Mars One CEO Bas Lansdorp holds a press conference in New York to announce the launch of astronaut selection for a Mars space mission project, April 22, 2013. EMMANUEL DUNAND/AFP/Getty Images

One hundred people are still in the running to become humanity's first Mars explorers.

The Netherlands-based nonprofit Mars One, which aims to land four pioneers on the Red Planet in 2025 as the vanguard of a permanent colony, has whittled its pool of astronaut candidates down to 100, organization representatives announced Monday, Feb. 16.

More than 202,000 people applied to become Red Planet explorers after Mars One opened the selection process in April 2013. The latest cut came after Mars One medical director Norbert Kraft interviewed the 660 candidates who had survived several previous rounds of culling. [Images of Mars One's Red Planet Colony Project]

Play Video

The Mars One program says it will send a colonizing team to the Red Planet in 2024. Kera Rennert talks with two astronaut hopefuls about the one-...

"The large cut in candidates is an important step towards finding out who has the right stuff to go to Mars," Mars One co-founder and CEO Bas Lansdorp said in a statement. "These aspiring Martians provide the world with a glimpse into who the modern day explorers will be."

The remaining pool consists of 50 men and 50 women who range in age from 19 to 60, Mars One representatives said. Thirty-nine come from the Americas (including 33 from the United States), 31 from Europe, 16 from Asia, seven from Africa and seven from Australia.

The remaining candidates will next participate in group challenges, to demonstrate their ability and willingness to deal with the rigors of Mars life. After another round of cuts, the finalists will be divided into four-person teams, which will train in a simulated Red Planet outpost.

Eventually, Mars One intends to select 24 astronauts (six four-person teams), who will become full-time employees of the organization and prepare for the Mars colonization mission.

More here:

100 people still in the running for a one-way trip to Mars