Plants on other planets may be yellow or red

By Julie Steenhuysen

CHICAGO (Reuters) - The same rules that make Earth plants green may make non-Earth plants yellow, red or green -- but likely not blue, NASA scientists said on Wednesday.

They said their findings -- which look at how plants absorb and reflect different types of light -- may help narrow the search for life on planets beyond our solar system.

And, as a bonus, they may have answered a basic question about life on Earth.

"We've uncovered maybe the best explanation of why plants are green," said Nancy Kiang, a NASA biometeorologist who led the study, which appears in the journal Astrobiology.

Understanding plant colours on other planets is important as scientists prepare for new information to be generated from giant space telescopes planned by NASA and the European Space Agency to study Earth-sized planets orbiting other stars.

"We can guess the plausible range of colours they might be," said Vikki Meadows, an astrobiologist the California Institute of Technology who heads NASA's Virtual Planetary Laboratory.

Meadows and a host of scientists from different disciplines first studied how light is absorbed and reflected by plants and some bacteria on Earth.

That led to computer model for predicting the colour of plants on other planets and new insights about plants on Earth.