Wednesday, November 10, 2010

A Milky-Way Shaped Bubble Wand of Death*

The Milky Way: It's just a giant bubble wand, blowing colossal gamma-ray bubbles that extend tens of thousands of light-years from the center of our galaxy.

Scientists who have been examining images of the Milky Way taken by NASA's Fermi Gamma-Ray Space Telescope announced yesterday that they've discovered two high-energy balloon-like structures protruding from the top and the bottom of the Milky Way's core.

The radiation-emitting orbs extend a total of 50,000 light-years above and below the center of the galaxy. Traveling the length of just one of the spheres would be the equivalent of traveling to the Moon and back about 6.1 trillion times.

Astronomers at the Harvard-Smithsonian Center for Astrophysics in Massachusetts, where the bubbles were discovered, said they don't yet understand the nature of the spheres, nor how old they are or how they were created.

The astronomers processed data taken by the telescope to filter out a gamma-ray fog that permeates the Milky Way. The resulting image revealed the two orbs filled with significant amounts of high energy radiation. The orbs also appear to have edges, suggesting they were created by a single massive, rapid release of energy.

Perhaps they were formed by the black hole at the center of the galaxy. It may have spewed a particle jet over a period of a few tens of thousands of years as other black holes have been known to do. Or perhaps the bubbles are remnants of several million years of star formation, when huge, short-lived stars formed and then exploded releasing massive amounts of energy. Or maybe both. As with many new discoveries, for the scientists, there are more questions than answers.

If you look anywhere between the constellations Virgo and Grus in the night sky, then you're looking right at the giant bubbles. Too bad gamma-rays aren't a part of the visible spectrum. The orbs would have revealed themselves years ago. It just goes to show that there's still a lot we have to learn about our own galaxy.

If you're feeling really peckish, check out the full paper published today in The Astrophysical Journal. Fair warning: It's 46 pages long.

*There isn't any need to fear. The bubbles could be deemed deadly simply because they are made up of gamma-rays, a form of electromagnetic radiation harmful to humans. Luckily, Earth's atmosphere protects humans from space-bound gamma-ray invaders.

1 comment:

  1. this idea has been with us for far longer than we realize: