2015 was a great year for planetary exploration in our solar system. Two little robot spacecraft gave us our closest looks at planet Pluto and dwarf planet Ceres this past year.

NASA's Dawn spacecraft was first to arrive at its target in March - Ceres, which surprised astronomers with still unexplained bright spots, such as the one pictured in the Occator Crater (see top photo). What are the spots? Recent suggestions include salt deposits.

Dawn, a very successful ion-drive spacecraft, has been orbiting Ceres in ever lower altitudes and now is circling at an average of 240 miles above the craters. Its fuel is expected to run out in the summer of 2016. Until then, the photos have been increasingly detailed, with more to come. The mission web site is fun to explore.

Meanwhile, the New Horizons spacecraft, a NASA speed demon traveling at over 32,000 miles per hour, zoomed by Pluto in July, snapping lots of photos and getting great information from other scientific instruments. All of its attention during the fly-by was on getting the information. After it passed by the planet, at began transmitting the images back to Earth, with short daily transmission times. Because of that, we've only seen less than half the "close-ups" of Pluto and its major moon Charon.

The color photos are intriguing (see photo below) and investigators are noticing glacial activity on Pluto's surface and have determined a large amount of solid nitrogen, along with an atmospheric haze.

New Horizons has just finished some course correction maneuvers to send it by a Kuiper Belt Object (KBO) called 2014 MU69. It'll reach that object in 2019, after traveling another billion miles.

Again, there are plenty of interesting details at the New Horizons website.

KLYQ will keep you informed about all sorts of space and science happenings in the new year.

A color photo of Pluto. The area marked in the box has a series of close-ups on the NASA website. (NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)