A team of astronomers recently completed a long -term observation of a comet far from the sun. This analysis proves that there is a lot going on in the icy depths of the solar system.
The targeted comet is C/2014 UN271 Bernardinelli-Bernstein. The COMET UN271 is one of the largest Oort -Cloud comet that have ever been observed and measures 140 kilometers. It is currently at a distance of 16.5 astronomical units (Au) from the sun, which makes it difficult to observe with everyone except for the largest telescopes. Astronomers used the strong Atacama Large millimeter/submillimeter array (Alma) in Chile to observe and observe the comets how jets from carbon monoxide gas break out of its core. This is a surprising level of activity for a comet that is so far from the sun.
Alma telescopes on the Chajnantor plateau. Credit: Alma/NSF/ESO
The COMET UN271 was discovered in 2014 by the astronomers Gary Bernstein and Pedro Bernardinelli. They noticed the weak fuzzball in archive images from the Dark Energy Survey and slowly moved as a fuzzlalle as the Aper 22.
A far -reaching orbit
Almost immediately, astronomers knew that the Comet UN271 was something special because his slow motion clearly lay through the sky that it was far out in the solar system and was therefore quite large. After they had followed the comet a little, the astronomers found that at the time of discovery it was 29 Au from the sun – on the way to Pluto from the sun – and had a core of about 120 kilometers (75 miles). For the context, Halleys Comet has a core of only 15 kilometers. This shows the Comet UN271 in terms of size as the largest Oort -Cloud comet.
The discovery picture for Comet Un271 (commented). Credit: Noirlab.
We are lucky enough to see Comet UN271 after his Perihel approach. In January 2031, the comet 10.9 Au will pass from the sun before the Saturn's orbit. On a orbit of 2.8 million years, the comet will then get out of the solar system with an orbit of 4.6 million years from the solar system in order to obtain a distant aphel 55,000 AU from the sun. That is 87% of a light year, about a fifth of the way to Proxima Centauri, the next star.
The Comet's orbit UN271 via the solar system. Credit: NASA/JPL HORIZONTE.
The difference in orbit compared to outbound for the comet is due to its interaction with solar system planets near the sun. Every new comet that enters the inner solar system has about 40% chance that the orbit will change. The COMET UN271 was probably chopped off from its Oort cloud bar by an outstanding pass near the solar system, which Sunward sent Sunward a long time ago.
Looking at a cold removed object like Comet Un271 has really brought Alma's sensitivity and dissolution to its limits. The thermal signal received by Alma not only helps to refine the size of the comet, but also to contribute to recording the observed dust production rate.
“The study gives us a look at the type of outgassing activity in this distant active comet,” said Nathan Roth (NASA/GSFC) today. “It indicates that carbon monoxide was underpinned directly from the Nucleus surface by ice in gas in gas instead of being produced in a coma instead of chemistry.”
Wrong color images from Comet Un271, which show activity. Credit: Alma/NSF/ESO.
This was not only a recording detection in relation to the distance, but also shows that comets can still have activities, far away from the sun.
“The comet was far from the sun during our observations (about half of Neptune), and since it is so cold in these distances, very few other molecules should be available as gases in a coma,” says Roth. “Our results mean that carbon monoxide is an essential part of the engine that promotes the activity in this comet. Insight into what comets tick from the sun in such great distances was a main goal of our study.”
Alma's observations can even characterize the activity in the comet, even at enormous distances. “Despite the size of the core of the comet, carbon monoxide from discrete jet on the core surface in areas with high lighting was released from the sun instead of uniformly from the entire core,” says Roth. “In addition, we observed the comets of two data about a week away from each other, and we found that the alignment of these jets has changed from one observation to the next. This can correspond to the history of the comet that measured repeated outbursts with optical wavelengths, but we need further observations to draw fixed conclusions.”
No missions are planned to give us a look at the COMET UN271 up close. The European Space Agency has a mission called Comet Interceptor in the works that runs on foot in the inner solar system and is ready to follow the next big comet. Comet Interceptor is planned for the start in 2029.
The Hubble world space telescope in January 2022 in January 2022. The Vera Rubin Observatory, which will also show its first pictures in the next week in the coming years, could also offer an amazing view of the comets.
“We look forward to learning more about the comet as he continues to approach the sun and warms up,” says Roth. If the sun continues to heat it, we may see that new molecules begin to be sublime from the core, which helps us to measure its chemical composition in more detail and give us indications of how it has formed. ”
Hubble's view of Comet UN271 in 2022. Credit: NASA/HST/STSCI
And yes, a comet of the size of UN271 would spell a bad day for the earth, although in this case it does not come near the inner solar system. UN271 is 12 times the size of the chicxulub impactor (which was only about 10 kilometers), which hit earth 66 million years ago. So it would definitely be an event on extinction if something of the size of UN271 ever came up with us.
A size comparison for other known comets compared to UN271. Credit: NASA/ESA/ZENA LEVY/STSCI
It's a shame that the Komet Un271 does not visit the inner solar system … (just not too close!) It is larger than Hale-Bopp and would offer an amazing show. At the moment we have to wait until the next Oort -Cloud interloper appears. Nevertheless, the appearance of Comet UN271 shows us exactly what lurks out there in the remote areas of the outer solar system.
