An atmosphere (New Latin atmosphaera, created in the 17th century from Greek á¼ÏÎ¼ÏÏ [atmos] "vapor" and ÏÏÎ±á¿ÏÎ± [sphaira] "sphere") is a layer of gases surrounding a material body of sufficient mass that is held in place by the gravity of the body. An atmosphere is more likely to be retained if the gravity is high and the atmosphere's temperature is low.
If you think today’s urban air, thickened with noxious smog, is terrible, just imagine how the Earth was filled in a shroud of hydrocarbons some 2.5 billion years ago. Back then, a haze dominated by methane engulfed the atmosphere such that light could barely reach the ground, similarly to what can be seen today on [...]
It’s been less than a month since we published the last thing about the Cassini probe, and the amazing spacecraft has done it again; this time it detected a thin, oxygen atmosphere, on a moon of Saturn – Dione. The study was published in the Geophysical Research Letters At 1122 km in diameter, Dione is [...]
Some species of bacteria can survive virtually anywhere: in acids, in nuclear waste, at extremely low or high temperatures, at extreme pressures, and so on; extreme microbes that survive on gases thrown out by Siberian hot springs may have played an extremely important role in the formation of our planet’s atmosphere and its composition, a [...]
Back in September, a meteorite crashed somewhere in Peru, scaring locals and digging a hole in the ground, but pleased scientists which had the opportunity of studying it. But it behaved so strangely that in fact it forces scientists to rethink the way alien objects behave when entering Earth’s atmosphere and when they hit out [...]