illustration, two distant galaxies formed about 2 billion years
after the big bang are caught in the afterglow of GRB090323, a
gamma-ray burst seen across the Universe. Shining through its
own host galaxy and another nearby galaxy, the alignment of
gamma-ray burst and galaxies was inferred from the afterglow
spectrum following the burst's initial detection by the Fermi
Gamma Ray Space Telescope in March of 2009. As seen by one of
the European Southern Observatory's very large telescope units,
the spectrum of the burst's fading afterglow also offered a
surprising result - the distant galaxies are richer in heavy
elements than the Sun, with the ever seen in the early Universe.
Heavy elements that enrich mature galaxies in the local Universe
were made in past generations So these young galaxies have
experienced a prodigious rate of star formation and chemical
evolution compared to our own Milky Way. In the illustration,
the light from the burst site at the left passes successively
through the galaxies to the rig