Ending its seven-year long expedition, a NASA space capsule carrying samples from the surface of an asteroid made its return to Earth on Sunday.

"We have touchdown!" Flight Control announced after the OSIRIS-REx capsule parachuted into the Utah desert in the US. 

It marks the third and largest asteroid sample to have ever been brought to Earth.

The OSIRIS-REx capsule is estimated to hold at least a cup of rubble from an asteroid known as Bennu.

"It's like 'Wow!'" said NASA astronaut Sunita Williams, who was in Utah training for her own space capsule mission. "This is just amazing. It can go from the movies, but this is reality."

Why is the OSIRIS-REx mission important?

The mission was launched in September 2016 by NASA in collaboration with the University of Arizona to gather samples from Bennu, an asteroid rich in carbon and classified as a "near-Earth object."

The capsule landed on Bennu's surface in 2020 and collected about nine ounces (250 grams) of dust from its stony surface.

"This sample return is really historic," NASA scientist Amy Simon told the AFP news agency. "This is going to be the biggest sample we've brought back since the Apollo moon rocks" were returned to Earth.

The sample was taken to NASA laboratories in Texas for examination. 

Scientists believe that by examining the samples, we can gain a better understanding of how our solar system was formed and how Earth became habitable.

mfi/kb (Reuters, AFP)