The gas shell of the Earth, as it turned out, extends twice as far as the orbit of our natural satellite.
Scientists from the Space Research Institute (IKI RAS) and their colleagues from the European Space Agency (ESA) came to the conclusion that the Earth's atmosphere is much larger than one could imagine. As reported in the Journal of Geophysical Research: Space Physics. And the IKI RAN announced this in its press release.
- The moon flies through the earth's atmosphere, - says the head of research Igor Balyukin, an employee of the Department of Planetary Physics of the IKI RAS. But he clarifies what he means the most distant regions of the gas shell of our planet - the so-called geocorona, consisting of neutral hydrogen atoms.
The dimensions of the Earth's atmosphere (blue shroud) are impressive. The moon is indeed within the earth's atmosphere.
The data that made it possible to determine the size of the hydrogen hecorona were found among those that were collected from 1996 to 1998 by the SWAN (Solar Wind Anisotropie) instrument installed on the SOHO (Solar and Heliospheric Observatory) spacecraft.
The SOHO observatory itself is located between the Earth and the Sun at an equilibrium point - the so-called Lagrange point L1 - about one and a half million kilometers from Earth.
The fact that the geocorona exists, moreover, glows in the ultraviolet range, was known before. A stunning photo of this glow - the so-called secondary Lyman-alpha radiation - was first taken by the astronauts of the Apollo 16 expedition, who landed on the moon in 1972. From there and filmed. But as it turned out now: they filmed being in the geocorona itself.
Analysis of the data showed that the glow, and therefore the geocorona, extends at least 100 Earth radii, or about 640 thousand kilometers. And this is much farther than the orbit of the Moon, which is located at a distance of 60 Earth radii or 380 thousand kilometers. On average, of course.
Promotional video:
View of the geocorona from the lunar surface: shot in the ultraviolet range.
Scientists explain that the hydrogen corona is formed by decaying molecules of water and methane. Observing it, you can judge whether the planet is losing water quickly or slowly.
“The hydrogen corona can be a sign that there is water vapor in the atmosphere of a planet, closer to the surface, as we see it on Earth, Venus and Mars,” says Jean-Loup Bertaux, co-author Balyukin from the LATMOS laboratory of the French National Center for Space Research, who previously led experiments with the SWAN instrument. - The potential twins of the Earth must have hydrogen crowns. It is worth looking for them in this way - looking out for the corresponding glow.
VLADIMIR LAGOVSKY