Enormous ‘Swiss cheese’ bubble surrounding Earth mapped in incredible new images
An enormous,1,000-light-year-wide “superbubble” surrounds our planet. Now, astronomers have made the first ever 3D map of its magnetic field.
The gigantic structure, known as the “Local Bubble,” is a hollow blob of diffuse, hot plasma enclosed by a shell of cold gas and dust along whose surface stars form. It is just one of numerous hollows found in the Milky Way — making our galaxy resemble an enormous slice of Swiss cheese.
Superbubbles are shock waves from the death throes of multiple massive stars, which in their final acts explode in enormous supernovas that blast out the gas and dust needed to birth new stars. As time passes, other stars, such as our own, wander inside the cavities left behind by these explosions.
Related: Earth is at the center of a 1,000-light-year-wide ‘Swiss cheese’ bubble carved out by supernovas
Despite having some insight into superbubble formation, astronomers are still unsure how these giant bubbles evolve through interaction with our galaxy’s magnetic field, and how this impacts star and galaxy formation. To find out more, a team of astronomers, working at a summer research program at the Harvard-Smithsonian Center for Astrophysics, charted the Local Bubble’s magnetic field.
“Space is full of these superbubbles that trigger the formation of new stars and planets and influence the overall shapes of galaxies,” Theo O’Neill, who at the time was an undergraduate student in astronomy, physics and statistics from the University of Virginia, said in a statement. “By learning more about the exact mechanics that drive the Local Bubble, in which the Sun lives today, we can learn more about the evolution and dynamics of superbubbles in general.”
The Milky Way, like many other galaxies, is filled with a magnetic field that gently steers stars, dust and gas into mind-bending structures such as gigantic, bone-like filaments. Astronomers are unsure what gives rise to galactic magnetic fields. The Milky Way’s magnetic field, though…
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