99 Interesting Facts about Space

By Karin Lehnardt, Senior Writer

Published March 19, 2017Updated September 5, 2019

The first person to look into space with a telescope was Galileo, nearly 400 years ago._[6]
Because fragrance is dependent on several environmental factors, such as temperature, humidity, and a flower’s age, flowers smell differently in space than they do on Earth. The fragrance of a variety of roses grown on the space shuttle Discovery was later replicated and incorporated into “Zen,” a perfume sold by the Japanese company Shiseido._[15]
Space is flexible. It’s been expanding at a measurable rate since the beginning of time._[4]
In 1895 Konstantin Tsiolkovsky, an early Russian rocket scientist, was the first to propose the concept of space elevators, a type of space transportation system._[8]
While Han Solo narrowly navigated a packed asteroid belt in the Star Wars film The Empire Strikes Back, in reality, asteroids have about 400,000 square miles all to themselves. Therefore, the chances of colliding with an asteroid are about one in a billion._[5]

In the vacuum of space, there is no sound

There is no sound in space._[6]
In the film 2001: A Space Odyssey, Bowman should have exhaled instead of inhaling before attempting to re-enter the ship from the pod after HAL locks him out. The vacuum of space would have damaged his lungs if they had been full of air._[5]
The first Earthling in space was Laika, a dog that was launched into space on the Soviet ship Sputnik 2 in 1957. After a week in space, the air in the capsule ran out and she died. After its orbit deteriorated, the craft left space and burned up, along with Laika’s body, as it re-entered Earth’s atmosphere._[13]
When water boils on Earth, it creates thousands of little bubbles. However, in space, boiling water produces one giant, undulating bubble. Scientists believe this is due to lack of convection and buoyancy that accompanies gravity._[15]
The Big Bang theory rests on an idea called inflation theory, which holds that at a fraction of a moment after the dawn of creation, the universe underwent a sudden dramatic expansion. It inflated, or ran away with itself, doubling in size every 10-34 seconds. The whole “bang” may have lasted no more than 10-30 seconds (one million million million million millionths of a second), but it changed the universe from something that could fit into a hand into something at least 10,000,000,000,000,000,000,000,000 times bigger._[4]
The first American in space was Alan Shepard, who was launched into space aboard Mercury 3 on May 5, 1961. His craft did not enter orbit, but it flew to a height of 116 miles and traveled 303 miles before safely parachuting into the Atlantic Ocean._[6]
On Earth, a flame will rise. In space, however, a flame will move outward from its source in all directions. Because space has no gravity, the expanding hot air experiences equal resistance in all directions, so it moves spherically from its source. A match would need to be struck in a space vehicle or station with an oxygen-bearing atmosphere because a flame needs oxygen._[15]
Most of the atoms in our bodies were created in stars through fusion._[4]

Our passionate preoccupation with the sky, the stars, and a God somewhere in outer space is a homing impulse. We are drawn back to where we came from.

- Eric Hoffer

The first woman in space was Valentina Tereshkova, a Soviet cosmonaut who flew aboard the Vostok 6 on June 16, 1963._[6]
The first African American in Space was Guion “Guy” Bluford, Jr., who was aboard the space shuttle Challenger in 1983 as well as 3 other shuttle flights (one other on Challenger and two on Discovery). Mae Jemison was the first African American woman in space. She flew aboard Endeavour on September 12, 1992._[6]
Because there is no gravity in space, there is no natural convection, which means body heat won’t rise off the skin. Because of this, the body will constantly perspire to cool itself but, unfortunately, the sweat won’t drip or evaporate—it will just build up._[15]
Without gravity, body fluids rise higher in the body than they do on Earth, which means there’s more fluid than usual in the skull pressing on the eyes. This squashes the eyeballs of the astronauts and blurs their vision._[10]
Some bacterial colonies grow much faster in space. For example, astro E-coli colonies grow almost twice as fast as E-coli on Earth. Additionally, salmonella grows much deadlier while on a space shuttle than on Earth._[15]
Theorists believe that if you tune a television to any channel it doesn’t receive, about 1% of the static on it is an ancient remnant of the Big Bang._[4]
Although everyone calls it the Big Bang, advocates of the theory caution us not to think of it as a conventional explosion but rather as a vast sudden expansion._[4]
Because there is no gravity in space, there is no buoyant force, which means nothing pushes bubbles up and out of carbonated drinks in space. Therefore, it is impossible to burp out the gas of, say, a root beer._[15]

