This Strange Jupiter-Like Planet Is Unlike Any Scientists Have Seen Before
NASA is constantly finding new planets all over the universe. Its latest discovery of a Jupiter-like planet with an unusual formation has become one of the year's most fascinating. The constant variety and strangeness of outer space is often difficult to comprehend. Just our own Solar System is fascinating enough on its own. Mars is a rocky world with an Earth-like past, Jupiter is a massive gas giant, and Saturn has a beautiful ring system. Those planets alone are enough to keep scientists busy for years.
But planets in the Solar System barely scratch the tip of the iceberg. Astronomers estimate that at least 100 billion planets are in the Milky Way — and even more in other galaxies across the universe. While humans may never locate all of those planets, astronomers and scientists are doing their best to find as many as possible. A strange 'potato planet' was discovered earlier this year, as was an alien planet with iron clouds and raining gemstones. As of March 2022, NASA's confirmed the discovery of 5000 exoplanets outside our Solar System. And as impressive as that is, NASA's not stopping its planet-hunting any time soon.
On April 4, NASA announced the discovery of the latest exoplanet — now known as AB Aurigae b. AB Aurigae b is a gas giant not unlike Jupiter. However, while the gaseous composition is similar, everything else about the planet is quite strange. For one thing, AB Aurigae b is believed to be nine times more massive than Jupiter. Considering Jupiter's mass is already over two and a half times greater than all other planets in the Solar System combined, the mass of AB Aurigae b is no joke. Making its huge size all the more perplexing is how the planet's forming. AB Aurigae b orbits its host star from 8.6 billion miles away. That's more than twice as far as Pluto is from the Sun — and it creates an exciting theory around AB Aurigae b's odd formation.
Like Jupiter, Saturn, and Neptune, gas giants often form through 'core accretion.' Planets that form like this originate within a circumstellar disk. Small objects orbiting the host start hit and stick to the disk, the planet's core gradually accumulates gas, and a gas giant is eventually formed. It's a theory that makes sense for most gas giants, but applying it to AB Aurigae b is where things get tricky. According to NASA, the massive distance between AB Aurigae b and its star means it would take "a very long time, if ever, for a Jupiter-sized planet to form by core accretion." Let alone a planet that's nine times more massive than Jupiter.
Instead of the widely-accepted core accretion theory, scientists believe AB Aurigae b formed through another process called 'disk instability.' Under this thinking, a large disk cools as it moves around its host star. As gravity breaks up the disk, "one or more planet-mass fragments" shoot off and create a planet like AB Aurigae b. NASA confirmed AB Aurigae b's bizarre qualities using photographs from Hubble (seen above). Commenting on the discovery, researcher Thayne Currie said, "Interpreting this system is extremely challenging. This is one of the reasons why we needed Hubble for this project – a clean image to better separate the light from the disk and any planet."
Like any discovery of this magnitude, it has great implications beyond AB Aurigae b. Finding the planet and understanding its unusual formation opens the door for other discoveries down the road. As explained by Alan Boss from the Carnegie Institution of Science, "This new discovery is strong evidence that some gas giant planets can form by the disk instability mechanism. In the end, gravity is all that counts, as the leftovers of the star-formation process will end up being pulled together by gravity to form planets, one way or the other." Whether it be future explorations with Hubble or the James Webb Space Telescope, AB Aurigae b just opened an exciting door for NASA.
Source: NASA