BOB HIRSHON (host):
Odd hollows on a tiny planet. I’m Bob Hirshon and this is Science Update.
Mercury is the closest planet to the sun, and one of the least known. Bright areas on the planet seen by earlier visits there were thought to be just some light-colored mineral. But now, the MESSENGER spacecraft, the first to orbit the planet, has taken a closer look. David Blewett is a planetary scientist at the Johns Hopkins Applied Physics Laboratory. He and his colleagues report in the journal Science that high-resolution images reveal that the bright material is made of many small depressions.
DAVID BLEWETT (Johns Hopkins Applied Physics Laboratory):
Small little pits in the ground, that have kind of flat floors, they’re sort of generally rounded, and they have bright interiors and sometimes halos around them.
The features needed a new name, so the team called them “hollows.” They don’t yet know what produces them, but their best bet is that there is some sort of volatile material in Mercury’s crust that boils off, leaving the hollows behind. I’m Bob Hirshon, for AAAS, the science society.