Sally Ride was the first American woman in space in 1983

The first American woman in space was Sally Ride, who was aboard the space shuttle Challenger on June 18, 1983. She was also the youngest American in space._[6]
Some astronomers speculate that the singularity that became the Big Bang was the relic of an earlier collapsed universe, and that our universe is just one of an eternal cycle of expanding and collapsing universes. Other astronomers speculate that the Big Bang represents a type of transition phase, where the universe went from a form we can’t understand to one we almost can._[4]
Some scientists believe that we can look back to 10-43 seconds after the Big Bang, when the universe was so small that it could be seen only under a microscope. The number 10-43 is 0.0000000000000000000000000000000000000000001, or one 10 million trillion trillion trillionths of a second._[4]
According to some astronomers, at one ten-trillionth of a trillionth of a trillionth of a trillionth of a second after the Big Bang, gravity emerged, which was soon joined by electromagnetism as well as strong and weak nuclear forces. These were joined an instant later by elementary particles._[4]
Some astronomers believe that there may have been many other “big bangs,” perhaps trillions and trillions of them spread across eternity. The reason we exist in this one is that we could exist in it. If gravity were fractionally stronger or weaker, if the expansion happened just a little more slowly or swiftly, then there might not have been stable elements from which to make humans beings._[4]
Astronomers hypothesize three different possible scenarios for our universe: 1) we have a closed universe, which means the universe will eventually collapse into another singularity; 2) we have an open universe, which means that the universe will keep expanding forever until everything is so far apart that the universe becomes inert and dead; and 3) we have a flat universe, which means gravity is just right and will hold the universe together at just the right dimensions to allow things to go on indefinitely. This last scenario is also known as the Goldilocks effect, where everything is “just right.”_[4]
A person could never get to the edge of the universe. If someone traveled outward in a straight line indefinitely, he would come back to where he began. The reason for this is that the universe bends, in a way that astronomers can’t adequately imagine._[4]
Most scientists agree that around ¾ of the universe is missing in the form of dark energy and dark matter—neither of which has been seen or measured. This energy and matter are needed to balance out the mathematics of the universe, but scientists admit that neither may ever actually be detected._[1]
A black hole is created when a large star explodes and the leftover core collapses into an object so small and dense that its gravity becomes too strong for even the fastest thing in the universe—light—to escape. The first confirmed black hole to be discovered was Cygnus X-1 in 1964._[2]

The closer you get to a black hole, the slower time runs

Dark matter (which is linked to dark energy) is the “glue” that holds the universe together. However, it has not been directly measured, though scientists believe it has a better chance of being detected than dark energy._[1]
Cosmic rays are highly energetic particles that flow throughout our solar system from deep in outer space, but astronomers are unsure of their origins._[1]
Theorists believe that around 98% of all the matter that exists was created with the Big Bang (helium, hydrogen, and lithium). Heavier matter such carbon, nitrogen, and oxygen emerged later._[1]
Our solar system—with the sun, the planets and their moons, and the billion of asteroids and comets—fills less than a trillionth of our universe._[4]
On a diagram of the solar system to scale, with Earth about the diameter of a pea, Jupiter would be over 1,000 feet away from Earth and Pluto would be a mile and a half distant—and about the size of a bacterium. Our nearest star, Proxima Centauri, would be almost 10,000 miles away._[4]
Pluto is not on the edge of our solar system. The edge of our solar system is past the theorized Oort cloud, which, starting from Pluto, would take 10,000 years to reach. Pluto is barely one-fifty-thousandth of the way to the edge of the solar system._[4]
Our nearest neighbor in space, Proxima Centauri (which is part of the three-star cluster known as Alpha Centauri), is 4.3 light years away—which is about a hundred million times farther than a trip to the Earth’s moon. To reach it by spaceship would take at least 25,000 years. To reach the next neighbor, Sirius (“the dog star”), would take another 4.6 light years of travel._[4]
Just reaching the center of our own galaxy would take longer than we have now existed as beings._[4]
In the Milky Way, the average distance between stars is about 5 light years, or 30 trillion miles._[4]
Nobody knows how many stars there are in the Milky Way. Estimates range from 100 billion to 400 billion. And the Milky Way is just one of 140 billion galaxies, many of them larger than ours. Some astronomers argue that with such a large number of stars, it is very likely that the number of advanced civilizations in the Milky Way is probably in the millions._[4]
While Big Bang theorists believe the universe is about 13.7 billion years old, they also estimated it to be 156 billion years across. They explain that its diameter is larger than its age because it has been expanding since the Big Bang._[4]

