NASA's Osiris-Rex capsule is set to re-enter Earth's atmosphere on Sunday at speeds exceeding 15 times that of a rifle bullet. This fiery descent will be followed by a gentle touchdown in Utah's West Desert, carrying with it a precious cargo – a handful of dust collected from the asteroid Bennu.

This space rock, comparable in size to a mountain, holds the potential to unlock profound answers about our origins.

Professor Dante Lauretta, the principal investigator of the mission, explains, "When we get the 250g (9oz) of asteroid Bennu back on Earth, we'll be looking at material that existed before our planet, maybe even some grains that existed before our Solar System."

The mission aims to uncover the mysteries of Earth's formation, the origins of water in our oceans, the composition of our atmosphere, and the source of organic molecules fundamental to all life on Earth.

The prevailing theory suggests that critical components were delivered to Earth through ancient asteroid impacts, possibly similar to Bennu. Engineers have completed the final trajectory adjustments, leaving the "go, no-go" decision for releasing the capsule this weekend.

The mission to collect Bennu fragments began in 2016, with two years spent reaching the asteroid and another two years mapping its surface. The key to selecting the sample site came from British rock legend and astrophysicist Dr. Sir Brian May, known for his expertise in stereo imaging. He and collaborator Claudia Manzoni helped identify the safest locations for the spacecraft to approach.

On October 20, 2020, the remarkable moment of sample capture occurred.

Osiris-Rex gently touched the asteroid's surface while releasing nitrogen gas to stir up dust. However, the surface unexpectedly behaved like a fluid, creating a crater and collecting material for the mission.

Now, Osiris-Rex is on the verge of delivering the Bennu sample after a seven-year, seven-billion-kilometer round trip. Once safely on the ground, the capsule will be transported to the Johnson Space Center in Texas, where a dedicated cleanroom has been prepared for analysis.

Dr. Ashley King from London's Natural History Museum is among the first scientists eager to examine the material. "Bringing back samples from an asteroid - we don't do that very often. So you want to do those first measurements, and you want to do them really well," he expresses.

Although Bennu is considered one of the Solar System's most potentially hazardous asteroids, the chances of an impact with Earth are very low, not expected until late next century. Bennu is believed to contain a significant amount of water, and scientists will investigate whether its hydrogen atom ratios match those in Earth's oceans.

This could provide insights into the origins of our planet's water.

Additionally, Bennu holds about 5-10% carbon by weight, sparking interest in the potential role of organic molecules delivered by asteroids in kickstarting life on Earth. Professor Sara Russell from the NHM notes, "This sample return gives us a chance to really find out what the pristine organic components of Bennu are."

The investigation includes a search for amino acids used in proteins, potentially advancing our understanding of the origins of life's building blocks.

In summary, the Osiris-Rex mission's imminent return with a sample from asteroid Bennu promises to unveil crucial insights into Earth's formation, the source of its water, and the origins of organic molecules vital for life on our planet.