Largest comet ever seen passes through our solar system
A huge comet with a solid center more than twice the width of Rhode Island is on an orbital path that will swing it inside our cosmic neighborhood, astronomers say.
The icy intruder is traveling at 22,000 mph from the edge of the solar system towards the sun. In a study published Tuesday in The Astrophysical Journal Lettersscientists said the comet was not of concern as it would not pass anywhere near Earth.
Even when the comet makes its closest approach to the sun, in 2031, it will still be at least 1 billion miles away, said study co-author David Jewitt, professor of planetary sciences and astronomy at UCLA.
“It won’t even cross Saturn’s orbit, so it’s definitely not a threat to us,” he said. The comet, officially known as comet C/2014 UN271, is the largest such object ever observed by astronomers, Jewitt said.
Its core – the solid center, which is usually made up of ice, rock and dust – measures about 85 miles in diameter. This makes it about 50 times larger than most known comets, with an estimated mass 100,000 times that of a typical comet, according to the study.
“That’s a huge amount of matter in one body,” Jewitt said.
Astronomers used the Hubble Space Telescope to observe the colossal comet and determine the size of its nucleus. Hubble took five photos of the icy object on January 8, revealing its luminous core shrouded in a glowing cloud of dust and gas, known as a coma.
“It’s an amazing object, given how active it is when it’s still so far from the sun,” said study lead author Man-To Hui, an assistant professor at the University of Science. and technologies from Macau. said in a press release at the Space Telescope Science Institute, which operates Hubble.
Scientists used a computer model developed from previous observations of the comet through ground and space telescopes to see past the dusty coma and map the core.
In addition to its immense size, astronomers have discovered that the surface of the comet’s nucleus is darker than previously thought.
“Only 3% of the light that hits its surface bounces back,” Jewitt said. “It’s a really, really dark surface. It’s blacker than coal.”
Further research is needed to understand why the core is so dark. Jewitt said it’s possible that prolonged exposure to high-energy cosmic rays “baked” the surface, coating it with a charred material similar to charcoal.
Comet C/2014 UN271 was first detected in 2010 by astronomers Pedro Bernardinelli and Gary Bernstein, when it was 3 billion kilometers from the sun. Although scientists have spent more than a decade studying the comet, the new study is the first to confirm its massive size.
Jewitt said it likely formed more than 4 billion years ago, when the solar system was in its infancy. It is possible, he said, that it developed in the region between Jupiter and Neptune, developing alongside the nascent planets.
“As it grew and the planets grew simultaneously, we think the gravity of the planets may have propelled the comet out of the planetary region,” Jewitt said.
He added that the expelled comet and other similar objects likely ended up in what is known as the Oort cloud, a region beyond Pluto where astronomers believe icy objects orbit the solar system. in a spherical bubble.
Sometimes the gravitational forces of passing stars can jostle distant comets in the Oort cloud, “throwing them into the solar system,” Jewitt said.
Comet C/2014 UN271 is less than 2 billion kilometers from the sun, according to the study. And in a few million years, it will migrate back into the Oort cloud, Jewitt said.
Astronomers hope to continue observing the comet until its closest approach in 2031. Jewitt said studying such objects can reveal information about the solar system and help solve the lingering mysteries of the cosmos.
“It’s a reminder that the outer solar system is not a very well-known place,” he said. “As you move away from the sun, everything is so dim that all kinds of things are waiting to be discovered.”