let it be known that because the oceans slosh around on Earth as it
rotates about it’s axis (these are called ocean tides), the speed of
Earth’s rotation is gradually slowing down. Billions of years ago a day
on Earth was only about 8 hours, and now it continues to slow down. We
compensate this twice a year by adding leap-seconds as needed.
slowing of the earth’s rotation causes the moon to drift further away
from us every year by about 1.5 inches, so eventually the Moon will
escape Earth altogether and drift away.
You don’t understand cameras, do you? Well, a quick lesson then. In cameras (other than cell phone cameras), there’s a thing called aperture. When there’s a bright light the aperture has to be small, to let less light in, so you can photograph something like the Earth. This avoids overexposure of the bright objects in your photo. In space, this blacks out the stars.
However, if like the Hubble Telescope, you just look away from Earth at the stars, you see a whole lot more of them than we can see here on Earth.
Here’s a photo taken of the Hubble Telescope from the point of view of the Space Shuttle Discovery. Notice, because the Earth is so bright, we don’t see any stars.
On the other hand, since the Hubble Telescope points away from the bright light source coming from Earth, we can capture images like these.
This would be so cool. Everyone would want one, even if they couldn’t afford it. But is the concept possible?
Well, the short answer is no. It’s not possible.
To understand that “no” requires a little bit of understanding in orbitology.
You see height is not the only problem when you want to stay up in space. If you want to stay up there for sometime you’ll need to be in orbit. To get in orbit you’ve got to go really, really fast – like around 17,000 mph fast.
That’s because an orbit simply put is when an object is going so fast in one direction that as it falls it misses the planet. You’ve got to be going a lot faster than a speeding bullet.
So if you had a vehicle in your garage that could not only fly like a plane, but could continue to fly above the atmosphere and get going 17,000 mph, then you\d be bad ass.
But you can’t and you won’t, because to do all that takes a lot of fuel. That’s why we have these big ol’ rockets boosting satellites and astronauts into space. Those big ol’ rockets are filled with fuel. Once the fuel is expended then the big ol’ rocket isn’t needed anymore and it’s detached to fall back to Earth.
So sadly, the idea of having a small shuttle that you park in your garage and fly into space is just not going to happen. Ever. Sorry!
It just moves forward. The moon isn’t stationary. It has inertia and no atmosphere in space to slow it down. It just goes. As it moves forward, the gravity of Earth tugs on it and it falls, but because it’s moving forward it misses Earth as it falls and goes around, again and again. That’s called an orbit.
Not very big! It would just have to be natural. Not made by man! And it wouldn’t have to be there for very long either. Just long enough for it to be in orbit.
The astronomical community doesn’t have a definition for moon other than it has to be a natural object. Thus captured asteroids can be moons. It’s even possible for a moon to have a moon!
Mars has two moons, neither of which are large enough to be round. Objects in space get round due to their own gravity. The first image above is Deimos and the second is Phobos, the Martian Moons. Deimos (top) is the smallest. It has a mean radius of 3.9 miles.
By looking at the illustration below, you would think so! Earth and Mars are so close, why not build an outpost between to make it easier to go there!
Unfortunately, this image only shows us the relative distances the planets have from the sun. Actually, Earth orbits the sun faster than Mars because Earth is closer to the sun. The closer to the sun, the faster the orbit. The further from the sun, the slower the orbit.
This means that sometimes the two planets are close together and other times they’re on opposite sides of the Sun.
If you could somehow position an outpost so it stayed midway between the two planets then as the planets move to opposite the sun from each other where would the outpost go? Into the sun!
You couldn’t have that! The best you could do is put an outpost in orbit around the sun, between Earth and Mars, but then the outpost would have the same problem for both Earth and Mars. Sometimes the outpost would be near one planet or the other and sometimes it would be on the opposite side of the sun. It would be very rare to find all three of them lined up in a row like stepping stones.
Now another idea might be to have an outpost orbiting Earth, way out in space halfway the distance to Mars. It could work, but it would take a long time to orbit Earth at that distance. It wouldn’t remain stationary. It would be in orbit, albeit a fairly slow one. Sometimes it will be on the opposite side of the Earth from Mars, being of no use. Such an orbit would be influenced by the orbit of Earth’s moon, and by Mars itself, throwing it off orbit, and would be inherently unstable.
So if somebody thinks we might one day build such an outpost to make going to the planet Mars easier, that idea wouldn’t work too well.