... Tonight's Sky . ... Sky this Month . ... Astronomy for Kids . ... Distant supernovae trace early universe's deceleration . The most distant supernovae ever seen confirm that the universe's expansion first slowed down before it started speeding up. ... Studies of distant supernovae suggest the expansion of the universe was slowing down after the Big Bang, but today, the universe's expansion rate is accelerating. ... Only registered members of Astronomy.com are allowed to comment on this article. ...