The 2MASS Galaxy Sky

The 2MASS Galaxy Sky



Are the nearest galaxies distributed randomly?A plot of over one million of the brightest "extended sources" detected by the Two Micron All Sky Survey (2MASS) shows that they are not. The vast majority of these infrared extended sources are galaxies. Visible above is an incredible tapestry of structure that provides limits on how the universe formed and evolved. Many galaxies are gravitationally bound together to form clusters, which themselves are loosely bound into superclusters, which in turn are sometimes seen to align over even larger scale structures. In contrast, very bright stars inside our own Milky Way Galaxy cause the vertical blue sash.

Hurricane Isabel Approaches

Hurricane Isabel Approaches



Where will Hurricane Isabel go? One of the stronger storm systems of modern times appears headed for one the more populated seaboards on planet Earth -- the east coast of the USA. Hurricane Isabel, pictured yesteday as it passed east of the Bahamas, has flirted with category 5 status, the most powerful hurricane category.Hurricanes are huge swirling storms with cloudsystems typically larger than a state. Tropical cyclones, called hurricanes inEarth's Western Hemisphere and typhoons in the Eastern Hemisphere, get their immense energy from warm evaporated ocean water. As this water vapor cools andcondenses, it heats the air, lowers pressure and hence causes cooler air to comeswooshing in. Winds can reach over 250 kilometers per hour and become very dangerous. Much remains unknown abou cyclones, including how they are formed and the exact path they will take.

Globular Cluster M3

Globular Cluster M3



This huge ball of stars predates our Sun. Long before humankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy. Of the 200 or so globular clusters that survive today, M3 is one of the largest and brightest, easily visible in the Northern hemisphere with binoculars. M3 contains about half a million stars, most of which are old and red. Light takes about 100,000 years to reach us from M3, which spans about 150 light years. The above picture is a composite of blue and red images.

The Crab Nebula from VLT

The Crab Nebula from VLT



The Crab Nebula, filled with mysterious filaments, is the result of a star that was seen to explode in 1054 AD. This spectacular supernova explosion was recorded by Chinese and (quite probably) Anasazi Indian astronomers. The filaments are mysterious because they appearto have less mass than expelled in the original supernovaand higher speed than expected from a free explosion.In the above picture taken recently from Very Large Telescope, the color indicates what is happening to the electrons in differentparts of the Crab Nebula.Red indicates the electrons are recombining with protons to form neutral hydrogen,while blue indicates the electrons are whirling around the magnetic fieldof the inner nebula. In the nebula's very center lies a pulsar: a neutron star rotating, in this case, 30 times a second.