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

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.

The WISE space telescope results go online

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.

Experiment fails to find dark matter

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.

Newly discovered asteroid orbits in union with Earth

Newly discovered asteroid follows the Earth as it orbits the Sun, and has been doing it for a quarter million years.

Currently, three other horseshoe companions of the Earth are known to exist but, unlike 2010 SO16, these linger for a few thousand years at most before moving on to different orbits. Also, with an estimated diameter of 200–400 metres, 2010 SO16 is by far the largest of Earth’s horseshoe asteroids. The team has already used the Las Cumbres Observatory’s Faulkes Telescope in an on-going campaign to track the object and refine its orbit further. “It is not that difficult to spot with a medium-sized professional telescope”, says Dr Asher. “It will remain as an evening object in Earth’s skies for many years to come.”

When is an Asteroid Not an Asteroid?

When is an asteroid not an asteroid?

The layered structure of Vesta (core, mantle and crust) is the key trait that makes Vesta more like planets such as Earth, Venus and Mars than the other asteroids, McCord said. Like the planets, Vesta had sufficient radioactive material inside when it coalesced, releasing heat that melted rock and enabled lighter layers to float to the outside. Scientists call this process differentiation.

This question immediately demonstrates once again the terrible mess the International Astronautical Union made when it decided several years ago to define what makes a planet, and came up with a definition that simply doesn’t work. For if Vesta should be considered a planet, why not Pluto?

Quarter-mile diameter asteroid to pass only 200,000 miles from the Earth on November 8, 2011

Get those telescopes out! A asteroid, a quarter-mile in diameter, is going to pass only 200,000 miles from the Earth on November 8, 2011. Key quote:

Although classified as a potentially hazardous object, 2005 YU55 poses no threat of an Earth collision over at least the next 100 years. However, this will be the closest approach to date by an object this large that we know about in advance and an event of this type.

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