London, April 30 : Researchers at Pennsylvania State University in State College have come up with a way of attracting the attention of aliens - mounting mirrors on the moon to throw back some extra sunlight in ET's direction.

Shawn Domagal-Goldman and Jacob Haqq-Misra of Pennsylvania State University in State College think that half of the moon's surface should be covered up with mirrors.

When angled to catch the Sun's rays, researchers said that the mirrors would increase the amount of light the Earth-moon system reflects by 20 percent, which would be more than enough to catch the eye of a vigilant alien astronomer.

The researchers proposed using a code of prime number flashes - just as aliens used to get in touch in Carl Sagan's book Contact.

This will ensure the flashes aren't mistaken for natural variations in brightness.

As an added bonus, the underside of the mirrors could be covered with photovoltaic cells.

When the mirrors aren't busy flashing they could be flipped to allow the cells to make electricity, which would be beamed by microwaves back to Earth.

"You could help solve the climate crisis, too," New Scientist quoted Domagal-Goldman, as saying.

The idea was presented last week at the 2008 Astrobiology Science Conference in Santa Clara, California, US.