The Solar System:
The Mercury Dual Imaging System (MDIS) on the MESSENGER space probe had 11 narrow-band spectral filters covering visible and near-infrared wavelengths (400 to 1050 nanometers). The specific colors of the filters were selected to discriminate among common minerals. Three-color images (480 nm, 560 nm, 630 nm) were combined to produce an approximation of Mercury's true color as might be seen by the human eye (left). From this rendition of Mercury it is obvious that color differences on the surface are small. Statistical methods that utilize all 11 filters in the visible and near-infrared highlight subtle color differences (right) and aid geologists in mapping regions of different composition.Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington [link]
Many (big) craters!
Victoria Rupes on Mercury in an image from the MESSENGER space probe. Rupes on Mercury are named for ships of discovery, and Victoria Rupes is named for the Victoria that formed part of Ferdinand Magellan's fleet in his 1519-1522 effort to circumnavigate Earth. The crater near image center that covers part of the rupes has a diameter of 42 km.Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington [link]
Mercury has a very large iron core
Mercury has a tail!
There is water on Mercury
Mercury's north pole from MESSENGER data. Red denotes areas that are always in shadow. Yellow shows the locations of bright (i.e., highly reflective) polar deposits (identified as water ice) imaged by Earth-based radar.Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/National Astronomy and Ionosphere Center, Arecibo Observatory [link]
Mercury's unique orbit
Orbits of three objects in our solar system: Earth, Mercury, and Comet Halley. Mercury's orbit has the largest eccentricity of all of the planets in our Solar System, yet its orbit is still very circular (the red dashed lines show only a small vertical deformation in the shape of Mercury's orbit compared to Earth's nearly circular orbit). But because the foci of Mercury's orbit have a significant separation compared to Earth's, Mercury's aphelion (furthest distance from the Sun; 0.47 AU) and perihelion (closest distance to the Sun; 0.31 AU) are significantly different. Comet Halley has a highly eccentric orbit, and spends most of the time far away from the Sun.Credit: D. W. Hoard (2018)