Universe And Solar System

Question 1

These are the hottest stars, with a surface temperature of more than 37,000°F.

Answer 1

Blue Stars

Question 2

These are warm stars, such as the Sun. Their temperature is about 10,000°F.

Answer 2

Yellow Stars

Question 3

The coolest stars are * . Their surface temperature is less than 5,500°F.

Answer 3

Red Stars

Question 4

When light coming from a distant star is seen through a spectroscope (an instrument that separates light into its different colors); the light we receive continues to shift toward the red area of the spectrum, which is the least powerful. This means that, since the light is becoming weaker and weaker, the stars must be traveling away from us. This makes scientists believe that our universe is expanding.

Answer 4

Red Shift

Question 5

A swirling cloud on the planet Jupiter is a raging storm of gases, mainly red phosphorus.

Answer 5

Red Spot

Question 6

are immense systems containing billions of stars

have different shapes: some are spiral, others are elliptical, or oval- shaped, and some are irregular

Answer 6

Galaxies

Question 7

spiral-shaped galaxy about 100,000 light-years in diameter and about 10,000 light-years in thickness.

Answer 7

Milky Way

Question 8

appear as dark spots on the Sun, and are believed to be cooler than the rest of the Sun. They appear in 11-year cycles.

Answer 8

Sunspots

Question 9

the term used for a body in orbit around the Sun. The word comes from the Greek planetes, and means “wanderers

Answer 9

planets

Question 10

term for a body in orbit around a planet

Answer 10

Satellite (or moon)

Question 11

But when Galileo Galilei discovered the four main moons of the planet *, Johannes Kepler wrote Galileo a letter suggesting he call them “satellites” (from the Latin satelles, which means attendant). The word means the same thing as “moon.”

Answer 11

Jupiter

Question 12

path traveled by a body in space. It comes from the Latin orbis, which means circle. Some orbits are nearly circular, but the orbits of most planets are ellipses—shaped like ovals.

Answer 12

orbit

Question 13

also known as the minor planets, are small bodies orbiting the Sun that resemble planets. most are found between Mars and Jupiter. Usually having an irregular shape, asteroids—at least those discovered thus far—can range in size from 580 miles (940 km) in diameter, which is the size of the asteroid Ceres, to just 33 ft. (10 m) in diameter

Answer 13

Asteroids

Question 14

are made up of frozen dust and gases, and have been described as large, dirty snowballs with icy centers. They often travel on extremely elongated orbits around the Sun. The tail of a comet, called a *, forms when the comet comes within 100 million miles of the Sun. It is then affected by the solar wind (hydrogen and helium that travel away from the Sun at high speeds), which causes a tail of dust and gases to form behind the comet.

Answer 14

comet, coma

Question 15

fragments of comets, planets, moons, or asteroids that have broken off. It is estimated that a billion meteors enter our atmosphere every day. Contact with our atmosphere causes most to disintegrate before reaching Earth. Those that do not disintegrate completely but fall to Earth are called * .

Answer 15

Meteors

meteorites

Question 16

occur when a star runs out of energy and shuts down. The force of gravity at its center pulls the mass of the star in on itself, forcing it to collapse. It resembles the glowing cinders of a fire that has died down. It is called a white dwarf because it emits a white glow.

Answer 16

White dwarfs

Question 17

are also called failed stars. They lack enough energy to be true stars but are also too massive and hot to be planets.

Answer 17

Brown Dwarfs

Question 18

is an extremely large exploding star. Just before the star dies, it releases huge amounts of energy, briefly becoming millions of times brighter than it was. Then it immediately shrinks.

Answer 18

supernova

Question 19

are formed after a supernova explodes and shrinks. The shrunken form of the star becomes incredibly dense and compact as gravity pulls all of its matter inward. It becomes so compressed that a million tons of its matter would hardly fill a thimble. This density crushes together the electrons and protons that make up its atoms, turning them into neutrons.

Answer 19

Neutron stars

Question 20

are believed to be rapidly spinning neutron stars that give off bursts of radio waves at regular intervals. * is a shortened version of Puls[ating st]ar.

