Orion nebula planet. Artwork of the Orion nebula seen from the surface of a planet only one light year from it. The four stars of the Trapezium dominate the night sky. This is a cluster of very young, hot stars that formed from the contraction of a dense cloud of gas. The radiation from the stars causes the remaining gas to glow. Gas heated by the stars also crashes into the surrounding material, compressing and heating it, and causing it to emit light. Stars seen through the nebula appear greatly reddened as their blue light is scattered away by the gas. The Orion nebula is a huge starbirth region that lies around 1400 light years from Earth.