astrophysics

• star

  giant balls of hot, burning gas, mainly hydrogen but with some helium and small amounts of other elements.
• moons


  they are small planetary bodies which are heavy enough to form a spherical shape, but still orbit another planetary body (a planet). they are natural satellites
• planets

  planets can be made of either rock or gas. they are heavy enough to form spherical shapes, and sometimes have moons. they orbit around a star, in the earth and all other planets in the solar system's case, the sun.
• comets


  comets are small balls of dust and ice which orbit the sun in irregular elliptical orbits. they have two tails which both point away from the sun, one ice, on dust.
• meteors


  meteors are balls of rubble held together by gravity. when entering the earth's atmosphere, they burn up due to the high entry speeds and friction. they become meteorites if they manage to survive the trip through the atmosphere of a planet and hit the ground.
• geostationary orbit?

  when a satellite remains in the same spot over the earth's surface. this means it is still moving very fast, but appears to stay still. it will always be located over the equator.
• polar orbit

  a polar orbit is when a satellite orbits above either the north pole or the south pole. they are usually used as spy satellites or monitoring the weather.
• how are seasons on the earth formed?

  the tilt of the earth's axis creates seasons, as one side of the earth is always closer to the sun than the other.
• lunar eclipse


  when the earth passes in between the sun and the moon, casting a reddish shadow on the moon. they are sometimes called "blood moons" because of this red hue.
• solar eclipse


  when the moon passes in between the sun and the earth, causing the earth to be in shadow, as the sun is blocked out temporarily.