Friday, October 27, 2006

APOD #2 on Antennae Galaxies


In the constellation Corvus, latin for Crow (it was associated with Apollo), two galaxies are fighting it out. The crow was not originally named because it looked like a crow, but rather because it reminded viewers of the sky of the fable about Apollo, which involved a crow, watersnake, and a cup.

The two galaxies are colliding, but there is no actual collision between stars. This is because galaxies are mostly empty space, with the chances of two stars colliding being very slim. The dust of the galaxies does, however, collide. The collision of dust creates massive molecular clouds which cause the rapid birth of millions of stars. Galaxy collisions usually takes hundreds of millions of years to fully merge with one another.

Friday, October 06, 2006

APOD #8 on SWAN Comet



Comet SWAN, discovered in June, 2006, brightened enough to be visible via binoculars. It was discovered in public pictures from the Solar Wind Anisotropies (SWAN) instrument that the SOHO (Solar and Heliospheric Observatory), which orbits the Sun, satellite has onboard. The comet is near magnitude 6, and is visible before dawn. It will reach its peak brightness within the week (starting Oct. 4, 2006). It passed the closet to our Sun on Oct. 2, 2006, and will be the closest to Earth near the end of the month. Its orbit is thought to be hyperbolic, so it will never return to our Solar System.