What are “solar winds” (or other such phenomena) and how do they affect spacecraft if space is essentially emptiness and vacuum?

Question

I’ve heard how space probes use their “sails” to make use of “solar winds” to travel distances. But isn’t space just vast emptiness with no resistance/ friction?

In: 4

Answer 1

The sun is not a lightbulb.

It’s a massive boiling sea of nuclear-powered hydrogen and helium in a constant state of explodium.

At any given time, that hydrogen is spraying off the sun in vast amounts and flying off into interstellar space.

By the time it gets out the 93 million miles to earth, it’s pretty tenuous and very low pressure. You wouldn’t notice it on your bare skin, A cloth sail wouldn’t noticeably ripple.

But for a very lightweight spacecraft with a large enough piece of foil as a sail, it’s a steady breeze outwards from the sun, and you can leverage that over long periods of time to get a fair amount of speed for free.