COPENHAGEN, Denmark, Sept. 6 (UPI) -- Dramatic climate variations on Mars, recorded in layers of ice and dust at the planet's poles, are driven by energy from the sun, Danish scientists say.
Researchers from the Niels Bohr Institute at the University of Copenhagen report layers in the ice cap on the planet's' north pole reveal variations in solar insolation, a measure of solar radiation energy received, providing a dated climate history for Mars.