Bianca P1

4. a source of comets, as it very slowly erodes itself away.
5. a measure of how much a conic section deviates from being circular.
6. long cliffs on mercury's surface
8. Kepler's First Law: each planet's orbit about the Sun is an _______
11. apparent motion of a body in a direction opposite to that of the (direct) motions of most members of the solar system or of other astronomical systems with a preferred direction of motion.
14. When a meteoroid survives a trip through the atmosphere and hits the ground
16. celestial event in which a number of meteors are observed to radiate, or originate, from one point in the night sky.
17. The planets Mercury, Venus, Earth, and Mars, are called _______ because they have a compact, rocky surface like Earth's terra firma.
18. a unit of measurement equal to 149.6 million kilometers, the mean distance from the center of the earth to the center of the sun.

1. a fundamental system in condensed matter sciences and the main constituent of gas giant planets.
2. a small body moving in the solar system that would become a meteor if it entered the earth's atmosphere.
3. a small body of matter from outer space that enters the earth's atmosphere, becoming incandescent as a result of friction and appearing as a streak of light.
7. cloud structures on jupiter
9. a solid object arising during the accumulation of orbiting bodies whose internal strength is dominated by self-gravity and whose orbital dynamics is not significantly affected by gas drag.
10. the distance from a star that allows liquid water to persist on its surface
12. an icy, small Solar System body that warms and begins to release gases when passing close to the Sun
13. These are also called the Jovian planets.
15. a celestial body resembling a small planet but lacking certain technical criteria that are required for it to be classed as such.