The Milky Way’s bulge is the ancient and crowded central hub of our Galaxy. It contains about one quarter of the total stellar mass of the Milky Way and has a very different stellar environment than our solar neighborhood. The stellar densities are on average over 10 times higher and include both very young but mostly very old stellar populations.
Increase Rate of Mass Extinctions of Life?
“We know from gravitational microlensing studies that Galactic bulge stars are roughly as likely to host planets as stars in the Solar neighborhood,” David Bennett, leader of the microlensing group at Goddard Space Flight Center, wrote in an email to The Daily Galaxy, “This is an observational result, not a conjecture. The higher density of stars in the Galactic bulge might increase the rate of mass extinctions of life compared to the Earth. However, the historical mass extinctions on Earth seem to have triggered faster rates of evolutionary development, and we aren’t sure if a higher rate of mass extinctions would help or hinder the development of advanced life.”
A new image of the violent center of our galaxy above was captured by the Murchison Widefield Array (MWA) radio telescope in the Western Australian outback in 20202 shows what our galaxy would look like if human eyes could see radio waves, with golden filaments indicating enormous magnetic fields, supernova remnants are visible as little spherical bubbles, and regions of massive star formation show up in blue. The supermassive black hole at the center of our galaxy is hidden in the bright white region in the center.
The mystery of the possibility of habitable planets residing at the galactic center will be probed by NASA’s Nancy Grace Roman Telescope, which will be launched in the mid-2020’s to explore uncharted regions of the galaxy for exoplanets, focusing on star-systems toward the crowded, chaotic Milky Way galaxy center.
Combining Roman’s findings with results from NASA’s Kepler and TESS missions will complete the first planet census that is sensitive to a wide range of planet masses and orbits, bringing us a step closer to discovering habitable Earth-like worlds beyond our own.
Research by astronomers at the Harvard-Smithsonian Center for Astrophysics shows that planets still can form in this cosmic maelstrom with the discovery in 2012 of a cloud of hydrogen and helium plunging toward the galactic center. They argue that this cloud represents the shredded remains of a planet-forming disk orbiting an unseen star.
“It’s fascinating to think about planets forming so close to a black hole,” said Harvard’s Avi Loeb. “If our civilization inhabited such a planet, we could have tested Einstein’s theory of gravity much better, and we could have harvested clean energy from throwing our waste into the black hole.”