Jun 3 2013

From The Space Library

RELEASE: 13-163 - NASA'S HUBBLE WILL USE RARE STELLAR ALIGNMENT TO HUNT FOR PLANETS --WASHINGTON -- NASA's Hubble Space Telescope will have two opportunities in the next few years to hunt for Earth-sized planets around the red dwarf Proxima Centauri. The opportunities will occur in October 2014 and February 2016 when Proxima Centauri, the star nearest to our sun, passes in front of two other stars. Astronomers plotted Proxima Centauri's precise path in the heavens and predicted the two close encounters using data from Hubble. Proxima Centauri's trajectory offers a most interesting opportunity because of its extremely close passage to the two stars, said Kailash Sahu, an astronomer with the Space Science Telescope Institute in Baltimore, Md. Sahu leads a team of scientists whose work he presented Monday at the 222nd meeting of American Astronomical Society in Indianapolis. Red dwarfs are the most common class of stars in our Milky Way galaxy. Any such star ever born is still shining today. There are about 10 red dwarfs for every star like our sun. Red dwarfs are less massive than other stars. Because lower-mass stars tend to have smaller planets, red dwarfs are ideal places to go hunting for Earth-sized planets. Previous attempts to detect planets around Proxima Centauri have not been successful. But astronomers believe they may be able to detect smaller terrestrial planets, if they exist, by looking for microlensing effects during the two rare stellar alignments. Microlensing occurs when a foreground star passes close to our line of sight to a more distant background star. These images of the background star may be distorted, brightened and multiplied depending on the alignment between the foreground lens and the background source. These microlensing events, ranging from a few hours to a few days in duration, will enable astronomers to measure precisely the mass of this isolated red dwarf. Getting a precise determination of mass is critical to understanding a star's temperature, diameter, intrinsic brightness, and longevity. Astronomers will measure the mass by examining images of each of the background stars to see how far the stars are offset from their real positions in the sky. The offsets are the result of Proxima Centauri's gravitational field warping space. The degree of offset can be used to measure Proxima Centauri's mass. The greater the offset, the greater the mass of Proxima Centauri. If the red dwarf has any planets, their gravitational fields will produce a second small position shift. Because Proxima Centauri is so close to Earth, the area of sky warped by its gravitation field is larger than for more distant stars. This makes it easier to look for shifts in apparent stellar position caused by this effect. However, the position shifts will be too small to be perceived by any but the most sensitive telescopes in space and on the ground. The European Space Agency's Gaia space telescope and the European Southern Observatory's Very Large Telescope on Mt. Cerro Paranal in Chile may be able to make measurements comparable to Hubble's. To identify possible alignment events, Sahu's team searched a catalog of 5,000 stars with a high rate of angular motion across the sky and singled out Proxima Centauri. It crosses a section of sky with the apparent width of the full moon as observed from Earth every 600 years.

