Stargazers can lean back in a lawn chair and watch what astronomers say will be the greatest meteor showers in 35 years light up the sky this weekend.

The only catch is that the showers are expected to appear between 3 a.m. and 6 a.m. Sunday morning. And it can get pretty cold in the middle of a mid-November night.

The meteors are expect to appear as the earth plows into dense debris from the comet Tempel-Tuttle.

The showers are known as the Leonids because they become visible in the November night sky at the same time as the constellation Leo, and appear to radiate from it.

The comet, which orbits the sun about every 33 years, was most recently near the earth in 1997.

Lee Anne Willson, university professor of physics and astronomy, said the show will be a result of the earth passing through the orbit of an old comet.

“When its debris of gravel and ice meets with the earth’s atmosphere, they melt and become a streak of hot gas across the sky,” she said.

In average years, 10 to 15 meteors can be seen in an hour, said Paul Martsching, Ames resident and volunteer observer for the American Meteor Society. But under this year’s conditions meteors will be larger and more frequent.

This Sunday morning, during the peak period, Martsching estimates viewers will be able to see 200 to 500 meteors an hour in a clear sky. In the central United States, the peak period is expected to occur between 3 a.m. and 6 a.m.

Because no one can actually predict the peak time with certainty, he suggests Ames residents begin observations as soon as Leo rises about midnight.

“This is probably the very best meteor shower that anyone could hope to see in a lifetime,” said David Oesper, a member of Ames Area Amateur Astronomers and a 1980 ISU graduate.

“There’s a real good chance to see hundreds to thousands an hour this weekend.”

Martsching and Oesper are hoping for clear skies Saturday and Sunday.

But they have a plan if the clouds predicted to roll in Saturday night appear. They plan to travel up to 500 miles to find that clear sky.

“In order to see the high counts, it helps to get out of city limits and away from all lights of any kind,” Oesper said. “[But] people could walk out in their yards in Ames and be able to see meteors.”

Ed Engel, member of the Ames astronomy group, said the group will have its regular meeting at 7:30 p.m. Saturday at the observatory in McFarland Park, about six miles northeast of downtown Ames. After the meeting, they will observe the sky and possibly travel to find a clear sky. Everyone is welcome to join them.

No special knowledge or equipment is needed.

In fact, the shooting stars, as some call the meteors, are moving so fast that they typically cannot be viewed with telescopes or binoculars.

“All you have to have are your eyes, warm clothes and clear sky,” Engel said.