Space Speed

488 viewsOtherPlanetary Science

So, a car against asphalt it’s pretty easy determinining the speed.
But when someone says a spaceship, for example Voyager, travels at about 61.5 kkm/h. What speed are we comparing against? According to Google, Earth rotates at the equator at about 1.5 kkm/h. So if we said that we compare Voyager speed vs Quito speed and assuming angle of Voyager vs Quito is 90 degrees then that should be +- 1.5 kkm/h?
And Earth itself is also according to Google running around the sun at a clip of about 107 kkm/h so that would mean that at some points Voyager is doing -40 kkm/h vs Earth.

Just standing “still” in the Universe some shit would be moving really really fast compared to me so where do we flip reference points?

edit: lost a couple of ks

In: Planetary Science

7 Answers

Anonymous 0 Comments

Your main problem is thinking of movement of space objects in linear way. In fact it is not.

Everything in space are controlled by forces of gravity. Every object orbits something – mostly in elliptic or circle orbit. [Read about Center of Gravity ]( https://en.m.wikipedia.org/wiki/Center_of_mass#Center_of_gravity) To escape gravity of something, there is equations on [Escape Velocity](https://en.m.wikipedia.org/wiki/Escape_velocity).

That velocity is actually 3-dimensional and all summed up creates a vector of movement. Depending on velocity we figure out gravity of what object we’ve escaped and in gravity of what object we are entering now. Our vector of movement would define how we gonna orbit that new object.

So basically, Voyager escaped Sun’s gravity, but vector of movement is different from vector of movement of Earth. Also, from the perspective of black hole in the center of our galaxy – some planets are going faster than Sun (get forward of Sun) , then slower than Sun (get behind of Sun)

Also, play Kerbal Space Program, where you could realistically launch stuff into cosmos.

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