We live next to the largest gas cloud in the Milky Way — and it's giving birth to new stars

• The largest gas cloud in the Milky Way is our immediate neighbour according to a new 3D map of the galaxy by astronomers at Harvard University.
• The ‘Radcliff wave’ is over 9000 lightyears long and 400 lightyears wide.
• Originally hypothesized to be a ring, the massive wave is a mere 500 lightyears away from the Sun.

A new 3D map of the Milky Way reveals that we live next to the largest gas cloud in the galaxy.

In fact, it’s our immediate neighbour.

According to astronomers at Harvard University, the 9000 lightyears-long wave of gas is surprisingly close to our Sun. Within its cacoons, new stars are being born.


"What we’ve observed is the largest coherent gas structure we know of in the galaxy, organized not in a ring but in a massive, undulating filament. The sun lies only 500 lightyears from the wave at its closest point. It’s been right in front of our eyes all the time, but we couldn’t see it until now," said Joao Alves, lead author of the study published in Nature.

It’s not even a local cloud of dust. Scientists have been able to determine that the high-velocity cloud is an interstellar visitor originally in another galaxy.


Re-thinking how the Milky Way galaxy formed
The Gould Belt Survey has been observing the star-forming region using data from the Spitzer Space Telescope and the Herschel Space Observatory in hopes of finding a 3D ring of stellar nurseries.

"Gould and Herschel both observed bright stars forming in an arc projected on the sky, so for a long time, people have been trying to figure out if these molecular clouds actually form a ring in 3D," explained Alves.

Instead, a giant wave of gas extending over 400 lightyears wide arching (CK THIS) over the Solar System was found using the European Space Agency’s (ESA) Gaia spacecraft. The phenomenon has been dubbed the ‘Radcliffe Wave’ overturning initial theories of a ring.


"No astronomer expected that we live next to a giant, wave-like collection of gas -- or that it forms the Local Arm of the Milky Way," said Alyssa Goodman, co-author of the study.

It talks to the Sun
The scientists are yet to determine what gives the Radcliffe Wave its shape, but they believe it has major repercussions for our Solar System.

"What we do know is that our sun interacts with this structure. It passed by a festival of supernovae as it crossed Orion 13 million years ago, and in another 13 million years it will cross the structure again, sort of like we are surfing the wave," explained Alves.


See also:
Supermassive black hole bigger than 7 billion Suns is spinning so fast that it's close to breaking the laws of physics

NASA's planet-hunter uncovers its first world with two stars 1,300 light-years away

A star that's slowly been getting brighter over the past decades will explode in 2083