19 January – ECOWAS forces, including troops from Senegal, Ghana, and Nigeria, intervene in Gambia's political crisis to force longtime PresidentYahya Jammeh to step down after losing the December 2016 elections to Adama Barrow.[1]
The UN warns that the world is facing the biggest humanitarian crisis since World War II, with up to 20 million people at risk of starvation and famine in Yemen, Somalia, South Sudan and Nigeria.[4]
29 March – The United Kingdom invokes Article 50 of the Treaty on European Union, beginning the formal EU withdrawal process.[5][6]
30 March – SpaceX conducts the world’s first reflight of an orbital class rocket.[7][8]
31 March – The Yucca Mountain nuclear waste repository is scheduled to begin accepting nuclear waste.[9]
April
6 April – In response to a suspected chemical weapons attack on a rebel-held town, the U.S. military launches 59 Tomahawk cruise missiles at an air base in Syria. Russia describes the strikes as an "aggression", adding they significantly damage US-Russia ties.[10]
21 August – From 16:50 to 20:02 UTC, the first total solar eclipse of the 21st century for the United States, and the first visible in the continental U.S. since 26 February 1979, takes place. Totality will occur along a path curving from Oregon to South Carolina, and will last at most 2 minutes 40.2 seconds. The location and time of "greatest eclipse" will be on the western edge of Christian County, Kentucky at 36.9715 degrees North and 87.6559 degrees West occurring at 18:25.4716 UTC.[13]
Unknown dates
Sealed government documents surrounding John F. Kennedy's assassination to be released.[14]
The government of China has announced it will start sending probes to the Moon in 2017, resulting in a manned Chinese landing on the moon in a few years.[15]