The observable universe is constantly expanding as more light from the Big Bang reaches us. This light has been travelling for billions of years, so we are looking at the universe as it was a few b…

This answer suggests that when there is zero radial velocity… there will be no Doppler shift but it's not likely to be intended as precise and absolute. I remember reading about something like t…

I am a beginner. Please let me know whether earth has retrograde motion If it does not, let me know the reason

Recent evidence ensures that methane is the second, after carbon dioxide, to create a greenhouse effect, although it is easier to control. Atmospheric methane has doubled in the last 200 years, and its extinction potential is more than 20 times greater than that of carbon dioxide.

Yes, it looks like Saturn, but Saturn is only one of the four giant planets ringed in our Solar System. While Saturn has the brightest rings, this system of rings and moons actually belongs to the planet Uranus, photographed here in quasi-infrared light by the Antu telescope, at the European Southern Observatory (ESO) in Chile .

Sunspots rise vertically? Do they float on the surface like oil? Do they flow up or down vertically from the Sun's core like a lava lamp?