COSMIC TODDLER COURSE : SCIENCE LAB

At Just 1.5 million years old, a planet still finding its footing.

Over the past 30 years, astronomers have found more than 5,000 exoplanets, an eclectic menagerie of worlds far from our stellar neighborhoods. The latest may be a mere infant.

In the journal The Astrophysical Journal Letters, scientists announced evidence of a world just 1.5 million years old, making it one of the planets ever found, perhaps the youngest.

This world - 395 light years from Earth - is so young that its building blocks of gas and dust are still coming together. ''It is like looking at our own past,'' said Myriam Benisty, an astronomer in France and the study's co-author.

As the suspected planet is shrouded by the matter that is making it, more observations are needed to confirm its existence. Presuming it isn't rocky detritus masquerading as a planet, scientists can use it to understand how worlds are made.

The torrent of newly discovered exoplanets has complicated or disproved longstanding theories of planet formation. But the location of this baby planet supports the idea that most planets spend much of their time growing up in a similar sort of nursery.

For the latest study, scientists pointed antennas at AS 209, a star just a tad heavier than the sun that has only recently started to burn hydrogen - the stellar equivalent of a toddler uttering its first words.

AS 209's circumstellar disk was found to have several gaps. And in one such gap, scientists detected the radio-wave signature of a planet-making tempest, gas that was presumably enveloping a Jupiter-like world still under construction. [ Robin George Andrews ]