NASA’s Hubble Space Telescope recently captured an image of 3 galaxies colliding and merging , forming new stars, causing black holes to merge and warping space-time.
For now, astronomers can watch merging galaxies from afar using space telescopes. Hubble, which was launched into Earth orbit in 1990, is the most powerful telescope to ever operate in space . It has photographed the births and deaths of stars , detected new moons orbiting Pluto, and tracked 2 interstellar objects passing through our Solar System. His observations have allowed astronomers to calculate the age and expansion of the universe and to observe the galaxies formed shortly after the Big Bang.
This cosmic crash is known as a triple galaxy merger, when three galaxies slowly approach and move away from each other with their gravitational forces competing. Mergers like these are common throughout the universe, and all large galaxies, including our own Milky Way, owe their size to violent mergers like this.
As chaotic as they may seem , mergers like these are more about creation than destruction . As gas from the three neighboring galaxies collides and condenses, a vast sea of material from which new stars will emerge is assembled at the center of the newly unified galaxy.
Meanwhile, existing stars will survive the crash mostly unscathed. While the gravitational wobble between the three galaxies will warp the orbital paths of many existing stars, there is so much space between those stars that relatively few of them are likely to collide.
The observed galaxy cluster is called IC 2431 and is located about 681 million light-years from Earth in the constellation of Cancer , according to NASA. Astronomers detected the merger thanks to a citizen science project called Galaxy Zoo , which invited more than 100,000 volunteers to classify Hubble images of 900,000 galaxies that were never fully examined.
The collaborative project accomplished in 175 days what it would have taken astronomers years to accomplish, according to NASA, and the initiative has already resulted in a number of strange and exciting discoveries, like this one.
In December, NASA launched a new deep space observatory, the James Webb Space Telescope, which is set to return a view of the universe 100 times more powerful than Hubble’s.
Because it uses infrared light , Webb will be able to see beyond dust clouds that can obscure galactic centers and star-forming regions from Hubble’s view. That will allow astronomers to track the speeding up and slowing down of starbursts in different galaxies.
Webb’s powerful gaze will also allow astronomers to study black holes that have the mass of millions, perhaps billions, of suns. If successful, Webb will look so far into the universe that he will see the first galaxies ever formed, as well as some of the first black holes.
When supermassive black holes collide , they produce ripples in space-time called gravitational waves. Researchers have detected such waves from some black hole collisions, but not from black holes at the center of galaxy mergers.
Scientists have theorized that a constant hum of low-level gravitational waves pervades the universe, with all the galaxies merging at any given time. Researchers are still working to build gravitational-wave detectors sensitive enough to detect this background noise .
That will help scientists figure out how supermassive black holes got so massive. The new observatory will even cast its infrared gaze on the supermassive black hole at the center of our own galaxy, to help scientists understand why it goes through cycles of burst and lull.
Webb completed the risky tasks of traveling to its orbit nearly a million miles away and deploying into space. Now he’s cooling down and calibrating his instruments. The new telescope is ready to begin observations this summer.
The study of galactic mergers can help astronomers better understand the past and future of the Milky Way. The Milky Way is believed to have engulfed more than a dozen galaxies in the last 12 billion years.
Meanwhile, our galaxy appears to be on track to merge with the nearby Andromeda galaxy in about 4.5 billion years. The merger totally alters the night sky over Earth, but will likely leave the solar system unscathed, according to NASA.
Reference:
NASA 2022. Three galaxies are tearing each other apart in a stunning new Hubble telescope image. (Press Release).
