spaceSpace and Physics

Our Most Distant Space Exploration Mission Depends Upon These Next Few Weeks


Jonathan O'Callaghan

Senior Staff Writer

Artist's impression of New Horizons and MU69. NASA

In two weeks, scientists will get an unprecedented look at a distant Solar System object – one that will be visited by a spacecraft in the not too distant future. And these observations will be vital in keeping that spacecraft safe from harm.

The object is called MU69, thought to be a remnant of the early Solar System. It’s the target of the New Horizons spacecraft, which is haring towards it at 56,000 kilometers (35,000 miles) per hour after flying past Pluto in 2015. New Horizons will fly past MU69 on January 1, 2019, the most distant object we’ve ever explored.


Things are a bit complicated though, as very little is known about MU69. We think it’s about 40 kilometers (25 miles) across, and we have a rough estimate of its orbit. But to make the flyby a success, we need to learn more.

In particular, we need to know if there are any hazards near MU69, such as rings, dust, or even small moons. Any of these could affect planning for the flyby, which is less than two years away. Scientists had seven years to prepare for the Pluto flyby, but this one will be a lot more last minute.

"We need to find out if there are rings or other dust that would be hazardous," Alan Stern, New Horizons Principal Investigator, told IFLScience. "[If not] it would mean we're flying in blind."

So that’s what makes this upcoming event so important. On June 3, and then July 10 and 17, MU69 will block the light from three different stars. Known as an occultation, these events will allow scientists on Earth to study its shape and brightness.


Each occultation will be incredibly brief, lasting just a couple of seconds. So to maximize the amount of data they will get, the New Horizons team are deploying small telescopes across the globe.

More than 50 telescopes will be positioned through Argentina and South Africa, the regions where the shadow of MU69 will pass, to maximize the data return. In addition, NASA’s SOFIA telescope – which flies in a converted Boeing 747SP – will also have its eye trained on the event.

NASA's SOFIA telescope will be used to peer at MU69. NASA

 If there is a lot of debris there, the trajectory of the flyby will need to be altered to keep New Horizons at a space distance, and prevent it being damaged or destroyed.

We also don’t know how reflective MU69 is. New Horizons will be snapping images, so mission scientists need to know what exposure times the cameras and instruments need. Get it wrong, and we could miss out on a ton of science.


“Spacecraft flybys are unforgiving,” Stern said in a statement. “There are no second chances.”


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