Sunday, August 29, 2004

Seeing the invisible

Jason draws our attention to the Chandra X-Ray Observatory's new image of the Cassiopeia A supernova remnant.

This lovely celestial blossom is a false-color image of a star that blew up about 300 years ago, Earth time. The progenitor star was about 10,000 light-years from Earth, a goodly way across the Milky Way Galaxy.

Cassiopeia A was first revealed with a radio telescope in 1944. Delicate wisps of matter were then photographed in visible light.

But much of the energy of the expanding shell of gas is in the X-ray spectrum, invisible to the eye -- but not to Chandra, which has orbited the Earth since 1999.

If you want an edge-of-your-seat space science adventure, read how Chandra got built and deployed in the terrific book by Wallace Tucker and Karen Tucker.