WASHINGTON- Floating in space, 450 light years away, are tadpole-shaped pods with comet-like heads twice the diameter of our solar system and tails 100 billion miles long - and they may just be the first of trillions of such objects in the universe .

Astounding news? A sci-fi movie? Hardly. This is high-tech, state-of-the-art science. The Hubble Space Telescope has returned pictures of these wraithlike formations and it's on a search for more.

Astronomers call the images ''cometary knots'' because their glowing heads and filmy tails superficially resemble comets. They resemble giant tadpoles, too. And sperm.

Hubble astronomer C. Robert O'Dell and graduate student Kerry P. Handron of Rice University in Houston found the knots while exploring the Helix nebula, a ring of glowing gases in the constellation Aquarius.

They believe they are the result of a dying star's final outbursts, when it ejects shells of gas into space.

Looking through ground-based telescopes, researchers had assumed such objects existed, but it took the Hubble, orbiting Earth, to find them.

''O'Dell expects the gaseous knots ... will eventually dissipate and vanish into the cold emptiness of interstellar space,'' said the Space Telescope Science Institute in announcing the findings.