From an article published on September 30, 2015 at www.space.com:
Colorful new maps of Ceres, charted by NASA’s Dawn space probe, have been unveiled at the European Planetary Science Conference in France. The maps highlight the dwarf planet’s topography and composition, as well as a pyramid-shaped mountain and the Occator crater, where many mysterious bright spots can be found.
Dawn scientists are also discussing three bursts of energetic electrons that have them puzzled. As Dawn principal investigator Chris Russell put it, “Ceres continues to amaze”.
To learn more about the outer Solar System, see Chapter 8 of The Cosmos.
Link to the full article on www.space.com
From APOD, June 3, 2105:
A new view of Saturn’s moon Hyperion was released by the Cassini team during a recent fly-by.
The images shows numerous unusually-shaped craters with dark material at the bottom. At around 250 km across, its gravitational pull on Cassini reveals that it is mostly empty space. The unusual crater shapes are thought to arise from surface impacts, which compress and eject surface material, unlike the regular circular shock-wave craters seen on other moons and planets.
Link: APOD, June 3, 2015.
NASA’s MESSENGER orbiter of Mercury ran out of fuel and crashed into Mercury on May 1, 2015, ending a very successful mission. The craft slammed into Mercury’s surface at about 8,750 mph and created a new crater on the planet’s surface.
MESSENGER’s demise went unobserved because the probe hit the side of the planet facing away from Earth, so ground-based telescopes were not able to capture the moment of impact. Space-based telescopes also were unable to view the impact, as Mercury’s proximity to the Sun would damage their optics.
MESSENGER had been in orbit more than four years and completed 4105 orbits around Mercury. Among its many accomplishments, the MESSENGER mission determined Mercury’s surface composition, revealed its geological history, discovered its internal magnetic field is offset from the planet’s center, and verified its polar deposits are dominantly water ice.
The movie below shows a NASA simulation of the spacecraft’s epic voyage.
Links: MESSENGER home, Sky & Telescope’s report, NY Times article, high-resolution image of the crash-site, map of gravity anomoalies measured by deviations of MESSENGER from its predicted orbit.