NOVEMBER 29, 1996: A team of researchers led by Stewart Nozette publishes their paper describing the tentative detection of water ice at the moon’s south pole in radar experiments conducted with the U.S. Defense Department’s Clementine spacecraft. This detection has been confirmed by later spacecraft missions, and these efforts, and the overall significance of this discovery, are discussed in a previous “Special Topics” presentation.
NOVEMBER 29, 2012: Members of the MESSENGER science team announce that they have confirmed the presence of water ice in permanently shadowed craters near Mercury’s north pole. The presence of this ice had been reported as far back as 1991, and the overall significance of this is discussed in a previous “Special Topics” presentation.
NOVEMBER 30, 1609: The Italian astronomer Galileo Galilei observes the moon for the first time with his primitive telescope and sees that it is covered with craters. This was one of the first steps in the road to our understanding of the role that impacts have played in Earth’s, and the solar system’s, natural history, and this story is discussed more thoroughly in a previous “Special Topics” presentation.
NOVEMBER 30, 1954: A 4-kg meteorite crashes through the roof of a house near Sylacauga, Alabama and strikes Elizabeth Hodges, who was sleeping on the couch, in the leg. She received a severe bruise from the impact but was otherwise unharmed. This was the first confirmed case of a meteorite striking a human being, although since then earlier reports of apparent such incidents have been unearthed.
DECEMBER 1, 1963: Then-Yale University graduate student Brian Marsden publishes his paper analyzing the orbits of several “lost” periodic comets. Three of these comets, including two previous “Comets of the Week,” were recovered as a direct result of Marsden’s calculations. Another one of the comets Marsden examined is 3D/Biela, another previous “Comet of the Week,” which has not been seen since the mid-19th Century and which almost certainly no longer exists.
DECEMBER 1, 1971: NASA’s Mariner 9 mission, having recently arrived at Mars, takes the first close-up photographs of Mars’ moon Phobos. Along with Deimos, which Mariner 9 photographed a few days earlier, these were the first close-up photographs ever taken of a solar system “small body.” The small moons of the various planets are the subject of a previous “Special Topics” presentation.
DECEMBER 1, 2020: The very tiny “asteroid” 2020 SO, discovered this past September 17 by the Pan-STARRS survey, will pass 0.00034 AU (51,000 km, or 0.13 lunar distances) from Earth. This object appears to have been recently “captured” as a temporary “moon” of Earth – a phenomenon discussed in a previous “Special Topics” presentation – but unlike the objects described there, this appears to be of artificial origin and is likely the upper-stage booster rocket of the unsuccessful Surveyor 2 mission launched in September 1966.
DECEMBER 1, 2257: The large Kuiper Belt object, and “dwarf planet,” (136199) Eris will pass through perihelion at a heliocentric distance of 38.09 AU. Eris and the other “dwarf planets” in the Kuiper Belt, together with the other objects in that part of the solar system, are the subject of a previous “Special Topics” presentation.
DECEMBER 2, 1989: NASA’s Solar Maximum Mission (SMM) satellite, launched in 1980 and repaired by Space Shuttle astronauts in 1984, re-enters Earth’s atmosphere and disintegrates. Following the spacecraft’s repair, SMM’s coronagraph detected several near-sun comets, all of these being Kreutz sungrazers which are the subject of a previous “Special Topics” presentation.
DECEMBER 2, 1995: The joint NASA/ESA SOlar and Heliospheric Observatory (SOHO) spacecraft is launched from Cape Canaveral, Florida. SOHO was placed at the Earth-sun L1 Lagrangian point 1.6 million km directly sunward of Earth, and as of now two of its coronagraphs, along with the Solar Wind ANisotropies (SWAN) ultraviolet telescope, have discovered over 4000 comets, the large majority of these being Kreutz sungrazers. Two of SOHO’s comets are, collectively, a previous “Comet of the Week,” and Kreutz sungrazers as a whole are the subject of a previous “Special Topics” presentation.
DECEMBER 2, 2020: The only known “Earth Trojan” asteroid, 2010 TK7, will pass 0.217 AU from Earth. It is currently traveling eastward through the constellation of Hydra and is a dim object of 21st magnitude. Trojan asteroids, including 2010 TK7, are the subject of a previous “Special Topics” presentation.
DECEMBER 2, 2023: Predictions suggest that the Andromedid meteor shower may produce a strong display, possibly as many as 200 meteors per hour. The Andromedids are the debris from Comet 3D/Biela – a previous “Comet of the Week” – and are discussed in that presentation.
DECEMBER 3, 1904: Charles Perrine at Lick Observatory in California discovers Jupiter’s sixth known moon, since named Himalia. It was the first-discovered of Jupiter’s outer moons, of which over 70 more have since been discovered; very recent survey results suggest that there could be several hundred additional small outer moons remaining to be discovered. The small moons of the various planets are the subject of a previous “Special Topics” presentation.
DECEMBER 3, 2014: JAXA’s Hayabusa2 mission is launched from the Tanegashima Space Center in southern Japan. Hayabusa2’s destination was the Apollo-type asteroid (162173) Ryugu, where it arrived in June 2018; since then it has deployed several landing rovers and collected soil samples. Hayabusa2 left Ryugu late last year and will be returning to Earth, with its collection of samples, next week. The Hayabusa2 mission is discussed in this week’s “Special Topics” presentation.
DECEMBER 3, 2018: NASA’s OSIRIS-REx mission arrives at the Apollo-type asteroid (101955) Bennu. After performing a detailed study of Bennu, OSIRIS-REx successfully retrieved samples from the surface this past October, and is expected to depart Bennu next March for a return to Earth, with its collection of samples, in September 2023. The OSIRIS-REx mission is discussed in this week’s “Special Topics” presentation.
DECEMBER 5, 2011: A moderately strong display of the Andromedid meteor shower – with a peak rate of close to 50 meteors per hour – is seen from Canada. There had not been any significant displays from the Andromedid shower in over a century, and thus this display was a complete surprise. The Andromedids are the debris from Comet 3D/Biela – a previous “Comet of the Week” – and are discussed in that presentation.