Chapters 30.3 and 4

Question 1

Extraterrestrial life

Answer 1

Life beyond earth

Question 2

Jupiter

Answer 2

It is the fifth planet from the sun and is the largest planet, containing more than twice the mass of all the other planets combined. It is made up of about 90 percent hydrogen and 10 percent helium with traces of ammonia, methane, and water vapor. Beneath Jupiter’s gaseous atmosphere, there is a layer of liquid metallic hydrogen subjected to extreme pressure. Scientists believe that a metallic core, 5 to 15 times the mass of Earth, resides beneath this layer. Temperatures in the core could reach 40,000 degrees Celsius. It has weak rings around it and it has a large red spot caused by its bands and clouds that it has around it white, red and brown.

Question 3

Saturn

Answer 3

It is the second largest and has the lowest density of any planet in the solar system, even less dense than water. Like Jupiter, Saturn is composed of hydrogen and helium with traces of methane, ammonia, and water vapor. Its interior has a Jupiter-like structure. Beneath the atmosphere is a thick layer of liquid hydrogen and probably a rocky core. Saturn has the largest and most complex ring system of all the planets. The Saturn rings are made up of water ice particles. These particles range in size from millimeters to ten meters in diameter. Every particle in the ring orbits Saturn. The rings appear as seven broad bands, each made up of thousands of thin curls.

Question 4

Uranus

Answer 4

Uranus is four times the diameter of Earth and has about 27 moons and a thin ring system made up of eleven rings. Unlike Earth and the other planets, Uranus’ axis of rotation is tilted so that it is almost parallel to the plane of the planet’s orbit.
Uranus’ atmosphere contains about 83 percent hydrogen, 15 percent helium, 2 percent methane, and other trace gases. Methane in the upper atmosphere absorbs red light from the Sun, and the planet’s clouds reflect blue-green light.

Question 5

Neptune

Answer 5

Neptune’s atmosphere contains about 3 percent methane, which makes it appear bluer than Uranus. Neptune’s atmosphere feeds on internal heat, creating the fastest winds (2,000 km / h) in the solar system. Neptune has a rocky core surrounded by an icy mantle and a layer of liquid metallic hydrogen on the surface. Like Uranus, Neptune also has a weak ring system. Neptune has at least 13 moons. Triton is the largest moon with a diameter of 2,700 km and a thick atmosphere composed mainly of nitrogen, although some methane is also present.

Question 6

Dwarf planet

Answer 6

The dwarf planets are almost round objects in orbit around the Sun that are not satellites and that have not cleared the debris in their orbits, they are Pluto, Eris, Ceres, Makemake, and Haumea.

Question 7

Comet

Answer 7

A comet is made up of dust and rock particles, frozen water, methane, and ammonia. When a comet approaches the Sun, it begins to vaporize due to the Sun’s heat. The released dust and gases form a bright cloud called a coma around the nucleus, which is the solid part of the comet.

Question 8

Asteroid

Answer 8

Rocky objects formed from material similar to material in the composition of planets are called asteroids. Most asteroids lie between the orbits of Mars and Jupiter. Asteroids vary in size, from minute particles to about 500 km in diameter.

Question 9

Meteoroid

Answer 9

Objects the size of sand to rock in the solar system are called meteoroids. Meteorites are smaller than asteroids, so small that they are not observable until they enter Earth’s atmosphere. When a meteoroid enters the atmosphere, it heats up and emits light. Most are completely burned up and we see them as meteors or “shooting stars.” Those that impact the Earth’s surface are called meteorites.

Question 10

Sedna

Answer 10

Sedna has been labeled a distant planetoid. With a diameter of 1,200 to 1,700 km, it is smaller than Pluto but larger than comets in the Kuiper Belt. In addition, it has an elliptical orbit; Sedna travels within the 76-950 AU range from the Sun. These greater distances are well beyond the Kuiper Belt, but much closer than the Oort Cloud. Remember that one astronomical unit (AU) equals 150 million kilometers. Another conundrum is Sedna’s apparent rotation rate of 40 days. This is best explained if the object has another object orbiting it. Even if Sedna has no partner, there may be other similar objects, some even larger than Pluto. Currently, objects as far away with orbits like this elliptical can be detected only when they are closer to the Sun.