According to new research, newly found deposits of stratified ice in craters spread over Mars’ southern hemisphere offer knowledge about how the planet’s orientation impacted the planet’s temperature during the past 4 million years.
The discoveries aid scientists in understanding what influenced Mars’ historical climate, which is critical for estimating when the planet may have been habitable. The report was written in Geophysical Research Letters, an AGU publication that publishes short-format, high-impact research with ramifications spanning the Earth and space sciences.
As on Earth, ice deposits on Mars reflect a mix of temperature, hydrology, and planetary dynamics. Temperature and sunlight on the planet’s surface are affected by the planet’s tilt and orbit, which contribute to climate. Thicker, more pure ice layers often represent colder eras with higher ice accumulation, whereas thin, dusty layers were likely warmer and less capable of accumulating ice.
The new analysis ties these ice layers to Mars’ axis tilt and orbital precession, or how the planet’s elliptical orbit revolves around the sun over time, with unparalleled precision and certainty.
The discoveries provide scientists with information on how Mars’ climate has altered throughout time. While the work is confined to the recent past, understanding these climate-orbit correlations helps scientists understand Martian climate more deeply in the past, which might assist pinpoint future habitability eras.
“It was surprising how well those patterns conformed to the orbital cycles,” said Michael Sori, a planetary scientist at Purdue University and main research author. “It was simply such a great fit, the best you could wish for.”
Previously, Martian climate experts concentrated on polar ice caps that stretched hundreds of kilometers. However, these deposits are ancient and may have lost ice over time, resulting in the loss of fine features required to securely establish links between the planet’s orientation and motion and its climate.
Sori and his colleagues focused on ice mounds in craters, which are just a few tens of kilometers broad but considerably younger and presumably less difficult. Sori added that after examining most of the southern hemisphere, they found Burroughs crater, which is 74 kilometers wide and contains “exceptionally well-preserved” strata seen in NASA HiRISE photos.
The thicknesses and forms of the strata were studied by the researchers, who discovered that they had surprisingly comparable patterns to two fundamental Martian orbital dynamics, the tilt of Mars’ axis and orbital precession, spanning the previous 4 to 5 million years.
The findings build on prior studies that used climatic records from Mars’ polar ice caps to make preliminary linkages to orbit. But some recordings were too “noisy” or convoluted to make a firm connection. Younger, cleaner crater ice retains less intricate climate data, which the researchers used to precisely connect climatic changes to orbital precession and tilt.
Understanding the links between orbital cycles and climate is critical for understanding Martian history as well as complicated climate dynamics on Earth. “Mars is a natural laboratory for researching orbital influences on temperature,” Sori remarked, pointing out that many of the complicated elements that present on Earth—biology, tectonics—are insignificant on Mars. For scientists, the entire world effectively isolates the variable.
“If we’re ever going to understand climate, we need to go to locations where these conflicting forces don’t exist,” said Isaac Smith, a planetary scientist at the Planetary Science Institute and York University who was not involved in the work. In that regard, “Mars is a beautiful planet. And there are a plethora of possible uses here. Mars shares a lot more similarities with Pluto and Triton than you may believe.”
Smaller ice formations may not always have clear, visible layers on the surface. Some may be hidden within the mounds. The ultimate aim, according to Sori, is to sample ice cores like scientists do on Earth, but Mars rovers don’t have that capacity yet.
Scientists can instead utilize ground-penetrating radar data to “look into” the ice and check for layers, ensuring that visible layers extend throughout the deposit. It’s an essential quality-control step in the current investigation, and the technology might aid future studies of Martian ice with no apparent layers on the surface.
“Being able to get a climatic signal from a little ice deposit is a pretty remarkable outcome,” Riley McGlasson, a Purdue University research co-author who used this strategy in the current study, stated. “With radar, we can get a better picture of what’s going on. That’s why I’m looking forward to taking this a step further in the future.”
Published By : Ankit Singh
Edited By : Khushi Thakur
