Farside

[Eieretertje Hayday]

What do the pictures of farside mean? how do you get them? Is not sun rotating?

[Marcel de Bont]

The sun is rotating yes but there are currently two spacecrafts in an orbit around the sun which can see parts of the farside. Farside = backside of the sun from Earth's perspective. Thanks to the images that those two spacecraft make we can see the entire Sun.

This is the STEREO (Solar TErrestrial RElations Observatory) mission. One spacecraft is in an orbit around the Sun slightly slower then Earth's. This is STEREO Behind (STEREO B) because it's trailing behind Earth's orbit. The other one is called STEREO Ahead (STEREO A) and is in a slightly faster orbit around the Sun then Earth's orbit. It's called STEREO Ahead because it's ahead of Earth in it's orbit.

If we take images from STEREO Ahead, STEREO Behind and images from the spacecrafts that observe the Sun from Earth's perspective, we can make an image that shows the entire Sun. Hopefully this answers your questions.