Earth Is Surrounded by a 1000 Light Year Wide Bubble Carved Out by Supernovas

The cosmic void is surrounded by multiple star-forming regions created by the explosions. Earth is slap bang in the middle of a 1,000 light-year-wide bubble with a dense surface birthing thousands of baby stars. 

Researchers have long wondered what created this "superbubble." Now, a new study suggests that at least 15 powerful star explosions inflated this cosmic bubble. 

Astronomers in the 1970s first discovered the gigantic void, known as the Local Bubble, after realizing that no stars had formed inside the blob for around 14 million years. The only stars inside the bubble either existed before the bubble emerged or formed outside the void and are now passing through; the sun is one such trespasser. 

This setup had suggested that several supernovas were responsible for this void. Those stellar explosions, the researchers said, would have blasted the materials needed to make new stars, such as hydrogen gas, to the edge of a huge area in space, leaving behind the Local Bubble that's surrounded by a frenzy of star births. 

In a new study, published online Jan. 12 in the journal Nature, researchers accurately mapped the star-forming regions surrounding the Local Bubble and, in doing so, calculated how fast the superbubble is expanding. 

This allowed the team to work out exactly how many supernovas were needed to carve out the gigantic cosmic void and better understand how star-forming regions are created across the Milky Way.