Miles O’brien spoke with Rich Zurek, chief scientist of Mars Program Office at NASA’s Jet Propulsion laboratory, about particles in comet Siding Spring’s tail that could collide with NASA’s Mars orbiters. The tiny tail particles, about a millimeter in size, can be traveling at up to 35 miles per second, so “if they encounter a spacecraft, they can go through just about anything,” Zurek said.
But the close flyby will give the the probes a chance for a detailed look at the comet. Zurek and his team hope to get a close look at the central ball of ice and dust that makes up the heart of the comment, called the nucleus.
Comet Siding Spring will make its close pass by Mars between 2 and 3 pm ET today.