an astronomical version
of the search for the source
of the Nile,
astronomers now have strong evidence for the origin of the
This composite image shows the long ribbon of gas,
discovered at radio wavelengths in the 1970s,
in pinkish hues against an optical all-sky view across the plane
of our Milky Way galaxy.
Both Large and Small
Magellanic Clouds, dwarf satellite galaxies
of the the Milky Way, are seen near the head of the stream at the right.
Data from Hubble's Cosmic Origins Spectrograph
were used to
of elements along sitelines to quasars that
intersect the stream.
The results indicate that most of the stream's material comes from the
Small Magellanic Cloud.
The Magellanic Stream is likely the result of gravitational
between the two dwarf galaxies
some 2 billion years ago, the Small Magellanic Cloud
losing more material in the encounter because of its lower mass.
A. Fox, P. Richter et al.
D. Nidever et al.,