The Kepler space telescope seeking Earth-like planets in a far-off region of the Milky Way has discovered more than 700 planetary "candidates" - some that just might be the right size and in the right places for life to be possible.

Astronomers on the Kepler team at NASA's Ames Research Center in Mountain View said Tuesday they are not releasing data on 400 of those objects after finding them so intriguing they want more time to analyze them.

In their first full-scale scientific report since the mission began in March 2009, the 28 members of the Kepler team announced they have found "viable exoplanet candidates with sizes as small as the Earth to larger than that of Jupiter."

It was only 15 years ago that Swiss astronomers discovered the first "exoplanet" orbiting another star beyond our solar system.

Yet in only the first 43 days of its mission, Kepler discovered the 706 strange objects that astronomers are listing as candidates for planetary status.

NASA officials allowed the Kepler team to publish full details on 306 of them in a forthcoming issue of the Astrophysical Journal to give astronomers everywhere an opportunity to view and analyze them.

In an interview, Geoffrey Marcy, the pioneer planet hunter at UC Berkeley and a Kepler team member, reflected the group's enthusiasm over those objects.

"It's an overwhelming amount of riches," Marcy said. "It's a planetary treasure map."

"There is only one appropriate assessment of this technical accomplishment and the haul of prospective small planets: WOW!" he added in an e-mail.

The details on everything Kepler has found so far, however, will be released in January, NASA said.

The Kepler space telescope was launched to scan a total of 156,000 relatively cool stars in the constellations Cygnus and Lyra. In gathering Kepler's data, the analysts at Ames look for a star's quick dimming that would indicate some object was passing in front it - possibly, a planet.

Analysts must then distinguish between planets and the many "false positives," as the planet hunters call them. For example, they could be two closely linked twin stars, known as eclipsing binaries, which can cause the dimming of one by the other - making it hard for astronomers to distinguish the twins from a planet. That is why the signals are so difficult to interpret.

"The team is working around the clock to process the data," Marcy said. "They're measuring the brightness of 156,000 stars every half hour, achieving a precision of a hundredth of 1 percent - an utterly unprecedented achievement.

Bill Borucki, an Ames physicist who is the Kepler mission's chief scientist, was in Denmark Tuesday, and NASA relayed a statement from him.

"The Kepler observations will tell us whether there are many stars with planets that could harbor life, or whether we might be alone in our galaxy," he said.