QUEST 1 Most stars are bigger than Earth the most obvious example being the sun which is a star and is bigger than the earth. And there are stars discovered which are 100-200 times bigger than the sun. Scientists study stars, and place them in groups based on how they are alike, and how they are different. QUEST 2 The sun is bigger than the earth and the moon. It has a diameter of about 1,392,000 km which is about 109 times that of the Earth and a mass of about 2Ã—1030 kilograms which is 330,000 times that of the Earth. Consequently, the sun accounts for about 99.86% of the total mass of the Solar System. The moon is a quarter of the diameter of Earth and it is 1„81 of the mass of Earth.