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mfb- t1_iyl8n0s wrote

Reply to comment by redlinezo6 in Did the impact from the asteroid that killed the dinosaurs change the earth’s orbit? by phoinex711

We don't know the precise impact speed and mass, but 10 km/s is a typical approach speed (leading to a 16 km/s impact due to Earth's gravity). It could be just 2 km/s, it could be 30 km/s, in extreme cases it could be up to 70 km/s. It can't be more for objects in our Solar System, only interstellar objects could impact faster but they are very rare. The conclusion is the same for all realistic speeds.

> I know you are throwing rough numbers around, but wouldn't a 50 meter change compound over 120million years? Or on that solar scale is that so trivial its like a fly hitting a baseball?

It's a one-time change. There is nothing that compounds.

If we put the mass of a fly at ~10 milligrams then it's like a fly hitting a truck.

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redlinezo6 t1_iymr23x wrote

We just did that with a satellite hitting an asteroid. Of course those masses are much closer in size, but it only changed the asteroids spin slightly, but measurable over days.

And there is totally things that compound, every change in mass or velocity changes it's interaction with all gravitational bodies. Which all act on each other...

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mfb- t1_iymwfwi wrote

They all act on each other but that's a small effect and moving Earth's orbit by 50 meter isn't going to change that. Forces will differ by something like one part in a billion, and a billionth of a small effect is completely negligible (far smaller than 50 meters, in particular).

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