Today's moment of awe

[deborahjross]

This beautiful spiral galaxy, which goes by the utterly inadequate name of NGC 3370, may be what our own Milky Way Galaxy looks like from the outside. It's about 100 million light-years away, in the direction of constellation Leo. This image is from the Hubble Space Telescope's Advanced Camera for Surveys, and is good enough so we can study individual stars. It contains a well-studied supernova as well as Cepheids, pulsating stars, that help us to measure the distance to NGC 3370. Combining this distance with observations of supernovas at even greater distances gives us information about the size and expansion rate of the universe.