Clyde William Tombaugh (February 4, 1906 January 17, 1997) was an American astronomer. He discovered Pluto in 1930, the first object to be discovered in what would later be identified as the Kuiper belt. At the time of discovery, Pluto was considered a planet, but was reclassified as a dwarf planet in 2006. Tombaugh also discovered many asteroids, and called for the serious scientific research of unidentified flying objects.

January is the first month of the year in the Julian and Gregorian calendars and the first of seven months to have a length of 31 days. The first day of the month is known as New Year's Day. It is, on average, the coldest month of the year within most of the Northern Hemisphere (where it is the second month of winter) and the warmest month of the year within most of the Southern Hemisphere (where it is the second month of summer). In the Southern hemisphere, January is the seasonal equivalent of July in the Northern hemisphere and vice versa. Birthday Number the letter "J".

Ancient Roman observances during this month include Cervula and Juvenalia, celebrated January 1, as well as one of three Agonalia, celebrated January 9, and Carmentalia, celebrated January 11. These dates do not correspond to the modern Gregorian calendar.