Important Chemicals for Life May Have Arrived from Space
2022-05-05
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1A study of meteorites has found more evidence that space rocks may have brought chemicals to Earth that helped start life on the planet.
2The meteorites studied had landed in Australia, Canada and the United States.
3Earlier research on the objects showed they contained three of the five chemical components necessary to form DNA and RNA.
4DNA is the molecule that carries genetic instructions in living things.
5RNA is the molecule important to the operation of genes.
6Researchers said recently they have now identified the final two chemicals.
7That information comes from Yasuhiro Oba of Hokkaido University's Institute of Low Temperature Science in Japan.
8Oba was the lead writer of the study that was published in Nature Communications.
9The research findings support the idea that meteorites could have been an important source of organic compounds necessary for the emergence of Earth's first organisms, said study co-writer Danny Glavin of NASA's Goddard Space Flight Center in Maryland.
10Scientists have been seeking to better understand how chemical compounds came together to form a living thing able to reproduce itself.
11The formation of DNA and RNA would be an important event as these molecules contain the instructions to build and operate organisms.
12"There is still much to learn about the chemical steps that led to the origin of life on Earth," Glavin said.
13He added, "This research certainly adds to the list of chemical compounds that would have been present" on Earth before the emergence of life.
14The researchers examined material from three meteorites.
15One fell in 1950 near the town of Murray in the U.S. state of Kentucky.
16Another fell in 1969 near the town of Murchison in Australia's Victoria state.
17The final meteorite fell in 2000 near Tagish Lake in the Canadian province British Columbia .
18All three are made of rocky material thought to have formed early in the solar system's history.
19They are carbon-rich, with the Murchison and Murray meteorites containing about two percent organic carbon by weight and the Tagish Lake meteorite containing about four percent organic carbon.
20Carbon is a primary ingredient of organisms on Earth.
21"All three meteorites contain a very complex mixture of organic molecules, most of which have not yet been identified," Glavin said.
22Earth formed about 4.5 billion years ago.
23In its early days, it was hit by meteorites, comets and other material from space.
24The planet's first organisms were simple microbes in the seas.
25The earliest-known fossils are of marine microbial life dating to around 3.5 billion years ago.
26The two chemical components discovered in the latest study are called cytosine and thymine.
27The five would not have been the only chemical compounds necessary for life.
28Among other things needed were sugars, fatty acids, and amino acids, which are components of proteins and enzymes.
29Oba said, "The present results may not directly" explain the beginning "of life on the Earth."
30But, it does help to understand what organic molecules were on the early Earth before life formed, he said.
31I'm Caty Weaver.
1A study of meteorites has found more evidence that space rocks may have brought chemicals to Earth that helped start life on the planet. 2The meteorites studied had landed in Australia, Canada and the United States. 3Earlier research on the objects showed they contained three of the five chemical components necessary to form DNA and RNA. DNA is the molecule that carries genetic instructions in living things. RNA is the molecule important to the operation of genes. 4Researchers said recently they have now identified the final two chemicals. 5That information comes from Yasuhiro Oba of Hokkaido University's Institute of Low Temperature Science in Japan. Oba was the lead writer of the study that was published in Nature Communications. 6The research findings support the idea that meteorites could have been an important source of organic compounds necessary for the emergence of Earth's first organisms, said study co-writer Danny Glavin of NASA's Goddard Space Flight Center in Maryland. 7Scientists have been seeking to better understand how chemical compounds came together to form a living thing able to reproduce itself. The formation of DNA and RNA would be an important event as these molecules contain the instructions to build and operate organisms. 8"There is still much to learn about the chemical steps that led to the origin of life on Earth," Glavin said. He added, "This research certainly adds to the list of chemical compounds that would have been present" on Earth before the emergence of life. 9The researchers examined material from three meteorites. One fell in 1950 near the town of Murray in the U.S. state of Kentucky. Another fell in 1969 near the town of Murchison in Australia's Victoria state. The final meteorite fell in 2000 near Tagish Lake in the Canadian province British Columbia . 10All three are made of rocky material thought to have formed early in the solar system's history. They are carbon-rich, with the Murchison and Murray meteorites containing about two percent organic carbon by weight and the Tagish Lake meteorite containing about four percent organic carbon. Carbon is a primary ingredient of organisms on Earth. 11"All three meteorites contain a very complex mixture of organic molecules, most of which have not yet been identified," Glavin said. 12Earth formed about 4.5 billion years ago. In its early days, it was hit by meteorites, comets and other material from space. The planet's first organisms were simple microbes in the seas. The earliest-known fossils are of marine microbial life dating to around 3.5 billion years ago. 13The two chemical components discovered in the latest study are called cytosine and thymine. 14The five would not have been the only chemical compounds necessary for life. Among other things needed were sugars, fatty acids, and amino acids, which are components of proteins and enzymes. 15Oba said, "The present results may not directly" explain the beginning "of life on the Earth." But, it does help to understand what organic molecules were on the early Earth before life formed, he said. 16I'm Caty Weaver. 17Will Dunham reported on this story for Reuters. John Russell adapted it for VOA Learning English. 18____________________________________________________________________ 19Words in This Story 20meteorite - n. a piece of rock or metal that has fallen to the ground from outer space 21component -n. one of the parts of something (such as a system or mixture) : an important piece of something 22organic - adj. of, relating to, or obtained from living things 23emerge - v. to rise or appear from a hidden or unknown place or condition : to come out into view 24microbe - n. an extremely small living thing that can only be seen with a microscope 25fossil -n. something (such as a leaf, skeleton, or footprint) that is from a plant or animal which lived in ancient times and that you can see in some rocks