Dark powder, sand-sized particles found as lid opened on Osiris-REx space probe which collected samples from asteroid.

NASA said on Tuesday that researchers discovered “dust and debris on the avionics deck of the Osiris-REx science canister when the initial lid was removed today”.

The space agency did not specify whether the materials discovered on opening the lid of the probe definitely belonged to the asteroid, though NASA said on social media that “scientists gasped as the lid was lifted from the [Osiris-REx] asteroid sample return canister”.

“A scientific treasure box,” NASA Astromaterials said in a social media post.

“Dark powder and sand-sized particles” were found on “the inside of the lid and base”, NASA said.

“A scientific treasure box.”

Scientists gasped as the lid was lifted from the #OSIRISREx asteroid sample return canister, showing dark powder and sand-sized particles on the inside of the lid and base.

Read more from the @NASA_Johnson curation lab: https://t.co/JBw6TCI7kB pic.twitter.com/t43QEDLH7G

— NASA Astromaterials (@Astromaterials) September 26, 2023

The residue on the avionics deck found on Tuesday was likely a result of issues during the collection phase of the space mission, which NASA said were eventually solved, allowing for the secure transfer of the sample from the asteroid to the probe’s storage canister.

The probe’s lid was opened in an airtight chamber at the Johnson Space Center in Houston, Texas.

“The aluminium lid was removed inside a glovebox designed to enable working with the large piece of hardware,” NASA said in a statement, accompanied by images shared on social media showing scientists in full protective wear working with the probe sitting inside a reinforced glass and steel box.

NASA scientists are now waiting eagerly to begin analysing the bulk of the sample scooped from the asteroid, which will require “intricate disassembly” of the probe, the space agency said.

A news conference is scheduled for October 11 during which information about the bulk of the sample will be revealed to the public.

The robotic spacecraft OSIRIS-REx was launched in 2016 and collected its specimen three years ago from Bennu, a small, carbon-rich asteroid discovered in 1999, which is classified as a “near-Earth object” because it passes relatively close to our planet every six years.

The retrieval marked only the third asteroid sample, and by far the biggest, ever returned to Earth for analysis, following two similar missions by Japan’s space agency ending in 2010 and 2020.

Landing on the asteroid, Osiris-Rex collected roughly 250 grams (9 ounces) of dust from its rocky surface. Analysis of the material taken from the asteroid, scientists believe, will help researchers better understand the formation of the solar system and how Earth became habitable.

NASA said the sample will also “help us better understand the types of asteroids that could threaten Earth”.

Though the odds of Bennu hitting the Earth are considered remote, such a possibility has not been ruled out.

Roughly one-quarter of the Bennu sample will be immediately used in experiments and a small amount will be sent to mission partners in Japan and Canada, while the remainder will be conserved for study by future generations.

The space probe ended its 6.21-billion-kilometre journey (3.86-billion-mile) after parachuting down in the desert in the western state of Utah on Sunday, following a fiery descent through Earth’s atmosphere.