NASA Will Keep Dawn Orbiting Ceres Instead of Moving On

While Juno’s arrival at Jupiter is getting all of the attention, Dawn – the little spacecraft that could reach an asteroid – has received its next orders from NASA. While it was rumored that Dawn would be moving on to a new location, the Who will instead be serenading it with “Meet the new boss … same as the old boss” as NASA decides to keep it in orbit around Ceres to possibly and definitively identify what those mysterious lights are.

NASA announced in April that it may send Dawn to explore its third space object after its mission was finished in July because it still had some fuel left in its ion thruster. It was leaked and then confirmed that the proposed destination was the asteroid 145 Adeona. The plan was to fly by the 150-km wide asteroid in May 2019.

It sounds like there was much dissension over the future of Dawn. Jim Green, director of NASA’s planetary science division, was for keeping it orbiting Ceres.

The long-term monitoring of Ceres, particularly as it gets closer to perihelion — the part of its orbit with the shortest distance to the sun — has the potential to provide more significant science discoveries than a flyby of Adeona.

Carol Raymond, deputy principal investigator for Dawn, felt there was nothing left to learn from Ceres and pushed for a mission to Adeona.

I think we’ve gotten so much already that the incremental amount of knowledge that we would gain would be maybe not as great as one would have thought.

A decision had to be made quickly because the window of opportunity to move to Adeona ends on July 12 when the amount of hydrazine fuel left drops below what is needed for the trip. Now that it will stay, Dawn has enough fuel to maintain its Ceres orbit until at least 2017.

That’s enough time to challenge the theories on the origin of the mysterious lights on Ceres. The latest explanation attributes their changes in brightness to reflections on plumes of gas heating and cooling due to some sort of not-yet-determined underground thermal activity.

Come on, Ceres! Show NASA you’re not washed up yet.