Are you fascinated by the mysteries of space? Well, who isn’t? And with new discoveries every few days, the interest just keeps building, feeding the brain’s curiosity. Yesterday, on August 23, NASA (National Aeronautics and Space Administration), which is one of the most popular space agencies in the world, has come up with a new discovery.
If you are not a fan of horror movies, this might unnerve you, for NASA has now managed to hear space sounds. And the noises verge on echoes of ghostly moaning and wailing! A clip of eerie noises coming from a black hole was shared yesterday by NASA on its official pages. And no, it is not aliens. Let us understand what this phenomenon means.
Where was the sound detected recently? And when was the first space sound detected?
The spooky sounds were detected as emerging from a black hole at the centre of the Perseus galaxy cluster, which is roughly 5.86x1016 km away from our galaxy, the Milky Way. Though this is the first time that such sounds were heard by humans, sound data from space was actually captured for the first time in 2003 from this very black hole. Acoustic waves, too low in frequency for the human year to hear, were detected by astonished astronomers.
How can the sounds be heard now?
Simply put, now NASA has managed to amplify the sound to the range to which the human ear can detect.
But if you are a science buff, here’s the explanation for you: In 2003, the lowest note detected was a B-flat, just over 57 octaves below middle C. This means that the frequency of the sound wave was 10 million years (roughly falling between the ranges of 3.17-15 Hertz). The human ear can detect sounds within the range of 20Hz (one-twentieth of a second) to 20KHz. So, this time, NASA extracted the sound radially or outwards from the centre of the black hole and played them in an anti-clockwise direction, so that they could be heard from all directions, with their pitches 144 quadrillion and 288 quadrillion times higher than their original frequency.
How has NASA explained this?
“The misconception that there is no sound in space originates because most space is a ~vacuum, providing no way for sound waves to travel. A galaxy cluster has so much gas that we've picked up actual sound. Here it's amplified, and mixed with other data, to hear a black hole!” reads NASA’s official Twitter page on such findings, NASA Exoplanets (@NASAExoplanets).
Here’s what this means: Parts of space are full of gases, especially places like galaxy clusters and black holes, which have tenuous gas and plasma drifting between the galaxies in galaxy clusters. This is known as the intracluster medium. It is denser and very hot. The heat helps to detect the sound.
Okay, but what are black holes and galaxy clusters?
A black hole is a dead star. After a star, which is formed of gases, eventually collapses due to gravity, it results in a supernova explosion. This creates a spacetime called a black hole, which is a single point in space with so much gravitational pull that it absorbs everything, even light.
And galaxy clusters are formed when hundreds to thousands of galaxies are bound by gravity.
What other great discoveries have been made this week?
1) Picture of Jupiter – NASA’s James Webb telescope came up with stunning pictures of Jupiter taken in infrared light. These pictures reveal more about our Solar System’s largest planet.
2) Stability of black holes – It was proved that rotating black holes are stable, and conform to Einstein’s Theory of Relativity.
3) Observation of supermassive black holes – This was done by a group of scientists nicknamed “Nickhull” using the Hubble Space Telescope and the Chandra X-ray Observatory. Their observation has shown that black holes have a role to play in galactic evolution.
