what makes a planet a planet nasa
Credit: NASA/ESA/Hubble Heritage Team (STScI/AURA). The planets in our solar system didnât appear out of nowhere. Neither did the sun. They were all part of a big cloud of gas and dust.Gravity collected lots of material in the center to create the sun. The left over stuff swirled around the forming sun, colliding and collecting together. Some would have enough gravity to attract even more gas and dust, eventually forming planets.ost of the time these clouds form a type of star called a brown dwarf. They are pretty big compared to most planets, but they are not big enough to turn into the kind of star that makes lots of energy and gives off light. Relative sizes of different planets, our sun, and things in between.