10 Misconceptions About Space

People have a lot of weird misconceptions about space (thanks, Hollywood). Here are a few myths about the universe and their real explanations—and we hope you like NASA, because they're going to come up a lot.

1. The Sun is on fire.

Artist's rendering of the sun
iStock/mrtom-uk

When some people picture the Sun, they imagine something like a campfire or an object on fire. But the Sun is actually a ball of gas. It burns thanks to nuclear fusion, which happens in its core. Every second, 700 million tons of hydrogen gets converted into 695 million tons of helium. When this happens, energy is released as gamma rays, which get converted to light. So, the Sun emits light and heat, but it's not on fire, because there's no oxygen involved.

2. The Sun is the only star that has planets.

Jupiter and Mars in the solar system
iStock/themotioncloud

Experts now believe that most of the stars in our Milky Way have planets surrounding them. Any planet that's found outside of our solar system is known as an exoplanet, and we can be pretty sure that they exist because they affect the way a star appears. One of the most common ways to detect exoplanets is to look for a decrease in light from certain stars at various times, which would indicate that a planet is passing in front of the star, affecting how the light appears to us.

3. Mercury is the closest planet to the Sun, so it's the hottest.

Colorized image of Venus's clouds
NASA/JPL // Public Domain

Distance from the Sun actually has little to do with the average temperature on a planet. Venus (the second planet from the Sun) is the hottest planet in the solar system, but that's because of its atmosphere, which contains mostly carbon dioxide and some nitrogen, making it very thick. Throughout the year the surface of Venus remains at a temperature of about 462°C. The surface of Mercury, on the other hand, has a lot of temperature variations. It can be as cold as -173°C at night, and during the day it might reach 427°C. Mercury has a very thin atmosphere, which is why there's so much variation in temperature.

4. People explode in space.

NASA astronaut performing a spacewalk
NASA/JSC // Public Domain

Space is a near-vacuum, which means that people can't survive out there for more than a few minutes—but exploding isn't a concern. A body exposed in space will expand and bloat, especially the air in the lungs and the water in body tissue, but human skin is actually tight enough to prevent exploding. A person exposed to space would eventually die when circulation stops, after dissolved gases in the blood form bubbles and block flow. Basically, it's like an extreme version of "the bends" that divers can get.

5. In the 1960s, NASA spent millions developing a pen that would write in space.

NASA astronaut writing with a space pen
NASA/JSC // Public Domain

This is a popular myth on the internet—and even in one episode of The West Wing. People tend to use this as a comparison between NASA and Soviet astronauts, who were smart enough to just bring pencils. But NASA used pencils as well, and they have the receipts to prove it. In 1965, NASA placed an order for 34 mechanical pencils from Houston's Tycam Engineering Manufacturing Incorporated. There was an independent company, the Fisher Pen Company, that developed a space pen for around $1 million. And later, both NASA and the Soviets started using Fisher's anti-gravity space pen (it was a great pen).

6. In space, you experience zero gravity.

NASA astronauts experiencing decreased gravity
NASA/JSC // Public Domain">NASA/JSC // Public Domain

Gravity is considered the most important force in the universe, and it doesn't just go away when we leave Earth. Gravity is necessary for everything from the Moon's ability to orbit the Earth to the Sun staying put in the Milky Way. What astronauts actually experience in space is what NASA calls micro-gravity. It has nothing to do with the actual strength of gravity, which is only very slightly less on the International Space Station. It's because astronauts are constantly falling, so they seem weightless.

7. Black holes are like vacuums.

As we learn more and more about black holes, experts are more likely to compare them to Venus flytraps than vacuums. Black holes don't suck up everything nearby; instead, they sit pretty dormant, then if a star approaches it and gets too close, the black hole becomes active. And still, only some of the objects nearby get ripped apart by the black hole.

8. The Moon orbits Earth once a day.

Earth's moon
NASA/JPL/USGS // Public Domain

It takes about 27.3 days for the Moon to orbit Earth. This is known as a sidereal month. It's worth noting that the Moon's orbit isn't considered regular—it has variations, and there are upwards of five different months that astronomers recognize.

