Planets
The third planet from the Sun and the only astronomical object known to harbor life.
What is Earth?
An astronomical object comprising a luminous spheroid of plasma held together by its gravity.
What is a star?
An area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
What is a constellation?
Also known as natural satellites, they orbit planets and asteroids in our solar system. There are more than 200 in our solar system.
What are moons?
The galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth.
What is the Milky Way.
The second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition.
What is Venus?
The star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core.
What is the Sun?
A large asterism consisting of seven bright stars of the constellation Ursa Major. Four define a "bowl" and three define a "handle". It is recognized as a distinct grouping in many cultures.
What is the Big Dipper?
Earth's only natural satellite. Its diameter is about one-quarter the diameter of the Earth. Is the fifth largest satellite in the Solar System.
What is the Moon?
A small planetary-mass object that is in direct orbit of the Sun, smaller than any of the eight classical planets but still a world in its own right.
What is a dwarf planet?
The fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined.
What is Jupiter?
A powerful and luminous explosion of a star. This transient astronomical event occurs during the last evolutionary stages of a massive star or when a white dwarf is triggered into runaway nuclear fusion.
What is a supernova?
It is one of the most conspicuous and recognizable constellations in the night sky. It is named after a hunter in Greek mythology. Its brightest stars are blue-white Rigel and red Betelgeuse.
What the Orion Constellation?
This planet has the most amount of moons, about 83 confirmed. Its largest moon is called Titan.
What is Saturn?
A region of spacetime where gravity is so strong that nothing, no particles or even electromagnetic radiation such as light, can escape from it.
What is a black hole?
The eighth planet from the Sun and the farthest known solar planet. In the Solar System, it is the fourth-largest planet by diameter, the third-most-massive planet, and the densest giant planet.
What is Neptune?
The two main elements that make up the composition of most stars. The two lights elements on the periodic table.
What are hydrogen and helium?
A belt-shaped region of the sky that extends approximately 8° north or south of the ecliptic, the apparent path of the Sun across the celestial sphere over the course of the year.
What is the Zodiac?
This planet has no moons and is smaller than the two largest moons in the Solar System, Ganymede and Titan.
What is Mercury?
A group of stars that share a common origin and are gravitationally bound for some length of time.
What are star clusters?
The seventh planet from the Sun. Its name is a reference to the Greek god of the sky. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System.
What is Uranus?
A gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter.
What is a galaxy?
Name for the North Star, sits more or less directly above Earth's north pole along our planet's rotational axis. Sits at the end of the Little Dipper.
What is Polaris?
The two moons of Mars, they are asteroid shaped and relatively small. Named after the Greek mythological twin characters who accompanied their father Ares into battle.
What are Phobos and Deimos?
The third United States human spaceflight program carried out by NASA, which succeeded in preparing and landing the first humans on the Moon.
What is the Apollo Program?