This is an artist's concept of a hypothetical 10-million-year-old star
system. The bright blur at the center is a star much like our sun. The
other orb in the image is a gas-giant planet like Jupiter. Wisps of white
throughout the image represent traces of gas.
Astronomers using NASA's Spitzer Space Telescope have found evidence
showing that gas-giant planets either form within the first 10 million
years of a sun-like star's life, or not at all. The lifespan for sun-like
stars is about 10 billion years.
The scientists came to this conclusion after searching for traces of gas
around 15 different sun-like stars, most with ages ranging from 3 million
to 30 million years. With the help of Spitzer's Infrared Spectrometer
instrument, they were able to search for relatively warm gas in the inner
regions of these star systems, an area comparable to the zone between
Earth and Jupiter in our own solar system. They also used ground-based
radio telescopes to search for cooler gas in the outer regions of these
systems, an area comparable to the zone around Saturn and beyond.
