And you can just see the remarkable clarity and advances that are made by this wonderful telescope. For example that point object in the middle you couldn't find in the observatory previous work and the Chandra itself will do much, much more. And we have yet another one which has come back. Tell us about this. Well, this is a comparison of optical data shown on the right with the X-ray data on the left.
Optical light comes from stars.
And you can see the field is studded with stars. The Cas A remnant is in the plain of our Milky Way Galaxy. But the very hot gas that is in that volume of the remnant is emitting in the X-rays. That's what we see. And you can even tell from the optical data and especially in the near future from the X-ray data what that is made of.