English: Hokusai crater on Mercury (also known as feature B) has an extensive system of rays.

NASA caption:
Date Acquired: October 6, 2008
Image Mission Elapsed Time (MET): 131774306
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 580 meters/pixel (0.36 miles/pixel) at the bottom left of the image
Scale: The extensively rayed crater is about 110 kilometers in diameter (68 miles)
Spacecraft Altitude: 22,500 kilometers (14,000 miles)

Of Interest: In one of the first images transmitted back to Earth following MESSENGER's second flyby of Mercury, an image of the entire departing planet, a spectacular and extensive system of rays can be seen. This NAC image shows a close-up view of the apparent source of those rays, a crater 110 kilometers (68 miles) in diameter located in the northern region of Mercury. The location of this bright crater is consistent with Earth-based radar images, which suggested a very fresh, rayed impact crater in this area. The amazing extent of this large ray system is visible for the first time in MESSENGER's newly acquired images.