Space has been "stretching" since the Big Bang

Astronomer Carl Sagan estimated that the number of probable planets in the universe is at 10 billion trillion. But he also posited that they are so spread out that if we were randomly inserted into the universe, the chances that we would be on or near a planet would be less than one in a billion trillion trillion, or 10-33. In other words, “worlds are precious.”_[4]
NASA officials have maintained that astronauts have never had sex on the International Space Station or during any space shuttle missions. Scientists speculate, however, that while sex in space might pose some mechanical problems, conceiving a child could be dangerous. Low gravity could raise the risk of an ectopic pregnancy, and radiation could raise the risk of birth defects._[9]
While no NASA astronauts have had sex in space, in 1999 porn stars Silvia Saint and Nick Lang did a 20-second zero-gravity intercourse scene for the film The Uranus Experiment: Part Two._[9]
The first space observatory may have been Stonehenge. Around 2600 B.C., Britons constructed stones that marked critical positions of the sun and moon throughout the year._[4]
The Outer Space Treaty regulates international space law. It states that outer space is free to explore for all nations and that no one can claim it. It also bans deploying nuclear weapons in outer space._[13]
The first use of the term “outer space” was in Lady Emmeline Stuart-Wortley’s 1842 epic poem The Maiden of Moscow. The term “space” was used as early as Milton’s Paradise Lost in 1697 to describe the region beyond Earth’s sky._[4]
The temperature of the cosmic microwave background radiation that permeates the entire universe is 2.7° K (-270.45° C, -454.81° F)._[8]
The most luminous and massive known star is R136a1 in the Large Magellanic Cloud. It’s 8.7 million times brighter than the sun._[8]
The oldest known star is the red giant HE 1523-0901. At 13.2 billion years old, it is almost as old as the universe itself._[8]
Light (photons) takes 8 minutes 22 seconds to reach Earth from the surface of the sun, but 100,000 years from its core._[8]

The very heart of the Crab Nebula includes a central neutron star (ESA/Hubble)

