly measure the rates at which the clusters accreted mass. And astronomers still need to confirm that assembly bias exists within clusters, a daunting task. But as Dalal writes in an informative opinion piece, “The confirmation of assembly bias means that cosmologists can breathe a temporary sign of relief.” If it hadn’t panned out, he explains, cosmology might have been in trouble. For now, it looks like physics works the way we think it does.

Well, probably.

Source: Sky & Telescope Return to Contents

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3. New and Improved Orion Crew Module Arrives at Kennedy Space Center

The Lockheed Martin and NASA Orion team has secured the 2,700 lb. Exploration Mission-1 (EM-1) Orion crew module into its structural assembly tool, also known as the birdcage.

The crew module is the living quarters for astronauts and the backbone for many of Orions systems such as propulsion, avionics and parachutes. The structure shown here is 500 pounds lighter than its Exploration Flight Test-1 (EFT-1) counterpart, said Mike Hawes, Lockheed Martin Orion vice president and program manager. Once the final structural components such as longerons, bolts and brackets are added, total crew module structural weight savings from EFT-1 to EM-1 will total 700 pounds. From experience gained by building test articles, building and flying EFT-1, and now building the EM-1 crew module, the Lockheed Martin team is learning how to shed weight, reduce costs and simplify the manufacturing process all in an effort to improve the production time and cost of future Orions. Our very talented team in Louisiana has manufactured a great product and now they have passed the baton to Florida, said Hawes. This is where we assemble, test and launch, and the fun really begins. At Kennedy Space Center, the crew module will undergo several tests to ensure the structure is perfectly sound before being integrated with other elements of the spacecraft. First it will undergo proof-pressure testing where the structural welds are stress tested to confirm it can withstand the environments it will experience in space. The team will then use phased array technology to inspect the welds to make sure there are no defects. Additional structural tests will follow including proof-pressure testing of the fluid system welds and subsequent x-ray inspections. Once the crew module passes those tests it will undergo final assembly, integration and entire vehicle testing in order to prepare for EM-1, when Orion is launched atop NASAs Space Launch System (SLS) for the first time. The test flight will send Orion into lunar distant retrograde orbit a wide orbit around the moon that is farther from Earth than any human-rated spacecraft has ever traveled. The mission will last about three weeks and will certify the design and safety of Orion and SLS for future human-rated exploration missions.

Source: SpaceRef.com Return to Contents

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The Night Sky Tuesday, February 9

• With the Moon new and Orion high, explore the rabbity telescopic sights of Lepus, the Hare under Orion's feet, using Sue French's Deep-Sky Wonders article, chart and photos in the February Sky & Telescope, page 50. Get to know winter's only globular cluster. And what about that sextuple star that got named NGC 2017?

Wednesday, February 10

• By 9 or 9:30 the Big Dipper stands on its handle in the northeast. In the northwest Cassiopeia also stands on end, at about the same height.

Thursday, February 11

• Look west-southwest at nightfall for the thin crescent Moon. High above it, by some 30°, the two brightest stars of Aries point down to it. Above or upper left from there you'll find the Pleiades.

• It's a busy night around Jupiter. Europa's shadow crosses the planet's face from 9:02 to 11:51 p.m. EST, followed by Europa itself from 10:15 p.m. to 1:00 a.m. EST. And Io's shadow moves onto Jupiter starting at 12:51 a.m. EST. Subtract 3 hours from these to get Pacific Standard Time.

Friday, February 12

• The sky's biggest asterism (informal star pattern) is the Winter Hexagon. It fills the heavens toward the east and south these evenings. Start with brilliant Sirius at its bottom. Going clockwise from there, march through Procyon, Pollux and Castor, Beta Aurigae and Capella near the zenith, Aldebaran over and down to Capella's lower right, down to Rigel in Orion's foot, and back to Sirius.

