The Moon occults Jupiter (again)

posted: 1699 days ago, on Thursday, 2012 Nov 29 at 09:53
tags: astronomy, astrophotography, Southern Sky Highlights 2012, occultation, Jupiter, Moon.

For the second time this month, the Moon occulted Jupiter in the wee hours this morning. Kos Coronaios battled heavy dew (and drooping eyelids) to capture the action. The previous occultation was on November 02.

The shifting position of the Moon, and Jupiter's moons, can be seen in the two images on the left, taken 48 minutes apart.

The image sequence on the right was made by Johan Moolman of Pretoria, despite the less-than-ideal conditions. Johan writes that the low altitude and hazy sky conditions were compounded by "photon shields" (a.k.a. thin cloud) at the critical moment.

In the last image of the sequence, the small bright crater near where Jupiter makes "moon fall" [to nick Johan's phrase] is Olbers, an ancient 77-km crater ("very interesting formation" according to Virtual Moon Atlas).

The crater is named in honour of Heinrich Wilhelm Matthias Olbers, who presumably had three first names because he had 15 brothers and sisters, and things could get confusing during roll-call.

Olbers, born in 1758, was a physician (specialising in ophthalmology) with a private practice in Bremen. After a brief stint hobnobbing with the glitterati of the Viennese social scene, Olbers spent three decades working at medicine during the day while observing at night, sleeping only four hours a day. He eventually closed his practice and devoted all his time to astronomy, presumably getting a bit more sleep.

Olbers was a skilled mathematician (despite having no formal training in its subtleties), and developed a method of comet orbit calculation that was better than those thought out by Lalande and Laplace. It was his discovery of a comet (in 1796) that inspired his mathematical efforts and fueled his life-long interest in cometography. His private library, purchased after his death by Friedrich Struve (Pulkovo Observatory) was said to be "essentially complete".

Olbers's mathematical inclination also had another important spin-off. After a public lecture one day in 1804 a young man approached him and enthusiastically showed him a ream of calculations he'd made for the orbit of Halley's comet. Olbers, no-doubt impressed by the young Friedrich Bessel's self-taught maths-foo, encouraged him to pursue an astronomical career, which culminated in Bessel becoming Director of the Konigsberg Observatory. But I digress.

More of Johan's occultation images can be see in the current edition of "Noctuary", and in the photo gallery of the November 02 event.

Also visit Oleg's Astronomical website for other images of the occultation.

Image sequence by Johan Moolman.

Find out more: Southern Sky Highlights for 2012

nothing more to see. please move along.