In a colorful lecture on Saturday, Eric Feigelson said we might not yet have images of planets outside our solar system, but there is substantial evidence that they exist.

"Come back in another 10 years," Feigelson, professor of astronomy and astrophysics, said.

His lecture, entitled "Planets, Planets, Everywhere," was an overview into new findings in our own solar system and a comparison between our solar system and the strong evidence of similar systems elsewhere in the universe.

Feigelson's lecture, aimed at non-astronomy majors, began with a lively astronomy lesson about the structure of our solar system, and he showed photos and film clips as evidence for the presence of water on the moon, Mars, and one of Jupiter's moons, Europa.

Michelle Stark (graduate-astronomy and astrophysics), a former student of Feigelson, said she was familiar with his animated lecture style.

"You learn very fast not to sit in the front row," she said, referring to Feigelson's tendency to run around the front of the room while speaking.

Feigelson said smaller bodies within our solar system like Plutinos, which are small rocky bodies similar to Pluto, challenge the way a planet is defined.

"This is an age of confusion," he said, explaining that if Pluto is considered a planet, then all the other Plutinos should be as well.

He stressed the importance in studying these nearby elements that can be seen through probes, telescopes and space shuttle missions. By studying them, we can gain an understanding into the complicated processes by which planetary systems form, he said.

Feigelson said the Spirit and Opportunity rovers studying Mars are offering the best images of landscape changes that are evidence of the presence of water at some point in the planet's lifetime.

"They're so cute -- little cameras and radios doing geology experiments," he said. " 'There's a rock! A rock on Mars!' "

Feigelson's own research is studying the formation of new stars and planets. He and his colleagues at Penn State are using images from the Chandra X-Ray Observatory, Doppler-effect studies and photographs of eclipses and planetary transits to observe distant systems.

He said the Chandra telescope has captured images of the Orion nebula, a massive, dark cloud of dust from which many stars have formed within the last 2 billion years, making them relatively new compared with others in the Milky Way galaxy.

The Chandra images reveal extraordinary flares in these young stars, Feigelson said, and these X-ray flares might fall on the forming planet.

"It is possible, but not at all certain, that X-rays may influence the processes of planet formation," he added.

Feigelson also showed data supporting the presence of other solar systems around stars closer in age and composition to our own sun. Presenting information gathered from Doppler observations and transits -- and mimicking the siren-like sound a Doppler radar might make -- Feigelson offered more evidence for the presence of orbiting planets around stars in our galaxy.

Throughout the lecture, Feigelson stressed the importance of this era in science. When he created the slide show a week before the lecture, the number of known planet-like structures was 136, but by Thursday, the number was 145, he said.

"This is the very edge of science," Feigelson said. "Our knowledge and our understanding is leaping forward."

He also defended the large funding required for NASA projects, saying: "This is a big commitment, but then, Queen Isabella made a big commitment to some guy named Christopher Columbus."

This lecture was the first Friedman lecture of the year, an annual event that is held by the Department of Astronomy and Astrophysics and sponsored by the Ronald M. and Susan J. Friedman Outreach Fund in Astronomy.

Christopher Palma, outreach fellow for the department, estimated that about 225 people were in attendance for the lecture, an average turnout from the Penn State and State College communities, he said.