The core of a neutron star is so dense that a single spoonful of matter from it would weigh 200 billion pounds._[4]
Only about 6,000 stars are visible to the naked eye from Earth, and only 2,000 can be seen from any one spot. With binoculars, the number of stars that can be seen from a single location is about 50,000. With a 2" telescope, the total leaps to 300,000. With a 16" telescope, you can begin to count in galaxies._[4]
Space is so dark because we can see light only when it hits an object and bounces off of it._[6]
Without gravity, food does not settle on taste buds like we are accustomed to on earth. Additionally, fluids tend to rise and gather in the sinuses, giving astronauts a stuffed up feeling, leading to a diminished sense of taste._[10]
NASA eventually conceded that some astronauts might have survived for up to two minutes after the initial 1986 Challenger explosion. While they might have survived the initial fireball, they would not have survived the plunge into the Atlantic Ocean at 200 mph._[8]
After Neil Armstrong and Buzz Aldrin returned to Earth from the moon, they were quarantined for 21 days until it was determined that they did not bring back some space plague. It was later determined that the moon was devoid of life._[8]
There have been six successful missions to put people on Earth’s moon between 1969 and 1972. A total of 12 astronauts have explored its surface. No one has been on the moon since December 14, 1972._[8]
Astronauts can grow up to 3% taller during the six months they spend on the International Space Station. Without gravity, their spines are free to expand. It takes a couple of months of being back on Earth for them to return to their preflight height._[10]
After returning to Earth, many astronauts have a difficult time adjusting to gravity and often forget that things fall if you drop them._[10]
Astronauts in space would lose about 1% of their muscle mass each month if they didn’t exercise at least 2 hours a day._[10]
Astronomers use 88 named constellations to find their way around the night sky, including Orion, the zodiac signs, and Ursa Major, which includes the Big Dipper. The Big Dipper is not its own constellation._[7]
Over 100 ashes of human beings have been launched into space, including Star Trek creator Gene Roddenberry and psychologist/writer Timothy Leary. The first human ashes to leave the solar system will be Clyde Tombaugh, the man who discovered Pluto. His ashes are aboard the New Horizons spacecraft, which is scheduled to pass Pluto in 2015._[7]
Real “shooting-stars” (not meteors) are called hypervelocity stars and are as rare as one in 100 million. Discovered in 2005, these stars shoot out of a galaxy at nearly 530 miles per second (10 times faster than ordinary star movement)._[4]
Black holes about 10,000 to 18 billion times heavier than the sun are thought to exist at the center of galaxies._[4]
Our universe consists of about 23% dark matter, 4% ordinary matter, and 73% dark energy._[1]
The full cost of a spacesuit is about $11 million. Almost 70% of this is for the control module and the backpack._[8]

One spacesuit costs over $11 million

Sixteenth-century English admiral and explorer Sir Francis Drake proposed the Drake Equation, which estimated that there could be millions of civilizations in our universe._[4]
The first human in space was Soviet cosmonaut Yuri Gagarin, who orbited Earth in Vostok 1 in 1961. The following year, American astronaut John Glenn, Jr., became the first American to orbit Earth. American Neil Armstrong was the first human being to set foot on the moon in 1969._[13]
While scientists can describe and predict gravity, its source within matter is still unknown. Some scientists believe that infinitesimal particles called gravitons create the force. Scientists are also searching for gravitational waves, which would ground Albert Einstein’s theory that the universe has a space-time “fabric.”_[1]
About 20 light years from Earth is star BPM 37093 (a.k.a. Lucy, after the Beatles’ song “Lucy in the Sky with Diamonds”). This white dwarf is actually one huge diamond that weighs in at 10 billion trillion trillion carats and is about the size of our moon._[7]
It takes the sun around 200 million years to travel around our galaxy. This is a journey of 100,000 light years._[8]
White holes are theorized time reversals of black holes. While the event horizon of a black hole attracts matter, the event horizon of a white hole ejects matter, even though the white hole itself still attracts matter. The difference is the action of the event horizon._[2]
The biggest star in our known universe is located in the constellation Cygnus, the Swan. It is a hyper giant that is almost a million times as big as the sun._[6]
Over 100 artificial satellites are launched into space each year._[8]
The most distant known objects in our universe are quasars, which are matter breaking apart as it spirals into a black hole. The nearest one is billions of light years away. Quasars are one of the most ancient, powerful, luminous, and energetic objects known in the universe, emitting up to 1,000 times the energy output of the Milky Way, which contains 200–400 billion stars._[4]
Scientists estimate that there may be as many as 20 trillion galaxies in our universe._[4]
NASA defines an astronaut as someone who has flown 50 miles above sea level. Some international groups define space as the area beyond the “Kármán line” (named after a Hungarian American physicist and engineer), which is actually 62 miles above sea level._[7]
The sun is not actually yellow. Because the temperature of the sun is 6,000° K (5,726.85° C, 10,340.33° F), it can be only one color: white. It appears yellow from Earth because of our atmosphere, which tints it yellow._[5]

