Mars Rover Opportunity Working At ‘Matijevic Hill’

Rock fins up to about 1 foot (30 centimeters) tall. Image credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.

NASA’s Mars rover Opportunity, well into its ninth year on Mars, will work for the next several weeks or months at a site with some of the mission’s most intriguing geological features.

The site, called “Matijevic Hill,” overlooks 14-mile-wide (22-kilometer-wide) Endeavour Crater. Opportunity has begun investigating the site’s concentration of small spherical objects reminiscent of, but different from, the iron-rich spheres nicknamed “blueberries” at the rover’s landing site nearly 22 driving miles ago (35 kilometers).

The small spheres at Matijevic Hill have different composition and internal structure. Opportunity’s science team is evaluating a range of possibilities for how they formed. The spheres are up to about an eighth of an inch (3 millimeters) in diameter.

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2012-306

6-Hour Webcast With Live Very Large Telescope Observations For ESO’s 50th Anniversary

On 5 October 2012, the European Southern Observatory (ESO) will broadcast A Day in the Life of ESO, a free, live event on the web, as part of its 50th Anniversary celebrations. There will be live observations from ESO’s flagship observatory, the Very Large Telescope (VLT), on Cerro Paranal in Chile’s Atacama Desert, as well as fascinating talks from astronomers at ESO’s Headquarters in Germany. Members of the public are invited to ask questions in advance of the event, or during the stream, by Facebook, Twitter, and email. A timetable for the webcast is available below and online.

For the first time in ESO’s history, the VLT will be pointed towards an object in the sky selected by members of the public — the Thor’s Helmet Nebula (NGC 2359). This striking nebula was selected as part of the Choose What the VLT Observes competition. Brigitte Bailleul, from France, won the Tweet Your Way to the VLT! competition, and will travel to the Paranal Observatory in Chile to help make the observations. The live link to Paranal will show the observations and the telescopes on the mountaintop, in the stunning landscape of the Atacama Desert, letting viewers join Brigitte on her trip of a lifetime.

Full Story: http://www.eso.org/public/announcements/ann12067/

Gale Crater Set For Summer Heat Wave?

Preliminary weather reports from the Curiosity’s Remote Environment Monitoring Station (REMS) are showing some surprisingly mild temperatures during the day. Average daytime air temperatures have reached a peak of 6 degrees Celsius at 2pm local time. A Martian day – known as a Sol – is slightly longer than Earths at 24 hours and 39 minutes. Temperatures have risen above freezing during the day for more than half of the Martian Sols since REMS started recording data. Because Mars’s atmosphere is much thinner than Earth’s and its surface much drier, the effects of solar heating are much more pronounced. At night the air temperatures sink drastically, reaching a minimum of -70 degrees just before dawn.

“That we are seeing temperatures this warm already during the day is a surprise and very interesting,” says Dr Felipe Gómez of the Centro de Astrobiología in Madrid. “It’s very early days and we are only now being able to test our models against REMS observations. If this warm trend carries on into summer, we might even be able to foresee temperatures in the 20s – and that would be really exciting from a habitability point of view. In the daytimes, we could see temperatures high enough for liquid water on a regular basis. But it’s too soon to tell whether that will happen or whether these warm temperatures are just a blip.”

Full Story: http://www.europlanet-eu.org/outreach/index.php?option=com_content&task=view&id=392&Itemid=41

Curiosity’s DAN Instrument Suggests Gale Crater Drier Than Expected

Preliminary data from the Curiosity Mars Science Laboratory, presented at the European Planetary Science Conference on 28 September, indicate that the Gale Crater landing site might be drier than expected.

The Curiosity rover is designed to carry out research into whether Mars was ever able to support life, and a key element of this search is the hunt for water. Although Mars has many features on its surface that suggest a distant past in which the planet had abundant liquid water in the form of rivers and lakes, the only water known to be abundant on Mars today is frozen, embedded in the soil, and in large ice caps at both poles.

The DAN instrument works by firing a pulse of neutrons at the ground beneath the rover and detecting the way it is reflected. The intensity of the reflection depends on the proportion of water in the ground, while the time the pulse takes to reach the detector is a function of the depth at which the water is located.

“The prediction based on previous measurements using the Mars Odyssey orbiter was that the soil in Gale Crater would be around 6% water. But the preliminary results from Curiosity show only a fraction of this,” said Maxim Mokrousov (Russian Space Research Institute), the lead designer of the instrument.

Full Story: http://www.europlanet-eu.org/outreach/index.php?option=com_content&task=view&id=393&Itemid=41

The First Evidence That A Yellow Supergiant Became A Supernova

A group of researchers led by Melina Bersten (Kavli IPMU) has presented evidence that the yellow supergiant (YSG) star found at the location of supernova SN 2011dh in the famous nearby galaxy M51 was indeed the SN progenitor, as well as produced a self-consistent model to explain how a star of such characteristics exploded. In their model, the exploding YSG star was a member of a close binary system. The authors further predict the detection of the companion star as a definitive test of their hypothesis. Their paper has been published in the September 20, 2012, issue of The Astrophysical Journal.

The nature and diversity of the progenitor star or progenitor system of core-collapse supernovae is an important and open question in the field of astrophysics. It is believed that most massive stars explode when the stars become red supergiants, or, alternatively, blue compact stars (so-called Wolf-Rayet stars). Recent detections of a yellow supergiant star as a possible supernova progenitor have posed serious questions on our understanding of the evolution of massive stars.

