Merrillville Community Planetarium
Bringing the Universe to the Merrillville Schools and Northwest Indiana

A Close Encounter With Mars This Summer

Mars is going to appear bigger and brighter in our night sky this summer. In fact, on August 27, 2003, Mars will make its closest approach to Earth in quite a while. From now through early fall is a good time to observe Mars -- with a telescope, binoculars, or your eyes!

While Earth completes an orbit around the sun every 365.25 days, Mars takes 687 days to complete one trip. Both planets circle the sun in elliptical or egg-shaped orbits. As a result, each planet is sometimes a little closer and sometimes a little farther from the sun. As Earth and Mars orbit the sun, the distance between the two planets is constantly changing.

Every 26 months (approximately), Earth passes near Mars, an event that astronomers call "opposition". When Mars is at opposition to Earth, the Red Planet appears relatively bright in our sky all night long.

If the opposition occurs when Mars is nearer to the sun, the two planet come even closer together. This event is call a perihelic opposition because it occurs when Mars is at perihelion -- the point in its orbit closest to the sun. Mars will be at perihelic opposition on August 27, 2003. At its closest, Mars will be only (!) 34.6 million miles from Earth. The last perihelic opposition occurred on September 28, 1988.

Because of small variations in the orbits of the planets, the minimum distance varies slightly from one perihelic opposition to another. According to calculations by several astronomers, the August, 2003 opposition is the closest in nearly 58,000 years. Mars won't be this close again until the year 2287.

Mars and Earth have almost been this close together in more recent times. Perihelic oppositions in August, 1924 and August, 1845 were almost as close as August, 2003.

Regardless of the exact miles between the two planets, there's no doubt that Mars will appear bigger and brighter in our sky in late summer and early fall. It's a great opportunity to go out and observe Mars with a telescope, binoculars, or just your eyes.

The Merrillville Community Planetarium will present "The Mars Show" from July 4 to 26. For more information on the program, contact the planetarium at (219) 650-5486 or visit our website at The Merrillville Community Planetarium is located in Clifford Pierce Middle School at 199 East 70th Avenue in Merrillville, Indiana.