Early Evidence of Water on Mars
A 4.45 billion-year-old zircon crystal unearthed from a Martian meteorite is shedding new light on the early history of water on the Red Planet.This significant discovery suggests that water may have been present even at Mars’s formation, providing vital clues about the planet’s potential to support life.
In stark contrast, Earth remains a planet of ample water, with roughly 70 percent of its surface covered by oceans, lakes, and rivers, along with moisture in the atmosphere and geological formations.
Geological studies indicate that stable water has been a fixture of Earth for approximately 4.3 billion years, making it a cradle for life. Yet, the timeline and nature of water on early Mars remain a mystery.
Key questions about the origin, location, and longevity of water on Mars are at the forefront of scientific inquiry.
The presence of water is essential to the hypothesis that Mars may once have harbored life, fueling ongoing exploration and research efforts into the planet’s watery past.
Insights from Martian Meteorites
In a recent study published in the journal Science Advances, scientists focused on a mineral called zircon found within a Martian meteorite.Their work reveals that water existed when these crystals formed around 4.45 billion years ago, possibly delivering the oldest evidence of water on Mars to date. Historically, the significance of water in Mars’s evolution has not gone unnoticed.
Both Mars and Earth originated about 4.5 billion years ago, and Mars’s geological history is divided into four distinct periods: Amazonian, Hesperian, Noachian, and Pre-Noachian.
The first signs of water on the Martian surface emerged in the 1970s when NASA’s Mariner 9 spacecraft transmitted captivating images of river valleys, hinting at a once-watery landscape.
Subsequent missions unveiled hydrated clay minerals scattered across the Martian terrain, underscoring the necessity of water for their formation. The Noachian period, which makes up around 45 percent of Mars’s surface, showcases these river valleys in all their ancient glory.
Furthermore, striking outflow channels discovered in the Hesperian terrain point to the transient presence of surface water during active geological episodes.
Theories on Mars’s Crust and Hydrothermal Activity
Most of the evidence concerning water on Mars is linked to geological materials dating back more than 3 billion years, with scant indications of stable liquid water in more recent epochs.To explore the Pre-Noachian—Mars’s enigmatic dawn—researchers have turned their attention to Martian meteorites that have journeyed to Earth, as they represent the only accessible sources of Pre-Noachian material.
A particularly notable specimen, dubbed NWA7034 or Black Beauty, contains zircon crystals estimated to have formed between 4.48 and 4.43 billion years ago, categorizing them as the oldest known materials from Mars. Through analysis of trace elements in these ancient zircons, researchers discovered signs of hydrothermal activity.
This indicates that hot water played a role in shaping these minerals amid the primal conditions of Mars.
The 4.45 billion-year-old zircon exhibits distinctive patterns of iron, aluminum, and sodium—elements that were absorbed during the zircon’s formation from molten rock. The intriguing presence of these elements within the crystalline structure of the igneous zircon suggests that magmatic hydrothermal systems might have been active during the early stages of Mars’s crust development.
While questions linger about whether liquid water could have been stable on the Martian surface back then, this evidence supports a compelling theory: that—much like Earth—Mars’s crust likely contained water soon after its formation.
This lends credence to the tantalizing possibility that Mars may have once harbored the necessary conditions for life to flourish.
Study Details:
- Title: A 4.45 billion-year-old crystal from Mars reveals the planet had water from the beginning
- Authors: Aaron J. Cavosie
- Journal: Science Advances
- Publication Date: November 22, 2024
- DOI: 10.1126/sciadv.adq3694