After determining that the coast was clear,
Osiris-Rex closed in the final few yards
(meters) for the sampling. The spacecraft was
programmed to shoot out pressurized nitrogen
gas to stir up the surface, then suck up any loose
pebbles or dust, before backing away.
By the time flight controllers heard back from
Osiris-Rex, the action already happened 18 1/2
minutes earlier, the time it takes radio signals to
travel each way between Bennu and Earth. They
expected to start receiving photos overnight
and planned to provide an update Wednesday.
“We’re going to be looking at a whole series of
images as we descended down to the surface,
made contact, fired that gas bottle, and I really
want to know how that surface responded,”
Lauretta said. “We haven’t done this before, so
this is new territory for us.”
Scientists want at least 2 ounces (60 grams)
and, ideally, closer to 4 pounds (2 kilograms)
of Bennu’s black, crumbly, carbon-rich material
— thought to contain the building blocks of
our solar system. Pictures taken during the
operation will give team members a general
idea of the amount of loot; they will put the
spacecraft through a series of spins Saturday for
a more accurate measure.
NASA’s science mission chief, Thomas
Zurbuchen, likened Bennu to the Rosetta Stone:
“something that’s out there and tells the history
of our entire Earth, of the solar system, during
the last billions of years.”
Another benefit: The solar-orbiting Bennu,
which swings by Earth every six years, has a
slight chance of smacking Earth late in the next
century. It won’t be a show-stopping life-ender.