Source: Sky & Telescope Return to Contents

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ISS Sighting Opportunities

For Denver:

Date Visible Max Height Appears Disappears

Mon Feb 8, 6:22 PM 3 min 13° 10° above NW 10° above NNE

Tue Feb 9, 7:08 PM < 1 min 10° 10° above N 10° above N

Wed Feb 10, 6:14 PM 1 min 10° 10° above NNW 10° above N

Thu Feb 11, 6:59 PM < 1 min 11° 10° above N 11° above N

Fri Feb 12, 6:06 PM < 1 min 10° 10° above N 10° above N

Fri Feb 12, 7:42 PM < 1 min 10° 10° above NNW 10° above NNW

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

NASA-TV Highlights (all times Eastern Daylight Time)

3 p.m., Tuesday, February 9 - Replay of the “State of NASA” Address (all channels)

1 p.m., Thursday, February 11 - ISS Expedition 46 In-Flight Interviews for ABC’s “This Week” and CNN’s Dr. Sanjay Gupta with Commander Scott Kelly of NASA (starts at 1:05 p.m.) (all channels)

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

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Space Calendar • Feb 09 - Comet 73P-AX/Schwassmann-Wachmann Closest Approach To Earth (2.769 AU) • Feb 09 - [Feb 08] Apollo Asteroid 2016 CK31 Near-Earth Flyby (0.009 AU) • Feb 09 - Asteroid 5261 Eureka (Mars Trojan) Closest Approach To Earth (0.766 AU) • Feb 09 - Asteroid 6296 Cleveland Closest Approach To Earth (0.866 AU) • Feb 09 - Asteroid 2933 Amber Closest Approach To Earth (1.737 AU) • Feb 09 - Aten Asteroid 341843 (2008 EV5) Closest Approach To Earth (1.832 AU) • Feb 10 - [Feb 04] Topaz 4 (NROL-45) Delta 4 Launch • Feb 10 - Comet 113P/Spitaler Closest Approach To Earth (2.000 AU) • Feb 10 - Comet 73P-BK/Schwassmann-Wachmann Closest Approach To Earth (2.708 AU) • Feb 10 - Comet 73P-BN/Schwassmann-Wachmann Closest Approach To Earth (2.725 AU) • Feb 10 - Comet 73P-BO/Schwassmann-Wachmann Closest Approach To Earth (2.732 AU) • Feb 10 - [Feb 07] Apollo Asteroid 2016 CU29 Near-Earth Flyby (0.021 AU) • Feb 10 - Atira Asteroid 413563 (2005 TG45) Closest Approach To Earth (0.592 AU) • Feb 10 - Asteroid 3769 Arthurmiller Closest Approach To Earth (1.105 AU) • Feb 10 - Asteroid 8209 Toscanelli Closest Approach To Earth (1.838 AU) • Feb 11 - Moon Occults Asteroid 21 Lutetia • Feb 11 - Comet 73P-BB/Schwassmann-Wachmann At Opposition (1.814 AU) • Feb 11 - Comet C/2014 W5 (Lemmon-PANSTARRS) Perihelion (2.596 AU) • Feb 11 - Comet 73P-BJ/Schwassmann-Wachmann Closest Approach To Earth (2.658 AU) • Feb 11 - Comet 73P-AB/Schwassmann-Wachmann Closest Approach To Earth (2.669 AU) • Feb 11 - Comet 73P-J/Schwassmann-Wachmann Closest Approach To Earth (2.698 AU) • Feb 11 - Comet 189P/NEAT At Opposition (3.133 AU) • Feb 11 - Comet 187P/LINEAR At Opposition (3.667 AU) • Feb 11 - Asteroid 9617 Grahamchapman Closest Approach To Earth (1.085 AU) • Feb 11 - Asteroid 82332 Las Vegas Closest Approach To Earth (1.579 AU) • Feb 11 - Asteroid 2620 Santana Closest Approach To Earth (1.947 AU) • Feb 11 - Apollo Asteroid 719 Albert Closest Approach To Earth (2.958 AU) • Feb 11 - Lecture: The Europa Mission, Pasadena, California • Feb 11-12 - Global Space and Technology Convention (GSTC) 2016, Singapore • Feb 12 - Astro-H (NeXT)/ Horyu 4/ ChubuSat 2/ ChubuSat 3 H-2A Launch • Feb 12 - Asteroid 253 Mathilde Occults TYC 0789-00337-1 (9.8 Magnitude Star) • Feb 12 - [Feb 08] Apollo Asteroid 2016 CD31 Near-Earth Flyby (0.009 AU) • Feb 12 - [Feb 08] Apollo Asteroid 2016 CW30 Near-Earth Flyby (0.013 AU) • Feb 12 - [Feb 06] Apollo Asteroid 2016 CF29 Near-Earth Flyby (0.031 AU) • Feb 12 - Asteroid 12413 Johnnyweir Closest Approach To Earth (1.901 AU) • Feb 12 - Asteroid 5811 Keck Closest Approach To Earth (2.424 AU) • Feb 12 - 15th Anniversary (2001), NEAR, Asteroid Eros Landing • Feb 12 - Fang Lizhi's 80th Birthday (1936)

