HOUSTON – In recent months, NASA has explored the smallest object ever orbiting and exploring the farthest body that ever existed – and found that both worlds are stranger than anyone could ever have imagined.
The 800 foot wide asteroid Bennu, which is currently being investigated by the spacecraft OSIRIS-REx, creates strange dust particles. Lead investigator Dante Lauretta, a planetary scientist at the University of Arizona, called the discovery "one of the biggest surprises in my scientific career."
Meanwhile, during the New Year's flight of the New Horizons spacecraft, data was collected that passed a faraway place. An icy object called MU69 suggests that the body is strangely flat. Planet scientist William McKinnon, a mission co-investigator, compared the two-piece body to a "meatball attached to a pancake."
The strange results of both missions were presented outside of Houston this week at the annual Lunar and Planetary Science Conference, raising questions and providing clues to the functioning of the solar system.
Although the dust clouds streaming from Bennu pose no threat to the spacecraft, OSIRIS-REx has revealed months on the asteroid in its four other, less pleasant surprises. The researchers said Tuesday that Bennu's surface is far rougher than expected; Some of the boulders that make up this cosmic "rubble heap" can be up to 150 feet in diameter – larger than a baseball diamond.
The finding could pose problems for plans to pick up a sample of the asteroid's surface material and bring back to Earth, researchers said. Because they believed that Bennu would be dusty, OSIRIS-REx has no mechanism for breaking up large stones. Instead, the mission team plans to give Bennu an air kiss, lift a cloud of dusty material with a cloud of gas, and collect it into a capsule that will eventually be sent home.
will carefully look for a site that contains the right material for this sampling process next year. And when the time comes to actually grab the sample, the spacecraft operators will find it difficult to move with Bennu's rough terrain in 2020. However, NASA assured reporters on Tuesday that it was up to the challenge.
"The first three months of Bennu's OSIRIS-REx & # 39; thorough investigation have reminded us of what discovery is all about – surprises, quick thinking, and flexibility," said Lori Glaze, deputy director of NASA's Planetary Science Division ,
The New Horizons spacecraft is already raging away from MU69, a dweller from a dark and distant region known as the Kuiper belt, surrounding the solar system beyond Neptune. The probe is now so far from Earth that it takes more than six hours for spacecraft signals to reach scientists on the ground.
But as the data trickle down to earth in the months since New Horizons' historic flyby, scientists have slowly built a probe image of the farthest body ever explored.
Its peculiar shape suggests that it consisted of two smaller bodies that danced around each other in a common orbit and came closer and closer until they merged gently. McKinnon said the whole collision would be about as strong as a human running briskly against a wall,
In a solar system where many objects have been born from catastrophic disasters, this gentle formation process is intriguing. It supports a theory in which the building blocks of the planets are slowly merging from rotating pebble clouds, McKinnon said. This would also explain the orientation of the two loupes of MU69, which seem to be side by side rather than being arbitrarily pushed together.
It will be many more months before all the data collected during the brief encounter of New Horizons will be retrieved at MU69 and years to understand what it all means. The scientists are still not sure what made the two lobes of the body so flat. it looks like a huge alien was sitting on it.
"It's a pretty spectacular object," said senior mission investigator Alan Stern. "It surprised us."