American eclipse needs citizen scientists

August's total solar eclipse in the US will almost certainly be the most watched such event in history.

More than 12 million people - from Oregon to South Carolina - live on the path of darkness that the Moon will cut as it sweeps in front of the Sun.

Nearly four times that many live within a two-hour's drive. And then there are all the tourists who will flock to America to witness the spectacle.

Astronomer and artist Tyler Nordgren from the University of Redlands in California spoke with our science correspondent Jonathan Amos.