– Okay, so the solar system is hurtling through space at around 200km/s and by extension so are the planets. I get that we can launch a rocket and land it on another planet, but does this mean that the rocket would also be travelling at approx 200km/s as well?

Question

And additionally, would it ever be possible to launch something into deep space and get entirely left in the dust by the solar system whizzing by? Completely untethered from its gravity?

In: 9

Answer 1

When we say that things are moving at a certain speed, we mean to say that they are moving that speed with respect to some point of reference. If you are on an airplane, the plane may be flying 500 mph relative to points on the ground, but when you are in your seat, we say that you’re sitting still because you aren’t moving relative to the plane or your seat.

The solar system is like that plane. For our spacecraft in the solar system, it’s not important how the solar system is moving through space (relative to, say the center of the galaxy). We’re concerned about the movement of things in the solar system so that we can steer the spacecraft to their destination. We are moving completely within the solar system.

This is sort of the starting point for something called “relativity” in physics, and it’s basically simple starts with the idea that the speed of things is measured relative to something else. Relativity get pretty mind-bending after that because how we think of speed changes as things get really fast.