APOD 2.6

Comet Hyakutake Passes the Earth
http://apod.nasa.gov/apod/ap091216.html

In March, 1996, The comet Hyakutake passed by Earth within one-tenth of an AU. In this picture, the tail, which consists of dust and ions, is easily visible behind the very bright main body of the comet. The end of the tail was distorted because of a magnetic disconnection event. The coma contains a nucleus of ice that is about five kilometers across. Hyakutake emitted X-rays, which may have been caused by interaction with solar wind particles. Hyakutake may have been seen by Magdalenians 17,000 years ago, and is not expected to pass Earth for another 100,000 years.

APOD 2.5

The Colors of IC 1795
http://apod.nasa.gov/apod/ap091210.html

IC 1795 is a star-forming region in the direction of Cassiopeia. This picture displays the nebula's gas and dust clouds. Interstellar matter consists mostly of gas, with some dust. 99% is gas, and of this, 75% is hydrogen. The dust is often made up of carbon, silicates, and ice. IC 1975 also contains sulfur. In the picture, blue corresponds to oxygen, green to hydrogen, and red to sulfur. IC 1975 is close in the sky to IC 1805 and the Double Cluster of Perseus.

APOD 2.4

Polar Ring Galaxy NGC 660
http://apod.nasa.gov/apod/ap091203.html

This is a picture of NGC 660, a polar ring galaxy in the constellation Pisces. In a polar ring galaxy, stars, gas, and dust orbit in a ring around a central disk. This type of galaxy may result from a collision of two galaxies, or from the capture of matter from another galaxy. NGC 660 is 20 million light years away and its ring is 40,000 light years across. NGC 660 is one of only a few known polar ring galaxies, and its central disk consists of a super massive star cluster.