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Scientists are discovering new objects in the solar system all the time. Most of these are small asteroids or icy bodies, but researchers recently spotted something unexpectedly huge heading our way.

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We might think we know our own  cosmic neighborhood pretty well, but scientists are discovering new  objects in the solar system all the time. Most of these are small asteroids or icy bodies, but researchers recently spotted something  unexpectedly huge heading our way. It’s called Comet Bernardinelli-Bernstein.

And it might just be the  biggest comet ever detected. As it gets closer to earth, not only will  we be able to get a good view of this giant, but scientists will also get  a chance to discover more about the far reaches of our solar system. The discovery came in June 2021 when researchers analyzed data from the Dark Energy Survey.

This was an international collaborative  project that ran from 2013 to 2019, with the aim of discovering  the nature of dark energy, which seems to be causing the  universe to accelerate its expansion. To do this, astronomers built an  extremely sensitive, 570 megapixel camera, and installed it on a 4-meter telescope in Chile. Over six years, this Dark Energy  Camera, or DECam, imaged a huge portion of the southern sky, taking pictures  of up to 300 million distant galaxies, supernovas, and cosmic structures.

And the camera’s incredible resolution  also allowed it to detect objects closer at hand, like comets  and trans-Neptunian objects, which have an average orbital  distance farther than Neptune. So two researchers from the  University of Pennsylvania,. Pedro Bernardinelli and Gary  Bernstein, fed the images from DECam into a suite of  supercomputers for analysis.

The supercomputers compared  images taken at different times to identify points of light that  appeared to be moving across the sky. It sounds simple enough, but with 16  billion different sources to compare across more than 80,000 images, it’s  no surprise that the supercomputers racked up more than 15 million CPU hours. If they’d tried this on a normal  PC, it would have taken 1700 years!

But the analysis successfully identified  more than 800 trans-Neptunian objects, including one, named 2014 UN271, that  snagged the scientists’ attention. The first images to capture it  were taken by DECam in 2014, when it was about 29 astronomical units away, or 29 times the distance  from the earth to the Sun. It was just a speck of light, but its  brightness suggested it was really big.

At somewhere between 100  and 200 kilometers across,. UN271 was originally designated a minor planet. But as soon as its detection was announced, amateur astronomers around the world  turned their telescopes to the skies in search of this new, intriguing object.

Originally, its surface had  seemed to be chemically inactive. By this time, though, it was closer,  just 20 astronomical units away, and the new observations  revealed something surprising:. UN271’s surface didn’t appear  to be so inert after all.

It seemed to be surrounded with  a faint haze of vapor and dust. Such hazes are typically known as  comas, and they’re a sign of comets. They form when comets travel toward the  sun in their orbit and start to heat up, causing some of their ice  to start turning into vapor.

So UN271 isn’t a minor  planet, but a gigantic comet. In fact, it’s likely the biggest ever  detected, at more than ten times the diameter and 1000 times the mass of  your typical icy traveler. The new designation also earned it a new name:.

Comet Bernardinelli-Bernstein, after  the scientists who discovered it. Tracing its trajectory over the  years, we now have a pretty good idea of where this monster comet  came from and where it's going. Bernardinelli-Bernstein is what’s  known as a long-period comet, taking about five and a half million years  to take a complete trip around the sun.   It likely started its inward journey from  about a light year away, in the Oort Cloud.

This shell of icy debris is left over  from the early years of the solar system, and was ejected by the migration of giant planets a few million years after their formation. Scientists think that this may be  Comet Bernardinelli-Bernstein’s first trip into the solar system  since its initial expulsion. So they’ll be watching it  closely as it comes nearer, hoping to study a relatively unaltered  Oort cloud object for the first time.

And this could help scientists learn more about what the solar system was like  back when the comet was formed. Right now, the comet is approaching from  above the solar system’s orbital plane, and it’ll pass closest to the sun about  ten years from now, on January 23rd, 2031. Even then, it’ll still be pretty dim and distant, so you’ll need a telescope  handy to be able to see it.

It’ll be passing by at  about 11 astronomical units, which is equivalent to the orbit of Saturn. As it warms, its coma will grow,  and it will possibly gain a tail. And researchers hope that  sensitive instruments will soon be able to probe the haze to  reveal its chemical composition.

Doing so will help to answer  questions about the nature of objects in the Oort cloud, which before  now has been largely out of reach. Until then though, be sure to mark  January 23rd on your 2031 calendar as a time to find a telescope and catch a glimpse of the biggest comet scientists have ever seen! And while you’re waiting for  the comet to swing by in 2031, why not learn a new language?

Thanks to Babbel for sponsoring  this episode of SciShow Space. Babbel is a language-learning app that  helps you not just learn a new language, but use it in real-life situations  after only five hours of practice. It’s the #1 language-learning app in  the world, and they offer 14 languages.

Their lessons focus on vocabulary  and grammar skills that you can use in practical situations, like asking  for directions, or ordering food. The courses also take into  account your native language as a way to help you learn. You can check it out and download Babbel  by clicking the link in the description.

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