Mars once had an Arctic-sized ocean, study finds
Scientists just found signs that a massive ocean once covered much of Mars's northern half—think the size of Earth's Arctic Ocean.
This ancient sea existed about three billion years ago, back when Mars was at its wettest and possibly more welcoming to life.
Deltas reveal a long-lost Martian coastline
By analyzing sharp satellite images from European and US orbiters, researchers spotted three fan-shaped sediment deposits—basically ancient river deltas—at similar elevations.
These features look a lot like where rivers meet oceans on Earth, hinting at a real Martian shoreline stretching across Valles Marineris.
Could Mars have supported life?
Lead researcher Ignatius Argadestya shared that water on Mars "may once have formed connected systems across vast distances," not just small lakes.
That means early Mars probably stayed habitable for longer than we thought—raising big questions about whether it could have hosted life.