They mentioned you can go to a settlement on Mars, so you can visit the Sol system, but Earth hasn’t been mentioned. Either it’s off-limits, like in Elite Dangerous where you need a permit to visit, or it’s heavily altered, perhaps by nuclear war or climate change so they don’t have to recreate all of Earth, or they actually have recreated all of Earth.
If Lemmy let me post the picture I wanted then that would show that yes, you can land on Earth. Can be seen in the IGN Starfield Performance Review at 0:35. You’ll have to go frame by frame to actually see it.