On this day — December 21

Czech Republic.

This is the closest conjunction between the two planets since 1623.

Festivities are held in parts of Mesoamerica to commemorate the conclusion of b'ak'tun 13, a roughly 5,126-year-long cycle in the Mesoamerican Long Count Calendar whose passing many New Age spiritualists had earlier held to portend a variety of cataclysmic or transformative events.

military airfield at Mosul, Iraq, the single deadliest suicide attack on American soldiers in Iraq.

killing 18.

flight Martinair MP 495, crashes at Faro Airport, Portugal, killing 56.

The leaders of 11 now effectively autonomous Soviet republics sign the Alma-Ata Protocol establishing the Commonwealth of Independent States in place of the collapsing Soviet Union.

This is to date the deadliest air disaster to occur on British soil.

An independence agreement for Rhodesia is signed in London by Lord Carrington, Sir Ian Gilmour, Robert Mugabe, Joshua Nkomo, Bishop Abel Muzorewa and S.C. Mundawarara.

Apollo 8 is launched from the Kennedy Space Center, placing its crew on a lunar trajectory for the first visit to another celestial body by humans.

the first man to undergo a human-to-human heart transplant, dies in Cape Town, South Africa, having lived for 18 days after the transplant.