Humans can survive 15-30 seconds in space

Humans can survive 15–30 seconds in outer space as long as they breathe out before the exposure. Breathing out prevents the lungs from bursting and sending air into the bloodstream. After roughly 15 seconds, a person will become unconscious due to lack of oxygen, which leads to death by asphyxiation. It is possible that a person’s eardrums would burst or swell, or for a person to get the bends. While a person’s blood would not likely boil due to blood pressure, saliva very well could. However, the worst problem would be lack of oxygen, not lack of pressure, in the vacuum of outer space._[5]
If the sun were replaced by a black hole of the same mass, it would not suck the Earth in. Its gravitational pull can be only as powerful as its mass allows it to be. If its mass were the same as the sun’s, then the pull would be the same as the sun’s pull._[5]
In 1992, more than 350 years after Galileo’s discoveries, the Catholic Church finally released a statement via Pope John Paul II acknowledging that Earth does move around the sun and apologizing for its treatment of Galileo—thereby vindicating the Italian astronomer whom it had persecuted in life and shunned for so many centuries._[4]
Every year, as much as 400,000 tons of cosmic material heads toward Earth. Fortunately, most of it burns up in our atmosphere. Scientists call objects “meteoroids” before they reach Earth’s atmosphere. If they burn up in the atmosphere, they are called “meteors.” Objects that reach Earth’s surface are called “meteorites.”_[4]
Light always travels at 186,000 miles per second. In one year, light can travel 5.88 trillion miles._[13]
The hottest stars in space are O-type stars, which are up to 72,000° F (40,000 C°). This is more than seven times hotter than our sun, which is a G2 star. Most O stars have close companions, forming a binary system. However, the relationship of the two stars is typically turbulent, with one star acting as a “vampire star,” sucking gas from the other._[6]
Small stars live longer than larger stars. A tiny star may live for hundreds of billions of year, while a huge star may live just a few million years. Our sun is a medium-sized star and will shine for 5 billion more years._[13]
Jupiter weighs more than twice as much as all our other planets together._[13]
Winds on Neptune are the fastest in our solar system at about 1,450 mph (2,400 km/h)._[4]
Saturn is the lightest planet. It is even lighter than water. If there were an ocean big enough to hold Saturn, this gas giant would float like a beach ball._[6]
The Milky Way is a barred spiral galaxy and contains about 200–400 billion stars. It is approximately 100,000–120,000 light years in diameter._[4]
To the ancient Norse, the Milky Way was the road to Valhalla, home of slain warriors. In China and Japan, it was the “river of heaven” or the “silver river.” The ancient Greeks thought it was milk spilled by the goddess Hera, hence the name we call it today._[4]
After six months, International Space Station astronauts return home having aged slightly less (0.007 seconds) than they would have if they had stayed on Earth. This is because space-time will bend depending on differences in either gravity or velocity—each of these affects time in different ways._[2]

Supernovae are the most violent events in the Universe

Only about a half dozen times in recorded history have supernovae been close enough to be visible to the naked eye. One was a blast in 1054 that created the Crab Nebula. Another in 1604 made a star bright enough to be seen during the day for over three weeks. The most recent was in 1987._[6]
A wormhole (a.k.a. an Einstein-Rosen Bridge) is a hypothetical “tunnel” that connects two different points in space-time. In theory, at the end of a wormhole could be two universes. Some scientists speculate that our universe could be located within the interior of a wormhole, which itself is a part of a black hole that lies within a much bigger universe._[2]
The abbreviation for pound, "lb.," comes from the astrological sign Libra, meaning "balance."_[3]
Scientists at NASA are working on the first practical field test toward proving the possibility of warp drives and faster-than-light travel. The trick is that it’s not the spaceship that is moving—it’s the space around it._[12]
The U.S. space exploration program helped create the TV satellite dish, MRIs, vision screening computer systems, ear thermometers, firefighter suits made of fire-resistant fabrics, smoke detectors, cordless tools, shock absorbing helmets, invisible braces for teeth, joystick controllers, and much more._[6]

Distance from Earth to . . . _[6]
Earth’s moon	1 light second
Sun	8 light minutes
Pluto	6 light hours
Proxima Centauri (nearest star)	4.2 light years
Orion Arm of the Milky Way	5,000 light years
Andromeda (nearest big galaxy)	2.5 million light years
Edge of the visible universe	13.7 billion light years