Oceanographers are now able to figure out how diverse the sea floor is without necessarily having to go down and look at it in its entirety.

The way it’s done is via satellite images of the surface of the ocean, according to a new National Geographic video. The satellites detect phytoplankton on the surface, and then scientists extrapolate that data to figure out where life exists at the bottom of the ocean.

Satellite imagery is especially useful in areas where it’s hard for humans to reach, like parts of the Antarctic/Southern Ocean. It also helps predict the effects of climate change.

To learn more, check out the NatGeo video below.