Squinting At Saturn Through 17th Century Technology

(ISNS) -- A team of French researchers has shed light on an important moment of astronomical history by testing the old lenses used by astronomer Jean-Dominique Cassini when he observed a minuscule gap between two of Saturn's rings in 1675. Questions have lingered over whether it was possible to see this gap, which was later named the "Cassini Division," with the optics he had at his disposal.