APOD: A Rose Made of Galaxies (Arp 273)

Text via the Hubble site:

This image of a pair of interacting galaxies called Arp 273 was released to celebrate the 21st anniversary of the launch of the NASA/ESA Hubble Space Telescope.

The distorted shape of the larger of the two galaxies shows signs of tidal interactions with the smaller of the two. It is thought that the smaller galaxy has actually passed through the larger one.

Via:Phantasmagoria

APOTD:Messenger at Mercury

Explanation: On March 17, the MESSENGER spacecraft became the first to orbit Mercury, the solar system's innermost planet. This is its first processed color image since entering Mercury orbit. Larger, denser, and with almost twice the surface gravity of Earth's moon, Mercury still looks moon-like at first glance. But in this view its terrain shows light blue and brown areas near craters and long bright rays of material streaking the surface. The prominent bright ray crater Debussy at the upper right is 80 kilometers (50 miles) in diameter. Terrain toward the bottom of the historic image extends to Mercury's south pole and includes a region not previously imaged from space.

Via:NASA, APOD

APOD: Cassiopeia A and a Cooling Neutron Star

Supernova remnant Cassiopeia A (Cass A) is a comfortable 11,000 light-years away. Light from the Cass A supernova, the death explosion of a massive star, first reached Earth just 330 years ago. The expanding debris cloud spans about 15 light-years in this composite X-ray/optical image, while the bright source near the center is a neutron star (inset illustration) the incredibly dense, collapsed remains of the stellar core. Still hot enough to emit X-rays, Cass A’s neutron star is cooling. In fact, 10 years of observations with the orbiting Chandra X-ray observatory find that the neutron star is cooling rapidly, so rapidly that researchers suspect a large part of the neutron star’s core is forming a frictionless neutron superfluid. The Chandra results represent the first observational evidence for this bizarre state of matter.

Source:NASA, Astronomy Picture of The Day

Eye Candy: Speaking of Exoplanets- Sunrise on Gliese 876d

In keeping with not only our exopoplanet theme but red dwarfs named "Gliese", the above is an artists depiction of a sunrise on a planet known as Gliese 876d, the third planet discovered orbiting the red dwarf Gliese 876- located fifteen light years away in the constellation of Aquarius. The rest of the text in this article as well as the image, comes directly from NASA's " Astronomy Picture of the Day" website.

-CAINE-

A Dangerous Sunrise on Gliese 876d
Illustration Credit & Copyright: Inga Nielsen (Hamburg Obs., Gate to Nowhere)

Explanation: On planet Gliese 876d, sunrises might be dangerous. Although nobody really knows what conditions are like on this close-in planet orbiting variable red dwarf star Gliese 876, the above artistic illustration gives one impression. With an orbit well inside Mercury and a mass several times that of Earth, Gliese 876d might rotate so slowly that dramatic differences exist between night and day. Gliese 876d is imagined above showing significant volcanism, possibly caused by gravitational tides flexing and internally heating the planet, and possibly more volatile during the day. The rising red dwarf star shows expected stellar magnetic activity which includes dramatic and violent prominences. In the sky above, a hypothetical moon has its thin atmosphere blown away by the red dwarf's stellar wind. Gliese 876d excites the imagination partly because it is one of the few extrasolar planets known to be close to the habitable zone of its parent star.

-CAINE-