Spirit Lander – 1st Color Image from Mars Orbit

1st Color image of Spirit lander and Bonneville Crater from Mars orbit
Near the lower left corner of this view is the three-petal lander platform that NASA's Mars Exploration Rover Spirit drove off in January 2004. Credit: NASA/JPL-Caltech/Univ. of Arizona
See more images of Spirit’s lander from orbit and her Traverse Map below
What did Spirit see from the lander ? - look below

The Lander platform for NASA’s Spirit rover has been photographed in stunning high resolution color for the first time from Mars orbit – just over 8 years after the now legendary robot survived the scorching atmospheric heat of the 6 minute plunge through the Martian atmosphere and bounced to a stop inside Gusev Crater on January 3, 2004.
Spirit’s three petaled landing pad was finally imaged in color by NASA’s powerful Mars Reconnaissance Orbiter (MRO) spacecraft just days ago on January 29, 2012 at 3:04 p.m. local Mars time.
The MRO spacecraft was soaring overhead and captured the image of Spirit’s lander with the high resolution HiRISE camera from a distance of some 262 kilometers, (162 miles).
“HiRISE has never before imaged the actual lander for the Spirit rover in color, [located] on the west side of Bonneville Crater,” writes Alfred McEwen, HiRISE Principal Investigator at the University of Arizona.

1st Color image of Spirit Lander and Bonneville Crater from Mars orbit
Spirit landing pad at lower left; Bonneville Crater rim at top right.
Credit: NASA/JPL/UA/HiRISE

While protectively cocooned inside the airbag cushioned lander, Spirit bounced about two dozen times before rolling to rest on the Martian plains about ¼ mile away from Bonneville Crater. Then her landing petals unfurled, the airbags were partially retracted and Spirit eventually drove off the landing pad.
“The lander is still bright, but with a reddish color, probably due to a [Martian] dust cover.”

Spirit rover images her Lander Platform after Egress
- Now imaged for the 1st time from Mars orbit by NASA’s MRO spacecraft. Lander had 3-petals and airbags. Credit: NASA/JPL-Caltech/Cornell

Spirit initially drove to Bonneville Crater and circumnavigated part way around the rim before speeding off towards the Columbia Hills, about 2 miles to the East. She eventually scaled the summit of Husband Hill and drove down the opposite side to the Home Plate” volcanic feature where she rests today – see travse map below.
“A bright spot from a remnant of the heat shield is still visible on the north rim of Bonneville Crater. The backshell and parachute are still bright, but were not captured in the narrow color swath.”
“The rover itself can still be seen near “Home Plate” in the Columbia Hills, but there is no obvious sign of rover tracks–erased by the wind,” McEwen notes.
Here is a photo taken by Spirit looking back to the lander – now imaged in color from orbit for the first time – for a comparative view, before she drove off forever.
Spirit endured for more than six years of bonus time exploration beyond her planned 90 day mission. And Opportunity is still roving Mars today !

Spirit Rover traverse map from Gusev Crater landing site near Bonneville Crater to Columbia Hills to Home Plate: 2004 to 2011. Credit: NASA/JPL/UA/HiRISE

Curiosity – NASA’s newest, biggest ever and maybe last Mars rover – is speeding through interplanetary space for an August 2012 landing inside Gale Crater.

