Tag: astronomy

Scientists find previously unknown deposits of CO2 on Mars

5:20 pm

Scientists find a gigantic and previously unknown deposit of CO2 at Mars’ south pole.

“We already knew there is a small perennial cap of carbon-dioxide ice on top of the water ice there, but this buried deposit has about 30 times more dry ice than previously estimated,” said Roger Phillips of Southwest Research Institute in Boulder, Colo. Phillips is deputy team leader for the Mars Reconnaissance Orbiter’s Shallow Radar instrument and lead author of the report. . . . “When you include this buried deposit, Martian carbon dioxide right now is roughly half frozen and half in the atmosphere, but at other times it can be nearly all frozen or nearly all in the atmosphere,” Phillips said.

What this discovery means is that, depending on Mars’ orbital circumstances, its atmosphere can sometimes be dense enough for liquid water to flow on its surface.

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Pluto’s atmosphere is expanding, and scientists don’t know why

5:59 pm

Pluto’s atmosphere is expanding, and scientists don’t know why.

Pluto travels along a highly elliptical path and last passed closest to the sun in 1989. Many planetary scientists expected the atmosphere to shrink as the icy orb began receding from the sun’s warmth. The unanticipated expansion may be related to changes in the darkness of the orb’s surface a decade or so ago, which may have caused the surface ices to absorb more solar radiation and more efficiently evaporate. Or, Greaves suggests, long-term variations in the sun’s ultraviolet output, changes linked to the roughly 11-year cycle of solar activity, may be playing a role.

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The WISE space telescope results go online

4:07 pm

The WISE infrared space telescope results are now online, for anyone to search.

Data from the first 57 percent of the sky surveyed is accessible through an online public archive. The complete survey, with improved data processing, will be made available in the spring of 2012. A predecessor to WISE, the Infrared Astronomical Satellite (IRAS), served a similar role about 25 years ago, and those data are still valuable to astronomers today. Likewise, the WISE legacy is expected to endure for decades.

You can hunt for new asteroids, comets, and galaxies here, with instructions on how to do it here.

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Experiment fails to find dark matter

9:28 am

The uncertainty of science: An underground experiment in Italy has failed to detect dark matter, as theorized by scientists.

In a paper published online last night, the XENON100 researchers report three events detected during a 100-day run of the experiment last year that might have been due to dark matter1. However, as they expected to see between 1.2 and 2.4 background events — interactions mostly caused by a radioactive contaminant in the xenon — their result is statistically negative and therefore rules out the existence of many of the more strongly interacting and heavier WIMPs.

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