PASADENA -

(CNS) - Eighteen planets -- each the size of Jupiter -- have been uncovered in distant solar systems, according to Caltech scientists writing in a scientific journal today.

Using the twin telescopes at the Keck Observatory on the Big Island of Hawaii, scientists said they have discovered planets in a step they called significant because they are the first such observations to be made from this planet.

Orbiting telescopes in space have identified about 1,200 potential planets, but the majority of those have not been confirmed, according to Caltech assistant professor of astronomy John Johnson. The new ground discoveries are "the largest single announcement of planets in orbit around stars more massive than the sun, aside from the discoveries made by the Kepler (orbital) mission," he said.

The Hawaiian observatory was able to spot wobbles in the movements of distant stars that are a bit older and larger than our sun, Looking for tell-tale "Doppler shift" indications led to the conclusion that 18 of the distant stars are pulled gently by unseen planets about the same size as our neighbor, Jupiter.

Johnson started looking for the planetary signs several years ago, but the evidence is slow in arriving because these giant planets take a long time to orbit their suns. "I liken it to a garden," Johnson said in a Caltech news release. "You plant the seeds, and put a lot of work into it. "Then, a decade in, your garden is big and flourishing. That's where I am right now. My garden is full of these big, bright, juicy tomatoes -- these Jupiter-sized planets."