A series of massacres in Baga, Nigeria and surrounding villages by Boko Haram kill more than 2,000 people.
Two gunmen belonging to Al-Qaeda's Yemen branch kill 12 people and injure 11 more at the Paris headquarters of satirical newspaper Charlie Hebdo.
NASA's Dawn probe enters orbit around Ceres, becoming the first spacecraft to visit a dwarf planet
The ancient city of Palmyra in Syria, famous for its remains of classical architecture, is captured by the Islamic State (ISIS)
Cuba becomes the first country in the world to eradicate mother-to-child transmission of HIV and syphilis
NASA's New Horizons spacecraft performs a close flyby of Pluto, becoming the first spacecraft in history to visit the distant world.
Iran agrees to long-term limits of its nuclear program in exchange for sanctions relief
Scientists announce the discovery in South Africa of Homo naledi, a previously unknown species of early human
Queen Elizabeth II, having been on the throne for 63 years, 217 days, becomes the longest-reigning British monarch, surpassing the reign of Queen Victoria
Gravitational waves are detected for the first time, by LIGO
Automaker Volkswagen is alleged to have been involved in worldwide rigging of diesel emissions tests, affecting an estimated 11 million vehicles globally
A stampede during the Hajj pilgrimage in Mecca kills at least 2,200 people and injures more than 900 others, with more than 650 missing
NASA announces that liquid water has been found on Mars
Hurricane Patricia becomes the most intense hurricane ever recorded in the Western Hemisphere with winds of 215 mph
Turkey shoots down a Russian fighter jet on the Turkish–Syrian border, in the first case of a NATO member destroying a Russian aircraft since the 1950s
A global climate change pact is agreed at the COP 21 summit, committing all countries for the first time to reduce carbon emissions
SpaceX lands an unmanned Falcon 9 rocket, the first reusable rocket to successfully enter orbital space and return