Related topics: nasa · climate change · solar wind · mars · solar radiation

10 years preparing for 'Armageddon'

It's a scenario made famous by the 1998 film "Armageddon": an asteroid is spotted on a collision course with Earth, and experts scramble to plan a space mission to rendezvous with the asteroid and mitigate the danger. It's ...

Monitoring microorganisms on the International Space Station

Crew members on the International Space Station have a lot of company—millions of bacteria and other microbes. The human body contains 10 times more microbes than human cells, and bacteria and fungi grow in and on just ...

Webb finds signs of possible aurorae on isolated brown dwarf

Astronomers using NASA's James Webb Space Telescope have found a brown dwarf (an object more massive than Jupiter but smaller than a star) with infrared emission from methane, likely due to energy in its upper atmosphere. ...

Iron snow ebb and flow may cause magnetic fields to come and go

Just as snow crystals form in the upper atmosphere, then fall to lower, warmer elevations and melt, scientists believe a phenomenon called iron snow happens in the molten iron cores of some planetary bodies. Cooling near ...

Atmospheric Waves Experiment's 'first light' images received

NASA's Atmospheric Waves Experiment (AWE) has recently captured initial images of the mesosphere from its perch on the International Space Station. AWE was installed on the Space Station on Nov. 18, and initial commands were ...

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Earth's atmosphere

The Earth's atmosphere is a layer of gases surrounding the planet Earth that is retained by the Earth's gravity. It has a mass of about five quadrillion metric tons. Dry air contains roughly (by volume) 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide, and trace amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night.

There is no definite boundary between the atmosphere and outer space. It slowly becomes thinner and fades into space. An altitude of 120 km (75 mi) marks the boundary where atmospheric effects become noticeable during atmospheric reentry. The Kármán line, at 100 km (62 mi), is also frequently regarded as the boundary between atmosphere and outer space. Three quarters of the atmosphere's mass is within 11 km (6.8 mi; 36,000 ft) of the surface.

This text uses material from Wikipedia, licensed under CC BY-SA