Image of the Day: Laser Strikes at Supermassive Black Hole at Core of the Milky Way Galaxy

It’s not the sequel to War of the Worlds! Astronomers at the Very Large Telescope (VLT) site in Chile are trying to measure the distortions of Earth’s ever changing atmosphere. Constant imaging of high-altitude atoms excited by the laser — which appear like an artificial star — allow astronomers to instantly measure atmospheric blurring.  In this case, the VLT was observing our Galaxy’s center, and so Earth’s atmospheric blurring in that direction was needed.

At the center of the Milky Way is Sagittarius A -believed to be a supermassive black hole, which lurk at the center of all spiral galaxies. If we can observe Sagittarius A*’s surroundings we can
confirm once and for all whether it’s a black hole - and prove Einstein
right (or wrong!) . Relativity theory predicts the existence of black holes. If relativity breaks down, we might not see a black hole at all, but something totally weird.

Relativity describes how large masses can bend
space, and a black hole is where the mass is so large that space gives
up altogether and becomes a singularity.  Black holes are already well
understood, we think, but we’ve only ever observed them at second hand
- the behavior of orbiting objects or bent light rays.  To actually
view the shadow of a black hole, the cut-off point where light is
swallowed and cannot escape, would be a massive advance - and only the
beginning.

Detailed observation of the area around the Sag A*
border would be a goldmine of information. The spin and rate of matter
inflow into the central black hole will tell us about the Milky Way’s
creation, as well as providing further extreme tests of general
relativity.  We could even see frame dragging, which sounds like a
video game hardware issue but is actually something that could happen
to reality - where a spinning black hole grabs hold of space and
literally pulls reality around after it.

The rock star at center of Earth’s microwave eye will be in the high deserts of
Chile, where the Atacama 66-dish Large Millimeter/Submillimeter Array (ALMA) is
being built, which should be up and running
by 2012. In concert with other scopes across the planet. ALMA will should
provide a much clearer picture of Sag A*

ALMA is a giant, international observatory
composed initially of 66 high-precision telescopes, operating at
wavelengths of 0.3 to 9.6 mm. The ALMA antennas will be electronically combined and provide
astronomical observations which are equivalent to a single large
telescope of tremendous size and resolution, able to probe the Universe
at millimeter and sub-millimeter wavelengths with unprecedented
sensitivity and resolution, with an accuracy up to ten times better
than the Hubble Space Telescope.

Casey Kazan with Luke McKinney

Image Credit: Yuri Beletsky (ESO)
Source: APOD