Who first observed the solar wind directly and when did this happen?
The Soviet spacecraft Luna 1 directly observed the solar wind in January 1959. This mission measured the strength of the stream using hemispherical ion traps.
Questions about Solar wind
Short answers, pulled from the story.
What is the velocity difference between slow solar wind and fast solar wind near Earth?
Slow solar wind has a velocity of 400 kilometers per second while fast solar wind reaches 750 kilometers per second. The slow solar wind is also twice as dense and more variable than the fast component.
When did Parker Solar Probe cross the Alfvén surface for the first time?
Parker Solar Probe encountered specific conditions indicating it had crossed the Alfvén surface on the 28th of April 2021. This event occurred at a distance of 18.8 solar radii from the Sun.
How does solar wind affect planets without strong magnetic fields like Mars or Venus?
Planets with weak or non-existent magnetospheres face atmospheric stripping by the solar wind. NASA's Mars Atmosphere and Volatile Evolution mission measured this loss rate at about 100 grams per second for Mars.
Where is the heliopause located relative to Pluto orbit and Voyager 1 spacecraft?
The heliopause was detected about 120 astronomical units away by Voyager 1 spacecraft. This boundary lies far outside Pluto orbit where the solar wind can no longer push back interstellar medium.