Washington, Mar 9 (IANS): NASA's Perseverance rover has grabbed one more sample from Mars, taking the total number of collection to seven.

Perseverance drilled the seventh sample from the floor of the Red Planet's Jezero Crater.

The car-sized robot will drill one more sample from the current site on the Red Planet and then head towards the ancient river delta, NASA has said.

"I've got my seventh core sample onboard," the Mars Perseverance team said in a tweet on Tuesday.

"I plan to get one more sample here before heading on toward the ancient river delta," it added.

Collecting samples for future return to Earth is one of Perseverance's two main tasks, along with hunting for signs of ancient Mars life.

According to the mission team members, the 45 km- wide Jezero harboured a lake and a river delta in the ancient past, so it's a great place to do such work, Space.com reported.

Perseverance spent its first (Earth) year on Mars exploring the crater floor to the south and west of its landing site, which was named after sci-fi author Octavia Butler.

The rover is now heading back toward the touchdown zone, on its way to an accessible segment of the ancient delta, the report said.

If all goes according to plan, Perseverance will end up collecting and caching several dozen Red Planet samples.

This material will be brought to Earth, perhaps as early as 2031, by a joint NASA-European Space Agency mission campaign.

"Bringing back a sample from this heavily cratered surface in Jezero could provide a tie-point to calibrate the Mars crater dating system independently, instead of relying solely on the lunar one," said Katie Stack Morgan, Perseverance's deputy project scientist at NASA's Jet Propulsion Laboratory in Southern California, which manages the rover mission, in a statement.