Answer 20

Pulsar

Question 21

are believed to be the most remote objects in the universe. Despite their small size they produce tremendous amounts of light and microwave radiation: not much bigger than Earth’s solar system, they pour out 100 to 1,000 times as much light as an entire galaxy containing a hundred billion stars.

Answer 21

Quasars

Question 22

is created by the total gravitational collapse of a massive star or group of stars. It is the final phase of some stars, in which gravity sucks the star in on itself—it implodes rather than explodes. This makes it so dense that not even light can escape its gravitational field.

Answer 22

black hole

Question 23

giant glowing cloud thought to be made up of dust and gas. * were thought to have been galaxies that appeared as a blur because they were so far away, but as more powerful telescopes were created, they showed that nebulae were not clumps of stars but in fact a hazy cloud of gasses. A * is illuminated by bright stars nearby.

Answer 23

nebula

Question 24

has almost no atmosphere, and its dusty surface of craters resembles the Moon

Answer 24

Mercury

Question 25

often called Earth’s twin because the two planets are close in size; The thick clouds that cover * create a greenhouse effect that keeps it sizzling at 864°F. named after the Roman goddess of love and beauty, is also known as the “morning star” and “evening star” since it is visible at these times to the unaided eye. * appears as a bright, white disk from Earth.

Answer 25

Venus

Question 26

Three-quarters red, * also has dark blotches on it and white areas at the poles—these are white polar ice caps.

Answer 26

Mars

Question 27

A belt of asteroids (fragments of rock and iron) between Mars and Jupiter separate the four inner
planets from the five outer planets

Answer 27

Asteroid belt, main asteroid belt or main belt

Question 28

Its most distinguishing feature is “the Great Red Spot,” an intense windstorm larger in size than Earth, which has continued for centuries without any signs of dying down. It has 63 moons and 4 rings.

the largest planet in our solar system

Answer 28

Jupiter

Question 29

the second-largest planet, has majestic rings surrounding it. Named for the Roman god of
farming, * seven rings are flat and lie inside one another. They are made of billions of ice particles. It has 31 moons and about 1000 rings.

Answer 29

Saturn

Question 30

a greenish-blue planet, twice as far from the Sun as its neighbor Saturn. * wasn’t
discovered until 1781. Its discoverer, William Herschel, named it Georgium Sidus (the Georgian star) after the English king, George III. Later its name was changed to Uranus, after an ancient Greek sky god, since all the other planets had been named after Roman and Greek gods. It has 27 moons and 11 rings.

Answer 30

Uranus

Question 31

*, named for an ancient Roman sea god, is a stormy blue planet about 30 times farther from the Sun than Earth. was discovered when astronomers realized that something was exerting a gravitational pull on Uranus, and that it was possible that an unknown planet might be responsible. Through mathematical calculations, astronomers determined there was indeed an undiscovered planet out in space—a year before it was actually seen for the first time through a telescope (in 1846). It has 13 satellites and 4 rings.

Answer 31

Neptune

Question 32

, named after the Roman and Greek god of the underworld, is the coldest, smallest, and outermost
planet in our solar system. *and its moon, *, are called “double planets” because Charon is so large it seems less of a moon than another planet. Pluto was predicted to exist in 1905 and discovered in 1930. It is the only planet that has not yet been studied closely by a space probe. During each revolution around the sun, Pluto passes inside Neptune’s orbit for 20 years, making Neptune the outermost planet for that time. Pluto passed inside Neptune’s orbit in 1979 and remained there until 1999.

Answer 32

Pluto

Charon

Question 33

The gravitational pull of the Moon on the Earth affects the * on Earth

Answer 33

ocean tides

Question 34

Neptune has 13 moons, with * the largest. It is covered with a frosty crust, where active volcanoes shoot crystals of nitrogen that look like geysers. The surface temperature of * is –390°F, making it the coldest object in the solar system. Five new Neptunian moons were discovered in 2002 and 2003.

Answer 34

Triton