Hubble views Smith Cloud traveling at 700000 miles per hour

The so-called Smith Cloud – measured at 11,000 light years long and 2,500 light years across – is expected to plough into the Milky Way in about 30 million years, igniting a spectacular burst of star formation, perhaps providing enough gas to make 2 million suns. However, the fiery gas, dubbed the Smith Cloud, is considered unique since its route is well-studied.

Astronomers have been watching the cloud since the 1960s and scientists estimate that it will finally crash into the galaxy in about 30 million years.

He said: ‘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 a lot of them, their origins remain a mystery.

“The cloud is an example of how the galaxy is changing with time”, said Andrew Fox of the Space Telescope Science Institute in Baltimore, Maryland, leader of the research team.

“It’s telling us that the Milky Way is a bubbling, very active place where gas can be thrown out of one part of the disk and then return back down into another”.

“The key moment was when we realized that the Smith Cloud has a chemical composition that matches the outer disk of the Milky Way, where the interstellar gas is less enriched in heavy elements than it is near the Sun”, Fox tells the Monitor.

How researchers used the Hubble Space Telescope to view three distant galaxies through the Smith Cloud, a technique that helped them determine the makeup of the cloud.

The astronomers found that the Smith Cloud is as rich in sulfur as the Milky Way’s outer disk, a region about 40,000 light-years from the galaxy’s center (about 15,000 light-years farther out than our sun and solar system). Astronomers trace the cloud’s origin to the disk of our Milky Way. If the cloud were viewable in visible light, it would be 30 times greater than the size of the full moon in the night sky.

The researchers looked specifically for absorption from the sulfur element, which is a good gauge of how many heavier elements reside in the cloud.

The discovery was made after astronomers managed to figure out the chemical composition of the Smith Cloud, a huge cloud of gas which is approaching the edges of the Milky Way at a speed of around 193 miles per second. The team then compared Hubble’s sulfur measurements to hydrogen measurements made by the GBT. Scientists were particularly interested in the composition of the giant gas cloud. One intriguing suggestion is that it’s a region of dark matter that collided with the Milky Way and somehow captured a clump of gas as it went. That, the researchers said, is a question that only additional research can answer. The new evidence, published this week in the journal Astrophysical Journal, suggests the cloud is in fact returning to its home – to the place where it was born.

The Hubble Space Telescope was used to analyze this phenomenon. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.