Curiosity Right Mastcam (M-100)

Sol 38 00:01 Site 4/0404 0038MR0173008000D1_DXXX
Used for calibration of the M34 and M100 cameras [observations]
Jan 1, 2000 at 11:58:56 AM UTC (approximate)
Credit: NASA / JPL-Caltech / Malin Space Science Systems

Image Source