solar wind tagged posts

Noctilucent clouds were once thought to be a fairly modern phenomenon. A team of researchers recently calculated that Earth and the entire solar system may well have passed through two dense interstellar clouds, causing global noctilucent clouds that may have driven an ice age.

The event is thought to have happened 7 million years ago and would have compressed the heliosphere, exposing Earth to the interstellar medium.

Interstellar clouds are vast regions of gas and dust between the stars within galaxies. They are mostly made up of hydrogen along with a little helium and trace elements of heavier elements.

They are a key part of the life cycle of stars, providing the materials for new stars to be formed, and are seeded with elements after stars die...

Physicists led by the University of Iowa have learned how a type of aurora on Mars is formed.

In a new study, the physicists studied discrete aurora, a light-in-the-sky display that occurs mostly during the night in the red planet’s southern hemisphere. While scientists have known about discrete aurora on Mars-which also occur on Earth – they did not know how they formed...

The further we move away from a heat source, the cooler the air gets. Bizarrely, the same can’t be said for the Sun, but University of Otago scientists may have just explained a key part of why.

Study lead Dr Jonathan Squire, of the Department of Physics, says the surface of the Sun starts at 6000 degree C, but over a short distance of only a few hundred kilometers, it suddenly heats up to more than a million degrees, becoming its atmosphere, or corona.

“This is so hot that the gas escapes the Sun’s gravity as ‘solar wind’, and flies into space, smashing into Earth and other planets.

“We know from measurements and theory that the sudden temperature ju...

On Feb. 4, 2022, SpaceX launched 49 satellites as part of Elon Musk’s Starlink internet project, most of which burned up in the atmosphere days later. The cause of this more than US$50 million failure was a geomagnetic storm caused by the sun.

Geomagnetic storms occur when space weather hits and interacts with the Earth. Space weather is caused by fluctuations within the sun that blast electrons, protons and other particles into space. When space weather reaches Earth, it triggers many complicated processes that can cause a lot of trouble for anything in orbit. And engineers are working to better understand these risks and defend satellites against them.

What causes space weather?

The sun is always releasing a steady amount of charged particles into space...