All five planets that can be visible to the naked eye will appear together
in the evening sky later this month in a viewing opportunity that won't be
matched for 32 years.
Going in order from West to East, the cast of planetary characters will be
Mercury, Venus, Mars, Saturn and Jupiter. All but Mercury are already
visible. The winged messenger is the most elusive of the five, being so
close to the Sun that it never gets very far above the horizon, and always
only near dawn or dusk.
By late March, Mercury will be about as high as possible at dusk for viewers
at mid-northern latitudes, setting the stage for a memorable few weeks of
easy-to-do backyard skywatching.
Where to look
Mercury will hover above the setting Sun in the West. Higher up, brilliant
Venus already dominates the stage, outshining all stars and planets. Mars,
much dimmer than it was last summer, is high in the southwestern sky. Saturn
is nearly overhead now at dusk and to the south. Jupiter, now stunningly
bright, is king of the eastern evening sky, rising just as the Sun goes
Robert C. Victor, a long-time astronomer at the Abrams Planetarium at
Michigan State University, now retired, has for some four decades
specialized in predicting and observing unusual configurations of the
planets. Victor said there won't be a more easily observed display of all
five naked-eye planets at dusk until April 2036.
"I would like to encourage astronomy clubs and planetariums to schedule
twilight public viewing sessions during March 22-31, including the final
weekend, March 26-28, for this wonderful occasion," Victor said. "Sessions
should begin by about 45 minutes after sunset, to insure catching Mercury
before it sinks too low."
Armed with a simple sky map, people can find the planets on their own from
any backyard. Each of the planets will be bright enough to be seen under
most urban lighting conditions, too.
The setup is possible this month because all of the planets are on the same
side of the Sun, as envisioned from above the solar system. The planets
create no light of their own, of course, but shine by reflecting sunlight.
A wide variety of different configurations involving the planets typically
occur during the course of any given year. It is quite unusual, however, to
spot the five brightest planets in the sky at the same time.
According to Jean Meeus of Belgium, a specialist in spherical and
mathematical astronomy, there are 12 similar cases between the years 1980
and 2020. But, he also points out that some of these (such as in August 2016
and July 2020) will be difficult to enjoy because some of the planets will
be very low in the sky.
Victor notes that there will be another fine chance to view all five
planets -- in the morning sky -- during late December 2004 through early
From our earthly vantagepoint, we can readily observe Mercury, Venus, Mars,
Jupiter and Saturn with our unaided eyes when they are favorably positioned
in their orbits around the Sun. Each of these planets appears to move
against the starry background at their own speeds and along their own
tracks. Since they are constantly moving at different speeds in relation to
other objects, the positions of all five planets at any particular time is
unique to that moment.
Veteran Lemac Dushae
Deceiver for <Gorilla Warfare>