Chapter 8: The Solar System

________ is about 2, 400 km in diameter and has one moon.

________ has at least 27 moons and also has a thin ring system made of eleven separate rings.

________ is the second- largest planet in the solar system, but it has only about one- third as much mass as Jupiter.

The ________ is much thinner than Earths and is composed mostly of carbon dioxide, with some nitrogen and argon.

________: Used to measure the large distances within the solar system; equals the average distance from Earth to the Sun, about 150 million km.

________ on Earth allow water to exist as a solid, a liquid, and a gas.

________ presented his geocentric model of the solar system in 140 A.D.

________ relatively large core and thin outer layers resulted in some extreme differences in its surface terrain.

________ was the first to discover these moons when he looked through his telescope and he drew a picture of what he saw.

________ 10 was the first American space probe sent to Mercury.

________ has two small, heavily cratered moons called Phobos and Deimos.

Unlike ________ and the other planets, Uranuss axis of rotation is tilted so that it is nearly parallel to the plane of the planets orbit.

________ is the largest planet and contains more than twice the mass as all other planets combined.

________ have devised new techniques and instruments to find planets around other stars.

________ atmosphere contains about 83 percent hydrogen, 15 percent helium, 2 percent methane, and traces of other gases.

________ is small and has a relatively weak gravitational pull.

________ has at least 13 moons.

________ also discovered colonies of bacteria living off the extremely hot material spewing from volcanic vents.

________ has been labeled a distant planetoid and with a diameter of 1, 200 to 1, 700 km, it is smaller than Pluto, but larger than comets in the Kuiper Belt.

The ________ in the atmosphere also contain droplets of sulfuric acid, which gives them a slightly yellow color.

________ could hold more than twice the amount of water that Earths oceans hold.

Most asteroids are found in a belt between the ________ and Jupiter.

They may have formed when ________ collided or when comets passed close to the Sun, leaving a trail of debris.

________: Other rocky objects orbiting within the solar system.

________: composed of dust and rock particles mixed with frozen water, methane, and ammonia.

The ________ of Venus, which has 92 times the surface pressure of Earths at sea level, is mostly carbon dioxide.

________: Sun- centered model of the solar system.

________: the second planet from the Sun.

________ is tilted 25° on its axis, which is very close to Earths tilt.

________ has more than 60 moons.

________ concluded that Earth and Venus revolve around the Sun and that the Sun is the center of the solar system.

________: the seventh planet from the Sun.

________ was discovered in 1846 after studies of Uranuss orbit indicated that the orbit was being affected by gravity of another unseen planet.

________ is composed almost entirely of hydrogen and helium, with traces of methane, ammonia, and water vapor.

Ozone in ________ atmosphere also protects life from the Suns intense radiation.

________ comes as close as 76 AU from the Sun, but travels to a distance of 950 AU- far beyond the Kuiper Belt, but much closer than the Oort Cloud.

________: Rocky objects formed from material similar to that of the planets.

________ often have two tails- one made of dust and one made of ions.

________: The smallest and closest planet to the Sun.

________: the eighth planet from the Sun.

________: The fifth planet from the Sun.

________ has been a priority of NASA planetary exploration for several decades.

________ is covered by craters, some of which have double rings.

________ is called the red planet because iron oxide in some of the weathered rocks on its surface gives it a reddish color.

Sun-centered model of the solar system

Used to measure the large distances within the solar system; equals the average distance from Earth to the Sun, about 150 million km

planets in orbit around other stars

The smallest and closest planet to the Sun

the second planet from the Sun

The third planet from the Sun

The fourth planet from the Sun; red planet

The fifth planet from the Sun

the sixth planet from the Sun

the seventh planet from the Sun

the eighth planet from the Sun

composed of dust and rock particles mixed with frozen water, methane, and ammonia

Rocky objects formed from material similar to that of the planets

Other rocky objects orbiting within the solar system

life on other worlds

Most comets come from a(n) ________ comets called the Kuiper Belt near Neptunes orbit, or from the Oort Cloud that surrounds the solar system.

The magnetic field around ________, discovered by Mariner 10, indicates that ________ has a much larger iron core than would be expected and is missing some lighter materials you would expect to find in its mantle.

pressure gas have been observed on Jupiter

action between the ring particles and some of Saturns moons