The mystery of the solar corona may be resolved.  ScientificBlogging has covered this, as did, Space Fellowship, and other sites.  Two of them couldn't resist the same money quote, too:
"Why is the sun's corona so darned hot?" said study member

James Klimchuk of NASA's Goddard Space Flight Center in Greenbelt, MD.
Why is this useful?
Our society is saturated with GPS, or Global Navigation Satellite System (GNSS), applications. GPS is the first GNSS and it is operated by US Air Force. Most people are not aware of the fact that GPS was developed and is run by the military. A reduced quality signal is released for civil use. After Europe decided to build their own GNSS, called Galileo, the US Air Force decided to released an improved signal. It was and is a matter of competition.

NASA scientists have discovered glycine, a fundamental building block of life, in samples of comet Wild 2 returned by NASA's Stardust spacecraft.

"Glycine is an amino acid used by living organisms to make proteins, and this is the first time an amino acid has been found in a comet," said Dr. Jamie Elsila of NASA's Goddard Space Flight Center in Greenbelt, Md. "Our discovery supports the theory that some of life's ingredients formed in space and were delivered to Earth long ago by meteorite and comet impacts."

If you have never seen a fireball lighting up the night sky I bet you will appreciate the video below, which was taken by Ivaldo Cervini over Italian skies a few days ago. It is a Perseid meteor, which lit up at a visual magnitude of approximately -10 (for comparison, the brigthest Venus can get is -4.5, and the full moon is -12.5: -10 is roughly 200 times brighter than Venus, and a tenth of the full moon).
Planetary nebulae are gas and dust shells ejected by stars near the end of their lives - typically seen around stars comparable or smaller in size than the Sun.

The existing population of planetary nebulae is found around small stars comparable in size to our Sun but a new population discovered due to the presence of unusually strong radio sources may be the long predicted class of similar shells around heavier stars.

A team of scientists in Australia and the United States call the new class of object “Super Planetary Nebulae.” They report their work in the journal Monthly Notices of the Royal Astronomical Society.
The Gravity Recovery and Climate Experiment (GRACE) is a twin-satellite system to study in detail the Earth's gravity field. The GRACE data consist of  accelerometer, GPS, and attitude measurements from each satellite plus the inter-satellite range change measurements. NASA says GRACE time-varying gravity signals measure seasonal variations in underground aquifers.
Small bursts of heat and energy called nanoflares cause temperatures in the sun's atmosphere to reach millions of degrees, according to NASA researchers..

The sun's outer atmosphere, or corona, is made up of loops of hot gas that arch high above the surface. These loops are comprised of bundles of smaller, individual magnetic tubes or strands that can have temperatures reaching several million degrees Kelvin (K), even though the sun's surface is only 5,700 degrees K.
After the Americans, Russians, Chinese, Japanese and Indians, the Germans have now also set their sights on the moon. The aerospace coordinator in the German federal government, Peter Hintze, proposed in a televised interview that an unmanned lunar mission by the year 2015 should be part of a government plan to strengthen the economy.

According to Hintze, a public investment of about 1.5 billion Euros spread out over five years would  not only put a robot lander on the moon, but also lead to the development of innovative technologies, in particular in robotics, that might be of use in industry and medical care and create new jobs in high-tech industries.
Tonight you have a chance to contribute to science -namely, the knowledge of our solar system- and have a lot of fun at the same time. Do you want to know how ? Then please read on.

Comet Swift-Tuttle (left, courtesy NASA) may be far away by now, but the debris that gets thrown out in space during each of its passages in the proximity of our Sun traces the full elliptical orbit of the comet, like droplets of sweat of an athlete running the 10,000 meters in a stadium. And tonight, the Earth is going to plunge in the core of the filament of debris following the comet's orbit.
The International Year of Astronomy has inspired many interesting projects.  Perhaps none are as visually compelling as Experience the Planets.  This growing site presents artists renditions of what it would look like to see our neighbors in the solar system up close and personal.  And, yes, for those of you who do not have pictures as cute as The Frogger being buzzed by a hippopotamus on your computer, there are wallpapers available.

The image below (Waters of Europa by Josef Barton) shows an artist's rendition of what it might be like to explore the oceans beneath the icy crust of Jupiter's moon Europa in a submersible vehicle.