January 17 


17 January 1865


Drawing of the Great Southern Comet of 1865 made on January 26, 1865

The Great Southern Comet of 1865 (C/1865 B1) was discovered on January 17, 1865, by Francis Abbott (1799–1883) in Hobart, Tasmania. Before its discovery, the comet reached its perihelion of approximately 0.026 au on January 14 and then on January 15 its closest approach to planet Earth of approximately 0.94 au. On January 24, the comet reached its maximum brightness of magnitude 1. The comet was visible to the naked eye only in the Southern Hemisphere for the entire month of February.


© 2026, Andrew Mirecki



17 January 1982


Discovery image of Allan Hills A81005 meteorite. Credit: NASA

Allan Hills (ALH) A81005, the first recognized meteorite from the Moon, was found on January 17, 1982, in the Allan Hills icefield in the Transantarctic Mountains by John Schutt (b. 1948) and Ian Whillans (1944–2001).

   The meteorite measures 3 × 2.5 × 3 centimetres. It has a dark fusion crust on the outside. The interior is made up of a black to dark grey groundmass (matrix) with larger grey and white angular crystals (clasts). This appearance is typical for breccias, including those originating on Earth. The size of the larger crystals ranges from sub-millimeter to 8 millimetres in diameter. The crystals are mostly plagioclase, with some pyroxene and olivine.

   The determination that ALH A81005 was of lunar origin was made by Robert Clayton and Toshiko Mayeda, researchers at the University of Chicago, following the determination by Smithsonian Institution scientist Brian Harold Mason that the meteorite was similar in chemical and isotopic composition to rocks returned by the Apollo program astronauts from lunar highland areas. Evidence that ALHA 81005 is a lunar sample, was presented at the March 18, 1983, meeting of the Lunar and Planetary Institute.

Allan Hills A81005 meteorite. Credit: NASA


© 2026, Andrew Mirecki

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