Modified & Updated: 30 Dec 2023

universe facts

It’s always fun to learn new things about the universe because it’s so mysterious yet we keep discovering more. These fascinating universe facts will make you realize how we’re all just a tiny speck in the grand scheme of things.

  1. The universe is constantly expanding.
  2. Our solar system is 4.6 billion years old.
  3. Scientists believe the Earth will be destroyed by celestial phenomena in the next billion years.
  4. The universe is made up of roughly 68% dark energy, 27% dark matter, and 5% normal matter.
  5. It would take 450 million years for a modern spacecraft to reach the center of our galaxy.
  1. Space refers to the expanse between the earth and other celestial bodies.
  2. Stars and galaxies formed from concentrated matter and other particles in space.
  3. A black hole can destroy a star if it passes too close to it.
  4. Prolonged exposure to microgravity (lesser force of gravity in space) can cause muscular dystrophy and bone loss in humans.
  5. Dark matter comprises 90% of outer space, and no one can tell what it is or what it does.
  6. Distance in space is measured in light-years.
  7. A light-year refers to the amount of distance light can cover in a year.
  8. We can only see 5% of the universe from Earth.
  9. Space is only 62 miles away.
  10. There are 3 main types of galaxies in space: elliptical, spiral & irregular.
  1. Humans have explored outer space more than the ocean: only 5% of the ocean has been discovered.
  2. Space smells “sulfuric,” like gunpowder or welding fumes.
  3. Tears don’t fall in space. All “free” liquids will float in a spherical shape.
  4. Your limbs will float when you sleep in zero gravity.
  5. Pluto is smaller than the U.S.
Table of Contents

Spacesuit helmets have a Velcro patch for scratching purposes.

Taking off your helmet would cost you your life. Now, what if you had an itch worth dying for? Velcro’s got your back.

astronaut, space suit, velcro, universe
Image source: Pixabay

Something is eating the Milky Way.

No, we’re not talking about the chocolate bar. One of the scariest facts about the universe is that there’s a large, unidentified mass sucking away portions of the Milky Way galaxy.

There’s a cannibal galaxy next door.

Speaking of eating, our galaxy is also set to collide with the neighboring Andromeda galaxy, which has a history of devouring other galaxies.

There are more than 200 moons in our solar system.

Out of all these moons, Jupiter and Saturn have the most orbiting around them. Meanwhile, Mercury and Venus are the only 2 planets that don’t have moons.

Venus is the hottest planet.

Although Mercury is the planet closest to the sun, Venus has the highest temperature due to the gases in its atmosphere. A Greenhouse Effect maintains its constant temperature of 430°C.

The sun contains over 99% of the mass in our solar system.

Over a million Earths could fit inside the sun.

sun, solar power, universe
Image source: Pxfuel

It would take 258 Earth days to drive around one of Saturn’s rings at a speed of 75 mph.

Made of ice and rock, Saturn’s rings vary in sizes and is as 175,000 miles long and 3,200 ft thick.

Scientists detected a radio signal in space from 5 billion light-years away.

5 billion light-years meant that the Earth did not exist at the time the source transmitted it! This is one of many mind-blowing facts about the universe.

We always see the same side of the moon.

Although the moon has phases, we will only ever see one side since it rotates on its axis at the very same time it orbits the Earth.

Jupiter has the most moons.

Jupiter has 79 moons orbiting it, with the Ganymede as the biggest moon in the solar system at 5,262 km in diameter. It’s even bigger than Mercury, and is visible to the naked eye with binoculars.

It snows metal and rains acid on Venus.

Venus is congested in sulfuric acid, which causes the planet’s metals to become gas, liquid, and solid, in the atmosphere before raining down.

Coca-Cola was the first soft drink consumed in space.

On July 12, 1985, astronauts on the Space Shuttle Challenger drank coke in order to test out the dispensers and study the behavior of carbonated drinks in space. On the other hand, applesauce was the first food eaten in space by John Glenn during the Friendship 7 mission of 1962.

Sputnik was the first artificial satellite in space.

It was launched by the Soviet Union on October 4, 1957 with a single shot. This feat shocked the Americans, whose technology seemed far more superior during that time.

satellite, sputnik I, universe
Image source: Wikimedia Commons

Astronaut stool has to be transported back to Earth via spacecraft.

