PureInsight | April 22, 2002
If you've not been paying much attention to the night sky, now would be a great time to start!
Throughout most of April and May, the five brightest planets — Mercury, Venus, Mars, Jupiter, and Saturn — will cluster together in the western sky at dusk. For several weeks these five worlds, all visible to the unaided eye, will form and reform new patterns as they move against the background stars — a slow-motion line dance that will be fascinating to watch as it progresses.
'Take the time to check this out,' advises Alan MacRobert, a senior editor at Sky & Telescope magazine. 'All you need to do is note where the Sun sets, then watch that general area of the sky as twilight darkens.'
Several evenings during the seven-week-long display hold the promise of especially attractive arrangements. For example, on April 17th all five planets, together with a thin crescent Moon, organize themselves into an evenly spaced line that begins near the western horizon and stretches upward a third of the way across the sky. On May 13th– 15th they'll be clustered within an area only 33° across. The dance culminates on June 3rd with a breathtakingly close pairing of Venus and Jupiter, the two brightest planets. Close gatherings of the five 'naked-eye' planets are relatively rare, cosmically speaking, occurring roughly every 20 years. At such times these worlds are all on the same side of the Sun in their orbits as seen from Earth's perspective. The last widely visible five-planet bunching was in February 1940 (a tight grouping occurred in May 2000 but was hidden in the Sun's glare). And another good one won't take place until September 2040. Thus, for many of us, this spring's display represents a once-in-a-lifetime opportunity. More than being a treat for sky watchers, the twilight gathering of planets above the western skyline provides a fine 'photo op' for those wanting a memento of the occasion. According to Dennis di Cicco, a veteran astrophotographer and senior editor at Sky & Telescope, 'Today's popular point-and-shoot cameras, as well as the new generation of digital cameras, can easily capture this celestial spectacle.' Simply place your camera on a firm support, disable the flash, frame the scene in the viewfinder, and open the shutter for a few seconds. If your camera offers manual overrides, set the focus for infinity and the lens to its maximum aperture (lowest f/number). Because twilight changes rapidly, snap a set of 'bracketed' exposures lasting from about 1 to 8 seconds each.
Having a tree or building silhouetted in the foreground will make the picture's composition more interesting, di Cicco suggests — and it will help during the processing of your film, since the planets create such small specks on the negative that the frame may look blank and not be printed.
Several pages on SkyandTelescope.com provide more information about this month's events, including a timetable describing the planetary patterns visible through early June. See: http://skyandtelescope.com/observing/objects/planets/article_572_1.asp
In addition, stargazers worldwide can use Sky & Telescope's Interactive Sky Chart to simulate the planetary parade as seen from their particular location.
In mid-May, right around Falun Dafa Day, the planets will line up in their closest apparent configuration. See diagram below. However you think of this, it is an amazing conjunction of celestial and earthly events, even if you only consider this dimension.
May 13: Go out about 40 minutes after sunset and scan just above the west-northwest horizon for the hairline crescent Moon. Binoculars will help. See if you can spot Mercury a little to the Moon's right, and Saturn to the Moon's upper left. Higher up is dazzling Venus. Barely below Venus, look for faint orange Mars. Jupiter shines much higher up, to Venus's upper left.