Ancient Zircon Reveals Hot Water Existed on Mars 4.45 Billion Years Ago

Mars had water as early as 4.45 billion years ago, shortly after its formation. Evidence arose from a tiny zircon grain found in a Martian meteorite. This grain contained minerals that required water for their formation, suggesting that hot water sources existed on Mars, similar to Earth’s hot springs or hydrothermal vents.

The finding indicates that early Mars and Earth shared some environmental similarities. Geologist Aaron Cavosie stated that both planets had liquid water, with Earth’s oldest zircons showing water existed by at least 4.3 billion years ago. Evidence also supports the idea of water on Mars during the Noachian period, which lasted from 4.1 to 3.7 billion years ago.

The water history of Mars is challenging to reconstruct due to the distance and limitations of exploration. However, Martian meteorites like NWA 7034, discovered in 2011, offer insights. This meteorite is composed of volcanic breccia, containing zircon crystals that provide valuable geological data.

Recent research on the zircon from NWA 7034 revealed signs of a significant asteroid impact around 4.45 billion years ago. Scientists, led by Jack Gillespie, analyzed the minerals trapped inside the zircon. They found traces of iron, yttrium, aluminum, and sodium. These elements indicated formation in hot, watery conditions.

The layers of minerals found in the zircon resemble those in Earth’s Olympic Dam, known for its hot aqueous systems. This suggests that hot fluids, rich in minerals, influenced zircon formation on Mars.

Although the exact temperature of the water on Mars is still unknown, it could range from a few hundred degrees to over 500 °C (932 °F). The discovery implies that water circulated in the Martian crust, heated by volcanic activity in the planet’s early history.

Warm and wet environments likely existed on Mars, similar to those on Earth. This points to potential ancient habitable conditions. The findings support the view that comets and asteroids brought water to Mars, just as they did for Earth.

The research aims to better understand the ancient Martian environment. Although more investigation is needed to discover the specifics of hydrothermal systems on Mars, the findings from the zircon offer significant clues.

The zircon’s journey is remarkable. It formed in a hydrothermal setting on Mars, survived impact events, and eventually landed on Earth. This meteorite continues to provide vital insights about Mars’ early conditions and water presence.

The research was published in Science Advances.