That’s right, astronaut poop has been to space, while you haven’t. Kidding aside, astronauts can’t take a regular bowel movement in zero gravity. Their stool is sucked into a machine, gathered, and then sent back to Earth for disposal, where it will burn up in the atmosphere.

Exoplanets are planets that orbit other stars.

While our planet orbits around the sun, there are faraway exoplanets that orbit other suns. Since Kepler has been launched, around 4000 exoplanets have been discovered.

There’s no wind on the moon.

No wind meant that marks left by astronauts and space rovers would stay on the moon indefinitely.

The moon moves 4 cm away from Earth every year.

Scientists believe that in a billion years, the moon will move out of the Earth’s field of gravity, although we won’t be around anymore to witness that.

Sunset is blue on Mars.

Mars has less than 1% of the Earth’s atmosphere. The sunset on Mars looks blue because the atmosphere mostly captures blue light from the sun.

mars, blue sunset, universe, space, planet
Image source Unsplash

The Earth weighs 81 times more than the moon.

The Moon is about 27% the size of the Earth.

Mercury has no atmosphere.

The reason why Mercury isn’t the hottest planet even if it is closest to the sun is that it has no weather nor wind. Instead, Mercury has a thin exosphere made of atoms weathered by solar wind and meteoroids.

Scientists measure a planet’s weight through its gravitational pull.

You might wonder how we have all these measurements for planets when it seems impossible to measure them in space. This is because scientists devised a formula for that. They calculate a planet’s weight by the time it takes for objects to orbit it, and the distance of those objects from the planet.

Halley’s Comet won’t be seen again until 2061.

Edmond Halley’s discovery in 1705 was last seen in 1986. This comet only comes once every 75 to 76 years.

halley comet

The Chinese began to document Halley’s Comet in 240 B.C.

After its sighting in 240 B.C., Chinese astronomers began to record its passing after 164 B.C.

If two pieces of the same type of metal touch in space, they will bond permanently.

Unlike on Earth, the process called cold welding will cause two pieces of the same metal to merge due to the absence of water and air molecules in space.

No one knows how many stars are in space.

Nobody knows the exact amount of stars found in space. An estimate for the Milky Way alone is around 200-400 billion stars.

The largest discovery of water ever found was in outer space.

Astronomers found a massive water vapor cloud that holds 140 trillion times the mass of water in the Earth’s oceans, about 10 billion light-years away.

The moon was once part of the earth.

Scientists theorize that the moon formed from a fragment of the Earth.

The Earth from the moon's surface, outer space
Image from Adobe Stock

Neptune radiates more heat than it gets from the sun.

Nobody knows why, but Neptune gives off more heat than it receives from the sun.

Neutron stars can spin 600 times per second.

Neutron stars are formed during a supernova or a star’s explosion of at least 8 solar masses. If a neutron star exceeds 3 solar masses, it can collapse and turn into a black hole.

Saturn has a two-tone moon.

Iapetus is a two-tone moon orbiting around Saturn, with one icy half and one dark half.

Uranus rotates on its side.

Uranus is the only planet in the solar system that spins sideways on its axis. Scientists theorize that a collision realigned its orientation.

Uranus, planet, solar system, outer space
Image source: Adobe Stock

The biggest volcano on Mars is three times the size of Mount Everest.

The Olympus Mons, a volcano found on Mars, is comparable in size to Arizona.

Jupiter is the dumping grounds of the solar system.

Jupiter pulls in most of the asteroids in the solar system. Jupiter’s gravity field sucks many of the asteroids that are potentially harmful to Earth.

Australia is wider than the moon.

In more amusing facts about the universe: Australia is 600 km wider in diameter than the moon.

Some U.S. astronauts drink recycled urine, sweat, and bathwater in space.

For NASA’s #YearInSpace mission, astronauts had to spend a year at the International Space Station. Since there’s no water in space, the U.S. team survives on recycled moisture from their immediate environment, namely, the breath and sweat of the crew, shower runoff, and urine from animals on the station.

This recycled water is actually cleaner than drinking water!?

