Archive

Archive for July 18, 2013

Snow Falling around Infant Solar System: Icy Region Gives Planet And Comet Formation A Boost


ALMA image of CO snow line. Credit: Karin Oberg, Harvard/University of Virginia

ALMA image of CO snow line. Credit: Karin Oberg, Harvard/University of Virginia

The sight of a snowfall can thrill children, but the first-ever snow line seen around a distant star gives astronomers an even greater thrill because of what it reveals about the formation of planets and our Solar System’s history.

Astronomers using the new Atacama Large Millimeter/submillimeter Array (ALMA) telescope have taken the first-ever image of a snow line in an infant solar system. This frosty landmark is thought to play an essential role in the formation and chemical make-up of planets around a young star.

On Earth, snow lines typically form at high elevations where falling temperatures turn atmospheric moisture to snow. In much the same way, snow lines are thought to form around young stars in the distant, colder reaches of the disks from which solar systems form. Depending on the distance from the star, however, other more exotic molecules can freeze and turn to snow.

“ALMA has given us the first real picture of a snow line around a young star, which is extremely exciting because of what it tells us about the very early period in the history of our own Solar System,” said Chunhua “Charlie” Qi, a researcher with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., who led the international research team with Karin Oberg, a researcher with Harvard University and the University of Virginia in Charlottesville.

Full Story:  http://www.nrao.edu/pr/2013/snowline/
Also: http://www.eso.org/public/news/eso1333/

SOFIA Has Gone South: Airborne Observatory Investigates The Southern Sky From New Zealand


For the first time SOFIA, the “Stratospheric Observatory for Infrared Astronomy”, has been deployed to the southern hemisphere. Based at the airport of Christchurch, New Zealand for three weeks, SOFIA has started to study celestial objects that are uniquely observable on southern flight routes. On the morning of July 18 New Zealand time, SOFIA landed after the first of its planned 9 science flights that included studies of the Magellanic Clouds, neighbours to the Milky Way galaxy, and of the circumnuclear disk orbiting the black hole in the center of our Galaxy. The GREAT instrument used in these flights has been developed by a consortium of German research institutes led by Rolf Güsten (Max Planck Institute for Radio Astronomy).

Full Story: http://www3.mpifr-bonn.mpg.de/public/pr/pr-sofia-jul2013-en.html
Also: http://www.nasa.gov/press/2013/july/nasas-sofia-investigates-the-southern-sky-from-new-zealand/#.UegEzz44XB4

A Warmer Planetary Haven Around Cool Stars, As Ice Warms Rather Than Cools


In a bit of cosmic irony, planets orbiting cooler stars may be more likely to remain ice-free than planets around hotter stars. This is due to the interaction of a star’s light with ice and snow on the planet’s surface.

Stars emit different types of light. Hotter stars emit high-energy visible and ultraviolet light, and cooler stars give off infrared and near-infrared light, which has a much lower energy.

It seems logical that the warmth of terrestrial or rocky planets should depend on the amount of light they get from their stars, all other things being equal. But new climate model research led by Aomawa Shields, a doctoral student in the University of Washington astronomy department, has added a surprising new twist to the story: Planets orbiting cool stars actually may be much warmer and less icy than their counterparts orbiting much hotter stars, even though they receive the same amount of light.

Full Story: http://www.washington.edu/news/2013/07/18/a-warmer-planetary-haven-around-cool-stars-as-ice-warms-rather-than-cools/

Hopkins Astronomer Holland Ford Receives NASA Award For Hubble Contributions


Holland Ford, an astronomer at The Johns Hopkins University in Baltimore, Md., has received NASA’s Distinguished Public Service Medal for his outstanding contributions to the Hubble Space Telescope.

Ford attributes his success to the thousands of people in government, industry, science institutes, and academia who worked together to build and use Hubble to revolutionize our view of the universe. “What a privilege to be part of this great endeavor!” he says.

The Distinguished Public Service Medal is NASA’s highest form of recognition, awarded to someone who has made a profound impact on the success of a NASA mission. The medal is one of several Agency Honor Awards given annually in a ceremony at NASA Headquarters in Washington and at each NASA center. Each nominee undergoes a careful selection process before the NASA administrator approves the final recipients.

Full Story: http://hubblesite.org/newscenter/archive/releases/2013/28/full/

Reports Detail Mars Rover Clues To Atmosphere’s Past


A pair of new papers report measurements of the Martian atmosphere’s composition by NASA’s Curiosity rover, providing evidence about loss of much of Mars’ original atmosphere.

Curiosity’s Sample Analysis at Mars (SAM) suite of laboratory instruments inside the rover has measured the abundances of different gases and different isotopes in several samples of Martian atmosphere. Isotopes are variants of the same chemical element with different atomic weights due to having different numbers of neutrons, such as the most common carbon isotope, carbon-12, and a heavier stable isotope, carbon-13.

“As atmosphere was lost, the signature of the process was embedded in the isotopic ratio,” said Paul Mahaffy of NASA Goddard Space Flight Center, Greenbelt, Md. He is the principal investigator for SAM and lead author of one of the two papers about Curiosity results in the July 19 issue of the journal Science.

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-226

NASA Interplanetary Probes To Take Pictures Of Earth


Two NASA spacecraft, one studying the Saturn system, the other observing Mercury, are maneuvering into place to take pictures of Earth on July 19 and 20.

The image taken from the Saturn system by NASA’s Cassini spacecraft will occur between 2:27 and 2:42 PDT (5:27 and 5:42 p.m. EDT, or 21:27 and 21:47 UTC) Friday, July 19. Cassini will be nearly 900 million miles (nearly 1.5 billion kilometers) away from Earth. NASA is encouraging the public to look and wave in the direction of Saturn at the time of the portrait and share their pictures via the Internet.

The Cassini Earth portrait is part of a more extensive mosaic — or multi-image picture — of the Saturn system as it is backlit by the sun. The viewing geometry highlights the tiniest of ring particles and will allow scientists to see patterns within Saturn’s dusty rings. Processing of the Earth images is expected to take a few days, and processing of the full Saturn system mosaic will likely take several weeks.

Full Story and Links: http://www.jpl.nasa.gov/news/news.php?release=2013-225