Tag: science

The double vortex at Venus’s south pole is gone

2:57 pm

Using data accumulated over the past four years by Venus Express, scientists have shown that the giant double vortex storm at Venus’s south pole was only a temporary phenomenon. You can download the actual paper here [pdf]. Key quote from the paper:

The polar region of Venus shows a dynamics regime quite different than the rest of the planet, with a separation region delimited by the cold collar zone. Average wind speeds presents an almost solid body rotation, while instantaneous view highlights the complex dynamic structure with air flowing almost toward all directions. The so called dipole shape is not a stable feature and the morphology of the vortex is significantly variable on both short and long timescales.

The “cold collar” is an atmospheric ring of colder temperatures that encircles the planet’s poles.

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The moons of Saturn

10:04 am

The Cassini spacecraft orbiting Saturn continues to send back a wealth of data, and some gob-smacking wonderful images. Below are two of the more recent examples. The first is not a computer-generated graphic: it shows the small moon Helene (21 miles across) during a fly-by on March 3, 2010, with Saturn’s atmosphere providing the background. The second captures Saturn’s two largest moons, with the smaller Rhea crossing in front of the larger Titan.

Saturn's moon Helene

Rhea eclipses Titan

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Opossums overrun Brooklyn

10:47 pm

We’re here to help you! The New York city government, in an effort to control its rat population (the small rodent kind), decided to release opossums in Brooklyn to eat rats. Instead, the opossums have ignored the rats, and now Brooklyn is overrun with both rats and opossums. More here. Key quote:

“Didn’t any of those brain surgeons realize that the opossums were going to multiply?”

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More caves on the Moon

5:28 pm

Check out these newly posted images of lunar cave pits, taken by Lunar Reconnaissance Orbiter. The depth estimates range from 100 to 300 plus feet.

[Ed. I should note that some of these images have already been posted on behindtheblack. For example, the center image found here) was first discovered by reader James Fincannon and posted by me on July 15 and July 26, when I discussed the challenges of accessing the bottom of these pits. I also posted an image of the Mare Ingenii pit on July 13.]

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The United States, as seen from the Moon

11:44 am

On August 9, 2010 the camera on Lunar Reconnaissance Orbiter took some routine calibration images and captured the Earth from lunar orbit, showing the western hemisphere with relatively little cloud cover. The picture below is a tiny piece from that global image, cropped to show the United States. The details are pretty remarkable, considering the distance. You can explore the full global image in detail here.

The U.S. from the Moon

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Something is recycling the methane on Mars

1:18 pm

Research results posted today [pdf] at the European Planetary Science Congress show that the methane in Mars’s atmosphere is seasonally variable and far more short-lived than predicted, disappearing in less than a year. Some process, therefore, must be both using it and replenishing it. On Earth, that’s almost always done by some form of life process. Key quote by one of the scientists, from the press release:

“Only small amounts of methane are present in the martian atmosphere, coming from very localised sources. We’ve looked at changes in concentrations of the gas and found that there are seasonal and also annual variations. The source of the methane could be geological activity or it could be biological ­ we can’t tell at this point.”

The image below shows the three regions (in yellow) where the methane is concentrated.

Mars methane locations

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Global topography of the Moon

2:34 pm

New results from Lunar Reconnaissance Orbiter, including a new global topographic map.

Global topography of the Moon

From the caption: A lunar topographic map showing the Moon from the vantage point of the eastern limb. On the left side of the Moon seen in this view is part of the familiar part of the Moon observed from Earth (the eastern part of the nearside). In the middle left-most part of the globe is Mare Tranquillitatis (light blue) the site of the Apollo 11 landing, and above this an oval-appearing region (Mare Serenitatis; dark blue) the site of the Apollo 17 landing. Most of the dark blue areas are lunar maria, low lying regions composed of volcanic lava flows that formed after the heavily cratered lunar highlands (and are thus much less cratered).

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Arctic icecap reaches 2010 minimum

1:07 pm

It appears that the Arctic icecap has reached its 2010 minimum. Though the icecap extent in the spring was the largest since 2002 (see image below), the melt was fast and the minimum appears to be the third lowest since 1979.

Icecap extent

Does this mean the icecap is melting and will disappear shortly, as some politicians like to believe? Hardly. Though the data suggests a long term decline in ice extent, recent trends also show evidence that the icecap might be recovering. What will actually happen is still anyone’s guess.

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How blind cave fish find food

9:10 am

How blind cave fish find food. Key quote:

“Vibration Attraction Behavior” (or VAB) is the ability of fish to swim toward the source of a water disturbance in darkness. Postdoctoral associate Masato Yoshizawa measured this behavioral response in both wild caught and laboratory raised cave and surface-dwelling fish using a vibrating rod at different frequencies as a stimulus. Most cavefish displayed VAB and would swim toward the vibrating rod and poke at it, while few surface fish did.

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Scientists predict when the first Earthlike planet will be discovered

11:27 pm

Don’t bet the bank on this: In a preprint paper posted tonight on the astro-ph website, scientists predict the discovery of the first Earthlike extrasolar planet — using statistical analysis alone! Fun quote:

Using a bootstrap analysis of currently discovered exoplanets, we predict the discovery of the first Earth-like planet to be announced in the first half of 2011, with the likeliest date being early May 2011.

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The variability of stars according to Kepler

10:02 am

More data from Kepler! In a paper [pdf] published today on the astro-ph website, scientists outline Kepler’s census of the variability of stars. Key quote from the abstract:

We have separated the sample in 129,000 dwarfs and 17,000 giants, and further sub-divided, the luminosity classes into temperature bins corresponding approximately to the spectral classes A, F, G, K, and M. G-dwarfs are found to be the most stable with < 20% being variable. The variability fraction increases to 30% for the K dwarfs, 40% for the M and F dwarfs, and 70% for the A-dwarfs. At the precision of Kepler, > 95% of K and G giants are variable.

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Amateur detection of Jupiter impact

9:52 am

The detection in June by two different amateur astronomers of an impact on Jupiter bodes well for asteroid/comet research. You can read the actual paper here. [pdf] Key quote from the abstract:

A systematic study of the impact rate and size of these bolides can enable an empirical determination of the flux of meteoroids in Jupiter with implications for the populations of small bodies in the outer Solar System and may allow a better quantification of the threat of impacting bodies to Earth. The serendipitous recording of this optical flash opens a new window in the observation of Jupiter with small telescopes.

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