17 ‘facts’ about space and Earth that you thought were true—but have been debunked by science
Whenever someone asks me about outer space, I get animated.
No surprise there: I’ve made a living speaking to experts and writing about the topic for more than a decade, and have read obsessively on these topics for much longer than that.
I’ve heard a lot of peculiar “facts” over the years — and even believed and shared a few myself — that I eventually learned were totally false.
Below are some of the most common myths, misconceptions, and inaccuracies I’ve encountered that should be thrown into a black hole.
MYTH: The sun is yellow.
If you look at the afternoon sun, you’d be forgiven for thinking it looks yellow — but the light it gives off is technically white.
The Earth’s atmosphere makes the star appear yellow. The gases bend the light in an effect called Rayleigh scattering, which is what also makes the sky appear blue and causes sunsets to blaze into brilliant oranges and reds.
It also doesn’t help that astronomers classify the sun as a yellow main-sequence G-type star, or “yellow dwarf” — which has nothing to do with color.
MYTH: The Asteroid Belt is dangerous.
Movie scenes of spaceships flying through a dense field of tumbling, colliding rocks are not realistic.
The Asteroid Belt — a zone 200 to 300 million miles from the sun — is an incredibly lonely and desolate void.
In fact, if you pulled all the asteroids in that belt together, they’d only weigh about 4{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of the mass of Earth’s moon.
That’s why NASA gets really excited when it catches even one asteroid colliding with another.
MYTH: Going into space makes you weightless.
Most scientists agree that space begins 62 miles up, where the Earth’s atmosphere is more or less a vacuum.
Yet going past this point does not magically make you weightless. If you’re in an accelerating rocket, you will feel many times Earth’s gravity. It’s only when you start falling that you feel weightless.
To orbit something is to fall forever around that object. The moon around the Earth, the Earth around the sun, the solar system around the Milky Way Galaxy… They’re all falling towards one another in a crazy cosmic dance.
If you’re 250 miles above the Earth, you have to travel 17,500 mph around the planet to experience continuous free-fall (the same speed that the International Space Station and its astronauts travel).
MYTH: A nuclear weapon could destroy an asteroid.
Nuking an asteroid would not vaporize the rock.
Most asteroids are heaps of rubble to begin with, so a powerful blast would probably just break everything apart further. That’s like turning a single bullet into a shotgun blast — not a good idea if you’re trying to save the planet.
However, some researchers think a well-directed, smartly designed nuclear attack could irradiate an asteroid’s surface, vaporize some of the rock, and shoot off gases that’d push an asteroid on off-course. Phew.
MYTH: Astrology can predict your personality or the future.
Wouldn’t it be nice to get a glimpse of tomorrow based on something as simple as where the sun, planets, and moon were located when you were born?
That’s what astrology claims to do — and as much as 2{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of people on the planet strongly buy into.
Yet thorough scientific investigations of astrology have failed, again and again, to back up any predictions from an astrological sign or horoscope.
In a 1985 study published in the journal Nature, scientists used a nonbiased, double-blind protocol and worked in conjunction with some of the top astrologers in the US to test the predictive power of astrological signs.
The results? The astrological predictions were no better than chance.
MYTH: When you call someone, the signal bounces off a satellite.
The military uses satellite phones every day, but your mobile phone works in a much different way.
Mobile phones broadcast a wireless radio signal and constantly look for, ping, and relay data to and from land-based cellular towers.
When you make a call, the nearest tower connects you to another phone via a vast network of tower-to-tower connections and buried cables.
At best, a satellite might be involved in an international call — but 99{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of worldwide communications data travels through undersea cables.
MYTH: The Great Wall of China is the only man-made structure visible from space.
It all depends on where you believe space begins above Earth.
From the International Space Station, 250 miles up, you can see the Great Wall and many other man-made structures. Tiny satellites that orbit even closer than that can see objects like Apple’s spaceship campus.
From the moon, you can’t see any structures at all — only a dim glow of city lights.
MYTH: The moon’s gravity pulling on water causes the tides.
This is only partly true, as the science behind Earth’s ocean tides is anything but straightforward.
The moon does pull on ocean water, but that tug at any one point is about 10 million times weaker than Earth’s gravity. It’s really the interplay of gravity between the moon, Earth, and sun that creates a tidal force — and it’s more of a “squeeze” than a “pull.”
Each molecule of water is pulled by the moon’s gravity, but alone that acceleration is so weak it isn’t noticeable. Because ocean water covers about 71{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of Earth’s surface and is connected as one liquid body, however, all of those tiny tugs add up to form a significant pressure — what we call the tidal force.
Molecules of water near the poles are pulled mostly straight down, those on the face of Earth closest to the moon experience the strongest pull toward the moon, and those on the opposite side of Earth feel the weakest acceleration.
Together, these interactions form a pressure on seawater that generally directs it away from the poles and toward the equator, where it’s strong enough to fight gravity to form two bulges: the high tides.
High tides stay put as the Earth rotates underneath them every day, and they follow the moon as it orbits Earth every 28 days. Low tides occur where the tidal force (or water pressure) is weakest, and dramatic tides can result where land and seafloor terrain funnel more seawater into one spot.
The sun’s gravity also affects the tides, accounting for roughly one-third of the phenomenon. When the sun’s gravity counteracts the moon’s, it leads to lower-than-average “neap tides.” When the sun lines up with the moon, it triggers larger “spring tides.”
Smaller bodies of water, like lakes and pools, don’t have noticeable tides because they lack enough liquid to create a pressure that can visibly overcome the pull of Earth’s gravity.
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