Other low hanging fruit is probably under the oceans, or on other celestial bodies in our solar system. In our solar system there might be well preserved fragments of the planets that may have collided to create our planet Earth and the moon. Since we get meteorites falling on Earth that originated from other planets, the reverse would've also happened in a big way. Some of those fragments are probably out in the Ort belt, just chilling. The Ort belt itself is an immeasurable treasure trove scientifically and in resources (I look forward to the day we have unmanned space drones exploring it).