At first glance, the photos captured by the Dawn spacecraft were unremarkable, showing a dull gray crater-pocked asteroid surface.

But by assigning different color ratios, filters and near-infrared light, scientists were able to transform the images, revealing structures that were not visible to the naked eye, NASA explains in a release.

Researchers at the Max Planck Institute for Solar System Research discovered that the treatment allowed them to see geological structures and compositional differences which were otherwise hidden.

“The key to these images is the seven color filters of the camera system on board the spacecraft,” Andreas Nathues of Max Planck said to NASA.

Dawn was launched in 2007 on a mission to study the asteroid Vesta and the dwarf planet Ceres in an attempt to learn more about the early solar system and its formation.

The photos were taken by the Dawn spacecraft from 2011 to 2012 on Vesta, one of the largest asteroids in the solar system. Vesta has a diameter of 329 miles and is the brightest asteroid in the sky, sometimes visible from Earth with the naked eye, according to Space.com.