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

New water cycle on Mars discovered

Approximately every two Earth years, when it is summer on the southern hemisphere of Mars, a window opens: Only in this season can water vapor efficiently rise from the lower into the upper Martian atmosphere. There, winds ...

The curious case of Earth's leaking atmosphere

Earth's atmosphere is leaking. Every day, around 90 tonnes of material escapes from our planet's upper atmosphere and streams out into space. Although missions such as ESA's Cluster fleet have long been investigating this ...

New kind of aurora is not an aurora at all

Thin ribbons of purple and white light that sometimes appear in the night sky were dubbed a new type of aurora when brought to scientists' attention in 2016. But new research suggests these mysterious streams of light are ...

Picture of Pluto further refined by months of New Horizons data

When the New Horizons spacecraft made its flyby of Pluto on July 14, 2015, there was worldwide celebration that we'd finally gotten our first detailed look at this completely new type of planet in the outer reaches of our ...

Tracking down the 'missing' carbon from the Martian atmosphere

Mars is blanketed by a thin, mostly carbon dioxide atmosphere—one that is far too thin to prevent large amounts of water on the surface of the planet from subliming or evaporating. But many researchers have suggested that ...

Close comet flyby threw Mars' magnetic field into chaos

Just weeks before the historic encounter of comet C/2013 A1 (Siding Spring) with Mars in October 2014, NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft entered orbit around the Red Planet. To protect sensitive ...

Jupiter's great red spot heats planet's upper atmosphere

Researchers from Boston University's (BU) Center for Space Physics report today in Nature that Jupiter's Great Red Spot may provide the mysterious source of energy required to heat the planet's upper atmosphere to the unusually ...

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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