By now we’ve all realized that NASA’s Mars rover Curiosity is a fine geologist. It’s also a great geochemist. And now, once again, the six-wheeled rover has underlined the fact that it’s also a damned good astronomer.

The rover’s latest astronomical project features the transit of Mercury across the disk of the sun — a cosmological alignment that could only be seen from the red planet. What’s more, this is the first time any planet has been seen transiting the sun from another world and the first ever observation of Mercury from the Martian surface.

Year One: Curiosity’s Key Discoveries

In the animation accompanying the NASA Jet Propulsion Laboratory news release, a fuzzy dark shape can be seen moving past two groups of sunspots. Mercury itself takes up only one-sixth of a pixel in Curiosity’s Mastcam instrument, which is why the tiny planet doesn’t have a sharply defined shape. But as the Mastcam optics were designed to be imaging the Martina landscape and not the sun’s disk, it’s not a bad effort.

Curiosity snapped this observation on June 3 and Mercury won’t make another solar dash from Mars’ vantage point until April 2015.

More Astronomical Awesomeness by Curiosity:

  • ‘Astronomer Curiosity’ Snaps Martian Eclipse

  • Mars Rover Watches the Sun Set and Moon Rise

  • Curiosity Spots Daytime Phobos Moon Crescent

  • Mars Eclipse Puts Curiosity in the Dark: Video

  • Curiosity Photographs the Earth and Moon from Mars