THIS WEEK IN HISTORY
WEEK 7: FEBRUARY 9-15
FEBRUARY 9, 1986: During its most recent return Comet 1P/Halley passes through perihelion at a heliocentric distance of 0.587 AU. Comet Halley’s 1986 return is a future “Comet of the Week,” and its entire history is the subject of a future “Special Topics” presentation.
FEBRUARY 10, 1907: August Kopff at Heidelberg Observatory in Germany discovers the asteroid now known as (624) Hektor, the third known “Jupiter Trojan” asteroid. The subject of Trojan asteroids is discussed in a future “Special Topics” presentation.
FEBRUARY 10, 2015: Eric Mamajek and his colleagues publish their paper in the Astrophysical Journal wherein they conclude that a recently-discovered nearby dwarf star (WISE 0720-0846, unofficially known as “Scholz’s Star”) passed through the Oort Cloud 70,000 years ago, likely triggering a shower of long-period comets that are still inbound. Scholz’s Star and other stellar passages through the Oort Cloud are discussed in next week’s “Special Topics” presentation.
FEBRUARY 10, 2020: The main-belt asteroid (191) Kolga will occult the 4th-magnitude star Nu Serpentis. The predicted path of the occultation crosses the southeastern U.S. from far eastern Colorado through South Carolina.
FEBRUARY 10, 2020: The main-belt asteroid (55099) 2001 QK137 will occult the 5th-magnitude star Nu Cancri. The predicted path of the occultation crosses New Zealand’s North Island and southern Australia from east to west.
FEBRUARY 11, 2003: The LINEAR program in New Mexico discovers the asteroid now known as (163693) Atira, the first confirmed example of the Atira-type asteroids, i.e., those whose orbits lie entirely interior to Earth’s orbit. The Atira asteroids and other near-Earth asteroids were discussed in a previous “Special Topics” presentation.
FEBRUARY 11, 2020: The large main-belt asteroid (4) Vesta will occult the 5th-magnitude star HD 19270 in Aries. The predicted path of the occultation passes over far southeastern Canada, specifically Nova Scotia and Newfoundland, and then portions of northern Europe, including Northern Ireland, northern England, Scotland, Denmark, southern Sweden, northern Poland, Lithuania, Latvia, Belarus, and far western Russia.
FEBRUARY 12, 1936: Eugene Delporte at the Royal Observatory of Belgium in Uccle discovers the near-Earth asteroid now known as (2101) Adonis, the second known Apollo-type asteroid. Adonis – which was discussed with other near-Earth asteroids in a previous “Special Topics” presentation – had passed just 0.015 AU from Earth a week earlier and was followed for two months but was then “lost” until it was recovered in 1977. There is some evidence that it may be an “extinct” cometary nucleus.
FEBRUARY 12, 1947: A brilliant daytime meteor appears over far eastern Siberia and falls to Earth near the Sikhote-Alin Mountains. The Sikhote-Alin meteorite was one of the largest observed meteorite impacts of the 20th Century and over 23 tons of fragments have been identified; these are primarily composed of iron. Sikhote-Alin and other large meteorite impacts are discussed in a future “Special Topics” presentation.
FEBRUARY 12, 2001: After orbiting the near-Earth asteroid (433) Eros for one year, the Near-Earth Asteroid Rendezvous (NEAR) Shoemaker spacecraft performs the first-ever soft landing by a spacecraft onto an asteroid. Following its landing NEAR Shoemaker continued transmitting for two more weeks before it was shut down. Eros, including the NEAR Shoemaker mission, is the subject of a previous “Special Topics” presentation.
FEBRUARY 13, 2020: The main-belt asteroid (112) Imphigenia will occult the 7th-magnitude star HD 73210 in Cancer (just southwest of the “Beehive” Cluster M44). The predicted path of the occultation crosses northern Brazil, southern Venezuela, northern Columbia, northern Panama, south-central Nicaragua, and parts of the southern coast of Mexico before crossing open waters of the central Pacific Ocean.
FEBRUARY 14, 1977: As a result of a prediction by Brian Marsden, Charles Kowal at Palomar Observatory in California recovers the near-Earth asteroid (2101) Adonis after it had been “lost” for 41 years. Adonis will pass 0.036 AU from Earth on February 7, 2036.
FEBRUARY 14, 1980: The Solar Maximum Mission (SMM) is launched from Cape Canaveral, Florida. After suffering an attitude control failure later that year, SMM was repaired by Space Shuttle astronauts in 1984. SMM discovered ten comets, all Kreutz sungrazers, from 1987 up until the time it re-entered Earth’s atmosphere in 1989. Kreutz sungrazers, including SMM’s discoveries of these objects, are discussed in a future “Special Topics” presentation.
FEBRUARY 14, 1996: The first-known centaur, (2060) Chiron (also known as Comet 95P/Chiron), passes through perihelion – 18 ½ years after its discovery – at a heliocentric distance of 8.454 AU. Centaurs are the subject of this week’s “Special Topics” presentation.
FEBRUARY 14, 2000: The Near-Earth Asteroid Rendezvous (NEAR) Shoemaker spacecraft arrives at the near-Earth asteroid (433) Eros and goes into orbit around it. NEAR Shoemaker would spend the next year orbiting Eros before performing a soft landing onto its surface.
FEBRUARY 15, 1997: Jim Scotti with the Spacewatch program in Arizona discovers the “asteroid” now known as (10199) Chariklo. Chariklo is the largest-known centaur and is now known to be accompanied by at least two rings. Centaurs are the subject of this week’s “Special Topics” presentation.
FEBRUARY 15, 2011: The Stardust spacecraft, which had previously flown through the coma of Comet 81P/Wild 2, collected samples, and delivered those to Earth, encounters Comet 9P/Tempel 1. This comet, which had earlier been visited by the Deep Impact mission in 2005, is a future “Comet of the Week.”
FEBRUARY 15, 2013: The tiny asteroid (367943) Duende passes just 0.00028 AU from Earth (4.3 Earth radii above the surface). Duende had been discovered a year earlier by the La Sagra Sky Survey based in Spain, and this encounter holds the current record for closest approach to Earth by a previously-discovered asteroid.
FEBRUARY 15, 2013: A brilliant daytime meteor passes over the city of Chelyabinsk in southwestern Russia and explodes. Although there are no fatalities, numerous people were injured. The Chelyabinsk meteorite is estimated to have been about 20 meters in diameter with an original mass of several thousand tons; the largest individual fragment recovered has a mass of 650 kg. This is the largest meteorite impact event of the 21st Century thus far, and it and similar events are covered in a future “Special Topics” presentation.