Source: JPL Space Calendar Return to Contents

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Food for Thought

Study: Long-Term Global Warming Needs External Drivers

A study by scientists at NASA’s Jet Propulsion Laboratory in Pasadena, California, and Duke University in Durham, North Carolina, shows, in detail, the reason why global temperatures remain stable in the long run unless they are pushed by outside forces, such as increased greenhouse gases due to human impacts.

Lead author Patrick Brown, a doctoral student at Duke’s Nicholas School of the Environment, and his JPL colleagues combined global climate models with satellite measurements of changes in the energy approaching and leaving Earth at the top of the atmosphere over the past 15 years. The satellite data were from the Clouds and the Earth’s Radiant Energy System (CERES) instruments on NASA’s Aqua and Terra spacecraft. Their work reveals in new detail how Earth cools itself back down after a period of natural warming.

Scientists have long known that as Earth warms, it is able to restore its temperature equilibrium through a phenomenon known as the Planck Response. The phenomenon is an overall increase in infrared energy that Earth emits as it warms. The response acts as a safety valve of sorts, allowing more of the accumulating heat to be released through the top of Earth's atmosphere into space.

The new research, however, shows it’s not quite as simple as that.

“Our analysis confirmed that the Planck Response plays the dominant role in restoring global temperature stability, but to our surprise, we found that it tends to be overwhelmed locally by heat-trapping changes in

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clouds, water vapor, and snow and ice,” Brown said. “This initially suggested that the climate system might be able to create large, sustained changes in temperature all by itself.”

A more detailed investigation of the satellite observations and climate models helped the researchers finally reconcile what was happening globally versus locally.

“While global temperature tends to be stable due to the Planck Response, there are other important, previously less appreciated, mechanisms at work, too,” said Wenhong Li, assistant professor of climate at Duke. These mechanisms include the net release of energy over anomalously cool regions and the transport of energy to continental and polar regions. In those regions, the Planck Response overwhelms positive, heat-trapping local energy feedbacks.

“This emphasizes the importance of large-scale energy transport and atmospheric circulation changes in reconciling local versus global energy feedbacks and, in the absence of external drivers, restoring Earth’s global temperature equilibrium,” Li said.

The researchers say the findings may finally help put the chill on skeptics’ belief that long-term global warming occurs in an unpredictable manner, independently of external drivers such as human impacts.

“This study underscores that large, sustained changes in global temperature like those observed over the last century require drivers such as increased greenhouse gas concentrations,” said Brown.

“Scientists have long believed that increasing greenhouse gases played a major role in determining the warming trend of our planet,” added JPL co-author Jonathan Jiang. “This study provides further evidence that natural climate cycles alone are insufficient to explain the global warming observed over the last century.”

The research is published this month in the Journal of Climate. The study was funded by the National Science Foundation and NASA.

NASA uses the vantage point of space to increase our understanding of our home planet, improve lives and safeguard our future. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.

For more information about NASA's Earth science activities, visit: http://www.nasa.gov/earth

Source: NASA Return to Contents

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Space Image of the Week

Earth observation taken by the Expedition 46 crew In orbit around the Earth on board the International Space Station NASA astronaut Scott Kelly captured this blue water image in his "Earth Art" series and tweeted it out with this message: " A splash of #EarthArt over the #Bahamas!#YearInSpace ".

Source: NASA Return to Contents