Special Topic: Putting It All Together

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Comet of the Week: Lovejoy C/2011 W3

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Special Topic: Formation of the Planets

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Comet of the Week: The Great Comet of 1680

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MAY 17, 1882: Observers in the path of a total solar eclipse that crossed central Egypt see and photograph a bright comet during totality. Comet Tewfik X/1882 K1, which was never seen again, was an apparent Kreutz sungrazer, and is this week’s “Comet of the Week.” Solar eclipse comets, in general, are the subject of …

Perihelion: 1882 May 17.5, q < 0.01 AU  On May 17, 1882, the path of a total solar eclipse crossed northern Africa, the Middle East, and southern Asia. As total eclipses go, it was a relatively short one, with the maximum duration of totality – which occurred in present-day Turkmenistan – being only 1 minute …

One of the most spectacular and awe-inspiring celestial sights is that of a bright, long-tailed comet – a “Great Comet,” the subject of a previous “Special Topics” presentation. On average, these appear about once a decade, and I have been privileged to have witnessed four of them during the half-century I have been observing comets …

MAY 10, 1999: The LINEAR survey in New Mexico discovers the near-Earth asteroid now known as (162173) Ryugu. Ryugu was the destination of JAXA’s Hayabusa2 sample-return mission, which arrived there in mid-2018 and departed there late last year, and which is now en route back to Earth with its collected samples. The Hayabusa2 mission is …

Perihelion: 1983 May 21.25, q= 0.991 AU  On January 25, 1983, the InfraRed Astronomical Satellite (IRAS) spacecraft was launched from Vandenberg Air Force Base in California. For the next ten months, until its supply of superfluid liquid helium coolant ran out, IRAS surveyed the entire sky in near- to far-infrared wavelengths, and its findings completely …

The “Comet of the Week” this week is Comet IRAS-Araki-Alcock 1983d, which passed just 0.031 AU (4.68 million km, or 12.2 lunar distances) from Earth on May 11, 1983 – the closest confirmed cometary approach to Earth during the 20th Century, and the fifth-closest confirmed such approach in all of recorded history. Within this context, …