Astro 1010 Final Exam Study Guide - Chapter 12 & 13

Flashcards about Asteroids, Comets, Dwarf Planets and Other Planetary Systems.

Asteroid Belt

Located between the orbits of Mars and Jupiter; consists of asteroids made of metals and/or carbon-rich rock.

Orbital Resonances (Asteroid Belt)

Set the inner and outer edges of the asteroid belt with Jupiter; gaps within the belt are also due to orbital resonances.

Jupiter's Gravity (Asteroid Belt)

Prevented a large, single object from forming in the asteroid belt.

Ceres

The only dwarf planet in the asteroid belt, containing 1/3 of the main belt's mass.

Ida

The first asteroid discovered to have its own moon.

Trojan Asteroids

Asteroids found in the L4 and L5 Lagrangian points of Jupiter, outside the main asteroid belt.

Kuiper Belt

Located beyond the orbit of Neptune; consists of icy objects similar in composition to comets.

Short-Period Comets

Originate in the Kuiper Belt (T < 200 years).

Orbital Resonances (Kuiper Belt)

Set the inner and outer edges of the main Kuiper Belt, due to interactions with Neptune.

Pluto

A dwarf planet in the Kuiper Belt with five moons, one of which (Charon) is half its size.

Eris

A dwarf planet slightly more massive than Pluto; its discovery prompted the creation of the dwarf planet classification.

Oort Cloud

A spherical distribution of icy objects at the extreme edge of the solar system; the origin of long-period comets.

Long-Period Comets

Originate in the Oort cloud (T > 200 years).

Comets (Composition)

Frozen lumps of ice that form comas and tails when close to the sun due to sublimation.

Coma Formation

Occurs when a comet is within 3-5 AU from the sun.

Tail Formation

Occurs when a comet is within about 1 AU from the sun.

Comet Tails

Comets have two tails: a plasma tail that points directly away from the sun and a dust tail that curves away from the sun.

Direct Imaging

A method of detecting extrasolar planets that can only be done for planets in wide orbits around nearby stars.

Astrometry

A method of detecting extrasolar planets that looks for the slight motion of a star in the sky as a planet pulls on it.

Doppler Shifts

A method of detecting extrasolar planets that looks for a blueshift/redshift of a star’s spectra as a planet pulls on it.

Transits

A method of detecting extrasolar planets that looks for a dip in a star’s luminosity when a planet passes directly in front of it.

Kepler Space Telescope

Found thousands of extrasolar planets using the transit method.

Habitable Zones

The range of distances around a star within which a planet with an atmosphere can support liquid water on its surface.

Brown Dwarf

An intermediate class of objects too massive to be a gas giant but of insufficient mass to be a star.

Rogue Planets

Objects that formed in orbit around a star but were later ejected and now orbit the center of the galaxy on their own.