It seems like it should be pretty easy to get to Mercury. The little rocky planet is so much closer to Earth than distant destinations like Jupiter, where we've successfully sent multiple spacecraft. Plus, it doesn't have a crushing atmosphere like our nearest neighbor Venus. But, in fact, it's actually really difficult to reach the innermost planet of our solar system--which makes it that much more impressive that the ESA and JAXA's BepiColombo mission has almost reached Mercury, recently completing its final flyby of the planet before entering orbit next year. Reaching Mercury is such a challenge because "the gravitational pull of the Sun is very strong near Mercury, which makes it difficult for spacecraft to slow down enough to enter orbit around the planet," explains Lina Hadid, staff scientist at CNRS in France and principal investigator of one of BepiColombo's instruments.

The BepiColombo spacecraft has sent back some incredibly detailed images of Mercury's north pole. The snapshots were collected during its closest ever flyby of our solar system's smallest planet. You can check out the awe-inspiring images below. On January 8, the robotic explorer operated by the European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA) came as close as 183 miles above Mercury. The newly released images show permanently dark craters spotting the surface of the planet closest to our Sun. Nearby volcanic plains and the largest impact cater on Mercury–over 930 miles wide–are also visible.