The ISS recycles 93% of the liquids it receives. It takes 8 days to recycle, and a long purification process makes it cleaner than the water people drink at home.

The International Space Station (ISS) is worth 1 billion US dollars.

It is also the largest manned object put into space.

Putting on a spacesuit takes 45 minutes.

This long process will ensure the maximum safety of the astronaut and any errors can be fatal.

A standard NASA spacesuit costs 12 million dollars.

NASA experienced a suit shortage in 2017. Only 11 suits are in use, with others built years ago.

NASA spacesuit, astronaut
Image source: Adobe Stock

Saturn is less dense than water.

Saturn is both the second-largest and the lightest planet in the Milky Way. It is mostly gas, so its low density will make it float in water.

Mercury is the fastest planet in our solar system.

It orbits the sun 65,000 kph (40,000 mph) faster than Earth. A year on Mercury takes only 88 Earth days. Maybe your favorite artist can release an album in the next Mercury year so you won’t have to wait for hundreds of days.

Buzz Lightyear of Toy Story has literally been to space.

A Buzz Lightyear figure traveled aboard the International Space Station for 15 months, returning to Earth on September 11, 2009.

There could be life on Mars.

NASA found many believed to be fossil specimens of microscopic living organisms in a rock on Mars’ surface.

Sound actually travels in space.

There are certain celestial bodies and elements from which low-frequency sounds can travel. These low-frequency sounds can’t be picked up by the human ear, which include the hum of the universe expanding, the groan of shifting tectonic plates, and other sounds from planets and black holes.

One moon orbits Neptune backwards.

Triton orbits Neptune in retrograde, which is the only large moon of any planets in the solar system to do so. No one really knows why.

A person who weighs 220 lbs on Earth would weigh 84 lbs on Mars.

Gravity pulls less on Mars.

planet mars, space ship
Image source: Pixabay

A day on Mars is 24 hours, 39 minutes, and 35 seconds long.

Mars orbits the sun slower than the Earth, so there are 687 Earth days in one Martian year.

One day on Venus takes 243 Earth days.

However, one orbit of Venus around the sun only takes 225 Earth days, which means 1 day on Venus is 18 Earth days longer. Where else would you find a day that takes longer than a year?

The sun takes over 1 Earth month to make a full rotation.

The Earth finishes a full rotation daily (hence day and night) but the sun takes 25-35 Earth days to make a full rotation.

Your face would puff up in space.

On Earth, the body prevents our blood flow from pooling at our feet due to gravity. In space, our bodily fluids get redistributed, which results in “shrinking” legs and a “puffy” face.

You can’t use a normal pen in space.

Normal pens work with gravity pulling the ink to the nib, which lets you write. Astronauts and scientists, however, need to use a special pen that works in zero gravity.

There are 88 recognized constellations.

You can observe these patterns of stars from the southern and northern hemispheres.

There are estimated to be billions of other galaxies.

If these universe facts aren’t enough to make you feel small, billions of other galaxies are yet to be discovered.

5 dwarf planets are recognized in the solar system.

Ceres, Makemake, Haumea, Eris, and Pluto are 5 celestial bodies too small to be recognized as regular planets.

Haumea is oddly football-shaped.

One look at the dwarf planets and you’ll notice one doesn’t look like the rest. Unlike other celestial bodies, Haumea is not spherical. It spins on its axis once every 4 hours, and this rapid motion causes its elongated shape.


Ceres is the smallest dwarf planet.

It is also the only dwarf planet still within the inner solar system.

Saturn has a hexagonal storm.

In the northern hemisphere of Saturn is a six-sided storm formation that has been there for hundreds of years.

They’ve found another planet we can live in.

First found in the Kepler 22 system in 2011, Kepler 22b was deemed habitable, like an Earth 2.0. However, at 600 light-years away, it is still debated whether this exoplanet can sustain life.

The Great Red Spot of Jupiter has shrunk in half.

The Great Red Spot is a raging storm in Jupiter’s atmosphere, observed since the 1600s. As of 2014, it has shrunk to half its original size. For now, no one can explain it, but it is being closely monitored by the authorities.

There are more stars in the universe than grains of sand on Earth.

