A comet from the outer reaches of the solar system makes a rare, close pass by Mars where a fleet of robotic science probes wait to study it.
Comet Siding Spring passed just 140,000km from Mars on Oct 19, less than half the distance between Earth and the moon and 10 times closer than any known comet that has passed by Earth, says NASA. During its closest approach to Mars at 2:27 pm EDT, the comet hurled past at a speed of about 203,000kph.
