Traces of ancient hot water on the Red Planet hint that Mars may have had a habitable past, according to new research by a Curtin University team.
Locating evidence of fluid on Mars is essential to studying the origin of water on rocky planets and any past habitability on the Red Planet. Now, the Curtin research team says they discovered such evidence, while investigating a tiny zircon grain from the Northwest Africa 7034 (NWA7 034) Martian meteorite, commonly known as “Black Beauty.”
Black Beauty
Between five and ten million years ago, an object smashed into the Martian surface with enough force to eject a fragment, eventually named ‘Black Beauty’ due to its distinctive black and grey coloring.
This relic from an ancient impact eventually crashed landed on Earth, and since its discovery by nomads in the Sahara Desert in 2011, scientists have been captivated by this extraterrestrial rock, the second oldest Martian meteorite known, as it potentially holds clues to the Martian past.
While weighing in at only 11 ounces, NWA 7034 contains more water than any Martian meteorite yet uncovered on Earth. Missions to Mars have collected data suggesting that Mars held surface water up to 3.8 billion years ago, potentially placing the rock’s formation on a wet Mars. Additionally, the sample is heavily magnetized, providing even more data.
The rock is so unusual that it does not fit into any of the three existing categories of Martian meteorites; instead, it begins the Martian (basaltic breccia) classification.
Ancient Hot Water and a Single Grain
Curtin University scientists used just one grain of zircon split from the NWA7034 sample in their research, a tiny grain that provided a wealth of new information. The team employed a range of advanced micro and nano-scale processes, including spectrometry and electron microscopy, to study the mineral.
The analysis uncovered ‘geochemical fingerprints’ of water-based fluids, a discovery that Dr. Aaron Cavosie of Curtin School of Earth and Planetary Sciences believes will enhance our understanding of Martian magmatism and ancient habitability.
“We used nano-scale geochemistry to detect elemental evidence of hot water on Mars 4.45 billion years ago,” Dr Cavosie said. “Hydrothermal systems were essential for the development of life on Earth, and our findings suggest Mars also had water, a key ingredient for habitable environments, during the earliest history of crust formation.”
“Through nano-scale imaging and spectroscopy, the team identified element patterns in this unique zircon, including iron, aluminium, yttrium and sodium. These elements were added as the zircon formed 4.45 billion years ago, suggesting water was present during early Martian magmatic activity,” Dr. Cavosie added.
A Hot and Violent Martian Past
Fundamentally, the new research demonstrates a violent Martian past. Enormous meteorites regularly pounded the surface of the red planet, causing upheaval in the Martian crust.
However, the Curtin team’s research also revealed the presence of ancient hot water between 4.5 and 4.1 billion years ago in the pre-Noachian period, a period in Martian history about which little is known. The pre-Noachian period extends from the formation of Mars around 4.5 billion years ago to the Noachian period around 4.1 billion years ago when many of the planet’s geological features were formed.
“A 2022 Curtin study of the same zircon grain found it had been ‘shocked’ by a meteorite impact, marking it as the first and only known shocked zircon from Mars,” Dr Cavosie said.
“This new study takes us a step further in understanding early Mars, by way of identifying tell-tale signs of water-rich fluids from when the grain formed, providing geochemical markers of water in the oldest known Martian crust,” he added.
The paper “Zircon Trace Element Evidence for Early Hydrothermal Activity on Mars” appeared on November 22, 2024 in the Science Advances.
Ryan Whalen covers science and technology for The Debrief. He holds a BA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.