The science world is a-twitter with excitement lately, following the recent arrival of the New Horizons spacecraft at 2014 MU69, dubbed “Ultima Thule” by popular vote. The name means “beyond the borders of the known world”, signifying Ultima Thule’s status as the most distant object ever visited by Earthly spacecraft. Ultima Thule is a dark reddish rock in the Kuiper belt, a contact binary formed by two smaller rocks coming together in what was presumably a gentle fashion.
Reaching this space snowman 6.5 billion kilometers away from Earth took brains, dedication, ingenuity and the help of an unnamed Argentinian man and his daughter.
To successfully intercept Ultima Thule, the New Horizons mission team needed to answer some questions, such as “What trajectory is Ultima Thule on?” and “Is there any space debris around Ultima Thule that will destroy our spacecraft?” Being so small (~30km diameter at its widest point), observing Ultima Thule directly from this far away would be too difficult, so the team relied on data gathered during stellar occultations, i.e., when Ultima Thule passed in front of a star.
One of these occultations occurred on July 17, 2017, in the Patagonia region of Argentina. The team had already struck out twice in trying to observe Ultima Thule passing over a star: once in South Africa, and again using the airborne telescope SOFIA over the Pacific Ocean, so tension was already running high.
On this particular night, it happened to be very windy where the observation team was, which is bad news when you’re trying to hold steady focus on a tiny object that’s really far away. The team found themselves needing help to shield the telescopes they had brought with them from wind vibrations, and get the data from the star “without it jiggling around all over the place”, as planetary scientist Anne Verbiscer puts it.
Where does one find volunteers for an astronomical observation? Well, apparently even in Argentina NASA is known and loved, and help can be found just by walking into the community. “If you just started out with ‘We’re from NASA,’ people started coming out of the woodwork,” said Dr. Verbiscer. And that is how one Argentinian man and his daughter ended up spending their evening blocking the wind from a telescope using a truck, a tarp and some plywood, allowing the NASA folks to collect the data they needed to send New Horizons to Ultima Thule.
Want to learn more about the search for Ultima Thule? Check out the episode of NOVA that inspired this blog!