Flyby anomaly

So, imagine you are playing catch with your friend and you throw the ball to them. But instead of going straight to where your friend is standing, the ball kind of curves a little bit and ends up going a little bit to the side. That's kind of what happens with spacecraft when they do what's called a "flyby" of another planet.

A flyby is when a spacecraft goes really close to a planet, just to take some pictures or get some data, before continuing on to its final destination. But sometimes, when the spacecraft does this, it doesn't go exactly where it's supposed to go. It kind of curves a little bit, just like the ball when you threw it to your friend.

Scientists call this the "flyby anomaly." They've noticed it when spacecraft have done flybys of Earth, Mars, and other planets. They've measured the speed and direction of the spacecraft, and they've calculated exactly where it should go after the flyby. But sometimes, the spacecraft doesn't go where they think it should go.

Scientists have tried to figure out why this happens, but they're not exactly sure yet. Some think it might have to do with the gravitational pull of the planet, or maybe even something like magnetic fields. Others think it might be something we don't understand yet, something new that we haven't discovered yet.

So basically, the flyby anomaly is when a spacecraft doesn't go exactly where scientists expect it to go when it does a flyby of another planet. Scientists are still trying to figure out why this happens, but they think it might have to do with things like gravity and magnetic fields.