OCEANSIDE -- The closest approach of Mars to Earth in nearly 60,000 years has spurred a booming interest in the planets and stars almost unequalled by past events, local astronomy buffs said Tuesday.

"We call it the Mars phenomenon," said Craig Weatherwax.

The owner of Oceanside Photo and Telescope since 1974, Weatherwax has organized a public party and skyviewing session from 8 to midnight tonight in the store parking lot at 1024 Mission Ave.

"It's going to be huge," he said.

When Mars rises in the southeastern sky tonight starting about 7:45 p.m., it will be fewer than 34.67 million miles away from Earth. That may still seem far away, but it is 9 million miles closer than the last close approach in 1991.

Weatherwax said he will have up to 15 telescopes set up for the public and that they will be manned by store employees or amateur enthusiasts from the 200-member Oceanside Photo and Telescope Astronomical Society.

There are other viewing options tonight, as well.

The Reuben H. Fleet Science Center in Balboa Park will have a variety of telescopes set up for visitors to use on the Prado in front of the science center beginning at 8 tonight, at 1875 El Prado in San Diego. Members of the San Diego Astronomy Association will be on hand to help, as will MiraCosta College's Shannon Rupert Robles.

Robles, an instructional associate at MiraCosta and a biology teacher at Miramar College, is also a researcher and member of the International Mars Society. The society is an advocacy group for manned missions to Mars.

"It's kind of funny," she said. "For me this, hopefully, isn't the closest approach to Mars that I ever see. I hope the closest approach is us going there."

Robles said she is not sure what is causing the public fascination with the planet, but that it could be because it's so easy to see because the night sky is so bright.

"You've seen it come up," she said. "It's, like, in your face: 'Hello, I'm here!'

"And I think the public's imagination is stirred by the fact this is the closest approach in 60,000 years. It's a once-in-a-lifetime thing … lots and lots of lifetimes."

Weatherwax said the Mars frenzy has triggered a business boom.

"It's like Christmas in August," he said. "We're having a bigger August than December."

While the Red Planet is big and beautiful to the naked eye or with binoculars -- its apparent diameter is six times greater than it was in February -- "you really need a telescope to see it well," Weatherwax said.

Amateur observers are reporting they are able for the first time able to see the white polar ice caps on Mars, as well as what may be the tallest volcano in the solar system: 16-mile-high Olympus Mons. Then there's the Mars equivalent of the Grand Canyon, except that it's 120 miles across and 2,000 miles long.

Said Robles, who has her own telescope: "I've been trying to observe Mars for years now, (but) I've never been able to see the polar ice caps before, and you see the different shadings."

Mars will continue to appear large and bright for weeks and months to come, said experts. For those who can wait a few days, Palomar College is inviting the community to look at Mars through several of the school's telescopes from the observatory on top of Palomar's Earth Science Building from 9 p.m. to 11 p.m. on Saturday.

Visitors are advised to obtain a pass from campus police at the main entrance and park in Lot 12.

Some amateur groups and individuals are also expected to head out to the desert for dark sky observations. One popular spot is the campground adjacent to Palomar Observatory.

Contact staff writer Tim Mayer at (760) 901-4043 or tmayer@nctimes.com.