Objects in the Sky astronomer - a scientist who studies objects in the sky
orbit - the path that one object in the sky follows around another
phases - patterns that happen over and over again
spin - to turn swiftly
shadow - an area where light from a light source cannot reach because another object is in the way
constellation - a group of stars that form a pattern or picture in the night sky
position - the location of a planet, star, constellation in the sky, which seems to change as Earth rotates and orbits
Earth - the third planet from the Sun, which is the fifth- largest of the eight planets in the Solar System
Sun - the star which provides Earth with energy, light, and heat
Moon - the only known natural satellite of Earth and the fifth largest satellite in the Solar System
satellite - an object naturally occurring in orbit (e.g.: a moon, a planet, a comet, an asteroid, etc.)
axis - a straight line that an object or body rotates or seems to rotate around
rotation - the motion of a planet, satellite or the Sun around its north south axis (ex. Every 24 hours the Earth rotates once on its axis).
year - the time it takes for a planet to go all the way around the Sun ex: on Earth a year is 365 days
planet - a celestial bodyorbiting a star or stellar remnant that is large enough to be a sphere because of its gravity and which has not joined to other planets or objects in the sky
dwarf planets - is a celestial bodyorbiting around the sun which is large enough to be a sphere but smaller than necessary to be designated a planet