Tag: science

Observations of Comet Hale-Bopp at 30 AU

8:52 pm

In a paper published tonight on the Los Alamos astro-ph preprint website, astronomers described new observations of Comet Hale-Bopp at a distance of 30 astronomical units, or 2.8 billion miles, from the sun. Their conclusions:

  • These observations were the most distant detection of any known comet.
  • The comet’s starlike appearance and its drop in brightness since the last observations suggest that the comet has finally ceased, or is about to cease, all activity, and that they are now looking directly at the comet’s nucleus instead of the coma cloud surrounding it.
  • Nonetheless, the comet is brighter than expected, which also suggests that a thin layer of new ice covers its surface and thus increases its albedo.

To quote the paper, “Observing Hale-Bopp in a completely frozen state would be extremely important because a thick coma was constantly present during the entire appariation [Ed. the fly-by of the Sun]. The coma obscured the nucleus which was not observed directly. Lack photometric data of the bared nucleus, its size — one of the most important input parameter in activity models — remains uncertain.”

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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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“Space beer,” one giant leap for mankind

9:35 am

The science of space beer.

“For example, many metals burn more easily in reduced gravity, liquids behave differently, both of which have important implications for safety and the way machinery and equipment operate in spacecraft and space stations. The beer experiments assisted in determining the correct level of carbonation, so that it can in the future be appropriately enjoyed by humans in reduced gravity,”

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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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Congress removes wolf from endangered list

11:16 pm

Congress removes the wolf from the endangered list. From Senator Jon Tester (D-Montana):

“Right now, Montana’s wolf population is out of balance and this provision will get us back on the responsible path with state management. Wolves have recovered in the Northern Rockies. By untying the hands of the Montana biologists who know how to keep the proper balance, we will restore healthy wildlife populations and we will protect livestock. This provision is best for our wildlife, our livestock and for wolves themselves.”

I don’t know if Tester’s description of the situation in Montana is accurate (though I tend to rely on local expertise in these matters). However, to get an opposing viewpoint the article above goes to the Center for Biological Diversity, an organization I do know something about. In caving matters relating to white nose syndrome, CBD has pushed extremist and outright ignorant policy positions (trying for example to have all caves and mines on all public lands closed in order to protect bats, even though there is literally no evidence that such an action made sense). I would not trust their opinions under any condition.

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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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Hot time on the ol’ Sun tonight!

10:09 pm

After literally years of inactivity, well below all initial predictions, the Sun truly came to life this past month. Below is the March monthly update of the Sun’s sunspot cycle, published by NOAA’s Space Weather Prediction Center. The red curve is the prediction, while the dotted black line shows the actual activity.

As you can see, the Sun’s sunspot activity shot up precipitously. Though I don’t have the data from past years, the March jump appears to me to probably be one of the fastest monthly rises ever recorded.

Does this mean the newest prediction from the solar scientists at the Marshall Space Flight Center calling for a weak solar maximum in 2013 is wrong? Probably not, though of course in this young field who knows? I would say, however, that the overall trend of the data still suggests the next maximum will be very weak.

Stay tuned! The next few months should finally give us a sense of where the next maximum is heading.

March Sunspot graph

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