Credit: Swift; NASA; A. Cucchiara et al. Now Who's Farthest?
Astronomers like to push limits, and almost nothing excites
astronomical competition like finding the most distant known
object. This competition is not merely for bragging rights in
the astronomical community; looking back at objects at great
distances provides a probe of the Universe in its infancy, and
helps us understand how we got from that exotic state to the
more mundane environs in which we currently find ourselves.
Bright objects like galaxies and quasars can be seen out to the
edge of the Universe. So too can gigantic explosions called
Gamma-ray bursts. Gamma-ray bursts are produced by the
conversion of a supermassive star at its death into a massive
black hole. The simple image above shows one such explosion,
called GRB 090429b, detected by the Swift Gamma-ray burst
observatory at earth on April 29, 2009 (as its name implies).
Some astronomers believe that light from this burst has been
traveling more than 13 billion years through dark sp