After a seven-year wait, NASA scientists on Tuesday finally pried open a space probe carrying the largest asteroid samples ever brought back to Earth, finding black debris.

Researchers "found black dust and debris on the avionics deck of the OSIRIS-REx science canister when the initial lid was removed today," the US space agency said, though without specifying whether they definitely belonged to the asteroid.

Scientists are eagerly awaiting researching the bulk of the sample, which will require "intricate disassembly" of the probe.

OSIRIS-REx launched in 2016, landing on the asteroid Bennu and collected roughly nine ounces (250 grams) of dust from its rocky surface.

Even that small amount, NASA has said, should "help us better understand the types of asteroids that could threaten Earth."

It ended its 3.86-billion-mile (6.21-billion-kilometer) journey after touching down in the desert in the western state of Utah on Sunday, following a high-stakes, fiery descent through Earth's atmosphere.

There are unexplored regions of the universe—and there are also unexplored times. In fact, there's a nearly 400-million-year gap in our universe's history that we've never seen: a time before stars known as the Dark Ages. To investigate that era, researchers want to pick up a particular radio signal that can't be measured from Earth.

The first step to listening for it is a pathfinder project known as the Lunar Surface Electromagnetics Experiment-Night, or LuSEE-Night. The experiment is slated to head to the moon in 2025, where it will test technology in the harsh lunar environment.

The project is a collaboration between NASA and the Department of Energy, with partners from Lawrence Berkeley National Laboratory (Berkeley Lab), Brookhaven National Laboratory (lead DOE lab), UC Berkeley, and the University of Minnesota.