byWayne Boyd Studied Physics (college major) & Psychology (college major) at St. Mary’s University, San Antonio, TX
You see, each planet orbits the sun at different speeds. Those planets orbiting closest to the sun, like Mercury and Venus, orbit faster. Further out from Earth, Mars takes about 2 years to orbit the sun. Further out, Jupiter, Saturn, Uranus and Neptune all take progressively longer. Then the sun itself is orbiting the galactic center once every 250 million years, and the Milky Way galaxy is moving toward the Andromeda Galaxy at about 67 miles per second. So no planet will ever be in the exact position it was before, ever. The first image shows the planets orbiting the sun in relationship to our own solar system. The second image shows the planets orbiting our sun in relationship to the sun orbiting the galactic center of the Milky Way Galaxy.
This is an interesting question. I’m going to answer it with illustrations.
In answer to “How big is the Moon compared to the Sun and Earth?” I’m going to give you some illustrations that will put all of this into perspective. First, let’s look at a comparison of our Moon with Pluto and other dwarf planets in our solar system. Here’s a picture to illustrate.
So here you can see our Moon is quite large! In fact, it’s so large, it’s bigger than all of the known dwarf planets in our solar system, including Pluto!
Even though the Moon is bigger than Pluto, it’s not big compared to Earth. Here’s the comparison of that.
So the moon is relatively small compared to our big Earth. But when you bring the Sun into the mix, then you have to understand that Earth itself is not very big. In fact, the Sun is so big it dwarfs even Jupiter. Here’s the image of that comparison:
So to sum up, our Moon is big compared to Pluto and other dwarf planets in our solar system, but small compared to Earth. Earth itself is like a pebble of sand compared to the size of our Sun. Fortunately for us, the sun is also a long way away, and therefore looms the same relative size as the Moon in our sky.
I hope that sheds some light on the subject! Thanks for asking a cool question.
If you count all the little nuts, bolts, loose wrenches and pieces of demolished satellites as satellites, then there’s a whole lot of junk floating around Earth. Thousands of pieces that pose a hazard.
Around the moon we have about three functioning spacecraft but have launched far more than that that have, over time, gone dead – perhaps crashed to the surface of the moon. Then we have the odd Juno spacecraft around Jupiter, the voyagers I and II and so on. We’ve put more space junk up there then anything else. This is a fairly accurate artist’s rendition of space junk around Earth.
The Russians have put several probes on Venus, the Americans and Europeans put a probe on Titan, we have probes on Mars, we flew a probe by Pluto and orbited Saturn for a long while before crashing deliberately. We presently have, as mentioned, the Juno spacecraft around Jupiter. We have hundreds of functioning satellites in orbit around Earth.
We spend 600 billion dollars every year on the military. What would happen if NASA had that kind of money? Here’s a very cool YouTube video that I love to watch!
There is no stigma. All of science is dedicated to discover extraterrestrial life. We would be completely excited to find even a fossil of a microbe from space because it would be the ultimate affirmation that life can evolve from matter on another world other than Earth. Our best hope at present is to find some kind of life on one of the moons of Jupiter or Saturn, or perhaps some fossils on Mars as of yet undiscovered. We are even spending billions of dollars with the SETI program to listen for radio waves from space!
However, much to the surprise and dismay of scientists, we have yet to discover anything at all.
Mechanical, intentional interstellar travel is unlikely since the distances are far too great to imagine. The best anyone could achieve is interplanetary travel within one’s own solar system. Therefore, if we pass the buck and say life didn’t start here but started somewhere else and arrived here, it would have had to arrive on a rock or asteroid as a microbe and somehow survive a fiery entry through Earth’s atmosphere and it would have had to survive the vacuum and temperature extremes of space. If the rock came from outside the solar system it would have had to survive a long, long time.