Planets Dance for Astronomy Celebration

(Note to Editors/Producers: This release is accompanied by three
publication-quality illustrations; see details at end.)

If you’ve never paid 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 Sunsets,
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 14th they’ll be clustered within a
circle only 33 degrees across. The dance culminates on June 3rd with a
breathtakingly close pairing of Venus and Jupiter, the two brightest
planets.

Even the directionally challenged will have extra support, when backyard
skygazers around the world celebrate “Astronomy Day” on Saturday, April
20th. Conceived in 1973, this annual observance typically spawns hundreds
of organized events in cities and towns throughout North America and
Europe. Especially popular are evening “star parties,” at which amateur
astronomers trot out their telescopes so that the general public can get an
eyeful of the Moon’s craters, Saturn’s rings, star clusters, and galaxies.

The planets now arrayed in the western sky after dusk will make this year’s
Astronomy Day that much more enjoyable.

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 skywatchers, 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:

* a timetable describing the planetary patterns visible through early June:
http://SkyandTelescope.com/observing/objects/planets/article_572_1.asp

* a comprehensive guide to finding local astronomy clubs and organizations
in North America, Europe, Australia, and selected countries in Asia:
http://SkyandTelescope.com/resources/organizations/

* a backgrounder on Astronomy Day:
http://SkyandTelescope.com/resources/calendar/article_472_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:
http://SkyandTelescope.com/observing/skychart/

* * * * *

SKY & TELESCOPE is making the following illustrations available to the news
media. Permission is granted for one-time, nonexclusive use in print and
broadcast media, as long as appropriate credits are included. These
illustrations, along with an online version of this release, are available
at:
http://SkyandTelescope.com/aboutsky/pressreleases/article_575_1.asp

* color illustration of the planets’ appearance in the western evening sky
for April 14-16, including the position of the crescent Moon each day.

* color illustration of the planets’ appearance in the western evening sky
for May 5th, showing Venus, Saturn, and Mars in a close triangle.

* color animated GIF showing the motion of the planets and Moon in the
western evening sky from April 8th to June 3rd.