A huge gas cloud known as the Smith Cloud is on collision course with the Milky Way. The cloud, which is approaching at a speed of 700,000 miles per hour, is expected to hit the Milky Way at an angle of around 45 degrees, in 30 million years. As per the news release, the Smith Cloud if visible, would have an apparent size of about 30 times the diameter of the moon from tip to tail.

Discovered in the year 1963, the Smith Cloud measures 11,000 light-years long and 2500 light-years wide. Astronomers believe that when the cloud collides with our galaxy, it could produce a massive burst of huge new stars.

For years, astronomers have not been able to determine the composition of this giant gas cloud, which would hold clues for its origin. But now it has been confirmed that the cloud contains elements similar to our sun, which means the cloud came from the Milky Way’s outer edges and not from intergalactic space.

Scientists expect if the Smith Cloud were visible in the sky, it would be 30 times larger than the Moon. This graphic shows the location of the cloud as seen from Earth. [NASA]
Trajectory of the Smith Cloud falling into the Milky Way galaxy. [NASA, ESA and A. Feild]

“We have found several massive gas clouds in the Milky Way halo that may serve as future fuel for star formation in its disk, but, for most of them, their origins remain a mystery,” said Nicolas Lehner, who is an astrophysicist at University of Notre Dame. “The Smith Cloud is certainly one of the best examples that shows that recycled gas is an important mechanism in the evolution of galaxies.”

Similar to our Milky Way’s outer disk, the Smith Cloud is rich in sulfur. Astronomers believe the Smith Cloud, has enough gas to generate two million suns when it strikes the Milky Way disk.

The findings were published in the Astrophysical Journal Letters.

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