The discovery of bright deposits on Mars, announced today by NASA, could indicate that liquid water has recently flowed on a few locations on the planet. The new data help planetary scientists involved with several missions orbiting the Red Planet focus their quest to understand the Martian water cycle.

It has been an established fact for several years now that water exists on Mars. However, the big question is how much of it – if any – is in liquid form. The newly discovered deposits were identified by comparing different images of the same area taken by NASA’s Mars Global Surveyor (MOC camera), over a period of few years. The images suggest that water may have flowed there sometime within the past seven years.

This gives planetary scientists an excellent target for follow-up work. Yet, just because water appears to have flowed does not automatically mean that underground reservoirs of liquid water are present.

ESA’s Mars Express has found large reservoirs of water underground using its radar experiment MARSIS. All are frozen, with the largest in Mars’s polar regions. Such frozen underground lakes might be driven to temporarily thaw and flow across the surface by changes in temperature, caused by changes in illumination from the Sun or, possibly, by local variations in the underground pressure.

In addition, much water is locked into so-called hydrated minerals that have been found by the OMEGA instrument on ESA’s Mars Express.

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December 7th, 2006 | Space | No comments

Scientists using NASA’s Swift satellite stumbled upon a rare sight: two supernovas side by side in one galaxy. Large galaxies typically play host to three supernovas per century. Galaxy NGC 1316 has had two supernovas in less than five months, and a total of four supernova in 26 years, as far back as the records go. This makes NGC 1316 the most prodigious known producer of supernovas.

The first supernova, still visible on the “right” in the image, was detected on June 19, 2006, and was named SN 2006dd. The second supernova, on the immediate “left” in the image, was detected on November 5 and has been named SN 2006mr. (Other objects in the image include a central bright spot, whic is the galaxy core, and a bright object to the far left, like an earring, which is a foreground star.)

NGC 1316, a massive elliptical galaxy about 80 million light years way, has recently merged with a spiral galaxy. Mergers do indeed spawn supernovas by forcing the creation of new, massive stars, which quickly die and explode. Yet all four supernovas in NGC 1316 appear to be Type Ia, a variety previously not associated with galaxy mergers and massive star formation. Scientists are intrigued and are investigating whether the high supernova rate is a coincidence or a result of the merger. Swift was launched on this date, November 20, in 2004.

Swift was launched in November 2004 and was fully operational by January 2005. Swift carries three main instruments: the Burst Alert Telescope, the X-ray Telescope, and the Ultraviolet/Optical Telescope. Swift’s gamma-ray detector, the Burst Alert Telescope, provides the rapid initial location and was built primarily by the NASA Goddard Space Flight Center in Greenbelt and Los Alamos National Laboratory and constructed at GSFC. Swift’s X-Ray Telescope and UV/Optical Telescope were developed and built by international teams led by Penn State and drew heavily on each institution’s experience with previous space missions. The X-ray Telescope resulted from Penn State’s collaboration with the University of Leicester in England and the Brera Astronomical Observatory in Italy. The Ultraviolet/Optical Telescope resulted from Penn State’s collaboration with the Mullard Space Science Laboratory of the University College-London.

Source: Eberly College of Science.

November 20th, 2006 | Space | No comments