SwRI Scientist Discusses NASA Space Probe Performing Historic Flyby

Feb 19, 2018

NASA’s New Horizons spacecraft is hurtling toward asteroid 2014 MU69. When it passes, it will be the most distant body a spacecraft has ever done a flyby of. The asteroid is more than four billion miles away, in the Kuiper belt, with so many unknowns that the margin of error is larger than other missions.


Marc Buie signals that five telescopes spotted the MU69 occultation
Credit Courtesy SwRI

“That’s what keeps me up at night,” said Marc Buie, Southwest Research Institute scientist assigned to the New Horizons mission, “is it gonna be there when we get there?”

Last year, NASA and SwRI spent months planning and executing a series of precise space observations from across the southern hemisphere to learn more about distant objects in a process called occultation. It is a process where scientists study the object as it passes in front of a star.

In July, they used 60 people and 24 mobile telescopes spread hundreds of miles down Argentina’s Chubut and Santa Cruz regions. Observers waited until nearly 1 a.m. to catch a glimpse of the shadow. Only five stations caught the 200 milliseconds of darkness.

“I saw it,” shouted one unnamed team member in a video SwRI played today at its annual stakeholders meeting.

MU69 flies in front of a star in this recording from NASA and SwRI's July 17, 2017 Argentina Occultation. The fraction of a second yielded lots of data for scientists.
Credit Courtesy NASA

The tiny star blinked out for just a fraction of a second and he and his partner began shouting.

The observation gave the team details about the MU69’s trajectory and began drawing a picture of what it looks like. Many have speculated the body is actually a binary asteroid, or two asteroids orbiting each other. Others said it could be peanut shaped, but Marc Buie said,“It’s like two ice cream balls smushed together.”

Despite conducting three occultations on two continents in a flying observatory in 2017, there is less data than Buie is comfortable with. So, he is making the case for one more.

“It’s a lot of people. It’s a lot of effort. It’s a lot of money,” Buie said. “On the scale of a space mission, it’s cheap. I think it’s a no brainer, but money doesn’t grow on trees.”

Buie estimated the effort would cost roughly $300,000. The final window before the probe arrives will be in August, when the shadow of MU69 falls across Colombia and Senegal.

Trajectory of the New Horizons space probe.
Credit NASA

Paul Flahive can be reached at paul@tpr.org or follow on Twitter @paulflahive