Oxygen ions from Earth are periodically transferred to the lunar surface, according to a new study:
A small bit of Earth's air leaks into space each day. (Don't worry, it's only about 90 metric tons out of a total of about 5 quadrillion metric tons.) Some atoms and molecules near the top of our atmosphere are simply moving so fast they overcome Earth's gravitational tug. Charged particles can be accelerated to even higher speed by our planet's magnetic field. Once these émigrés escape our world, they remain inside a teardrop-shaped region of space surrounding Earth called the magnetosphere (whose rounded end is pointed toward the sun) and are eventually blown away from the sun by the solar wind and into interplanetary space.
For the largest part of each month, the moon is bombarded with high-speed, highly charged atoms spewing from the sun and carried by the solar wind. But for 5 days every month, Earth's magnetosphere passes over the moon, shielding it from the solar particles and allowing slower speed particles from Earth to take their place, says Kentaro Terada, a cosmochemist at Osaka University in Toyonaka, Japan. Moon-orbiting probes experience the same conditions, he notes.
[...] During each burst of oxygen, an estimated 26,000 ions per second passed through each square centimeter of [the Kaguya moon-orbiting probe's] sensor, the researchers say. [...] Those atoms' origin in the ozone layer might also help explain a longstanding mystery about some grains of lunar soil brought back by Apollo astronauts. A few of those grains sport higher-than-normal proportions of oxygen-17 and oxygen-18 isotopes (as compared with the universe's predominant form of the element, oxygen-16). Notably, Terada and his colleagues say, previous studies have shown that the overall proportions of oxygen isotopes in the ozone layer also are skewed toward above-average concentrations of oxygen-17 and oxygen-18.
Biogenic oxygen from Earth transported to the Moon by a wind of magnetospheric ions (open, DOI: 10.1038/s41550-016-0026) (DX)
Related Stories
The presence of large quantities of oxygen ions may be able to distinguish habitable exoplanets with life from barren exoplanets in the habitable zone (resembling Venus or Mars):
Like Earth, Venus and Mars are small rocky planets; they have permanent atmospheres like Earth, and their atmospheres are exposed to the same solar radiation as Earth's. Data from the Pioneer Venus Orbiter and the Viking descent probe on Mars show that they have very similar ionospheres to each other—which don't contain a lot of atomic O+ ions. Know what else Venus and Mars are missing? Photosynthesis.
[Astronomy PhD candidate Paul] Dalba's contention is that photosynthesis on a planet's surface, which generates a surfeit of molecular oxygen, is the only thing that can account for these atomic O+ ions in a planet's ionosphere. The mere existence of life throws a planet's atmosphere out of chemical balance. O+ would be a neat biomarker because there isn't a numerical cutoff required—just the dominance of O+ among the ionic species in the upper atmosphere would indicate "thriving global biological activity" on the planet below.
Dalba claims that Venus and Mars act as negative controls, demonstrating that planets like Earth but lacking life don't have this O+ layer. Some may think that continuous volcanic activity on the surface could also generate enough oxygen, but Dalba doesn't. Chemistry involving water and UV light [open, DOI: 10.1038/srep13977] [DX] can also release oxygen. But the amount of water on Earth is insufficient to account for the requisite oxygen content, so he thinks that the presence of water on other planets wouldn't make enough oxygen there either.
Atomic oxygen ions as ionospheric biomarkers on exoplanets (DOI: 10.1038/s41550-017-0375-y) (DX)
Related: Nitrogen in Ancient Rocks a Sign of Early Life
Oxygen Ions From Earth Escape to the Moon
Researchers Suffocate Hopes of Life Support in Red Dwarf "Habitable Zones"
Seven Earth-Sized Exoplanets, Including Three Potentially Habitable, Identified Around TRAPPIST-1
Cosmic Methyl Chloride Detection Complicates the Search for Life on Exoplanets
Mars Colonists Could Produce Oxygen by Making a Plasma Out of Atmospheric Carbon Dioxide
Analysis of Microfossils Finds that Microbial Life Existed at Least 3.5 Billion Years Ago
To Detect Life on Other Planets, Look for Methane, Carbon Dioxide, and an Absence of Carbon Monoxide
(Score: 0) by Anonymous Coward on Wednesday February 01 2017, @05:57AM
Oxygen can escape, but you can't!
(Score: 0) by Anonymous Coward on Monday February 06 2017, @09:39AM
Excellent, excellent movie!
(Score: 2) by FakeBeldin on Wednesday February 01 2017, @08:20AM
https://www.youtube.com/watch?v=21ZED1M9eSw [youtube.com].
(Score: 2, Informative) by Anonymous Coward on Wednesday February 01 2017, @09:01AM
it does not match previous measurements...
http://archive.is/uqr6F [archive.is]
Lunar Atmospheric Composition
The Lunar Atmospheric Composition Experiment on the MoonThe Moon has an atmosphere, but it is very tenuous. Gases in the lunar atmosphere are easily lost to space. Because of the Moon's low gravity, light atoms such as helium receive enough energy from solar heating so that they escape in just a few hours. Heavier atoms take longer to escape, but are ultimately ionized by the Sun's ultraviolet radiation, after which they are carried away from the Moon by the solar wind. This process takes a few months. Because of the rate at which atoms escape from the lunar atmosphere, there must be a continuous source of particles to maintain even a tenuous atmosphere. Sources for the lunar atmosphere include capture of particles from the solar wind and of material released from the impact of comets and meteorites. For some atoms, particularly helium-4 and argon-40, outgassing from the Moon's interior may also be a source.
The Lunar Atmospheric Composition Experiment was deployed on Apollo 17. It was a mass spectrometer that measured the composition of the lunar atmosphere. On earlier missions, only the total abundance of the lunar atmosphere was measured by the Cold Cathode Gauge. The three primary gases in the lunar atmosphere are neon, helium, and hydrogen, in roughly equal amounts. Small amounts of methane, carbon dioxide, ammonia, and water were also detected. In addition, argon-40 was detected, and its abundance increased at times of high seismic activity. Argon-40 is produced by the radioactive decay of potassium-40 in the lunar interior, and the seismic activity may have allowed escape of argon from the interior to the surface along newly created fractures.
(Score: 1) by anubi on Wednesday February 01 2017, @10:30AM
I understand that once Helium is released, you will never see it again. [millerwelds.com]
The earth's gravity simply isn't strong enough to hold it.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 4, Funny) by Sulla on Wednesday February 01 2017, @02:25PM
Space wall now. I am fed up with the moon stealing our Oxygen.
Ceterum censeo Sinae esse delendam
(Score: 0) by Anonymous Coward on Wednesday February 01 2017, @06:57PM
It's the only way to protect our air from Space Balls.
(Score: 2) by bob_super on Wednesday February 01 2017, @07:05PM
Correct. Walls are not for keeping things out, but in.
(Score: 1) by DavePolaschek on Wednesday February 01 2017, @08:54PM
Need to make the Moonies pay for it!
(Score: 2) by Sulla on Thursday February 02 2017, @12:52AM
What are they going to do? Throw rocks at us?
Ceterum censeo Sinae esse delendam
(Score: 2) by Joe Desertrat on Thursday February 02 2017, @10:01PM
They might moon us!