Scientists Study Unusual Comet
2020-04-26
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1Scientists recently reported new details about the second interstellar object ever seen passing through our solar system.
2It is a comet called 2I/Borisov.
3Comets are made up of frozen gases, rock and dust that orbit stars.
4The Reuters news agency likens them to dirty snowballs.
5Comets leave behind a mix of gas and dust in space as they move.
62I/Borisov is different from other comets, scientists have observed.
7Researchers reported on Monday that gas coming off 2I/Borisov had high levels of carbon monoxide - far more than comets formed in our solar system.
8Carbon monoxide is poisonous to human beings.
9It forms as ice only in the coldest places.
10The presence of so much carbon monoxide, the researchers said, suggests 2I/Borisov was formed differently than comets from our solar system.
11It could have formed in a very cold part of its home star system or around a star cooler than the sun.
12Dennis Bodewits is a planetary scientist at Auburn University in the United States.
13He was the lead author of one of two 2I/Borisov studies.
14Both appear in the publication Nature Astronomy.
15"We like to refer to 2I/Borisov as a snowman from a dark and cold place," Bodewits said.
16He noted that, "comets are left-over building blocks from the time of planet formation. For the first time, we have been able to measure the chemical composition of such a building block from another planetary system while it flew through our own solar system."
17Amateur astronomer Gennady Borisov was the first person to identify the comet in August of 2019.
18The comet is thought to be about 1 kilometer wide.
19It has flown through interstellar space after being forced out from its original star system.
20Bodewits said the comet was born long ago in a mix of gas and dust circling around a newly formed star.
21He said it came from a place that must have been rich in carbon monoxide.
22That star may have been what is called an M-dwarf, far smaller and cooler than our sun.
23M-dwarf stars are the smallest kind of star known to scientists, Bodewits said.
24At first, researchers believed that 2I/Borisov was like comets made in our solar system.
25However, information gathered by the Hubble Space Telescope and an observatory in Chile showed differences.
26The researchers also found a large amount of hydrogen cyanide at levels similar to comets from our solar system.
27Martin Cordiner was the lead author of the second study.
28He said, "This shows that 2I/Borisov is not a completely alien object, and confirms some similarity with our 'normal' comets, so the processes that shaped it are comparable to the way our own comets formed."
29Cordiner is an astrobiologist working for NASA, the U.S. space agency.
30He is with the Goddard Space Flight Center in Maryland.
31The only other interstellar visitor discovered in our solar system was a rocky object called 'Oumuamua.' It was found in 2017.
32I'm John Russell.
1Scientists recently reported new details about the second interstellar object ever seen passing through our solar system. It is a comet called 2I/Borisov. 2Comets are made up of frozen gases, rock and dust that orbit stars. The Reuters news agency likens them to dirty snowballs. Comets leave behind a mix of gas and dust in space as they move. 32I/Borisov is different from other comets, scientists have observed. 4Researchers reported on Monday that gas coming off 2I/Borisov had high levels of carbon monoxide - far more than comets formed in our solar system. 5Carbon monoxide is poisonous to human beings. It forms as ice only in the coldest places. The presence of so much carbon monoxide, the researchers said, suggests 2I/Borisov was formed differently than comets from our solar system. It could have formed in a very cold part of its home star system or around a star cooler than the sun. 6Dennis Bodewits is a planetary scientist at Auburn University in the United States. He was the lead author of one of two 2I/Borisov studies. Both appear in the publication Nature Astronomy. 7"We like to refer to 2I/Borisov as a snowman from a dark and cold place," Bodewits said. He noted that, "comets are left-over building blocks from the time of planet formation. For the first time, we have been able to measure the chemical composition of such a building block from another planetary system while it flew through our own solar system." 8Amateur astronomer Gennady Borisov was the first person to identify the comet in August of 2019. The comet is thought to be about 1 kilometer wide. It has flown through interstellar space after being forced out from its original star system. 9Bodewits said the comet was born long ago in a mix of gas and dust circling around a newly formed star. He said it came from a place that must have been rich in carbon monoxide. 10That star may have been what is called an M-dwarf, far smaller and cooler than our sun. M-dwarf stars are the smallest kind of star known to scientists, Bodewits said. 11At first, researchers believed that 2I/Borisov was like comets made in our solar system. However, information gathered by the Hubble Space Telescope and an observatory in Chile showed differences. 12The researchers also found a large amount of hydrogen cyanide at levels similar to comets from our solar system. 13Martin Cordiner was the lead author of the second study. He said, "This shows that 2I/Borisov is not a completely alien object, and confirms some similarity with our 'normal' comets, so the processes that shaped it are comparable to the way our own comets formed." 14Cordiner is an astrobiologist working for NASA, the U.S. space agency. He is with the Goddard Space Flight Center in Maryland. 15The only other interstellar visitor discovered in our solar system was a rocky object called 'Oumuamua.' It was found in 2017. 16I'm John Russell. 17Will Dunham reported on this story for Reuters. John Russell adapted it for VOA Learning English. George Grow was the editor. 18We want to hear from you. Write to us in the Comments Section. 19________________________________________________________________ 20Words in This Story 21interstellar - adj. existing or occurring between stars 22solar - adj. of or related to the sun 23author - n. a writer of a book or report 24refer - v. to note or suggest 25composition - n. the way in which something is put together or arranged 26amateur - n. a person who does something (such as a sport or hobby) for pleasure and not as a job