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

Sulfur may be a new tool for finding alien life

Astronomers have identified sulfur as a potentially crucial indicator in narrowing the search for life on other planets. While sulfur itself is not necessarily an indication of habitability, significant concentrations of ...

A balloon mission that could explore Venus indefinitely

Sometimes, the best innovative ideas come from synthesizing two previous ones. We've reported before on the idea of having a balloon explore the atmosphere of Venus, and we closely watched the progress of the Mars Oxygen ...

How to deploy and talk to LEAVES on Venus

Universe Today reported before about a NIAC-funded project known as the Lofted Environment and Atmospheric Venues Sensors (LEAVES) mission to study Venus' atmosphere. While the technology behind the idea is still under development, ...

Three ways to track Venusquakes, from balloons to satellites

Instruments aboard robotic landers have measured seismicity on the moon and Mars, helping researchers learn about the inner workings of those celestial bodies. But the internal makeup of Venus is still not known, in part ...

'Bomb cyclone' adds to growing extreme weather trend

The "once-in-a-decade" storm that devastated the Pacific Northwest last week caused widespread outages, damage, and at least two deaths. Data shows the storms are becoming more common. Could climate change be a key driver?

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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