Watch live: NASA’s OSIRIS-REx probe to reach Asteroid Bennu today

An
illustration of OSIRIS-REx in orbit around asteroid
Bennu.

NASA’s
Goddard Space Flight Center/Conceptual Image
Lab

• NASA launched a 1.7-ton probe called OSIRIS-REx toward Asteroid Bennu in
  September 2016.
• On Monday, the $1 billion mission will catch up to
  its
  asteroid
  target and begin
  an 18-month study of it.
• NASA will eventually use OSIRIS-REx to grab
  about 2.1 ounces of Bennu and launch that sample back to Earth.
• You can watch live video coverage of OSIRIS-REx’s
  arrival at Asteroid Bennu on NASA TV starting at 11:45 a.m.
  EST.

After a two-year chase through deep space, a truck-size NASA
space probe is about to arrive at its alien target: asteroid
Bennu.

NASA’s $1 billion OSIRIS-REx spacecraft — short for Origins,
Spectral Interpretation, Resource Identification-Regolith
Explorer —
launched on September 8, 2016. The probe’s mission is to
sample a small handful of dirt from the surface of Bennu, which
is an ancient space rock some 1,600 feet in diameter.

If all goes according to plan, the 1.7-ton robot will bring the
space agency’s first-ever pristine sample of asteroid back to
scientists on Earth.

NASA’s OSIRIS-REx
spacecraft took this image of the asteroid Bennu on November 16,
2018, from a distance of 85 miles (136
kilometers).

NASA/GSFC/University
of Arizona

Bennu is thought to be rich with carbon-based molecules, so the
tiny sample may help reveal how our solar system formed and gave
rise to life on Earth (and
perhaps other worlds, like Mars).

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Yet NASA has a lot of work left to do before trying to bring home
a bit of Bennu.

On Monday, OSIRIS-REx will perform a critical maneuver to pull up
closer to the asteroid and begin to scan every nook and cranny
for the best sampling site.

NASA TV, which you can watch via the YouTube embed at the bottom
of this post, began airing an overview of the OSIRIS-REx mission
at 11:15 a.m. EST this morning. Live coverage of the rendezvous
will begin at 11:45.

A dirty yet pristine space rock

Asteroids are like floating time capsules, since they’re made of
the same stuff that was present during the birth of the solar
system some 4.6 billion years ago. The space rocks spawned out of
a super-heated cloud of hydrogen, helium, and dust, and formed
before the first planets.

Aside from a handful of asteroids that occasionally burn up in a
planet’s atmosphere or strike its surface, the rocks have floated
around in the void of space ever since. 

Some asteroids are rich in water and carbon-based materials, and
many astronomers think that when Jupiter formed, its massive
gravity flung countless ones like this toward the sun. They
rained down on the inner planets and may have carried the
ingredients of life to early Earth.

Artist’s
impression of early Earth being bombarded with
asteroids.

NASA

If scientists can capture a
pristine piece of an asteroid in space — one that’s
untarnished by a blazing-hot reentry to Earth and unchanged by
our planet’s microbe-rich air, soil, and water — they’d get a
chance to analyze it and see how strong this hypothesis is.

According to NASA, Bennu (the asteroid formerly known as “1999
RQ36”) is one such dirty asteroid in near-Earth orbit, or
within
about 121 million miles of our planet. (In fact, Bennu is
considered potentially hazardous since there is a 1-in-2,700 chance it might hit
Earth over the next 200 years. If that happened, it’d release the
energy of roughly 1,300 one-megaton thermonuclear weapons.)

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After it arrives on Monday, the OSIRIS-REx probe will first

map the asteroid in 3D to locate the best sampling sites.

How to taste an asteroid

On July 4, 2020, the probe will scoot up close to Bennu, extend
a
long robotic arm until it touches the surface, and then shoot
out a blast of sterile nitrogen gas.

In the chaos of flying grit, NASA
hopes to filter out at least one 2.1-ounce (60-gram) sample
of carbon-laced asteroid rock — about a small bag of chips’ worth
of weight. The dirt would then be stored in a vacuum bag-like
sample container.

If NASA gets lucky, the spacecraft is designed to gobble up to 2
kilograms (4.4 lbs) of dust and grit over three attempts.

The maneuver is akin to playing tag in space, NASA explains in
a video
about the mission, since OSIRIS-REx will bounce off the
asteroid’s surface right after gathering up each sample.

An
artist’s concept of NASA’s OSIRIS-REx spacecraft sampling
asteroid Bennu.

NASA’s
Goddard Space Flight Center

After it bags some asteroid grit, the probe will begin a long
journey back to Earth starting in 2021 and land on September 24,
2023.

Scientists will then spend at least two years testing the samples
in hopes of learning what, exactly, the early solar system
“tastes” like.

 You can watch NASA’s live coverage of today’s rendezvous
from about 11:45 a.m. through 12:15 p.m. EST.