Milky Way's Black Hole Found Grazing On Asteroids

The giant black hole at the center of the Milky Way may be vaporizing and devouring asteroids, which could explain the frequent flares observed, according to astronomers using data from NASA's Chandra X-ray Observatory.
For several years Chandra has detected X-ray flares about once a day from the supermassive black hole known as Sagittarius A*, or "Sgr A*" for short. The flares last a few hours with brightness ranging from a few times to nearly one hundred times that of the black hole's regular output. The flares also have been seen in infrared data from ESO's Very Large Telescope in Chile.
"People have had doubts about whether asteroids could form at all in the harsh environment near a supermassive black hole," said Kastytis Zubovas of the University of Leicester in the United Kingdom, and lead author of the report appearing in the Monthly Notices of the Royal Astronomical Society. "It's exciting because our study suggests that a huge number of them are needed to produce these flares."
Zubovas and his colleagues suggest there is a cloud around Sgr A* containing trillions of asteroids and comets, stripped from their parent stars. Asteroids passing within about 100 million miles of the black hole, roughly the distance between Earth and the sun, would be torn into pieces by the tidal forces from the black hole.
These fragments then would be vaporized by friction as they pass through the hot, thin gas flowing onto Sgr A*, similar to a meteor heating up and glowing as it falls through Earth's atmosphere. A flare is produced and the remains of the asteroid are swallowed eventually by the black hole.
"An asteroid's orbit can change if it ventures too close to a star or planet near Sgr A*," said co-author Sergei Nayakshin, also of the University of Leicester. "If it's thrown toward the black hole, it's doomed."
The authors estimate that it would take asteroids larger than about six miles in radius to generate the flares observed by Chandra. Meanwhile, Sgr A* also may be consuming smaller asteroids, but these would be difficult to spot because the flares they generate would be fainter.
These results reasonably agree with models estimating of how many asteroids are likely to be in this region, assuming that the number around stars near Earth is similar to the number surrounding stars near the center of the Milky Way.
"As a reality check, we worked out that a few trillion asteroids should have been removed by the black hole over the 10-billion-year lifetime of the galaxy," said co-author Sera Markoff of the University of Amsterdam in the Netherlands. "Only a small fraction of the total would have been consumed, so the supply of asteroids would hardly be depleted."
Planets thrown into orbits too close to Sgr A* also should be disrupted by tidal forces, although this would happen much less frequently than the disruption of asteroids, because planets are not as common. Such a scenario may have been responsible for a previous X-ray brightening of Sgr A* by about a factor of a million about a century ago. While this event happened many decades before X-ray telescopes existed, Chandra and other X-ray missions have seen evidence of an X-ray "light echo" reflecting off nearby clouds, providing a measure of the brightness and timing of the flare.
"This would be a sudden end to the planet's life, a much more dramatic fate than the planets in our solar system ever will experience," Zubovas said.
Very long observations of Sgr A* will be made with Chandra later in 2012 that will give valuable new information about the frequency and brightness of flares and should help to test the model proposed here to explain them. This work could improve understanding about the formation of asteroids and planets in the harsh environment of Sgr A*.

A new study provides a possible explanation of mysterious X-ray flares detected by Chandra over the period of several years. It suggests that there is a cloud around Sgr A* containing trillions of asteroids and comets, stripped from their parent stars. The flares occur when asteroids of six miles or larger in radius are consumed by the black hole. The panel on the left shows a very long Chandra observation of the region around the Sgr A*, while the three panels on the right are artist's impressions of the path that a doomed asteroid would take on its way to the black hole. (Credit: X-ray: NASA/CXC/MIT/F. Baganoff et al.; Illustrations: NASA/CXC/M.Weiss)


The above story is reprinted from materials provided by Chandra X-ray Center. 

