Sky-watchers disappointed by the comets Halley and Kohoutek, don't give up: This is the year of "a great Martian adventure."

Mars in September makes its closest approach to Earth in a generation - just over 36 million miles, and at its nearest on Sept. 21 the red planet will rival Jupiter as the brightest object in the sky after the moon and Venus."It won't be this close again until 2003," says Jack Horkheimer, the "Star Hustler" of the Public Broadcasting System and executive director of Miami's Space Transit Planetarium. "And there are a lot of kids out there who have never seen it this bright."

Unlike Halley and Kohoutek, Mars's brightness is more predictable and it will be visible from almost everywhere in the world. "I see 1988 as a great Martian adventure," says Horkheimer. "I'm like a kid in a candy store."

Earth passes Mars every two years, but only every 15 to 17 years do they come this close. The year began with Earth and Mars 200 million miles apart.

The unblinking reddish-orange light is expected to spark UFO sightings, Horkheimer says, and as if to show the heavens have a sense of humor, the peak of the show is weeks shy of the 50th anniversary of Orson Welles' "War of the Worlds" broadcast that panicked the nation with fictional invaders from Mars.