Electromagnetic radiation (light, radio waves, X-rays, and microwaves) contains a varying electric field. When we talk about Polarization of this field, we refer to its direction. A new satellite named the Gravity and Extreme Magnetism Small Explorer (GEMS),  will be the first to systematically measure the polarization of cosmic X-ray sources. It is a new astrophysics mission led by NASA's Goddard Space Flight Center in Greenbelt, Md.

A new study in Nature offers an explanation for the origin of dwarf spheroidal galaxies, one of the current puzzles in our understanding of galaxy formation.

Dwarf spheroidal galaxies are small and very faint, containing few stars relative to their total mass. They appear to be made mostly of dark matter - a mysterious substance detectable only by its gravitational influence, which outweighs normal matter by a factor of five to one in the universe as a whole.

Enjoy star gazing? Lucky enough to be in the northern hemisphere August 11th and 12th?
Citizen scientists working through an online project called Galaxy Zoo have discovered a group of rare galaxies called the "Green Peas" which could lend unique insights into how galaxies form stars in the early universe.

Galaxy Zoo users volunteer their spare time to help classify galaxies in an online image bank.  When they came across a number of objects that stuck out because of their small size and bright green color, they dubbed them the Green Peas. Employing the help of the volunteers to further analyze these strange new objects, the astronomers discovered that the Green Peas are small, compact galaxies forming stars at an incredibly high rate. 
A surprising impact on Jupiter is big news this past week.   The eyes of the entire space world have been riveted on the discovery of amateur astronomer Anthony Wesley of Canberra, Australia.   Now Hubble is in on the act and has provided the clearest picture yet.

You don't want carbon dioxide (CO2) build up in your space suit. Even those who argue to love huge CO2 emissions into our atmosphere should learn from the AP news: Two astronauts cut short their spacewalk and hurried back to the safety of the international space station (ISS) on Wednesday after a suit problem resulted in rising carbon dioxide levels for one of the men.

First, here is an image of a spacewalk. Two astronauts, Robert L. Curbeam (USA) and Christer Fuglesang (Sweden), work to attach a new truss segment to the ISS and begin to upgrade the power grid. This occurred on December 12, 2006.

Clusters, the largest structures in the Universe, are comprised of many galaxies, like the Milky Way. One mystery about clusters is why the gas in the centers of some are rapidly cooling and condensing but not forming into stars. Until recently, no model existed that successfully explained how this was possible.
To commemorate the 40th anniversary of Apollo 11's moonwalk, Google Earth now lets you explore the moon (as well as Mars).  Here is the annotated Sea of Tranquility:
Ice Volcano

Ice Volcano

Jul 22 2009 | 0 comment(s)

Check out this amazing picture of an ice volcano eruption on Saturn's moon Enceladus from the Cassini probe (description here).

Is Enceladus the "lost" planet from the Ice Pirates?  Did Cassini figure out the only route to approach it that would not get the probe lost in time?
Scientists in Hangzhou joined residents and tourists across China and India in observing the longest total solar eclipse in a century - and probably the most-viewed one ever.  The moon's shadow traced a path across the world's two most populous countries for five minutes and 36 seconds, a treat for scientists and spectators alike. 

"We saw it! The clouds kept getting thinner, and we even had a pretty good-sized hole in the clouds for the five minutes of totality," reported Expedition Leader Jay Pasachoff, Field Memorial Professor of Astronomy at Williams and chair of the International Astronomical Union's Working Group on Solar Eclipses, at an observatory near Hangzhou, China as part of the Williams College Eclipse Expedition.