Engineering

Setting the airways for urban air mobility

Flying drones are doing great things today, from powerline inspection to security surveillance to precision agriculture (fertilizer and pesticide application).

Business

Airline industry sees long-term rebound for sector

After flying into the financial turbulence of the Covid pandemic, the airline sector expects passenger traffic to take off despite concerns about the industry's impact on climate change.

Business

United Airlines sees a supersonic future

United Airlines aims to bring back supersonic travel before the decade is over with a plane that is currently just an artist's drawing—even the prototype hasn't flown yet.

Engineering

Merlin Labs develops autonomous 55-craft King Air fleet

Inspired by a close encounter with a fellow aircraft during his years as a novice pilot, Merlin Labs founder Matt George found himself drawn to the idea of applying ground transportation safety methods to air traffic. Now, ...

Energy & Green Tech

Researchers create new zinc-air pouch cells

Zinc-air batteries (ZABs) are among the most promising next-generation battery technologies due to their many advantageous characteristics. Most notably, these batteries have unique half-open structures, a significant theoretical ...

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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