In this month: January
1st January 1801
Italian astronomer Giuseppe Piazzi of the Palermo Observatory discovers Ceres, the first asteroid to be discovered and the largest asteroid in the main asteroid belt. At 940 kilometres in diameter, it is the only asteroid large enough for its gravity to make it spheroid in shape. The Photograph below was taken by NASA's Dawn Spacecraft in 2015 and is courtesy NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.
Ceres follows an orbit between Mars and Jupiter, near the middle of the asteroid belt, the only one always inside the orbit of Neptune. It takes Ceres 4.6 Earth years, to orbit the Sun and completes one rotation every 9 hours making its day length one of the shortest in the solar system. In 2006, it was reclassified as a dwarf planet, along with Pluto and Eris, by the International Astronomical Union. Ceres is named for the Roman goddess of corn and harvests. The word “cereal” comes from the same name.
6th January 1978
Comet Wild 2 is discovered by Swiss astronomer Paul Wild. The comet, measuring about 1.65 x 2 x 2.75 kilometres, is the shape of a flattened sphere and takes nearly six and a half years to orbit the Sun. Originally its orbit lay between Uranus and Jupiter, however on the 10th September 1974 gravitational interactions between the comet and Jupiter pulled its trajectory into a new shape and it now orbits between Mars and Jupiter. In 2004 NASA sent the Stardust mission to fly by the comet and gather particles. What remains of Wild 2, along with the fragments captured by Stardust, is considered pristine. As this is the comet's first trip to the inner solar system, its composition has been mostly unaltered for the billions of years it spent in the depths of space. The study of these stardust samples could provide clues about the early days of the solar system.
30th January 2020
The Spitzer Space Telescope is turned off.
Launched on the 25th August 2003 to study the universe in infrared light it exceeded expectations over its 17 year mission. The telescope studied comets and asteroids, the solar system, and found a previously unidentified ring around Saturn. It also studied star and planet formation, the evolution of galaxies, the composition of interstellar dust and proved to be a powerful tool in detecting exoplanets, notably the seven Earth-size planets in the TRAPPIST-1 system. Due to its specific orbit Spitzer faces a different fate to other decommissioned spacecraft. Trailing about 254 million kilometres behind Earth, to keep it away from interfering heat, it will fly by Earth in about 53 years and then drift off in the opposite direction into the emptiness of space.
14th January 1911 Edward George "Taffy" Bowen CBE.