I heard that the sun does not have a surface ( that it is for example as dence as a cloud) if ths is true, what keeps the sun in a spherical shape? does it have a force acting upon it to keep its shape?

I've heard that most of the earth's energy comes from the sun (oil, wind, solar etc). Where does the rest of it come from?

If we are hit by a CME what may happen? Also, can we predict them and how? What can we do to protect ourselves?

If we consider thermodynamics and its law that heat travels from hot to cold, I was curious as to how or what occurs when sunlight is travelling to Earth. The gap between the Sun and the Earth is effectively a vacuum and also the low pressure at high altitudes mean that it is very cold, surely the heat should be dispersed by then and not reach sea level.

I would like to know how we still manage to feel the heat.

Thank you

if we dont have sun in our solar system ? and All the planets were not moving ? Like the thought as Earth is moving rotational spin and other planets are freezed position !

As far as our techology concerned Are there any chances to land on the surface of SUN in future?

This photo was taken on a train travelling south to Hastings. The flat windows had horizontal and vertical scratches, perhaps from cleaning. The arc that is illuminated by the sun appears to be centred on the vanishing point of the axis of the carriage. The Sun lies on the arc. Why this arc?

Why do we perceive the sun as yellow? I understand that its colour arises from the mixture of wavelengths in sunlight. But as sunlight has been the main source of illumination throughout evolution - the background light to everything on the planet up to the invention of electric light - it gives us our default colour for everything. So why don't we consider it to be the neutral colour - in other words, white?

Perry Bebbington, Kimberley, Nottinghamshire, UK

Whenever you see the Starship Enterprise off on a mission, an 'outside' shot always shows the vessel in full visiblity - but how visible would it be? must you always be illuminated by lights on the top, or a planet nearby? If we were away from any planets and suns, and I were to space walk a few hundred yards away from the ship, and it had no lights on the outside, would I only see stars and a black 'shadow' where the ship was? Or is there always residual light? could I for example see my own hand in front of my face? or is there a point where you can see nothing nearby, but only stars and galaxies in the distance?

Melanin is a pigment found in the iris (eye), hair and skin. Melanin protects DNA from damages caused by the sun, hence the darkening of skin. However, hair tends to get lighter in the sun despite containing melanin....does the pigment have a different role here?