Planets move around, so finding them may be hard from outside their system, where the star mass overwhelms most other local signals.

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Doing a bit of math, our sun has ~330,000 times more mass than Earth. Knowing that the force of gravity is proportional to the mass of the attracting object and the inverse square of the distance to said object, if you were the same distance from both Earth and the sun (which you effectively would be if you are jumping from another system as the distances involved are so large), the force of Earth's gravity would only be 0.0003% of the force of the sun's gravity. In this case, the Earth would be indistinguishable from background noise for all but the most sophisticated sensors.
Now, how far much closer would you need to be to Earth than the sun in order for the forces of gravity acting on you from both of them to be the same? taking the square root of 330,000, we find that you would need to be ~574 time closer to Earth than the sun in order to be experiencing the same gravitational pull from each of them. When you consider that Earth is 506 ls from the sun, you would need to
within 1 light second of Earth in order to experience the same gravitational pull from both the Earth and the sun.
Yeah, I don't like my odds of my FSD being able to pick up on the gravity well of the Earth, and I'm certainly not going to trust my FSD to jump me there.