RELEASE: 13-169 - NASA'S SWIFT PRODUCES BEST ULTRAVIOLET MAPS OF THE NEAREST GALAXIES --WASHINGTON -- Astronomers at NASA and Pennsylvania State University have used NASA's Swift satellite to create the most detailed ultraviolet light surveys ever of the Large and Small Magellanic Clouds, the two closest major galaxies. We took thousands of images and assembled them into seamless portraits of the main body of each galaxy, resulting in the highest-resolution surveys of the Magellanic Clouds at ultraviolet wavelengths, said Stefan Immler, who proposed the program and led NASA's contribution from the agency's Goddard Space Flight Center in Greenbelt, Md. Immler presented a 160-megapixel mosaic image of the Large Magellanic Cloud (LMC) and a 57-megapixel mosaic image of the Small Magellanic Cloud (SMC) at the 222nd American Astronomical Society meeting in Indianapolis on Monday. The new images reveal about 1 million ultraviolet sources in the LMC and about 250,000 in the SMC. The images include light ranging from 1,600 to 3,300 angstroms, which is a range of UV wavelengths largely blocked by Earth's atmosphere. Prior to these images, there were relatively few UV observations of these galaxies, and none at high resolution across such wide areas, so this project fills in a major missing piece of the scientific puzzle, said Michael Siegel, lead scientist for Swift's Ultraviolet/Optical Telescope (UVOT) at the Swift Mission Operations Center at the university in State College, Pa. The LMC and SMC lie about 163,000 light-years and 200,000 light-years away, respectively, and orbit each other as well as our own Milky Way galaxy. The LMC is about one-tenth the size of the Milky Way and contains only 1 percent of the Milky Way's mass. The SMC is half the size of the LMC and contains about two-thirds of its mass. Despite their modest sizes, the galaxies loom large in the sky because they are so close to us. Both extend far beyond the UVOT's field of view, which meant thousands of images were needed in order to cover both galaxies in three ultraviolet colors centered at wavelengths of 1,928 angstroms, 2,246 angstroms, and 2,600 angstroms. Viewing in the ultraviolet allows astronomers to suppress the light of normal stars like the sun, which are not very bright at such higher energies, and provides a clearer picture of the hottest stars and star-formation regions. No telescope other than UVOT can produce such high-resolution wide-field multicolor surveys in the ultraviolet. Swift's wide-field imaging capabilities provide a powerful complement to the deeper, but much narrower-field imaging power of NASA's Hubble Space Telescope. To produce the 160-megapixel LMC mosaic, Swift's UVOT acquired 2,200 snapshots for a cumulative exposure of 5.4 days. The 57-megapixel SMC image comprises 656 individual images with a total exposure of 1.8 days. Both images have an angular resolution of 2.5 arcseconds, which is a measure of their sharpness. Sources separated by this angle, which is equivalent to the size of a dime seen from 1 mile away, are visible as distinct objects. With these mosaics, we can study how stars are born and evolve across each galaxy in a single view, something that's very difficult to accomplish for our own galaxy because of our location inside it, Immler said. The Large and Small Magellanic Clouds are readily visible from the Southern Hemisphere as faint, glowing patches in the night sky. The galaxies are named after Ferdinand Magellan, the Portuguese explorer who in 1519 led an expedition to sail around the world. He and his crew were among the first Europeans to sight the objects. Pennsylvania State University manages the Swift Mission Operations Center, which controls Swift's science and flight operations. Goddard manages Swift, which was launched in November 2004. The satellite is operated in collaboration with Penn State, the Los Alamos National Laboratory in New Mexico and Orbital Sciences Corp. in Dulles, Va. International collaborators are in the United Kingdom and Italy, and the mission includes contributions from Germany and Japan.

RELEASE: C13-026 - NASA EXERCISES CONTRACT OPTION ON ENGINEERING SUPPORT CONTRACT --WASHINGTON -- NASA's Langley Research Center in Hampton, Va., has exercised the second option of its Technology, Engineering, and Aerospace Mission Support (TEAMS) 2 contract with Analytical Mechanics Associates Inc. (AMA), also of Hampton, to continue providing engineering support to the center. The current potential value of the contract, including the approximately $45 million one-year option that starts Oct. 1, is $327.5 million. This is a cost-plus award-fee, indefinite-delivery, indefinite-quantity contract. Under TEAMS 2, Analytical Mechanics Associates supports research and technology on complex, long-term NASA missions. This includes scientific research; engineering design, analysis, and development; and technology readiness level advancement of work associated with evolving NASA missions. The company also will implement technology programs, tests, operations, systems analysis and conceptual design, as well as provide program and project management support.

MEDIA ADVISORY: M13-091 - NASA TO HOST JUNE 5 TELECONFERENCE ON CURIOSITY MARS ROVER --PASADENA, Calif. -- NASA will hold a media teleconference at 11:30 a.m. PDT (2:30 p.m. EDT), Wednesday, June 5, to provide an update about the Mars Science Laboratory (MSL) mission and activities of the Curiosity rover. The briefing participants will be: -- Jim Erickson, MSL project manager, NASA's Jet Propulsion Laboratory, Pasadena, Calif. -- Joy Crisp, MSL deputy project scientist, JPL -- Joe Melko, MSL sampling activity lead, JPL The NASA Mars rover Curiosity is approximately 10 months into a two-year prime mission to investigate the environmental history of an area inside Mars' Gale Crater. Curiosity already has found evidence of ancient environmental conditions favorable for microbial life in the crater.