Why haven’t we seen the other side of the moon?

Answer by Award-Winning Scifi Author C Stuart Hardwick

The far side of the moon was first photographed by Luna 3 in 1959. The above is a recent image captured by NASA’s LRO.

If you are asking why we can only see the near side from Earth, that’s because the moon tidally locked. It used to spin faster than it orbits, but just as its gravity causes a tidal bulge in Earth, our gravity causes a bulge in the moon.

Tidal bulges are carried along by the rotation of the body in question, and so create a slight gravitational imbalance. Today, this imbalance is pushing the moon away as a rate of 3.5 cm per year and slowing Earth’s rotation by about a millisecond per century. In the past, that same process slowed the moon’s rotation until it’s rotational and orbital periods became the same.

Now the moon’s stuck with it’s tidal bulge facing us. Any perturbation that would tend to turn the moon with respect to Earth gets cancelled out by the pull of our gravity on the moon’s bulge, and nothing is ever likely to disturb it enough to break free.

Will the moon be closer to Earth one day and will it make ocean tides more severe?

No. The moon is drifting away about 4 centimeters a year. Over time it will drift out to space and Earth will have no moon.

Of course, the sun might become a red giant before that, killing everything, but the answer to your question is no.

As a result the tides will become less severe.

However, as the climate warms and the ocean rises as much as it is now, cities and communities near the sea will become flooded. This has nothing to do with the moon.

What are the similarities of the moon and the earth?

Mysteriously, they are made largely of the same materials which casts doubts on the Giant-impact hypothesis (which predicts the moon should be made of 70% material from Theia, the so-called planet that collided with Earth).

Anyway, they are both rocky. Planets beyond Mars are gas giants with rocky moons, so they have that difference, but the earth and Mars are rocky planets with rocky moons.

What planets are bigger than Earth?

The four gas giants are larger than Earth: Jupiter, Saturn, Uranus and Neptune.

Venus is slightly smaller, but very nearly the same size as Earth. Mercury and Mars are smaller than Earth.

So there are 4 planets larger than Earth in our solar system, and they are the four gas giants.solar_system_3

Why can I see the Moon stand still in the sky if it orbits the Earth at a speed of 2,288 miles per hour?

You think that’s fast? Think again. At it’s orbital distance, as you know by watching the moon itself, it takes about 28 days to orbit the earth.

Very roughly speaking, the moon rises about an hour later each day.

That’s why you can still see it.

But you don’t believe this answer because you think the earth is flat.

Partial lunar eclipse
I took this photo from the street in front of my house in Amarillo, Texas, during a partial lunar eclipse. You can see the upper left corner of the moon is darker. The green light in the foreground is a streetlight on Pagoda Drive, Amarillo.

Are there photographs of the planets from their surface?

As Bobby Sherman has already pointed out, we have sent spacecraft to the surface of Venus and Mars. We’ve also sent people to our moon and a lander to Titan orbiting Saturn. We’ve retrieved photos from all these places. Here they are.

First, our sister planet Venus (sister because it’s almost the same size as Earth), was photographed by the Russians.

Next, Mars has been photographed many, many times by our Mars Rovers.

Our moon was photographed by astronauts walking on it:

Titan was imaged by NASA by sending a probe to the surface.

Those are the places we visited on the surface. Of course, we’ve orbited and passed by many other bodies in our solar system, but this is where we have images from the ground.