New Image Captures 'Stealth Merger' of Dwarf Galaxies

New images of a nearby dwarf galaxy have revealed a dense stream of stars in its outer regions, the remains of an even smaller companion galaxy in the process of merging with its host. The host galaxy, known as NGC 4449, is the smallest primary galaxy in which a stellar stream from an ongoing merger has been identified and studied in detail.
"This is how galaxies grow. You can see the smaller galaxy coming in and getting shredded, eventually leaving its stars scattered through the halo of the host galaxy," said Aaron Romanowsky, a research astronomer at the University of California, Santa Cruz, and coauthor of a paper on the discovery that has been accepted for publication in Astrophysical Journal Letters. The study was carried out by an international team of astronomers led by David Martínez-Delgado of the Max Planck Institute for Astronomy in Heidelberg.
According to modern cosmological theory, large galaxies were built up from smaller progenitors through a hierarchical process of mergers. Astronomers can see many examples of mergers involving massive galaxies, but mergers of two dwarf galaxies have been hard to find. "We should see the same things at smaller scales, with small galaxies eating smaller ones and so on," Romanowsky said. "Now we have this beautiful image of a dwarf galaxy consuming a smaller dwarf."
NGC 4449 is located 12.5 million light-years from Earth and is a member of a group of galaxies in the constellation Canes Venatici. In size and morphology, it is very similar to one of the Milky Way's satellite galaxies, the Large Magellanic Cloud.
The stellar stream in NGC 4449 was first detected by another group of astronomers as a mysterious, faint smudge in digitized photographic plates from the Digitized Sky Survey project, and it is also visible in archival images from the Sloan Digital Sky Survey. But if it had been just a bit fainter, more diffuse, or farther from the host galaxy, it could easily have been missed. The authors of the new study called it a "stealth merger," where an infalling satellite galaxy is nearly undetectable by conventional means, yet has a substantial influence on its host galaxy.
Martínez-Delgado organized a campaign to follow up on the initial report with more detailed observations. R. Jay GaBany, a Bay Area amateur astronomer and astrophotographer with whom Martínez-Delgado has frequently collaborated, obtained exceptionally deep, wide-field images of NGC 4449 with the half-meter Black Bird Observatory telescope (located in the Sierra Nevada mountains). Those images confirmed the presence of a faint substructure in the halo of the galaxy. Romanowsky, along with UCSC graduate student Jacob Arnold, then used the 8.2-meter Subaru Telescope in Hawaii to obtain high-resolution images in which the individual stars in the stellar stream can be seen.
"I don't think I'd ever seen a picture of a galaxy merger where you can see the individual stars," Romanowsky said. "It's really an impressive image."
The new observations support the idea that the stellar haloes around many dwarf galaxies are the remnants of smaller satellites that were shredded in past merger events. The ongoing merger in NGC 4449 may also be responsible for the intense burst of star formation seen in the galaxy. "This galaxy is famous for its starburst activity, and it seems we've found the reason for that. The gravitational interaction of the incoming galaxy has probably disturbed the gas in the main galaxy and caused it to start forming stars," Romanowsky said.
The companion galaxy was also independently discovered by a team of scientists led by UCLA astronomer Michael Rich. Their study, based on images obtained by the Centurion 28-inch telescope located at the Polaris Observatory Association near Frazier Park, California, will be published in the February 9 issue of Nature.
In addition to Martínez-Delgado, Romanowsky, Arnold, and GaBany, the coauthors of the Astrophysical Journal Letters paper include Jean Brody, professor of astronomy and astrophysics at UC Santa Cruz; Francesca Annibali at the Astronomical Observatory of Bologna; Jurgen Fliri at the Observatory of Paris; Stefano Zibetti at the University of Copenhagen; Roeland van der Marel and Alessandra Aloisi at the Space Telescope Science Institute; Hans-Walter Rix and Andrea Maccio at the Max Planck Institute; Taylor Chonis at the University of Texas, Austin; Julio Carballo-Bello at the Canary Astrophysics Institute; J. Gallego-Laborda at Fosca Nit Observatory in Spain; and Michael Merrifield at the University of Nottingham, England.

The dwarf galaxy NGC 4449 is the first dwarf galaxy with an identified stellar stream (faintly seen at the lower right, and in inset). The star stream represents the remains of a smaller satellite galaxy merging with NGC 4449. The inset image shows the stream resolved into red giant stars. (Credit: Image credit and copyright: R. Jay Gabany (Black Bird Obs.); Insert credit: Subaru/Suprime-Cam (NAOJ))

The above story is reprinted from materials provided by University of California - Santa Cruz. The original article was written by Tim Stephens. 

