NASA Astronomy Picture of the Day Collection

The Local Bubble and the Galactic Neighborhood

What surrounds the Sun in this neck of the Milky Way Galaxy [ http://www.seds.org…]? Our current best guess is depicted in the above map [ http://www.sigmaxi.…] of the surrounding 1500 light year [ http://chandra.harv…]s constructed from various observations and deductions [ http://www.sigmaxi.…]. Currently, the Sun is passing through a Local Interstellar Cloud [ http://antwrp.gsfc.…] (LIC), shown in violet, which is flowing away from the Scorpius-Centaurus Association [ http://www.mpifr-bo…] of young stars. The LIC resides in a low-density hole in the interstellar medium [ http://spacsun.rice…] (ISM) called the Local Bubble [ http://spacsun.rice…], shown in black. Nearby, high-density molecular clouds [ http://antwrp.gsfc.…] including the Aquila Rift [ http://www.a.phys.n…] surround star forming regions, each shown in orange. The Gum Nebula [ http://antwrp.gsfc.…], shown in green, is a region of hot ionized [ http://csep10.phys.…] hydrogen [ http://pearl1.lanl.…] gas. Inside the Gum Nebula [ http://www.edpscien…] is the Vela Supernova Remnant [ http://antwrp.gsfc.…], shown in pink, which is expanding to create fragmented shells of material like the LIC [ http://antwrp.gsfc.…http://www-ssg.sr.u…]. Future observations should help astronomers discern more about the local Galactic Neighborhood [ http://www.sigmaxi.…] and how it might have affected Earth's past climate [ http://whyfiles.new…].

Linda Huff (American Scientist [ http://www.sigmaxi.…]), Priscilla Frisch [ http://astro.uchica…] (U. Chicago [ http://astro.uchica…])

sun

interstellar medium

Local Bubble

Milky Way Galaxy

Chicago

Goddard Space Flight Center (GSFC)

Earth

Sun

Centaurus

Aquila

Scorpius

Vela

http://antwrp.gsfc.…

SPD-APOD-ap020217