smith-cloud
This composite image shows the size and location of the Smith Cloud on the sky. Z. Levay—NASA/ESA

A Giant Hydrogen Cloud Is Heading Toward the Milky Way

Jan 29, 2016

A vast formation of hydrogen gas is heading toward the Milky Way galaxy, astronomers from the Hubble Space Telescope say, but it won't reach our galaxy for about 30 million years.

The huge haze, known as the Smith Cloud, is barreling toward the galaxy at a speed of over 702,1oo mph. When the cloud, which astronomers say is 11,000 light years long and 2,500 light years across, reaches the galaxy it is has enough gas to create a burst of 2 million suns.

The Smith Cloud is a well-known formation, discovered by doctoral student Gail Smith in the 1960s. It is unique because scientists have the ability to map its trajectory.

The cloud can't be seen in visible light, but if it could scientists say it would appear to be 30 times the size of the full moon.

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