When you look up at the night sky, you see a lot of things glowing like stars, planets, and galaxies. So it might sound strange to hear that most of the Universe is actually dark. The truth is the protons, neutrons and electrons that make up everything we can see - and that means with every telescopes we've got -- accounts for only about 4% of the mass and energy of the Universe. The rest is dark and mysterious. More specifically, about 70% of the Universe is what is known as dark energy; about 26% is so-called dark matter.

Hello! Hopefully by now you'll have read a little about 3C 321, aka the "Death Star Galaxy" from last week's blog entry, which was a transcribed from a presentation I gave a few months ago. I wanted to take this opportunity to give you the insider's view on how we came to discover this amazing system, the point when we knew we had a pretty major result on our hands, and the media frenzy that ensued.

Dr. Dan Evans from the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA, shares some information on 3c321, as of December 2007 now known as the Death Star Galaxy. Dan Evans has never seen Star Wars, so who came up with the nickname? Read on.

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NASA's Chandra X-ray Observatory has opened up a new era of performing x-ray astronomy and x-ray astrophysics.

The press and image releases from the Chandra X-ray Center cover only a small fraction of the science results produced by Chandra each year. Some results are clearly not good candidates for publicity because they're obviously incremental - I've written papers like that myself. Or they can be highly esoteric, addressing questions that only the authors knew enough about the subject to ask! It also doesn't help if the results are completely unsurprising or if there isn't a decent image.

The detectors we use on Chandra are different from detectors on optical telescopes. Most of the Chandra images are taken with what's known as a Charged Coupled Device (CCD). The CCD is the type of detector that's in the camera in your cell phone, or in your digital camera.

Shown from left:  Chandra X-ray image of supernova remnant G292.0+1.8, Chandra X-ray image of young star cluster Westerlund 2, and a multiwavelength view of galaxy M82 (Chandra X-ray, Spitzer Infrared, Hubble Optical).
 

Last week, the American Astronomical Society held its bi-annual meeting in Austin, TX.  (The AAS, as it's known, always has a winter meeting in early January and then a spring meeting around Memorial Day.)  The AAS meetings are important because the AAS is the largest professional group of astronomers in the US and so they often bring some of their most exciting results to share.

Explore the Universe from your computer using Sky in Google Earth. The latest version of Sky in Google Earth, released on January 9, 2008, now contains X-ray images from NASA's Chandra X-ray Observatory.  Pictured:  Cas A and M82.  Learn more about Sky in Google Earth.

The latest version of Sky in Google Earth, released on January 09, 2008 at the American Astronomical Society meeting in Austin, Texas, now contains X-ray images from NASA's Chandra X-ray Observatory. Along with images from other NASA satellites, the addition of Chandra into Sky in Google Earth provides scientists, students, and amateur stargazers new opportunities to explore the Universe across the electromagnetic spectrum.  Eli Bressert, Image Processor at the Chandra X-ray Center, discusses the Sky in Google Earth update.

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Like the jelly beans in this jar, the Universe is mostly dark: 96 percent consists of dark energy (about 70%) and dark matter (about 26%). Only about four percent (the same proportion as the lightly colored jelly beans) of the Universe - including the stars, planets and us -is made of familiar atomic matter.  Read about the make up of the Universe