DECISION T I M E NASA'S NEW FRONTIERS

摘要

Where to: a comet or Saturn's icy moon Titan? That's the question NASA managers will need to answer in July 2019 when they select the next mission in the agency's New Frontiers series.For planetary scientists, comets are tantalizing ancient messengers from the early solar system, while Titan is on the short list of places in our solar system that, though a long shot, could harbor life of some form. The decision is not an easy one. "'Agonizing' falls far short of describing this" decision, says NASA's Curt Niebur, lead program scientist for New Frontiers. "The teams pour all of their talent and passion into this work, and they produce amazing missions. Picking only one is the worst part of my otherwise great job." Whoever wins will have the challenge of continuing what has been a great run for New Frontiers since the initiative's founding in 2002. Its first three probes have achieved household name status among those who follow planetary science. New Horizons flew by Pluto in 2015 and is now flying by other mysterious Kuiper Belt objects. Juno began orbiting Jupiter in 2016, and OSIRIS-Rexin 2020 will attempt a sample return from the asteroid Bennu.