The Messenger spacecraft that zipped past Mercury two weeks ago found more evidence of the innermost planet’s turbulent past, including ridges that run hundreds of miles and a unique feature made up of more than 100 troughs radiating in all directions, scientists said Wednesday reports the New York Times.

A preliminary look at data from the flyby, including 1,213 images, shows a small, cratered planet that superficially looks like Earth’s moon but is very different in reality, they said.

The robot spacecraft, the first to visit the planet in more than three decades, passed 124 miles above Mercury’s surface on Jan. 14 before continuing on a path that is to bring it back three more times in the next three years before settling into orbit.

During the encounter, the Messenger’s seven scientific instruments scanned the planet, its magnetic field and its wispy atmosphere in great detail.

“Our little craft has returned a gold mine of exciting data,” said Dr. Sean C. Solomon of the Carnegie Institution of Washington, the mission’s lead investigator.

“We were continually surprised,” Dr. Solomon said at a NASA news conference. “It was not the planet we expected. It was not the moon.”

Read it here: Pictures Reveal Mercury’s Tumultuous Past