A new study suggests that Earth may have lost up to 60 percent of its atmosphere in collision of space objects that created the moon.
Most scientists believe this event occurred about 4 billion years ago, when the Earth was still developing. They think that a huge object, possibly the size of the planet Mars, hit the Earth, sending vaporized particles in space. Gravity is believed to have joined these particles to form the moon.
The study presents evidence that this collision may have caused the Earth to lose between 10 and 60 percent of the atmosphere it had. A study report appeared in the publication Letters from astrophysics journals.
The researchers set out to explore how massive collisions of objects affected rocky planets with thin atmospheres. To do this, they built more than 300 “supercomputers simulations. “
The experiment considered the locations where objects hit the planet, the speed of the impacts, as well as the size and mass of the colliding object.
Previous research suggested that impact collisions during the latter stages formation of a planet can affect its atmosphere. The computer models in this study expanded on this idea. They showed that a collision like the one that could have formed the moon probably occupied much of the Earth’s atmosphere.
The study’s principal investigator, Jacob Kegerreis, works with Durham University in Great Britain. He is a cosmologist, a scientist who specializes in the beginnings and development of the universe.
Kegerreis noted in a statement that computer simulations do not directly explain how the moon was created. However, “the effects on the Earth’s atmosphere could be used to restrict the different ways it could have formed.”
Kegerreis said the study shows a new way of looking at how similar collisions have led to the loss of atmosphere of other rocky planets. Such methods could be used by scientists studying how the moon was born, as well as other very large impacts.
The study also suggests that large, slow impacts between newer planets and massive objects could add to the planet’s atmosphere if the colliding object also has its own atmosphere.
The researchers say they hope the study will provide scientists with a better understanding of the moon’s formation and help explain how atmospheres on other planets develop.
I’m Bryan Lynn.
VOA News and Durham University reported this story. Bryan Lynn adapted the reports for Learn English. George Grow was the editor.
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Words in this story
collision – n. a violent crash involving several objects
vaporize – v. transform from a solid or liquid into a gas
impact – n. the force or action of one object striking another
hypothesis – n. an idea or explanation for something that is based on known facts but has not yet been proven
simulation – n. a recreation of a process or situation
stage – n. part of a business or development