Vocabulary Ch 19 Flashcards
Explanation for natural events that involves gradual changes as opposed to sudden catastrophic changes for examples, the formation of the planets in the gas cloud around the forming sun.
Evolutionary Hypothesis
Explanation for natural processes that depends on dramatic and unlikely events, such as the collision of two stars to produce our solar system.
Catastrophic Hypothesis
The proposal that our solar system formed when two stars passed near each other and material was pulled out of one to form the planets.
Passing Star Hypothesis
The proposal that the solar system formed from a rotating cloud of gas.
Nebular Hypothesis
The proposal that the planets formed from the same cloud of gas and dust that formed the sun.
Solar Nebula Theory
Earth-like planet small, dense, and rocky.
Terrestrial Planets
Jupiter-like planet with large diameter and low density
Jovian Planets
Small, rocky world; most asteroids lie between Mars and Jupiter in the asteroid belt.
Asteroids
The collection of icy planetesimals that orbit in a region from just beyond Neptune out to about 50 AU.
Kuiper Belt
One of the small, icy bodies that orbit the sun and produce tails of gas and dust when they near the sun.
Comets
A small bit of matter heated by friction to incandescent vapor as it falls into earth’s atmosphere.
Meteors
A meteor that has survived its passage through the atmosphere and strikes the ground
Meteorites
The time required for half of the atoms in a radioactive sample to decay.
Half-Life
The sticking together of solid particles to produce a larger particle.
Accretion
One of the small bodies that formed from the solar nebula and eventually grew into protoplanets.
Planetesimals
Massive object resulting from the coalesence of planetesimals in the solar nebula and destined to become a planet.
Protoplanets
The puzzle that protoplantery disks around young stars dont seem to survive long enough to form Jovian planets by condensation, accretion, and gravitational collapse, yet Jovian-mass extrasolar planets are common.
Jovian Problem
The period of intense meteorite impacts early in the formation of the planets, when the solar system was filled with debris.
Heavy Bombardment
A planet orbiting a star other than the sun
Extrasolar Planets
A massive and presumably Jovian planet that orbits close to its star and consequently has a high temperature
Hot Jupiters
A meteor in space before it enters Earth’s atmosphere.
Meteoroids
