How fast do comets that pass thru our solar system travel?
Comets obey Kepler’s laws, which means they go really fast near the Sun, like over 100,000 MPH, and really slow far from the sun, like only a few thousand MPH. However, to land softly on a comet, you have to match its speed and orbit. In other words, it does not save fuel. You can put the space craft in a comet like orbit without landing on a comet and without using a drop more fuel than going to and then landing on a comet would take. That assumes a soft landing of course. You could make some super rugged probe and just crash into the Comet at thousands or tens of thousands of miles per hour, but what can do that and survive to do useful work?