Stellar Nursery: A Pocket of Star Formation

A new view shows a stellar nursery called NGC 3324. It was taken using the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. The intense ultraviolet radiation from several of NGC 3324's hot young stars causes the gas cloud to glow with rich colours and has carved out a cavity in the surrounding gas and dust.
NGC 3324 is located in the southern constellation of Carina (The Keel, part of Jason's ship the Argo) roughly 7500 light-years from Earth. It is on the northern outskirts of the chaotic environment of the Carina Nebula, which has been sculpted by many other pockets of star formation (eso0905). A rich deposit of gas and dust in the NGC 3324 region fuelled a burst of starbirth there several millions of years ago and led to the creation of several hefty and very hot stars that are prominent in the new picture.
Stellar winds and intense radiation from these young stars have blown open a hollow in the surrounding gas and dust. This is most in evidence as the wall of material seen to the centre right of this image. The ultraviolet radiation from the hot young stars knocks electrons out of hydrogen atoms, which are then recaptured, leading to a characteristic crimson-coloured glow as the electrons cascade through the energy levels, showing the extent of the local diffuse gas. Other colours come from other elements, with the characteristic glow from doubly ionised oxygen making the central parts appear greenish-yellow.
As with clouds in Earth's sky, observers of nebulae can find likenesses within these cosmic clouds. One nickname for the NGC 3324 region is the Gabriela Mistral Nebula, after the Nobel Prize-winning Chilean poet. The edge of the wall of gas and dust at the right bears a strong resemblance to a human face in profile, with the "bump" in the centre corresponding to a nose.
The power of the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory also reveals many dark features in NGC 3324. Dust grains in these regions block out the light from the background glowing gas, creating shadowy, filigree features that add another layer of evocative structure to the rich vista.
The sharp sight of the Hubble Space Telescope has also been trained on NGC 3324 in the past. Hubble can pick out finer details than the panoramic view of the Wide Field Imager, but only over a much smaller field of view. The two instruments when used in tandem can provide both "zoomed-in" and "zoomed-out" perspectives.

The above story is reprinted from materials provided by European Southern Observatory - ESO.

LARES 'mirror ball' sat will test Einstein's theory

You don't have to be big to challenge Einstein. A pocked ball just 36 centimetres wide is the latest space probe tasked with measuring general relativity, one of the cornerstones of modern physics.

The Laser Relativity Satellite, or LARES, is a tungsten sphere with reflectors mounted in 92 holes punched into its surface. It is due to launch from Kourou, French Guiana, on a new European Space Agency rocket called Vega, designed to cheaply launch payloads of less than 2500 kilograms. The launch window opens on 13 February.

LARES's orbit will be tracked by bouncing ground-based lasers off the reflectors. General relativity states that gravity arises from the curvature of space and time. If this is true, Earth should drag space-time around with it as it spins, slightly perturbing the orbits of satellites.

Though general relativity is the accepted theory of gravity, it might break down if measured with greater accuracy. The beleaguered Gravity Probe B satellite achieved an accuracy within 19 per cent of the expected orbit change; earlier satellites got within 10 per cent. Researchers hope to achieve 1 per cent with LARES, built by the Italian Space Agency.

Most Detailed Infrared Image of the Carina Nebula Ever

ESO's Very Large Telescope has delivered the most detailed infrared image of the Carina Nebula stellar nursery taken so far. Many previously hidden features, scattered across a spectacular celestial landscape of gas, dust and young stars, have emerged. This is one of the most dramatic images ever created by the VLT.
Deep in the heart of the southern Milky Way lies a stellar nursery called the Carina Nebula. It is about 7500 light-years from Earth in the constellation of Carina (The Keel) [1]. This cloud of glowing gas and dust is one of the closest incubators of very massive stars to Earth and includes several of the brightest and heaviest stars known. One of them, the mysterious and highly unstable star Eta Carinae, was the second brightest star in the entire night sky for several years in the 1840s and is likely to explode as a supernova in the near future, by astronomical standards. The Carina Nebula is a perfect laboratory for astronomers studying the violent births and early lives of stars.
Although this nebula is spectacular in normal visible-light pictures (eso0905), many of its secrets are hidden behind thick clouds of dust. To penetrate this veil a European team of astronomers, led by Thomas Preibisch (University Observatory, Munich, Germany) has used the power of ESO's Very Large Telescope along with an infrared-sensitive camera called HAWK-I [2].
Hundreds of individual images have been combined to create this picture, which is the most detailed infrared mosaic of the nebula ever taken and one of the most dramatic images ever created by the VLT. It shows not just the brilliant massive stars, but hundreds of thousands of much fainter stars [3] that were previously invisible.
The dazzling star Eta Carinae itself appears at the lower left of the new picture. It is surrounded by clouds of gas that are glowing under the onslaught of fierce ultraviolet radiation. Across the image there are also many compact blobs of dark material that remain opaque even in the infrared. These are the dusty cocoons in which new stars are forming.
Over the last few million years this region of the sky has formed large numbers of stars both individually and in clusters. The bright star cluster close to the centre of the picture is called Trumpler 14. Although this object is seen well in visible light, many more fainter stars can be seen in this infrared view. And towards the left side of the image a small concentration of stars that appear yellow can be seen. This grouping was seen for the first time in this new data from the VLT: these stars cannot be seen in visible light at all. This is just one of many new objects revealed for the first time in this spectacular panorama.
Notes
[1] Carina is the keel of the mythological ship Argo, of Jason and the Argonauts fame.
[2] Dusty regions of space absorb and scatter short wavelength blue light more than the longer wavelength red. This effect also explains why sunsets on Earth are often red, particularly when the atmosphere is dusty. In some dusty parts of the sky, particularly in star formation regions such as the Carina Nebula, this effect is so strong that no visible light gets through at all. Astronomers overcome this problem by observing in infrared light using special cameras such as HAWK-I on ESO's VLT or the VISTA infrared survey telescope.
[3] One of the main goals of the astronomers was to search for stars in this region that were much fainter and less massive than the Sun. The image is also deep enough to allow the detection of young brown dwarfs.

