Test Your Space IQ

Explanation: Jupiter and Saturn's atmospheric contents are 89% hydrogen, 11% helium, and traces of methane. Jupiter though also has traces of ammonia. Jupiter and Saturn are both Gas Giants.

Explanation: Sedna is a large minor planet in the outer reaches of the Solar System that was, as of 2015, at a distance of about 86 astronomical units (AU) from the Sun, about three times as far as Neptune. It is most likely a dwarf planet. Diameter: 1,800 km. Ganymede is the largest moon of Jupiter and in the Solar System. Diameter: 5,268 km. Phobos is the larger and inner of the two natural satellites of Mars, the other being Deimos. Phobos is a small, irregularly shaped object with a mean radius of 11 km. Ceres is the largest object in the asteroid belt, which lies between the orbits of Mars and Jupiter. Its diameter is approximately 945 km.

Explanation: The Sun - in fact, our whole solar system - orbits around the center of the Milky Way Galaxy. We are moving at an average velocity of 828,000 km/hr. But even at that high rate, it still takes us about 230 million years to make one complete orbit around the Milky Way. The Milky Way is a spiral galaxy.

Explanation: There are two main types of rocket fuel used on modern rockets: liquid and solid. Liquid propellants separate fuel and oxidizers and the two are combined in a combustion chamber where they burn and are fired out from the base of the rocket. Solid rocket fuels are those in which the fuel and oxidizer compounds are already combined. Most use an aluminum powder as the fuel and an ammonium perchlorate as the oxidizer, while an iron powder is used as a catalyst for the reaction. All that’s required is a spark to start them burning. While they are much simpler than their liquid counterparts, they cannot be stopped once they have been ignited. For that reason, most modern rockets have hybrid engines, which use a combination of both solid and liquid fuel boosters. Solid fuels are generally used more for the initial launch sequence, when the speed needs to be at its maximum, whereas liquid fuels are used later so the speed can be adjusted to get the rocket’s payload on to the right trajectory.

Explanation: The Apollo program, also known as Project Apollo, was the third U.S. human spaceflight program carried out by the NASA, which accomplished landing the first humans on the Moon from 1969 to 1972. First conceived during Dwight D. Eisenhower's administration as a three-man spacecraft to follow the one-man Project Mercury which put the first Americans in space, Apollo was later dedicated to President John F. Kennedy's national goal of "landing a man on the Moon and returning him safely to the Earth" by the end of the 1960s, which he proposed in a May 25, 1961, address to Congress. The first manned flight of Apollo was in 1968.

Explanation: On April 12 1961, Russian cosmonaut Yuri Gagarin became the first human in space, making a 108-minute orbital flight in his Vostok 1 spacecraft. Mercury astronaut Alan Shepard became the first American in space less than a month later on May 5, 1961. The first cooperative human space flight project between the U.S. and the Soviet Union took place in 1975. The Apollo-Soyuz Test Project was designed to test the compatibility of rendezvous and docking systems for American and Soviet spacecraft and to open the way for future joint manned flights.

Explanation: Apollo 17 was the final mission of the U.S.' Apollo program, the enterprise that landed the first humans on the Moon. Launched on December 7, 1972, with a three-member crew consisting of Commander Eugene Cernan, Command Module Pilot Ronald Evans, and Lunar Module Pilot Harrison Schmitt, it was the last use of Apollo hardware for its original mission.

Explanation: Pluto's equatorial diameter is 2,274 km. Earth's Moon - diameter 3,476 km. Jupiter has four moons larger than Pluto - Ganymede - diameter 5,262 km; Callisto - diameter 4,800 km; Io - diameter 3,630 km; Europa - diameter 3,138 km. Saturn has one moon larger than Pluto - Titan - diameter 5,150 km. Neptune has one moon larger than Pluto - Triton - diameter 2,700 km. There are 7 moons larger than Pluto in our Solar System.

Explanation: NASA's Discovery Program gives scientists the opportunity to dig deep into their imaginations and find innovative ways to unlock the mysteries of the solar system. When it began in 1992, this program represented a breakthrough in the way NASA explores space. For the first time, scientists and engineers were called on to assemble teams and design exciting, focused planetary science investigations that would deepen the knowledge about our solar system.

Explanation: An orbit is an elliptical path around a celestial body. The point on an orbit which is closest to the orbited body is called the periapsis and the furthest point is the apoapsis. When the object is closest to the orbited body during its orbit, it is moving fastest. The object moves slowest when it is the farthest away from the orbited body.

Explanation: There is no firm boundary where space begins. However the Kármán line, at an altitude of 100 km (62 mile) above sea level, is conventionally used as the start of outer space in space treaties and for aerospace records keeping.

Explanation: Luna 9 was an unmanned space mission of the Soviet Union's Luna program. On February 3, 1966 the Luna 9 spacecraft became the first spacecraft to achieve a soft landing on the Moon, or any planetary body other than Earth, and to transmit photographic data to Earth from the surface of another planetary body. Surveyor 1, the first U.S. lunar soft-lander in the unmanned Surveyor program by NASA, landed on the Moon on June 2, 1966.

Explanation: The direction a spacecraft or other body travels in orbit can be direct, or prograde, in which the spacecraft moves in the same direction as the planet rotates, or retrograde, going in a direction opposite the planet's rotation.

Explanation: Mariner 10 was the 7th successful launch in the Mariner series and the first spacecraft to visit Mercury. It was also the first spacecraft to use the gravitational pull of one planet (Venus) to reach another (Mercury), and the first spacecraft mission to visit two planets. The spacecraft flew by Mercury three times in a retrograde heliocentric orbit and returned images and data on the planet. Mariner 10 returned the first-ever close-up images of Venus and Mercury.

Explanation: History changed on October 4, 1957, when the Soviet Union successfully launched Sputnik I. The world's first artificial satellite was about the size of a beach ball (22.8 inches in diameter), weighed only 183.9 pounds, and took about 98 minutes to orbit the Earth on its elliptical path. That launch ushered in new political, military, technological, and scientific developments. While the Sputnik launch was a single event, it marked the start of the space age and the U.S.-U.S.S.R space race.

Explanation: An orbiting satellite is in free falling. Without gravity the satellite would move with constant velocity in a straight line, which would take it further from the planet that is orbiting. Gravity causes it to free fall toward the planet at the rate that is the same as the planet’s surface falls away from the straight-line path.

Explanation: In a flyby, the spacecraft passes close, but is not "captured" into an orbit by gravity. Year of the first flyby of each planets/dwarf planet: 1962: Venus 1965: Mars 1973: Jupiter 1974: Mercury 1979: Saturn 1986: Uranus 1989: Neptune 2015: Pluto

Explanation: Wernher von Braun was a German (and later American) aerospace engineer and space architect credited with inventing the V-2 Rocket (for Nazi Germany) and the Saturn V (for the U.S.). He was one of the leading figures in the development of rocket technology in Nazi Germany. Following World War II he, as well as about 1500 other scientists, technicians, and engineers, were moved to the U.S. as part of Operation Paperclip, where he developed the rockets that launched America's first space satellite and first series of moon missions.