Download Chapter 14

Chapter 14
Section 1
1. Geocentric- an Earth-centered model.
2. Heliocentric- this sun-centered model.
3. Eclipse- is an oval shape, which may be elongated or nearly circular.
4. Moon- is a natural satellite that revolves around a planet.
5. Astronomical unit- equals Earth’s average distance from the sun.
Section 2
1. Nuclear fusion- two atomic nuclei combine, forming a larger, more massive
nucleus and releasing energy.
2. Core- the central region of the sun, where nuclear fusion takes place.
3. Radiation zone- is a region of very tightly packed gas where energy is transferred
mainly in the form of electromagnetic radiation.
4. Conventional zone- is the outermost layer of the sun’s interior.
5. Photosphere- the inner layer of the sun’s atmosphere.
6. Chromosphere- the middle layer of the sun’s atmosphere.
7. Corona- the outer layer of the sun’s atmosphere.
8. Solar wind- streams of electrically charged particles.
9. Sunspots- areas of gas on the sun’s surface that are cooler than the gases around
them.
10. Prominences- huge, reddish loops of gas.
11. Solar flare- an eruption of gas from the sun’s surface that occurs when the loops
in sunspot regions suddenly connect.
Section 3
1. Terrestrial planets- the name often given to the four inner planets: Mercury,
Venus, Earth, and Mars.
2. Greenhouse effect- trapping of heat by the atmosphere.
Section 4
1. Gas giants- the name often given to the first four outer planets: Jupiter, Saturn,
Uranus, and Neptune.
2. Ring- is a thin disk of small particles of ice and rock.
Section 5
1. Comet- a loose collection of ice, dust, and small rocky particles, typically with a
long, narrow orbit.
2. Coma- clouds of gas and dust from a fuzzy outer layer.
3. Nucleus- the solid inner core of a comet.
4. Kuiper belt- is a doughnut-shaped region that extends from beyond Neptune’s
orbit to about 100 times Earth’s distance from the sun.
5. Oort cloud- is a spherical region of comets that surrounds the solar system from
about 1,000 to 10,000 times the distance between Pluto and the sun.
6. Asteroids- rocky objects revolving around the sun that are too small and
numerous to be considered planets.
7. Asteroid belt- the region of the solar system.
8. Meteroid- is a chunk of rock or dust in space.
9. Meteor- a streak of light in the sky produced by the burning off a meteoroid in
Earth’s atmosphere.
10. Meteorites- Meteoroids that pass through the atmosphere and strike Earth’s
surface.
Section 6
1. Extraterrestrial life- life other than that on Earth.