Osiris-Rex arrives at Bennu asteroid, while on New Year's Day New Horizon makes an historic flyby of Ultima Thule.
On Monday NASA's Osiris-Rex probe enters into orbit around the near-Earth Bennu asteroid, the first step towards spending a month mapping its surface. The orbital insertion is a delicate operation, but NASA is confident of success.
Then on New Year's Day New Horizon will make history by reaching Ultima Thule, four billion miles from the sun, and a billion past Pluto. It is the furthest object ever visited by man, right on the edge of the solar system.