Full Story: http://www.ipmu.jp/node/1404

Simulations Uncover ‘Flashy’ Secrets Of Merging Black Holes

According to Einstein, whenever massive objects interact, they produce gravitational waves — distortions in the very fabric of space and time — that ripple outward across the universe at the speed of light. While astronomers have found indirect evidence of these disturbances, the waves have so far eluded direct detection. Ground-based observatories designed to find them are on the verge of achieving greater sensitivities, and many scientists think that this discovery is just a few years away.

Catching gravitational waves from some of the strongest sources — colliding black holes with millions of times the sun’s mass — will take a little longer. These waves undulate so slowly that they won’t be detectable by ground-based facilities. Instead, scientists will need much larger space-based instruments, such as the proposed Laser Interferometer Space Antenna, which was endorsed as a high-priority future project by the astronomical community.

A team that includes astrophysicists at NASA’s Goddard Space Flight Center in Greenbelt, Md., is looking forward to that day by using computational models to explore the mergers of supersized black holes. Their most recent work investigates what kind of “flash” might be seen by telescopes when astronomers ultimately find gravitational signals from such an event.

Full Story: http://www.nasa.gov/topics/universe/features/black-hole-secrets.html

Measuring The Universe’s ‘Exit Door’

The point of no return: In astronomy, it’s known as a black hole — a region in space where the pull of gravity is so strong that nothing, not even light, can escape. Black holes that can be billions of times more massive than our sun may reside at the heart of most galaxies. Such supermassive black holes are so powerful that activity at their boundaries can ripple throughout their host galaxies.

Now, an international team, led by researchers at MIT’s Haystack Observatory, has for the first time measured the radius of a black hole at the center of a distant galaxy — the closest distance at which matter can approach before being irretrievably pulled into the black hole.

The scientists linked together radio dishes in Hawaii, Arizona and California to create a telescope array called the “Event Horizon Telescope” (EHT) that can see details 2,000 times finer than what’s visible to the Hubble Space Telescope. These radio dishes were trained on M87, a galaxy some 50 million light years from the Milky Way. M87 harbors a black hole 6 billion times more massive than our sun; using this array, the team observed the glow of matter near the edge of this black hole — a region known as the “event horizon.”

Full Story: http://web.mit.edu/newsoffice/2012/measuring-a-black-holes-event-horizon-0927.html

NASA Rover Finds Old Streambed On Martian Surface

NASA’s Curiosity rover found evidence for an ancient, flowing stream on Mars. Image credit: NASA/JPL-Caltech/MSSS

NASA’s Curiosity rover mission has found evidence a stream once ran vigorously across the area on Mars where the rover is driving. There is earlier evidence for the presence of water on Mars, but this evidence — images of rocks containing ancient streambed gravels — is the first of its kind.

Scientists are studying the images of stones cemented into a layer of conglomerate rock. The sizes and shapes of stones offer clues to the speed and distance of a long-ago stream’s flow.

“From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep,” said Curiosity science co-investigator William Dietrich of the University of California, Berkeley. “Plenty of papers have been written about channels on Mars with many different hypotheses about the flows in them. This is the first time we’re actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it.”

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2012-305#1

Peering To The Edge Of A Black Hole

Black hole powered jet of sub-atomic particles. Credit: NASA and the Hubble Heritage Team

Using a continent-spanning telescope, an international team of astronomers has peered to the edge of a black hole at the center of a distant galaxy. For the first time, they have measured the black hole’s “point of no return” – the closest distance that matter can approach before being irretrievably pulled into the black hole.

A black hole is a region in space where the pull of gravity is so strong that nothing, not even light, can escape. Its boundary is known as the event horizon.

“Once objects fall through the event horizon, they’re lost forever,” says lead author Shep Doeleman, assistant director at the MIT Haystack Observatory and research associate at the Harvard-Smithsonian Center for Astrophysics (CfA). “It’s an exit door from our universe. You walk through that door, you’re not coming back.”

Full Story: http://www.cfa.harvard.edu/news/2012/pr201228.html

Cause Of Supernova SN 1006 Revealed

Between 30 April and 1 May of the year 1006 the brightest stellar event ever recorded in history occurred: a supernova, or stellar explosion, that was widely observed by various civilizations from different places on the Earth. More than a thousand years later a team led by researchers from the University of Barcelona, the Instituto de Astrofísica de Canarias (IAC) and the CSIC has found that the supernova of 1006 (SN 1006) probably occurred as a result of the merger of two white dwarfs. The finding has been published in and made the front cover of today’s edition of the international science journal Nature.

Different communities of astronomers all over the world observed the supernova of the year 1006. Some of them, including Chinese astronomers, highlighted the fact that the astronomical event was visible for three years. The most explicit record, made by the Egyptian doctor and astronomer Ali ibn Ridwan (988-1061), notes that the phenomenon was about three times brighter than Venus, and that it emitted light of a quantity equivalent to almost a quarter of the Moon’s brightness.

As co-director of the work, Pilar Ruiz-Lapuenteexplains, “In this work the existing stars in the area have been studied, regarding distance and possible contamination by elements of the supernova, and the results show that there is no star that could be considered the progenitor of this explosion”.

Full Story: http://www.ub.edu/web/ub/en/menu_eines/noticies/2012/09/049.html