As San Antonio rings in the New Year, NASA expects to celebrate a historic first flyby on the edge of our solar system.
NASA’s New Horizons spacecraft will shoot past rock 2014 MU69, nicknamed Ultima Thule, at more than 31,500 mph Monday night. Four billion miles from Earth, it will be the farthest object explored in history.
New Horizons passed Pluto in a historic 2015 flyby and has been traveling to Ultima Thule since then. Scientists still know almost nothing about the icy rock because of its distance from Earth.
“That’s gonna change overnight,” said Alan Stern, planetary scientist at Southwest Research Institute and principal investigator on the mission. “We’re gonna not rewrite a textbook about Ultima, we’re gonna write it from scratch.”
New Horizons was always intended to travel to what scientists call a “third zone” of our solar system, named the Kuiper Belt. Scientists are interested in the belt because it is filled with comets, asteroids, and other minor planets that can tell us about the formation of the solar system, Stern said.
“It’s like an archeological dig of our solar system,” he added.
The discovery of the Kuiper Belt in the mid-1990s made Pluto — the largest body in the belt — an attractive target, and many, including Stern, credit the discovery with getting the mission approved. NASA launched New Horizons without knowing which object in the belt they would target after Pluto, identifying Ultima Thule with the Hubble telescope in the summer of 2014.
WATCH | Alan Stern Talks about discovery of Kuiper Belt
https://www.youtube.com/watch?v=dq6CoSXR6co
Special cameras designed to shoot in low-light at high speeds, along with spectrometers and other instruments — some designed and built in San Antonio — will capture information about Ultima Thule’s actual shape, and whether or not it has rings, a moon or an atmosphere.
“Remember, it’s about the size of greater San Antonio, and about as reflective as garden variety dirt,” Stern said.
They knew so little about the minor planet when they selected it that scientists had to travel the world to do special occultations to observe the far-off planet when it passes in front of a star.
From that 200 milliseconds of recorded shadow, they learn tidbits about Ultima’s trajectory, speed, and shape.
Occultations were conducted across the globe, from Argentina’s windswept Patagonia to remote parts of Africa and Colombia.
“That’s what keeps me up at night,” said Marc Buie, who talked with TPR in February about executing occultations for the New Horizons mission, “is it gonna be there when we get there?”
Buie argued successfully to add a sixth occultation to the planned five this summer.
No debris has been observed in the flight path, which is good because the spacecraft is extremely fragile at this speed.
“At 32,000 miles an hour, if we hit something as small as a rice pellet, it would destroy the spacecraft — that would be the equivalent of hitting a Mack truck on the highway,” Stern said.
New Horizons is scheduled to pass Ultima Thule at its closest point at 11:33 p.m. Monday.
More information will be available from New Horizons as early as the end of the week, but according to mission leaders, it will be more than a year and a half before all the data downloads.
Paul Flahive can be reached at paul@tpr.org or on Twitter @paulflahive.
