50 Fun Facts About Space Trivia for Kids

How many planets are in our Solar System?

Eight have made the list since 2006, when astronomers ruled that a planet must have cleared other objects out of its orbit, a test that Pluto fails.

The Sun is made mostly of which gas?

Hydrogen is the Sun's fuel: in the core it is fused into helium, releasing the energy that leaves as heat and light.

Which planet is closest to the Sun?

Mercury is so close that it laps the Sun every 88 days, the fastest of any planet. Yet it turns so slowly that one sunrise-to-sunrise day lasts two of those years.

Which planet is the largest in the Solar System?

Jupiter is more than twice as massive as all the other planets put together, yet it spins so fast that its day lasts under ten hours, the shortest of any planet.

What is the Great Red Spot on Jupiter?

A giant storm that has been spinning for well over a century. It lasts so long partly because Jupiter has no solid ground to slow its winds down.

Saturn's bright rings are made mostly of what?

Ice, in billions of chunks from tiny grains to boulders as big as a house. The rings span hundreds of thousands of kilometres, yet are typically only about ten metres thick.

Which planet is nicknamed the Red Planet?

Mars owes its colour to rust: iron minerals in its dust and rocks have oxidised, much like an old nail left out in the rain.

Astronomers released the first picture of which kind of object in 2019?

A black hole gives off no light of its own, so the picture shows its shadow: a dark circle ringed by hot gas that glows as it swirls around it.

Which planet is the hottest in the Solar System, hotter even than the one closest to the Sun?

Venus is wrapped in a thick blanket of carbon dioxide that traps the Sun's heat, keeping its surface hot enough to melt lead.

Which planet spins on its side, tilted over by more than 80 degrees?

Uranus may have been knocked over by a collision with an Earth-sized object long ago. The tilt gives it extreme seasons, with each pole left in darkness for decades at a time.

Which planet is farthest from the Sun?

Neptune is so remote that it was found by arithmetic: astronomers saw something tugging Uranus off course, calculated where it must be and spotted it there in 1846.

In 2006, Pluto was officially reclassified as what?

A dwarf planet. The trigger was Eris, a world about Pluto's size found in 2005: faced with a possible tenth planet, astronomers voted on what a planet is, and both missed the cut.

The asteroid belt sits between the orbits of which two planets?

Mars and Jupiter have the belt between them. For all its countless rocks, everything in it lumped together would weigh less than our Moon.

Who was the first person to walk on the Moon?

Neil Armstrong had to earn it first: with the computer steering toward a field of boulders, he took the controls and landed by hand with well under a minute of fuel left.

What was the name of the Apollo 11 lunar module that landed on the Moon?

Eagle landed with two astronauts while Columbia, the command module, circled overhead with the third. Its lower half, with a commemorative plaque attached, is still standing on the Moon.

As of 2025, how many people had walked on the Moon?

Twelve, two at a time on six Apollo landings. It would have been fourteen, but Apollo 13 had to swing around the Moon and head home after an explosion on board.

Who was the first human to travel into space, in 1961?

Yuri Gagarin answered the launch call with 'Poyekhali!', or 'Off we go!', circled the Earth once and was back on the ground, by parachute, in under two hours.

Who was the first woman in space?

Valentina Tereshkova was a textile-mill worker with no pilot training. Her hobby got her picked: she was a keen parachutist, and Vostok cosmonauts had to eject and float down on their own.

What was Sputnik 1, launched by the Soviet Union in 1957?

The first artificial satellite was a beeping metal ball about the size of a beach ball. Its success so alarmed the United States that Congress created NASA within a year.

What kind of animal was Laika, the first creature to orbit the Earth?

A dog, and a stray at that, picked up from the streets of Moscow. She was trained for the tiny cabin by being kept in smaller and smaller cages.

What is the name of the galaxy that our Solar System belongs to?

The Milky Way is named for the pale band it paints across a dark night sky. The word galaxy itself comes from the Greek for milk.

Which is the largest moon in the whole Solar System?

Ganymede is wider than the planet Mercury, and beneath its icy crust there is thought to be a salty ocean bigger than all of Earth's seas put together.

Halley's Comet can be seen from Earth roughly how often?

Every 76 years or so. Edmond Halley realised that comets seen in 1531, 1607 and 1682 were one visitor on repeat, and it came back in 1758 just as he had predicted.

Which star stays almost fixed in the night sky while the other northern stars wheel around it?

Polaris sits almost exactly above Earth's axis, so the sky seems to turn around it. It will lose the job: the axis slowly wobbles, and in about 12,000 years it will point at Vega instead.

Which spacecraft, launched in 1977, became the most distant human-made object in 1998?

Voyager 1 overtook Pioneer 10 that year and reached interstellar space in 2012. It carries a gold-plated record of greetings and sounds from Earth, a message for anyone who finds it.

Which famous space telescope, launched into orbit in 1990, was still working in 2025?

Hubble sent back blurry pictures at first, because its main mirror had been polished very slightly too flat. In 1993 astronauts flew up and fitted corrective optics, rather like a pair of glasses.

