An asteroid belt around the bright star Vega.
Should you be getting your facts about space from Hollywood? Probably not. Here are ten myths about space you should stop believing.
1. We explode in space
Like many of the myths that will follow, this idea was mostly created by Hollywood. Oftentimes, moviemakers aren’t really that concerned with the facts. They will readily take liberties with reality in order to make a scene look more interesting. From movies, we know that the instant a human is exposed to outer space without a protective suit, he’s a goner who, most likely, will explode in a splatter of blood and guts (depending on the rating of the film).
Exposure to space will definitely kill you, but not instantly and not in such a visceral way. A human being can survive exposed to space for about half a minute with no permanent damage. It won’t be pleasant, but it’s not instant death. You would probably die of asphyxiation due to lack of oxygen. There is one movie that got this right – Kubrick’s 2001: A Space Odyssey.
2. Venus and Earth are identical
Venus is often referred to as our twin but this shouldn’t give you the impression that it is exactly like our planet. We’ve covered Venus in-depth before so we won’t go into detail, but this idea came about mainly when we had no clue exactly what the surface of the planet is really like. Due to its incredibly thick atmosphere, it wasn’t until we sent a spacecraft to Venus that we discovered how deadly and unwelcoming the surface of the planet really is.
3. The Sun is a ball of fire
The Sun is actually glowing, not burning. This might seem like an insignificant distinction to the average person, but the heat generated by the sun is actually the result of a nuclear reaction, not a chemical one which is what burning is. While we’re at it…
4. The Sun is yellow
Ask anyone to draw a Sun and they will immediately reach for the yellow crayon. It seems normal. We’ve been using that yellow crayon for the Sun ever since we were little and all we could draw was the crappy front of a house and the Sun smiling in the corner (come on, that definitely wasn’t just me, right?). If we ever needed more evidence, we could just go outside and look at the sun and it definitely appears to be yellow.
Thing is, though, that we see it yellow thanks to our atmosphere. If you’re sure that you’ve seen NASA photographs or similar images and the Sun was yellow there, too, you might actually be right. This image we have of a yellow Sun is so prevalent that sometimes astronomers will actually modify the color of their pictures in order to make them more recognizable. However, the real color of the Sun is white. If you ever meet as astronaut or someone who has been to space, feel free to ask them.
Regardless, we don’t need to see the Sun to know what color it is because we can tell from the temperature. Cool stars start off with a brown/dark red color and increase in intensity as they get hotter. Something with only a few thousand degrees Kelvin surface temperature will be red. At the opposite end of the spectrum, the hottest stars with a surface temp above 10000 Kelvin are blue. With a surface temperature of almost 6000 Kelvin, the Sun is somewhere in the middle, giving it a distinct white color.
5. Earth is closer to the Sun in the summer
At a glance, this one seems logical enough. Our planet is hottest when it is closest to the thing that makes our planet hot. However, this idea is caused by a misunderstanding of what actually causes the seasons. It’s not the proximity to the Sun, it’s the tilt of our orbital axis. The axis on which our planet spins is actually tilted to one side. When that axis points towards the Sun, it’s summer in that hemisphere. When it points away, it’s winter.
What isn’t a myth, however, is the idea that the Earth is sometimes closer and sometimes further away from the Sun. Our planet has an elliptical orbit (like most other planets). The distance given from Earth to Sun (known as an astronomical unit) is approx 93 million miles (150 million km). However, at perihelion (Earth’s closest point to the Sun) that distance shrinks to 91.4 million miles (147 million km) and at aphelion (the longest distance) it goes up to 94.5 million miles (152 million km). So, as you can see, during the course of a year, the distance between Earth and the Sun changes by as much as 3 million miles (5 million km).
6. There is a dark side of the Moon
Again, something we’ve talked about, but it is mentioned often so it bears repeating. The idea that the Moon has a side which is constantly bathed in darkness is false. The Moon is tidally locked with the Earth, meaning that the same side is always facing us, not the Sun. All sides of the Moon receive sunlight at various points.
7. Sound in space
Movies rarely get sound right in space. I guess that if you’re spending a fortune on filming an explosion or a dramatic death, you definitely want the audience to hear it. However, space means no atmosphere which means there is nothing for the sound waves to travel though. Again, Kubrick got this one right in 2001. However, this shouldn’t suggest that there is no sound in the universe apart from our planet. If you go someplace else with an atmosphere, then there will be sound, but it will probably be a little weird. On Mars, for example, sound will be higher in pitch.
8. You can’t travel through an asteroid belt
This one we all know from Star Wars. Han Solo showed us he’s a badass pilot by flying the Millennium Falcon through a deadly asteroid belt and making it out the other side despite almost zero chances of survival. That’s impressive…except for the fact that you could also probably do the same thing (if you had a spaceship handy).
One of the main things that movies are bad at when it comes to space is accurately portraying size. And it’s not really their fault. If they were to show things how they really were, they’d just show a black screen with a tiny dot here and there which was meant to be a planet or something. The idea here is that space is big. Really, really, really big. Even if an asteroid belt has millions and millions of asteroids in it, you’d have to be the unluckiest person in the universe to hit one. It’s not impossible, but the chances are astronomical.
Let’s look at our own asteroid belt as an example. It has millions of objects in it; possibly a lot more depending on how small an object can be and still be worth mentioning. The biggest thing in it is Ceres, a former asteroid, now classified as a dwarf planet. It’s around 600 miles (950 km) in diameter. The distance between two objects in the asteroid belt ranges in the hundreds of thousands of miles. Chances of hitting one of them are 1 in 1,000,000,000. So far we’ve sent 11 probes through the belt without incident.
9. You can see the Great Wall of China from Space
Another “fact” we’ve talked about before, along with everybody else on the internet. It’s weird that it still gets mentioned as fact at this stage.
10. NASA takes up almost a quarter of the government budget
Without a doubt, the USA has contributed more than any other nation to the exploration of space but, unfortunately, those contributions have been relatively tame in recent years because NASA is starting to lose public support. More and more people are becoming less interested in space and that is a real shame because it truly is one of the most ambitious and important undertakings of mankind as a whole.
One of the biggest problem NASA faces is the public perception that it spends way too much money. People really overestimate how much money NASA gets on a yearly basis. Polls constantly reveal that the average person thinks NASA receives a significant chunk of the federal budget, going as high as 25% of the whole thing. In a time when many people are struggling economically, it’s no wonder that they want to see the space program gone.
The issue here is that NASA gets nowhere near that. You can see here a detailed rundown of the budget for 2015 which will be around 0.5% of the federal budget. In fact, throughout its history, NASA’s budget has hovered around the 1% mark. It was at its highest during the space race of the 1960s and still it only reached a peak of 4.4%, nowhere near the 25% some people claim.
Photo credit: Wikimedia
Via IFL Science