Solar System Flocabulary

​What is a Solar System?

​A solar system is a neighborhood of objects orbiting around a star. The star's gravity keeps the objects surrounding it from moving away. These objects are planets, moons, asteroids, comets and meteoroids. Most stars have planets orbiting them. That means that there are a lot of solar systems out in space. Just think about how many stars there are in the sky! Our solar system's star is the Sun. Solar means "related to the sun." Our solar system includes the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, the dwarf planet Pluto and many other smaller space objects. It is located within the Milky Way Galaxy.

Multiple Choice

Which of the following describes a solar system?

• a planet with five moons orbiting it

• two dwarf planets orbiting around each other

• a star without any objects in its field of gravity

• a star with planets and their many moons orbiting it

​The Sun

​The Sun is a star that clocks in at 4.7 billion years old. Everything in the solar system orbits the Sun. It's so hot that nothing solid or liquid can exist on its surface. It's huge! It contains more than 99% of the mass of the whole solar system. And at 92.96 million miles away, it can still give you a terrible burn. The Sun sustains all life on Earth and is the source of all food and fossil fuel, which is where fuels like oil and natural gas come from. The Sun's power doesn't even stop there. Interactions between Earth and the Sun drive the seasons, ocean currents, weather and climate. We owe just about everything to the Sun.

Multiple Choice

Which of these describes the relationship between the Sun and the Earth?

• The Earth contains twice as much mass as the Sun.

• The Sun orbits the Earth, affecting the ocean's tides.

• The Earth orbits the Sun, which affects seasons on Earth.

• The Sun reflects the moon’s light but is not visible from Earth.

​Mercury

Mercury was named after a god of Roman mythology. The Roman god Mercury was a speedy messenger. Similarly, Mercury is the speediest of the planets. It takes just 88 days for it to orbit the Sun. Mercury is the Sun's closest neighbor, too. There's a wide range of temperatures on Mercury, from 872 Fahrenheit to -300 Fahrenheit. In 1974 and 1975, the spacecraft Mariner 10 visited Mercury, but besides that, we Earthlings have kept our distance.

Multiple Choice

How does Mercury's name offer a clue to one of its defining characteristics?

• The surface of Mercury is made up of a metal of the same name.

• Mercury is named after a quick mythological figure and is the fastest planet.

• Mercury does not have any moons, and the Roman god Mercury did not have any friends.

• Mercury is named after a poisonous plant of the same name and is covered in poisonous gases.

Multiple Choice

Which planet is MERCURY?

​Venus

Venus and Earth are about the same size, but that's where their similarities end. Venus has a lot going on. It's the hottest planet and second from the Sun. In the early 1990s, the Magellan spacecraft checked out the surface of the planet. It features faults from venusquakes, craters from meteors and flowing lava. There's even a lava lake larger than the United States. One of the volcanoes on Venus is taller than Earth's tallest mountain, Mt. Everest. On top of all that, Venus has a thick, poisonous atmosphere of sulfuric acid and CO2​​.

Multiple Choice

Which of the following best describes Venus’s surface?

• frozen and icy

• smooth and flat

• filled will different landforms

• covered by a freshwater lake

Multiple Choice

Which planet is VENUS?

​Earth

You're pretty familiar with Earth already, but here are some facts just in case. Earth is the third planet from the Sun, located in a "just right" distance so that it's neither too hot nor too cold. Most of the planet is covered by water, and the air is a mixture of nitrogen, oxygen and CO​2​​. These are the two characteristics—water and the right mixture of gases—critical for life as we know it. Earth is the only planet where we know life exists, although scientists are pretty certain that some life form exists elsewhere in space. They just haven't discovered it yet. Earth is hard and rocky, with meteor craters, mountains and valleys. It's also the fifth largest planet.

Multiple Choice

On which of the following space objects would scientists most likely expect to find life?

• a planet with no solid surface

• a planet with an ocean on its surface

• a large planet very far away from the Sun

• a small, rocky planet with no atmosphere

​Mars

Mars is popular. NASA has sent spacecrafts to visit the planet 44 times! Quite a few of these attempts were failures, though. Still, it's the planet that has been most visited by spacecrafts. Mars features the tallest volcano in the solar system, which is three times the height of Mt. Everest and the size of New Mexico. It's a dry, rocky, cold planet situated fourth from the Sun. It's called the red planet because of its red hue. Mars has two moons called Phobos and Deimos.​

Multiple Choice

The tallest volcano on Mars...

• is three times the height of Mt. Everest.

• is almost as tall as Mt. Everest.

• has been visited 44 times.

• is wet, rocky and cold.

Multiple Choice

Which planet is MARS?

​Jupiter

Jupiter has been crowned the "King of the Planets" and is the most massive planet in the solar system. It's a gas giant, like the planets that come after it: Saturn, Uranus and Neptune. Jupiter is fifth from the sun and resembles a star in composition, but it's not as massive. The Great Red Spot is a storm on Jupiter that has been raging for more than 300 years and is as large as three Earths. Jupiter is kept company by more than 50 confirmed moons. Ganymede is the largest moon and has its own magnetic field. Io has hundreds of active volcanos. Europa and Callisto may have liquid oceans beneath their thin crusts.​

Multiple Choice

Ganymede, Io, Europa and Callisto are

• moons of Jupiter

• stars of Jupiter

• galaxies of Jupiter

• rings of Jupiter

Multiple Choice

Which planet is JUPITER?

​Saturn

Saturn is the sixth planet from the Sun. It was first seen by Galileo Galilei in 1611 through a telescope. It's a gas giant made mostly of helium and hydrogen. Saturn is called the "Jewel of the Solar System," and it's indeed fancy. It has a complex ring system with over 50 moons. Titan is the second largest moon in the solar system. Scientists think Titan may have had an atmosphere like Earth's a long time ago.​

Multiple Choice

The helium and hydrogen on Saturn is most likely...

• solids

• liquids

• gases

Multiple Choice

Which planet is SATURN?

​Uranus

Scientists pronounce Uranus with an emphasis on the first syllable: YER-in-is. It's the only planet that rotates on its side. It's called the "Tilted Planet." It's the third largest planet in the solar system and seventh from the Sun. It takes Uranus 84 years to orbit the Sun. Uranus is another gas giant with no solid surface. Methane gas above the cloud layers colors it blue-green. Voyager was the only spacecraft to stop by, and it didn't see much. Uranus has 27 moons and some rings.

Multiple Choice

Why is Uranus called the "Tilted Planet?"

• It rotates on its side

• The name means tilted

• Methane on the planet causes it to wobble

• It orbits in the opposite direction

Multiple Choice

Which planet is URANUS?

​Neptune

Neptune is a gas giant planet and the eighth planet from the Sun. It has 13 confirmed moons. One of them is called Tritan and has active geysers. Nitrogen gas erupts from the geysers on Titan. Neptune is known as the windiest planet with 1,200 mph wind. For comparison, the strongest hurricanes on Earth have wind speeds exceeding 156 mph.​

Multiple Choice

What is a geyser?

• a moon with many craters

• the eighth planet from the sun

• a hurricane with 1,200 mph winds

• a hole from which liquid or gas escapes

Multiple Choice

Which planet is NEPTUNE?

Multiple Select

Choose the FOUR INNER planets

• Jupiter

• Mercury

• Venus

• Earth

• Mars

Multiple Select

Choose the FOUR OUTER planets

• Jupiter

• Saturn

• Venus

• Uranus

• Neptune