Three “Down Under” Occultations of Jupiter

Jupiter at first contact
Observers across the eastern part of North America were treated to a daytime occultation of Jupiter by the thin crescent Moon on November 9, 2004. Jupiter was readily visible even in 7 x 35 binoculars as it approached the lunar limb. Here Jupiter's belts are faintly visible as it disappears behind the Moon's bright limb.
Sky & Telescope photo by Gary Seronik.
During the first three months of 2005, observers in the southwestern corner of Australia will have three opportunities to watch the Moon hide the giant planet Jupiter. The extreme southern part of the country will be able to catch some of the action as well. But all three events will be challenging to observe.

January 4, 2005
The first occultation will be the most difficult to view as it takes place during daylight hours with the last-quarter Moon low in the sky (or setting, depending on your observing site). Skywatchers from Perth south can see Jupiter disappear and reappear; others will be able to witness only the planet's disappearance just prior to moonset. (All the listed times are local.)

  • Perth: disappearance 10:44 a.m., reappearance 11:05 a.m.
  • Adelaide: disappearance 1:15 p.m.
  • Hobart: disappearance 1:33 p.m (only 2° above the horizon).

    February 27
    This time the occultation occurs in darkness, but the 18-day-old Moon will again be near the horizon. In fact, the observing opportunities on the 27th are the exact reverse of those a month earlier: Perth does not get to see Jupiter vanish, but observers located elsewhere along the extreme southern edge of the continent will be able to catch the planet's disappearance and reappearance. The occultation last less than 20 minutes because Jupiter is barely covered by the northern limb of the Moon.

  • Perth: reappearance 8:56 p.m.
  • Adelaide: disappearance 11:09 p.m., reappearance 11:26 p.m.
  • Hobart: disappearance 11:54 p.m., reappearance 12:19 a.m.

    Occultation of Jupiter
    While clouds covered most of the United States, a few lucky observers did witness the occultation of Jupiter by the Moon on the morning of December 7, 2004. Don Parker of Coral Gables, Florida, captured it with his 10-inch Cassegrain telescope and a webcam. Click on the image for a 364 kilobyte animated gif showing the beginning of the Jupiter occultation.
    Courtesy Don Parker.
    March 26
    The final occultation in the series is visible for observers in Perth and the extreme southwestern tip of Australia only. While the event occurs at night with Jupiter reasonably high in the sky, it takes place at the time of full Moon and so will be challenging to watch. Just like the February event, Jupiter passes behind the northern lunar limb and the occultation is brief, but because the Moon is full this time, the planet's disappearance and reappearance is set against the brilliant lunar limb.

  • Perth: disappearance 10:10 p.m., reappearance 10:29 p.m.

    Northeastern Australia has its turn when the 9-day-old Moon hides Jupiter on the afternoon of June 16th. More information about lunar occultations worldwide is provided in the online article "Lunar Occultation Highlights for 2005."