solar wind tagged posts

When the sun expels plasma, the solar wind cools as it expands through space – but not as much as the laws of physics would predict. Physicists now know the reason. University of Wisconsin-Madison physicists provide an explanation for the discrepancy in solar wind temperature. Their findings suggest ways to study solar wind phenomena in research labs and learn about solar wind properties in other star systems.

“People have been studying the solar wind since its discovery in 1959, but there are many important properties of this plasma which are still not well understood,” says Stas Boldyrev, professor of physics and lea...

Scientists re-inspected 45-year-old Helios data, finding long trains of massive blobs – like lava lamp’s otherworldly bubbles, but 50 to 500 times the size of Earth – that ooze from the sun every 90 minutes or so. When Simone Di Matteo first saw the patterns in his data, it seemed too good to be true. “It’s too perfect!” Di Matteo, a space physics Ph.D. student at the University of L’Aquila in Italy, recalled thinking. “It can’t be real.” And it wasn’t, he’d soon find out.

Di Matteo was looking for long trains of massive blobs – like a lava lamp’s otherworldly bubbles, but anywhere from 50 to 500 times the size of Earth — in the solar wind...

When a stream of charged particles known as the solar wind careens onto the Moon’s surface at 450 kilometers per second (or nearly 1 million miles per hour), they enrich the Moon’s surface in ingredients that could make water, NASA scientists have found.

Using a computer program, scientists simulated the chemistry that unfolds when the solar wind pelts the Moon’s surface. As the Sun streams protons to the Moon, they found, those particles interact with electrons in the lunar surface, making hydrogen (H) atoms. These atoms then migrate through the surface and latch onto the abundant oxygen (O) atoms bound in the silica (SiO2) and other oxygen-bearing molecules that make up the lunar soil, or regolith...

Particles from the sun are constantly hitting the surface of mercury. Credit: NASA, montage: TU Wien

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.

New results of the TU Wien now show that previous models of this process are incomplete. The effects of solar wind bombardment are in some cases much more drastic than previously thought...