Scientists Use Model to Predict Conditions for Life on Ancient Mars

2022-10-17

00:00 / 00:00
复读宝 RABC v8.0beta 复读机按钮使用说明
播放/暂停
停止
播放时:倒退3秒/复读时:回退AB段
播放时:快进3秒/复读时:前进AB段
拖动:改变速度/点击:恢复正常速度1.0
拖动改变复读暂停时间
点击:复读最近5秒/拖动:改变复读次数
设置A点
设置B点
取消复读并清除AB点
播放一行
停止播放
后退一行
前进一行
复读一行
复读多行
变速复读一行
变速复读多行
LRC
TXT
大字
小字
滚动
全页
1
  • A new study suggests that ancient Mars might have been able to support a large population of microscopic organisms.
  • 2
  • French scientists used computer models to predict climate and land conditions under the planet's surface about 4 billion years ago.
  • 3
  • The study said the microorganisms might have been growing just beneath the Martian surface.
  • 4
  • The microbes could have been covered by several centimeters of dirt.
  • 5
  • This would have protected them from severe radiation.
  • 6
  • The researchers said any place free of ice on Mars could have been filled with the living organisms.
  • 7
  • But, if they did exist, these simple life forms would have changed the atmosphere so much that they would not have survived the new environment.
  • 8
  • Boris Sauterey was the lead writer of the study, which recently appeared in the publication Nature Astronomy.
  • 9
  • He is a postdoctoral researcher at Sorbonne University in Paris.
  • 10
  • Sauterey said that in the time period studied, Mars was thought to contain lots of water and had less severe conditions than today.
  • 11
  • But he told The Associated Press the research results present a picture of how things can develop in the universe.
  • 12
  • Sauterey said that life on Mars - even simple life like microbes - "might actually commonly cause its own demise."
  • 13
  • He added that while the findings might seem "a bit gloomy," he also finds them exciting.
  • 14
  • The researchers said ancient Mars likely had a wet, warm climate.
  • 15
  • But this environment would have been threatened by large amounts of hydrogen being removed from the thin, carbon dioxide-rich atmosphere.
  • 16
  • Temperatures then dropped by about minus 200 degrees Celsius.
  • 17
  • The researchers said any organisms at or near the surface would likely have buried themselves deeper underground in an attempt to survive.
  • 18
  • This is unlike Earth, where microbes may have helped keep climate conditions more moderate.
  • 19
  • Researchers say this is because Earth had an atmosphere rich in a nitrogen.
  • 20
  • Kaveh Pahlevan is a planetary scientist at the SETI Institute, a nonprofit space research center in California.
  • 21
  • He told the AP he thinks any future models of Mars' climate should consider the new French research.
  • 22
  • Pahlevan recently led a separate study suggesting Mars was born wet with warm oceans that lasted millions of years.
  • 23
  • At the time, the atmosphere would have been dense and mostly hydrogen.
  • 24
  • But over time, some gases were likely transported higher into the atmosphere and lost to space.
  • 25
  • The French study investigated the climate effects of possible microbes when Mars' atmosphere was mostly carbon dioxide.
  • 26
  • So Pahlevan said the research would not relate to earlier times.
  • 27
  • "What their study makes clear, however, is that if (this) life were present on Mars" during this earlier period, "they would have had a major influence on the prevailing climate," Pahlevan said.
  • 28
  • The French researchers offered some suggestions about where to look on Mars for signs of past life.
  • 29
  • They named the Hellas Planitia area, as well as around Jezero Crater.
  • 30
  • Jezero Crater is where the American space agency NASA's exploring vehicle, Perseverance, is carrying out research activities.
  • 31
  • Next, Sauterey said he would like to begin research into the possibility that microbial life could still exist deep within Mars.
  • 32
  • I'm Bryan Lynn.
  • 1
  • A new study suggests that ancient Mars might have been able to support a large population of microscopic organisms.
  • 2
  • French scientists used computer models to predict climate and land conditions under the planet's surface about 4 billion years ago.
  • 3
  • The study said the microorganisms might have been growing just beneath the Martian surface. The microbes could have been covered by several centimeters of dirt. This would have protected them from severe radiation.
  • 4
  • The researchers said any place free of ice on Mars could have been filled with the living organisms. But, if they did exist, these simple life forms would have changed the atmosphere so much that they would not have survived the new environment.
  • 5
  • Boris Sauterey was the lead writer of the study, which recently appeared in the publication Nature Astronomy. He is a postdoctoral researcher at Sorbonne University in Paris. Sauterey said that in the time period studied, Mars was thought to contain lots of water and had less severe conditions than today.
  • 6
  • But he told The Associated Press the research results present a picture of how things can develop in the universe.
  • 7
  • Sauterey said that life on Mars - even simple life like microbes - "might actually commonly cause its own demise." He added that while the findings might seem "a bit gloomy," he also finds them exciting.
  • 8
  • The researchers said ancient Mars likely had a wet, warm climate. But this environment would have been threatened by large amounts of hydrogen being removed from the thin, carbon dioxide-rich atmosphere. Temperatures then dropped by about minus 200 degrees Celsius. The researchers said any organisms at or near the surface would likely have buried themselves deeper underground in an attempt to survive.
  • 9
  • This is unlike Earth, where microbes may have helped keep climate conditions more moderate. Researchers say this is because Earth had an atmosphere rich in a nitrogen.
  • 10
  • Kaveh Pahlevan is a planetary scientist at the SETI Institute, a nonprofit space research center in California. He told the AP he thinks any future models of Mars' climate should consider the new French research.
  • 11
  • Pahlevan recently led a separate study suggesting Mars was born wet with warm oceans that lasted millions of years. At the time, the atmosphere would have been dense and mostly hydrogen. But over time, some gases were likely transported higher into the atmosphere and lost to space.
  • 12
  • The French study investigated the climate effects of possible microbes when Mars' atmosphere was mostly carbon dioxide. So Pahlevan said the research would not relate to earlier times.
  • 13
  • "What their study makes clear, however, is that if (this) life were present on Mars" during this earlier period, "they would have had a major influence on the prevailing climate," Pahlevan said.
  • 14
  • The French researchers offered some suggestions about where to look on Mars for signs of past life. They named the Hellas Planitia area, as well as around Jezero Crater. Jezero Crater is where the American space agency NASA's exploring vehicle, Perseverance, is carrying out research activities.
  • 15
  • Next, Sauterey said he would like to begin research into the possibility that microbial life could still exist deep within Mars.
  • 16
  • I'm Bryan Lynn.
  • 17
  • The Associated Press reported this story. Bryan Lynn adapted the report for VOA Learning English.
  • 18
  • __________________________________________________________________
  • 19
  • Words in This Story
  • 20
  • post-doctoral -adj. relating to work done after a PhD degree has been completed
  • 21
  • demise - n. the end of something
  • 22
  • gloomy - adj. unhappy and without hope
  • 23
  • prevail - v. to be common among a group of people
  • 24
  • _______________________________________________________________________
  • 25
  • What do you think of this story? We want to hear from you. We have a new comment system. Here is how it works:
  • 26
  • Each time you return to comment on the Learning English site, you can use your account and see your comments and replies to them. Our comment policy is here.