During the months of April, May and June in 2002, five planets were visible in the same section of the sky. Mercury, Venus, Mars, Jupiter and Saturn were within 33 degrees at their closest. This alignment was unusual, it will be almost 20 years before the next time these planets will be this close together.
This alignment was easy to observe from the Northern Hemisphere; you only had to go outside any clear night in the early evening during April, May or June and look toward the west. Three bright objects were easily seen with the naked eye (they are Saturn, Jupiter and Venus). Mars was dimmer, but also visible; under the right conditions Mercury was visible as well.
Mercury is tricky to observe, but if you plan ahead and observe from a location with a good horizon without obstructions (such as trees, buildings and so on), you should be able to see it. The easiest time to observe Mercury is at the greatest elongation (which occurs every few months), however it can be observed for a few weeks before and after greatest elongation.
It is very difficult to see any detail on Mercury in earth bound telescopes.
Venus is the brightest planet and easy to observe with the naked eye. However it shows little detail when observed through a telescope.
Mars varies in brightness more than other planets. It can vary from bright red to pale pink over its two year cycle. Observation from earth based telescopes is worthwhile only near opposition (which occurs once every two years).
Jupiter is easy to observe with the naked eye. If you use binoculars you may be able to see some of the four brightest moons (which may be visible as small dots near the bright disk of Jupiter). With a small telescope, you can see bands in the atmosphere and up to four moons (sometimes one or more of the moons are behind the planet and not visible).
Saturn is easy to observe with the naked eye. If you use a small telescope, you will able to see the rings (except every few years when the rings are “edge-on,” and thus not visible from our vantage point). Normally you can see the brightest moon, Titan, and possibly other moons.
More on the Planets
- Mercury—the U. S. Geological Survey (Flagstaff Field Center).
- Venus—an Ultraviolet image as seen by the Pioneer Venus Orbiter; It was taken February 5, 1979.
- Mars—the Valles Marineris canyon system. Three volcanoes are visible on the left. This photograph is copyright 1997-1999 by Calvin J. Hamilton, all rights reserved.
- Jupiter—Voyager 1.
- Saturn—High Energy Astrophysics Science Archive Research