Perseverance’s journey

The landing site is named after Octavia E. Butler, an African-American science-fiction writer whose novels include stories set on Mars. She grew up in Pasadena near JPL, where Mars rovers are controlled. Nearby craters and rocks receive Navajo names with help from JPL’s Navajo engineer Aaron Yazzie. Navajo lands resemble Martian landscapes.

Perseverance landed in Jezero crater beside a large delta beyond the mouth of the ancient Neretva Vallis river. “Jezero” means “lake” in South Slavic languages. Neretva, Sava and Pliva Vallis are named after rivers associated with Bosnia and Herzegovina. The mission seeks rocks formed or altered in water-rich environments suitable for microbial life. The rover drills rock or collects regolith, seals samples in airtight tubes and deposits them at future rendezvous sites for another spacecraft to return to Earth. Laboratory dating will reveal when lava flooded the area. Another experiment produces oxygen from atmospheric carbon dioxide in preparation for human expeditions. A miniature helicopter is also tested, potentially useful for investigating steep cliffs. Contrary to expectations, after landing Perseverance found volcanic lava covering the ancient lake floor rather than lake sediments; its source was not yet known.