Trending Now - New Discovery on Mars Suggests Ancient Ocean Existence

WHO:

CNN - Michael Lamb, senior author of the study, professor of geology at the California Institute of Technology.

CNN - Abdallah Zaki, lead author, distinguished postdoctoral researcher at the University of Texas at Austin.

CNN - James W. Head, professor of Earth, environmental and planetary sciences at Brown University.

CNN - Brian Hynek, professor in the department of geological sciences at the University of Colorado Boulder.

CNN - Bryony Horgan, professor of Earth, atmospheric and planetary sciences at Purdue University in West Lafayette, Indiana.

WHAT:

Space.com - Scientists found a geological structure on Mars resembling a "bathtub ring," suggesting the existence of an ancient ocean.

CNN - The proposed ocean may have covered one-third of Mars before evaporating billions of years ago.

CNN - The coastal shelf identified is about 200 to 400 meters wide (650 to 1,300 feet).

CNN - The study was published in the journal Nature.

WHERE:

CNN - The geological features are located in the northern hemisphere of Mars.

WHEN:

CNN - The study describing the new evidence was published on April 13th, 2026.

CNN - The Zhurong rover landed on Mars in 2021.

CNN - The European Space Agency’s rover Rosalind Franklin is expected to launch in late 2028 and land on Mars in 2030.

WHY:

CNN - Confirming the existence of an ancient ocean on Mars could deepen understanding of the planet's history and its potential for hosting life.

HOW:

CNN - Researchers ran computer simulations to model the drying up of oceans on Earth and identify geological traces left behind.

CNN - The research team used data from NASA’s Mars Orbiter Laser Altimeter (MOLA) to search for analogs of Earth's continental shelf on Mars.

(UPDATED April 20, 2026 19:35 UTC)

Scientists have discovered a geological structure on Mars that resembles a "bathtub ring," indicating the possible existence of an ancient ocean that may have covered one-third of the planet before evaporating billions of years ago. The study, published on Monday, in the journal Nature, involved researchers from institutions including the California Institute of Technology and the University of Texas at Austin, who utilized data from NASA’s Mars Orbiter Laser Altimeter to identify features in the northern hemisphere of Mars. This finding could enhance our understanding of Mars' history and its potential for hosting life, as the coastal shelf identified measures about 200 to 400 meters wide.