Keplers Third Law. The ratio of the periods squared of any two planets around the sun is equal to the ratio of their average distances from the sun cubed. In equation form, this is. T 1 2 T 2 2 = r 1 3 r 2 3 , where T is the period (time for one orbit) and r is the average distance (also called orbital radius). Thesun is the closest star to Earth.Even at a distance of 150 million kilometers (93 million miles), its gravitational pull holds the planet in orbit. It radiates light and heat, or solar energy, which makes it possible for life to exist on Earth. Plants need sunlight to grow. Animals, including humans, need plants for food and the oxygen they produce. Thesun has been rotating for a long, long time — it started around the time that it formed from a whirling cloud of dust and hydrogen gas about 4.6 billion years ago. "Pretty much everything in the universe rotates," explains Claire Raftery, head of education and outreach for the National Solar Observatory, the U.S. center for ground-based solar physics, which is located on the campus of OpNifRT.

nonton film the sun does not move