That makes almost trillions of stars.

stars, universe, night sky
Image source: Unsplash

Neptune’s winds are the fastest in the solar system.

At 2,575 kmph, Neptune’s giant storms could swallow the entire Earth.

Jupiter has the most volcanically active body in our solar system.

Jupiter’s moon, Io, has hundreds of volcanoes and is the most active moon in the solar system. It sends plumes for up to 250 miles into its atmosphere.

The moon’s craters might be the coldest places in the solar system.

The moon’s craters in the southern hemisphere have temperatures that never rise above -238°C.

Mars has extreme temperatures.

When you stand on Mars’ equator, the temperature at your feet would be warm, but above your head, it would be freezing cold.

About once a year, an asteroid the size of a car enters Earth’s atmosphere.

It burns up in the atmosphere before it hits us, fortunately.

asteroid approaches the earth, celestial body
Image source: Adobe Stock

Pluto could theoretically sustain life.

If Pluto had a liquid ocean and enough energy, some scientists think Pluto could harbor life.

Mars has the longest valley known to man.

The Valles Marineris is almost as long as the United States. At 4,000 km long, it is more than 10 times the length of the Grand Canyon.

There’s a planet made of diamonds 2 times the size of Earth.

55 Cancri e is a so-called “super-Earth” made of diamonds discovered in 2004 around a nearby star in the Milky Way.

3 to 7 different galaxies are visible from Earth.

The Andromeda Galaxy (M-31), Magellanic Clouds, Milky Way galaxy, Triangulum Galaxy (M-33), Omega Centauri, and the Sagittarius Dwarf Spheroidal Galaxy, are all visible to the naked eye.

man looking at the sky, galaxies, space
Image source: Unsplash

It rains diamonds on Jupiter and Saturn.

Jupiter and Saturn both have high amounts of methane in their atmosphere, which creates diamond hailstones. Lightning storms turn methane into soot (carbon) which hardens into chunks of graphite, and finally, diamond.

Saturn has a UFO-shaped moon.

Pan is another strangely-formed celestial body in space. Its walnut-like appearance is due to sweeping up ring material from the Encke gap.

There are currently 6 spacecrafts on Mars.

Space rovers and spacecrafts are the only known population of Mars.

Pluto has mountains.

Icy 11,000 ft mountains cover Pluto’s surface. This indicates that Pluto was geologically active 100 million years ago. However, this raises brows on Pluto’s energy source for tectonic motion, since it is so distant from the sun or other planets.

All planets in the solar system could fit between Earth and the moon.

Only distance-wise, though, since all the planets can’t be so close without destroying each other via collisions.

The biggest asteroid in the solar system is 329 miles in diameter.

Vesta is 25 times as long as Manhattan.

You could expand twice your size when exposed to outer space.

If you were exposed to the vacuum of space, the water in your body would expand into water vapor which would make you swell two times your size. However, it won’t make you explode as the common myth says.

The first black hole photographed is 3 million times the size of Earth.

It was first photographed in April 2019.

black hole, dead star, space
Image source: Wikimedia Commons

Being in space is like having a bad cold.

Different conditions in space would congest your nose and reduce your sense of taste.

Mercury was 100% mapped in 2013.

The Messenger completed the map of Mercury’s surface in 2013.

There might be a huge planet at the end of the solar system.

In 2015, theories of a “Planet Nine” surfaced regarding a massive planet beyond Neptune. However, it has not been located yet in the solar system.

Uranus has a funky-looking moon.

Miranda is believed to be half water ice and half rock materials, which makes it look very rugged like a jigsaw puzzle.

Mars has running water.

NASA used imaging technology to detect signatures of hydrated minerals on slopes of Mars. This means there’s seasonal running water on the planet.

Earth’s Van Allen belts move according to solar activity.

The bands of radiation belts surrounding our planet change formation according to the sun’s activity.

On a distant planet, it rains glass sideways.

The Hubble telescope found a blue planet that has a temperature of 1,000°C. Surprisingly, it rains glass sideways there at 4,300 mph.

Astronauts will grow 2” in space.

The lack of gravity causes the discs between vertebrae to expand, making a subtle increase in height. However, once astronauts come back to Earth, gravity will compress their spine and revert them back to their normal height.