Forget the Brooklyn Bridge, try buying an acre of Mars

Pssst! Want some land cheap? Only 2 cents an acre. The purchase price is tax-deductible, and the view's out of this world.

If this sounds like the deal of a lifetime, talk to David Aguilar. As director of the Fiske Planetarium at the University of Colorado, he will sell you a 1,000-acre plot on the slopes of Olympus Mons, the biggest volcano in the solar system, for only $20. It just happens to be on the planet Mars.

''People have been selling stars for years. I wanted to do something different,'' explains Mr. Aguilar. Like most public institutions these days, planetariums are facing severe financial problems. The Mars Land Rush is Fiske's unique way of responding. And it seems to be catching on.

Although the land sale wasn't supposed to start until April 1, a member of the staff leaked news of the gimmick to a journalist writing about planetarium promotions. It was picked up by the wire services. Paul Harvey mentioned it on one of his nationally syndicated television shows. And Fiske has been besieged by calls and letters from around the world ever since.

In return for your donation you get: an official-looking Deed of Trust; a topographical map of Olympus Mons; a special spaceflight insurance policy; and, some ''Genuine Simulated Martian Soil.'' Minimum purchase is 1,000 acres.

''We are treating this totally tongue-in-cheek,'' the director confesses. The possibilities for satire are almost endless. Take, for instance, a few samples from the ''promotional flyer'' that the planetarium staff put together:

* ''This land steal features pink skies, unlimited rock gardens, and not one, but two moons. So peaceful, quiet, and romantic -- even the natives are friendly.''

* ''At one-sixth gravity of Earth, your golf game will improve immensely.''

* ''Be the first in your neighborhood to own a piece of the rock.''

* Your purchase is guaranteed ''free of mosquitoes and swamps.''

From the letters they have received it seems obvious that the public is entering into the spirit of the promotion. ''The letters are wonderful. People have been writing pages, not just sending money,'' Aguilar reports.

For instance, one buyer is purchasing the land as a present for a friend because ''he already spends a fair amount of time out there anyway.'' A Canadian customer requested a ''river or ex-river view.'' A couple claimed that Mars was perfect for them because the location would ''cut down on unwanted visits by deadbeat relations.'' And another writer explained that he recently buried his pet rock in the backyard because he thinks Martian land will be a much better conversation piece.

''It seems to have simultaneously sparked people's imagination and sense of humor -- something that's difficult to achieve,'' Aguilar observes.

The planetarium will soon be putting on a Mars Fever Week -- featuring Viking spacecraft pictures of the Red Planet, Mars-related science fiction movies, and a Martian laser light show. In the near future, they will begin offering Martian Land Dealerships: sell 10,000 acres and get 1,000 free.

''I'd love to see it get as big as pet rocks,'' says Aguilar wistfully. He hopes to raise $20,000 with the promotion. This will go toward the planetarium's ambitious program, which includes: activities for 1,000 students weekly; guest lectures on a variety of science topics; live musical productions; and a continuous science fiction film festival.

If you're interested in purchasing a plot on the Red Planet, write: Fiske Planetarium, University of Colorado, Campus Box 408, Boulder, Colo. 80309. Aguilar says hurry if you want a spot on Olympus Mons. The giant volcano is going fast and they will soon have to begin subdividing Valles Marineris, the Martian Grand Canyon which makes its counterpart in Arizona look small by comparison.