What kind of light does the James Webb Space Telescope mainly study?

Infrared light is heat, so the telescope's own warmth would drown out the faint glow it hunts. It hides behind a sunshield the size of a tennis court that keeps it below minus 223 degrees Celsius.

What was Ingenuity, which made history on Mars in April 2021?

A helicopter, built to make no more than five short test hops. It ended up flying 72 times over nearly three years before damage to a rotor blade grounded it.

A glowing streak of light from a small space rock burning up in Earth's atmosphere is called what?

A meteor is the flash, not the rock. The rock, a meteoroid, hits the air at many kilometres a second and burns up, and any piece that survives to reach the ground is a meteorite.

The word astronaut comes from two Ancient Greek words meaning what?

Star sailor, from the Greek astron and nautes. The word is older than spaceflight: an 1880 novel gave the name Astronaut to an imaginary spaceship.

A light-year measures what?

Distance, not time: a light-year is how far light travels in one year, about 9.46 trillion kilometres. Astronomers use it because the gaps between stars are far too big for kilometres.

How high above the Earth does the International Space Station orbit?

About 400 km up, the station laps the Earth roughly every 90 minutes, which means its crew sees 16 sunrises and 16 sunsets in a single day.

Which moon is the only one in the Solar System with a thick atmosphere?

Titan, Saturn's biggest moon, is wrapped in air denser than Earth's. Beneath the haze it even rains: liquid methane fills rivers, lakes and seas, the only ones known beyond Earth.

What is the tallest volcano in the Solar System, found on Mars?

Olympus Mons rises more than twice as high as Mount Everest. It could grow so big partly because the crust of Mars stays put, so lava kept piling up over the same hot spot.

Which US president challenged America to land on the Moon before 1970?

John F. Kennedy set the goal in a speech to Congress in May 1961. Apollo 11 met it with five months to spare, though he did not live to see it.

How long does light from the Sun take to reach Earth?

About 8 minutes, even at the speed of light, because the Sun is 150 million kilometres away. So we never see the Sun as it is now, only as it was eight minutes ago.

The James Webb Space Telescope was launched on which holiday in 2021?

Christmas Day, 2021. The telescope was too wide for its rocket, so its tennis-court-sized sunshield was folded up to fit inside the nose cone and had to open out again in space.

Apollo 11 touched down on which of the Moon's dark lava plains?

Sea of Tranquility: astronomers named it in 1651, when the Moon's dark plains were taken for real seas. The crew added a name of their own for the landing spot, Tranquility Base.

Astronomers class our home galaxy as which type?

Spiral: a flat disc of stars with arms winding out from the centre. The Sun rides in one of those arms, about halfway out, and needs well over 200 million years to make a single lap.

Roughly how many people watched the first moonwalk live on TV in 1969?

600 million, about a fifth of everyone alive at the time. Most of the pictures they saw came down through the Parkes radio telescope in Australia, which had the clearest signal.

Which planet is so light for its size that it would float in a big enough bathtub of water?

Saturn is a ball of the lightest gases, so although it outweighs Earth 95 times over, its average density is lower than water's. No other planet is that light for its size.

Which event happens when the Moon passes between the Sun and Earth and blocks the Sun's light?

A solar eclipse is possible thanks to a lucky match: the Sun is about 400 times wider than the Moon but also about 400 times farther away, so the two look the same size in our sky.

Which spacecraft was the first to fly past both Uranus and Neptune?

Voyager 2 borrowed speed from the planets themselves, swinging past each giant so that its gravity flung the probe on toward the next. It passed Neptune in 1989 and crossed into interstellar space in 2018.

Which company began launching NASA astronauts into orbit in 2020?

SpaceX ended a long wait: since the Space Shuttle retired in 2011, NASA had relied on Russian rockets and capsules to get its astronauts to the space station.

Who discovered the four largest moons of Jupiter in 1610 using an early telescope?

Galileo Galilei saw that the four specks were circling the planet, not the Earth. Finds like that led him to argue that Earth goes around the Sun, for which he was sentenced to house arrest in 1633.

NASA named its programme to return astronauts to the Moon after which Greek goddess?

Artemis is the twin sister of Apollo in Greek myth and in later times was also identified with the Moon, which made her a fitting namesake for the follow-up to the Apollo landings.

Which NASA rover, which landed in 2021, was named by a seventh-grader in a national essay contest?

Perseverance was Alexander Mather's pick. His essay argued that earlier rovers, such as Curiosity, Spirit and Opportunity, were named for human qualities, but the most important one was missing.

Which mission was the first to set a lander down on a comet?

Rosetta spent ten years catching up with its comet before releasing the lander Philae in 2014. The harpoons meant to pin Philae down failed to fire, so it bounced twice before settling.

What is the explosion of a massive dying star called?

A supernova can briefly outshine its entire galaxy. The blast also flings out the elements forged inside the star, raw material for new stars and planets.

Apollo moonwalkers kept cool in long underwear laced with thin tubes that carried what?

Water, pumped through the tubes, carried body heat to the backpack, which got rid of it by venting a separate supply of water out into space.