9. There's a dark side of the Moon.

Earth's Moon from the International Space Station
NASA/JSC // Public Domain

As the Moon is orbiting Earth, it's also rotating on its axis, so we're always seeing the same side of the Moon. But the opposite side isn't dark: it gets the same amount of sunlight as the other side.

10. A light-year measures time.

It actually measures distance. NASA defines a light-year as "the total distance that a beam of light, moving in a straight line, travels in one year." Light travels at around 300,000 kilometers per second, so a light-year is around 10 trillion (10,000,000,000,000) kilometers.

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This story was republished in 2019.

NASA's First All-Female Spacewalk is Really Happening This Time

NASA astronaut Christina Koch is suited up in a U.S. spacesuit ahead of her history-making spacewalk.
NASA astronaut Christina Koch is suited up in a U.S. spacesuit ahead of her history-making spacewalk.
NASA

After a surprising cancellation in March, plans for NASA's first all-female spacewalk are back on track. Astronauts Christina Koch and Jessica Meir are scheduled to make history on October 21, 2019.

Earlier this year, NASA canceled the first all-female spacewalk because of an issue with spacesuit sizing. Both astronauts originally scheduled for the walk needed medium-sized suits. At the time, the International Space Station had two—but only one was properly configured for a spacewalk. Preparing the other suit in time would have taken hours of crew labor, The New York Times reported, so NASA decided to switch out the astronauts.

“When you have the option of just switching the people, the mission becomes more important than a cool milestone,” NASA spokesperson Stephanie Schierholz told The New York Times.

Still, the milestone is a significant one. Since 1961, nearly 550 people have been sent to space. Of those, only about 11 percent have been female.

“I think it’s important because of the historical nature of what we’re doing and in the past, women haven’t always been at the table,” Koch said on NASA TV. “There are a lot of people that derive motivation from inspiring stories from people who look like them, and I think it’s an important aspect of the story to tell.”

The mission itself is fairly routine—Koch and Meir are scheduled to swap out batteries on the station’s solar panels. Live video of the spacewalk (the 222nd spacewalk in history) will be available on NASA’s website.

A Huge Full Hunter’s Moon Will Light Up The Sky This Weekend

Chayanan/iStock via Getty Images
Chayanan/iStock via Getty Images

This weekend’s full moon will likely draw your eye even more than a regular one does.

Newsweek reports that what’s known as the full hunter’s moon—the first full moon after the harvest moon—will rise right around sunset, making it seem both much larger and more orange than usual. Though you’ll likely be able to spot it from Saturday, October 12 through the early morning hours of Tuesday, October 15, the best time to look up is Sunday night, October 13, when the moon reaches peak fullness.

According to The Old Farmer’s Almanac, the hunter’s moon may seem so huge because of a simple trick our eyes play on us called the “moon illusion.” Usually, when the moon is high and far from the horizon, it’s the main thing we see in the sky. Because the sky itself is so unfathomably vast, the moon looks pretty small. The hunter’s moon, however, appears lower in the sky, giving us a chance to view it next to things like trees and buildings. Since the moon is so much larger than those objects, our brains may process it with a better sense of scale.

The reason the hunter’s moon often glows orange is also related to its lower position. The moon is actually closer to us when it’s higher in the sky, so the light it reflects has to travel a shorter distance to reach our eyes, leaving the shorter wavelengths of blue light intact. When the moon is low, the air scatters those short blue wavelengths before they get to us, and only the longer, reddish wavelengths make it through.

Though we don’t know for sure why it’s called a hunter’s moon, The Old Farmer’s Almanac suggests that it may have once indicated the beginning of prime hunting season, when hunters could easily spot animals in fields that harvesters had just cleared after the previous month’s harvest moon.

And, after the hunter’s moon has come and gone, be sure to catch the full beaver moon in November.

[h/t Newsweek]

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