Four panels show the evolution of a disk of gas around a young star. Photo: McMaster University handout

Toronto — A new report by a team of astronomers suggests the existence of many more planets than the 100 or so currently documented — a finding that opens the door to the possibility of more Earth-like worlds.

The findings, published in Thursday's edition of the respected U.S. magazine Science, show that giant gaseous planets the size of Jupiter can form in hundreds of years, not millions as previously thought.

"The implication here is if we find planets form quickly, planets must be ubiquitous," said Thomas Quinn, astronomy professor at Seattle's University of Washington, who worked on the report with three other scientists, two of them Canadian.

"On the other hand, if planets form slowly then we would expect planets to be a rather rare phenomena."

Dr. Quinn stressed the numerous other planets that might exist as a result of his team's finding wouldn't be like Earth. Rather, they would be like our solar system's giant outer planets, Saturn, Uranus, Neptune and Jupiter, which is 318 times bigger than Earth.

"On the other hand, there could be Earth-like bodies orbiting these giant planets, much like Europa orbits Jupiter."

So far, Dr. Quinn said, observers have surveyed about 1,000 stars looking for planets, finding about 100.

While some scientists have theorized since the 1950s that giant gas planets could have been formed quickly, the theory had never been proved.

"Previously the only way we could think of which could be effective (in planet formation) was the method where you collide rocks together and build something up very slowly," said James Wadsley, a research associate at Hamilton's McMaster University.

"We've actually proven for the first time that it can done another way."

The new model suggests the disc of gas — the protoplanetary nebula — that forms before a planet does begins to fragment after a few spins around its star. As the disc fragments, clusters of matter begin to form quickly, immediately drawing in the gases that form vapour shrouds around giant gas planets.

John Landstreet, astronomy professor at the University of Western Ontario in London, characterized the report not so much as a major scientific breakthrough but as a "comment in a long conversation" about the formation of the solar systems.

"It's a thoughtful and useful comment but it's a conversation which has been ongoing for a long number of years and will probably continue for a number of years."

Mr. Wadsley, an Australian-born landed immigrant, and Joachim Stadel, who has been doing his research at the University of Victoria, worked on the computer algorithms that allowed Dr. Quinn's four-person team to model planet formations.

The fourth scientist on the team was Lucio Mayer, who resides in Switzerland.

All four men had previously worked together at the University of Washington.