Earlier this week, NASA announced that Mars rover Curiosity had taken its third scoop of Martian soil. Based on a previously announced plan, the third scoop was to be the first sample analyzed by Curiosity’s on-board equipment.

Today NASA announced that a sample of Martian soil has successfully been placed into the rover’s Chemistry and Minerology (CheMin) instrument and is being analyzed. The instrument is now determining the mineral composition of the sample.

“We are crossing a significant threshold for this mission by using CheMin on its first sample,” said John Grotzinger, Curiosity project scientist. “This instrument gives us a more definitive mineral-identifying method than ever before used on Mars: X-ray diffraction. Confidently identifying minerals is important because minerals record the environmental conditions under which they form.”

NASA stated that the sample placed in the CheMin instrument was a sieved portion of the total sample and consisted of about as much material as a baby aspirin.

Curiosity has been stationed for over two weeks on a patch of dusty Martian soil NASA dubbed “Rocknest.” During that time, the rover vibrated two scoops of soil to scrub the internal surfaces of its sample processing chambers of any residual Earth particles. This cleaning method will be repeated before a future sample is placed in the rover’s Sample Analysis at Mars instrument, which will determine its chemical composition.

The soil sampling was delayed last week when a bright piece of material was spotted in a photo of the rover’s first scoop. The material was later determined by researchers to be a small bit of plastic that was possibly jarred loose from the Mars lander during its landing sequence. On subsequent scoops different small, bright particles were spotted and determined to be native Martian material.

“We plan to learn more both about the spacecraft material and about the smaller, bright particles,” said Richard Cook, Curiosity project manager at NASA’s Jet Propulsion Laboratory. “We will finish determining whether the spacecraft material warrants concern during future operations. The native Mars particles become fodder for the mission’s scientific studies.”