How Do Astronauts Know Which Way to Go?
By pumpkinjam
@pumpkinjam (8876)
United Kingdom
September 16, 2008 1:27am CST
Is it necessary to take off from different places on Earth to reach different destinations in space? Or to go at certain times so that the Earth is facing the right way?
How do we know that, for example, when a space probe reached Mars, it actually was Mars and not, say, Venus? I know scientists and space explorers, etc. have ideas of what the planets are like before taking a closer look at them but it doesn't necessarily mean they have found what they are looking for, does it?
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1 response
@stvasile (7306)
• Romania
16 Sep 08
It's not necessary to take off from a certain point on Earth to reach a certain destination. If that would be so, probably NASA won't launch spacecrafts from Cape Canaveral all the time, right?
The thing is once they leave the Earth, a different coordinate system is taken into account, having as reference The Sun. So, if you report yourself to The Sun, by distance and position, you can figure out where in the Solar System you are.
And, of course, as the previous responder said - computers do the navigation much easier today.
@pumpkinjam (8876)
• United Kingdom
22 Sep 08
But people must programme computers. It has to be possible that mistakes could be made. Also, what if the Sun is not where we think it is?
I know computers are used and wotnot. The thing is, how can anyone be absolutely completely sure that they are where they think they are? I mean, they could say certain co-ordinates thinking that that's where the Moon is, for example, but might end up on a different piece of space rock because the Moon isn't where they thought it was or because there is something else which they think is one thing but it might turn out to be another. It's not unknown for people to get things wrong. I mean, we had 9 planets in our Solar System since 1930 and now, apparently, there are only 8 because Pluto was declassified.
@stvasile (7306)
• Romania
22 Sep 08
Planets and satellites have a certain orbit, at exact distances from The Sun, calculated by many means for many years (optics, gravitational influence, wave reflection). You can't be at one distance from The Sun and reach a different planet by mistake. Things don't work that way.
And if they get lost, they can take pictures of planets with them. Planets do have distinct features like specific color, temperature, landscape.
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