Question

3. some of the planets much further out than earth are brighter in earth’s night sky than planets closer to earth. what could that tell us about those brighter outer planets?

Answer 1

Jupiter is extremely bright in the night sky; only the Moon and Venus are brighter (Figure below). This brightness is all the more impressive because Jupiter is quite far from the Earth — 5.20 AUs away. The outer planets are gas giants Jupiter and Saturn and ice giants Uranus and Neptune. Beyond Neptune, a newer class of smaller worlds called dwarf planets reign, including longtime favorite Pluto. Thousands more planets have been discovered beyond our solar system.