Planets of the Solar System

Discover the Solar System! Learn facts about planets, comets, and asteroids.

The four inner planets of our solar system are gas giant planets interplanetary asteroids terrestrial planets meteorites The closest planet to the Sun is Venus Mercury Mars Earth How many times bigger than Mercury is Earth? two times three times four times five times The surface of Mercury is similar to the surface of Earth the Moon Venus Mars Observations of Mercury suggest that it was originally much larger, with a mantle and crustsimilar to that of Earth the Moon Venus Mars The brightest planet in Earth’s nighttime sky is Mercury the Moon Venus Mars One day on Venus is equal to how many days on Earth? 243 days 43 days 143 days 4 days Radar measurements show that the surface of Venus is very hot and that it is rotating quickly orbiting quickly rotating slowly orbiting slowly Venus’s spin is an example of retrograde motion backward rotation retrograde rotation backward motion The atmosphere of Venus is mostly nitrogen and oxygen sodium oxygen carbon dioxide and nitrogen Earth’s distance from the Sun and its nearly circular orbit allowwater to exist on its surface as a solid, liquid, and gas. True False Earth’s atmosphere is moderately dense and is composed of 78percent oxygen and 21 percent nitrogen. True False Only Earth has a greenhouse effect. True False Mars is referred to as the red planet as a result of its high ironcontent and reddish appearance. True False Mars’s atmosphere is similar to that of Venus, and it has a stronggreenhouse effect. True False The southern hemisphere of Mars is dominated by sparselycratered plains. True False What percentage of all planetary matter in the solar system is in Jupiter’s mass? 40% 60% 50% 70% Galileo discovered Jupiter’s rings 12 smaller satellites four major satellites Great Red Spot Elements in Jupiter’s atmosphere remain in only liquid form both gas and liquid form only gas form gas, liquid, and solid form The form of hydrogen that has properties of both a liquid and a metal is liquid metallic hydrogen magnetic hydrogen liquid hydrogen electric hydrogen Jupiter spins once on its axis in a little less than 5 hours 12 hours 10 hours 2 hours Low, warm, dark-colored, sinking clouds in Jupiter’s atmosphere are known as belts the Great Red Spot zones rings Jupiter’s four moons are composed of clouds ice and rock hydrogen and oxygen ice What is Jupiter’s Great Red Spot? a surface ocean a large moon an atmospheric storm an ice cap Which of Jupiter’s largest moons is almost completely molten inside? Io Europa Ganymede Callisto Saturn’s average density is lower than that of helium hydrogen water methane The ringlets and open gaps in Saturn’s rings are caused by the gravitational effects of Saturn Jupiter Saturn's moons the Sun Many astronomers hypothesize that Saturn’s rings were formed from debris left over from the formation of Saturn and its moons. debris left over from collisions of asteroids and other objects. debris that escaped from Jupiter’s gravitational pull. asteroids attracted by Saturn’s gravitational pull. Saturn’s largest moon is named Io Titan Europa Ganymede True or False Determine if the statement is true or false Uranus was discovered accidentally in 1781. True Today, we are certain that Uranus has no moons and 15 rings. False Most of Uranus’s atmosphere is composed of helium andhydrogen, which causes its atmosphere to reflect blue light backinto space. False Uranus has a large, solid core that extends almost to the planet’ssurface. False The rotational axis of Uranus is tipped over so far that the northpole almost lies in its orbital plane. True Saturn is the only planet with rings. False Uranus’s tilt and its great distance from the Sun result in seasonson Uranus that last about 21 Earth years. False Until 1994, Neptune had a persistent storm, the Great Dark Spot,with characteristics similar to Jupiter’s Great Red Spot. True Neptune’s largest moon, Triton, has a retrograde orbit, whichmeans it orbits like every other satellite in the solar system. False Triton has nitrogen geysers and a thin atmosphere. True Neptune’s six rings are composed of microscopic dust particles. True Neptune has a cloud-streaked atmosphere like Jupiter. True A meteoroid is a broken fragment of an asteroid or otherinterplanetary material. True False A meteor is a meteoroid that bypasses Earth’s atmosphere. True False A large meteorite will cause an impact crater when it collides with Earth. True False Pluto is not classified as a terrestrial planet because of its low density and small size, among other things. True False Pluto is larger than Earth and is made of ice. True False Like Earth’s Moon, Pluto has no atmosphere. True False The orbit of Pluto is a perfect circle. True False Pluto has three moons: Charon, Nix, and Hydra. True False Pluto’s properties more closely resemble those of the gas giants’ large moons than of the other planets. True False Which of the following is NOT and outer planet? Jupiter Venus Saturn Uranus _are small, icy bodies that have highly eccentric orbits around the Sun. Planetesmials Meteors Comets Meteorites The tail of a comet always points towards the Sun away from the Sun disappears in the presence of the Sun North _is defined as an object that, due to its own gravity, is spherical in shape, orbits the Sun, is not a satellite, and has not cleared the area of its orbit of smaller debris. dwarf planets inner solar system objects comet asteroid