Venus past is mysterious. But scientists just revealed a big clue.

Even robots die quickly on Venus.The most long-lived of the 10 Venusian landers, the Soviet Union's Venera 13 probe, lasted two hours before succumbing to pizza oven-like temperatures of some 870 degrees Fahrenheit (465 degrees Celsius) and the crushing surface pressure of 1,350 psi — which The Planetary Society describes as "like having a small car sitting on your thumbnail." Even so, there's an ongoing scientific debate as to whether this now-hellish world was once hospitable, perhaps ha