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Hubble confirms that megacomet aimed at internal solar system is the largest ever seen in news and research

The giant comet is actually the largest ever seen, new observations from the Hubble Space Telescope confirm.

Stretching about 80 miles (129 kilometers), the comet’s core (or solid center), known as C / 2014 UN271 (Bernardineli-Bernstein), is larger than Rhode Island, according to a NASA statement. And it’s about 50 times larger than the comet’s average nucleus.

“This comet is literally the tip of the iceberg for many thousands of comets that are too faint to be seen in the farther reaches of the solar system,” said David Juitt, co-author of a new study confirming the comet’s size and a professor of planetary science. astronomy at the University of California, Los Angeles (UCLA), NASA said in a statement. “We’ve always suspected that this comet must be big because it’s so bright at such a long distance. We now confirm that this is the case. “

This comet is currently far from Earth, approaching about 22,000 miles per hour (35,405 km / h). Comet Bernardinelli-Bernstein has been falling into the sun for more than 1 million years. But don’t worry; the closest to us, according to NASA, is about 1 billion miles (1.6 billion km km), which will not even reach 2031.

Previously, the comet with the title of “largest nucleus” was C / 2002 VQ94, which was spotted in 2002 and estimated at about 60 miles (96 km) in diameter.

This new comet hippopotamus was first observed in 2010. A few years later, astronomers Pedro Bernardinelli and Gary Bernstein discovered the object in archival data collected by the Dark Energy Survey at the Cerro Tololo Inter-American Observatory in Chile. Since its initial discovery, the object has been studied using a wide range of instruments, including both ground-based telescopes and space telescopes such as Hubble.

With Hubble’s observations, researchers have finally been able to officially confirm the enormous size of this “dirty snowball.” (Comets are called “dirty snowballs” because they are made up of rocks, ice, and other materials and debris, although objects can vary in composition.) At this point in the Bernardineli-Bernstein comet’s orbit, where About 2 billion miles (3.2 billion km) from the sun, the ice sheet is about minus 348 degrees Fahrenheit (minus 211 degrees Celsius).

While cool, this temperature is warm enough to allow carbon monoxide to sublimate (a process in which solid material is converted to gas) from the comet’s rocky surface, creating a “coma”, a shell of dust and gas that surrounds the solid center of the comet.

“This is an amazing site, given how active it is when it’s still so far from the sun,” said NASA lead author Man-To Hui, a researcher at the University of Macau in a statement. “We thought the comet might be quite large, but we needed the best data to confirm that. So his team used Hubble to take five pictures of the comet on January 8, 2022.

The main challenge the team had in confirming the size of the nucleus was to distinguish between the nucleus and the comet’s coma.

Bernardinelli-Bernstein is too far away for Hubble to pinpoint its nucleus, but the team intercepted a light signal with a telescope showing the comet’s location. They were then able to use Hubble’s observations, and with the help of computer modeling techniques to show where the object’s coma would be, they were able to determine the size of its nucleus.

The team compared its data with earlier observations made by the Atacama Large Millimeter / Submilimeter Array (ALMA) in Chile and found that earlier size estimates made with ALMA were consistent with Hubble’s new findings. And ALMA’s radio observations allowed them to improve the object’s reflectivity, showing that the comet’s surface is darker than they expected.

“It’s big and blacker than coal,” Juit said.

Scientists believe that the comet Bernardinelli-Bernstein travels from the Oort cloud, the most remote region of our solar system, where a huge number of comets are located. The comets that lie in this huge, diffuse cloud are thought to have formed closer to the sun, but have been ejected much farther from gravitational interactions with the newborn giant planets of our solar system. And they tend to stay there unless another gravitational thrust pushes them in our path.

This comet, which is so far from Earth and originates from the farthest reaches of our solar system, is thought to travel in an elliptical orbit around the Sun for 3 million years. Scientists believe that it can travel about half a light year from the sun in the most remote parts of its orbit.

These findings are described in a study published today (April 12) in The Astrophysical Journal Letters.

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