Solar Wind, Earths magnetosphere. Image: NASA
The Solar Wind is a torrent of space weather cruising past at 500 — 800 kilometers per second which is around 1.5 million miles per hour or, if you prefer, Mach 2,000.* It’s so powerful it erodes rocks on Mars, ejects particles up high and creates a kind of atmosphere of tiny rock particles which we can study. Then it blows that Martian atmosphere away.
In this new research people realized it was not just the rain of tiny high-speed protons fritzing Mars at 800 km per second that were carving up the rocks — the main role was from the heavy and highly charged He2+. (Now there’s a molecule you don’t see too often).
You might think that a variable torrent of charged particles that are constantly changing speed and direction might have an impact on our atmosphere, but you’d be wrong (or at least, politically incorrect). On Earth the solar wind “just causes the northern lights”. How do we know? We’ve got climate models. In all known GCMs the total global forcing for solar wind is “zero”. Must be true.
Thus and verily the IPCC can conclude that a flow of high speed charged particles *definitely* doesn’t change jet streams or affect ozone in any way, nor does it change cloud cover. Don’t bother looking. CO2 can cause droughts, floods, volcanoes and belly fat, but the solar wind is just a trace gas, I mean, a magnetized plasma. Whatever.
In IPCC “Science” our magnetic field and dense atmosphere protects us from the solar wind like a perfect Level 3 Containment field — see the USS Enterprise, Stardate 2369. Obviously.
Nobody mention that the Solar Wind correlates with the surface temperature of the North Atlantic, or that it dumps energy into the far upper atmosphere.
But anyhow — for the astrochemistry buffs – another example of a model gone wrong:
The true power of the solar wind
The planets and moons of our solar system are continuously being bombarded by particles hurled away from the sun. On Earth this has hardly any effect, apart from the fascinating northern lights, because the dense atmosphere and the magnetic field of the Earth protect us from these solar wind particles. But on the Moon or on Mercury things are different: There, the uppermost layer of rock is gradually eroded by the impact of sun particles.
An Exosphere of Shattered Rock
“The solar wind consists of charged particles — mainly hydrogen and helium ions, but heavier atoms up to iron also play a role,” explains Prof. Friedrich Aumayr from the Institute of Applied Physics at TU Wien. These particles hit the surface rocks at a speed of 400 to 800 km per second and the impact can eject numerous other atoms. These particles can rise high before they fall back to the surface, creating an “exosphere” around the Moon or Mercury — an extremely thin atmosphere of atoms sputtered from the surface rocks by solar wind bombardment.
This exosphere is of great interest for space research because its composition allows scientists to deduce the chemical composition of the rock surface — and it is much easier to analyse the exosphere than to land a spacecraft on the surface.
Forgot the charge — it’s only physics:
Charge matters
However, this requires a precise understanding of the effects of the solar wind on the rock surfaces, and this is precisely where decisive gaps in knowledge still exist. Therefore, the TU Wien investigated the effect of ion bombardment on wollastonite, a typical moon rock. “Up to now it was assumed that the kinetic energy of the fast particles is primarily responsible for atomization of the rock surface,” says Paul Szabo, PhD student in Friedrich Aumayr’s team and first author of the current publication. “But this is only half the truth: we were able to show that the high electrical charge of the particles plays a decisive role. It is the reason that the particles on the surface can do much more damage than previously thought.”
They forgot the ol’ double-plus-helium
When the particles of the solar wind are multiply charged, i.e. when they lack several electrons, they carry a large amount of energy which is released in a flash on impact. “If this is not taken into account, the effects of the solar wind on various rocks are misjudged,” says Paul Szabo. Therefore, it is not possible to draw exact conclusions about the surface rocks with an incorrect model from the composition of the exosphere.
Protons make up by far the largest part of the solar wind, and so it was previously thought that they had the strongest influence on the rock. But as it turns out, helium actually plays the main role because, unlike protons, it can be charged twice as positively. And the contribution of heavier ions with an even greater electrical charge must not be neglected either.
REFERENCES
- Paul S. Szabo, R et al (2018) Solar Wind Sputtering of Wollastonite as a Lunar Analogue Material – Comparisons between Experiments and Simulation. Icarus, 2018; DOI: 10.1016/j.icarus.2018.05.028
*Though in space, no one can hear you break the sound barrier.
Image: NASA