NASA's Messenger probe entered orbit around Mercury just this month after a journey of six and a half years, but it's already hard at work. Hundreds of images have been sent back in the past couple of days. Take a look at this trio of highlights, and then get the full story behind these marvels from Mercury:

NASA / JHUAPL / CIW

Messenger acquired this image of Mercury's horizon on March 29 as the spacecraft was flying northward along the first orbit during which its dual-camera system was turned on. Bright rays from Hokusai Crater can be seen running north to south in the image.

NASA / JHUAPL / CIW

Mercury isn't the solar system's most colorful planet, but you can make out subtle shades in this first color image from Messenger, acquired on March 29. This is actually part of an eight-image sequence highlighting the bright rayed crater known as Debussy.

NASA / JHUAPL / CIW

Here's a closer look at Debussy Crater, acquired by Messenger's Narrow Angle Camera on March 29. The bright rays, consisting of impact ejecta and secondary craters, spread out from Debussy at the top of the image. The rays extend for hundreds of miles across Mercury's surface.

More about Mercury:

• Scientists tell the story behind the pictures
• First look at Mercury from orbit
• 10 surprising facts about the Mercury probe
• Mercury just might hit us someday
• Interactive: The new solar system 

Join the Cosmic Log community by clicking the "like" button on our Facebook page or by following msnbc.com science editor Alan Boyle as b0yle on Twitter. To learn more about my book on Pluto and the search for planets, check out the website for "The Case for Pluto." And if you want to stay on my good side, don't ever call Mercury the "smallest planet."