This broad panorama of the Carina Nebula, a region of massive star formation in the southern skies, was taken in infrared light using the HAWK-I camera on ESO's Very Large Telescope. Many previously hidden features, scattered across a spectacular celestial landscape of gas, dust and young stars, have emerged. (Credit: ESO/T. Preibisch)

The above story is reprinted from materials provided by ESO. 

NASA Mission Returns First Video from Moon's Far Side

A camera aboard one of NASA's twin Gravity Recovery And Interior Laboratory (GRAIL) lunar spacecraft has returned its first unique view of the far side of the moon. MoonKAM, or Moon Knowledge Acquired by Middle school students, will be used by students nationwide to select lunar images for study.
GRAIL consists of two identical spacecraft, recently named Ebb and Flow, each of which is equipped with a MoonKAM. The images were taken as part of a test of Ebb's MoonKAM on Jan. 19. The GRAIL project plans to test the MoonKAM aboard Flow at a later date.
To view the 30-second video clip, visit: http://go.nasa.gov/zZXAPs .
In the video, the north pole of the moon is visible at the top of the screen as the spacecraft flies toward the lunar south pole. One of the first prominent geological features seen on the lower third of the moon is the Mare Orientale, a 560-mile-wide (900 kilometer) impact basin that straddles both the moon's near and far side.
The clip ends with rugged terrain just short of the lunar south pole. To the left of center, near the bottom of the screen, is the 93-mile-wide (149 kilometer) Drygalski crater with a distinctive star-shaped formation in the middle. The formation is a central peak, created many billions of years ago by a comet or asteroid impact.
The quality of the video is excellent and should energize our MoonKAM students as they prepare to explore the moon," said Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology in Cambridge.
The twin spacecraft successfully achieved lunar orbit this past New Year's Eve and New Year's Day. Previously named GRAIL-A and GRAIL-B, the washing machine-sized spacecraft received their new names from fourth graders at the Emily Dickinson Elementary School in Bozeman, Mont., following a nationwide student naming contest.
Thousands of fourth- to eighth-grade students will select target areas on the lunar surface and send requests to the GRAIL MoonKAM Mission Operations Center in San Diego. Photos of the target areas will be sent back by the satellites for students to study. The MoonKAM program is led by Sally Ride, America's first woman in space. Her team at Sally Ride Science and undergraduate students at the University of California in San Diego will engage middle schools across the country in the GRAIL mission and lunar exploration. GRAIL is NASA's first planetary mission carrying instruments fully dedicated to education and public outreach.
"We have had great response from schools around the country; more than 2,500 signed up to participate so far," Ride said. "In mid-March, the first pictures of the moon will be taken by students using MoonKAM. I expect this will excite many students about possible careers in science and engineering."
Launched in September 2011, Ebb and Flow periodically perform trajectory correction maneuvers that, over time, will lower their orbits to near-circular ones with an altitude of about 34 miles (55 kilometers). During their science mission, the duo will answer longstanding questions about the moon and give scientists a better understanding of how Earth and other rocky planets in the solar system formed.
NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the GRAIL mission for NASA's Science Mission Directorate in Washington. The GRAIL mission is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver built the spacecraft.
For more information about GRAIL, visit: http://www.nasa.gov/grail .
Information about MoonKAM is available at: https://moonkam.ucsd.edu/ .