OSIRIS-REx Exciting Mission to the Asteroid Bennu
Asteroid Bennu from NASA’s OSIRIS-REx

OSIRIS-REx Exciting Mission to the Asteroid Bennu

The movie Don’t Look Up was interesting if not weird. However you feel about the movie, its premise of a comet is coming to destroy Earth is low, but not impossible. That’s one of the main reasons NASA launched the OSIRIS-REx Mission to explore the asteroid Bennu. It’s not a comet, however, the asteroid is close enough to cause damage.

“OSIRIS-REx” is an acronym that stands for Origins, Spectral Interpretation, Resource Identification, Security, and Regolith Explorer.

The OSIRIS-REx mission sent a space probe to Bennu back in December 2018 to “touch down” on the near-Earth asteroid Bennu some 200 million miles away to collect a sample and return to Earth in 2023. Yes, 200 million miles is NEAR Earth.

The $1.16 billion OSIRIS-REx mission will be the first American spacecraft to return samples from an asteroid if the mission is successful.

Bennu is one of the millions of asteroids in our Solar System. However, the asteroid is unique in that it is a NEO or a “near-earth object.” NEO’s are asteroids that orbit the Sun at a distance of 1.3 astronomical units. An astronomical unit is equivalent to about 93 million miles and is the equivalent of the Earth’s distance from the Sun.

One fun fact about this asteroid is that its name, Bennu was derived from an Egyptian mythological bird associated with the Sun, creation, and rebirth. Michael Puzio, a third-grade student from North Carolina proposed the name because the extended arm of the OSIRIS-REx spacecraft resembled the Egyptian mythological bird.

OSIRIS-REx Mission

One of the primary reasons the OSIRIS-REx team chose Bennu as a destination for the OSIRIS-REx mission is that it has a 1/2700 chance of impacting Earth between 2175 and 2199. It’s unusual orbit consistently brings it within 100,000 to 460,000 miles from Earth every six years. This distance is alarmingly close, as the Moon is 238,900 miles away from Earth. Bennu will pass by us in 2060, 2135, and 2175.

This means that Bennu has the potential to crash into Earth so we need to learn as much as we can about NEO’s such as Bennu.

NASA’s New Frontiers program launched the OSIRIS-REx space probe in early September 2016. The probe reached Bennu in early December 2018 making the asteroid the smallest body that a NASA spacecraft has ever orbited. The probe’s close orbit around the Bennu is also the closest orbit for any spacecraft around an object.

During its orbit, the spacecraft extensively mapped the asteroid in great detail until early April 2021 when it successfully touched down briefly upon the surface of Bennu to collect a sample of the asteroid. But this wasn’t a “touch down” in the traditional sense of a plane landing.

The “landing” was what the team calls a “touch-and-go” event and lasted a little bit over 5 seconds with the spacecraft launching back into orbit after collecting samples of debris it kicked up during those 5 seconds.

It will take the OSIRIS-REx mission teams about another week to determine how much of a sample was collected by the spacecraft from the landing site, named Nightingale. As far as we know, the collection is was successful during the “Touch-and-Go” event.

You may have noticed that the two landing sites are named after birds. Well keeping with the same bird theme, the NASA team has named all of the potential landing sites after birds. In all, there are four, Nightingale, Kingfisher, Osprey, and Sandpiper.

OSIRIS-REx Mission Sample Collection Sites
OSIRIS-REx images of the four candidate sample collection sites on asteroid Bennu: Nightingale, Kingfisher, Osprey and Sandpiper.


If enough sample material wasn’t collected in the initial TAG, OSIRIS-REx will attempt another TAG at another chosen site, “Osprey” next year, January 2021. Once the sample is secured, the probe will leave Bennu on Bennu in March 2021 for the two-year trip home to Earth and parachuting into Utah’s west desert on September 24, 2023.

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