As the northern hemisphere of Mars bid farewell to its four-season year on November 12, 2024, a new spring began to bloom on the Red Planet. Unlike the gentle transition of seasons on Earth, spring on Mars is a spectacle of explosive phenomena, as described by Selina Diniega, a researcher at NASA’s Jet Propulsion Laboratory (JPL) who studies the planet’s surface.
With a tilted axis of rotation similar to Earth, Mars experiences four distinct seasons, each lasting longer due to the planet’s 687 Earth-day year. The Martian atmosphere, thin and dilute, undergoes dramatic changes in the spring season as frozen water and carbon dioxide on the planet’s surface transition directly from solid to gas with rising temperatures. This unique phenomenon creates a dynamic and active springtime on Mars, capturing the attention of scientists like Diniega.
To document these captivating seasonal changes, NASA’s Mars Reconnaissance Orbiter, launched in August 2005, diligently surveys the Martian landscape from above, providing a bird’s-eye view of the planet’s dramatic springtime transformations.
Martian Spring Spectacles: Explosive Avalanches and Geysers
One of the most striking images captured by the Mars Reconnaissance Orbiter showcases a 20-meter-long chunk of frozen carbon dioxide plummeting off a cliff, highlighting the prevalence of avalanches during the Martian spring. The warming temperatures trigger ice fractures, setting off a chain reaction of breaking and falling ice formations, creating a visually stunning display of nature in motion.
Diniega emphasizes the critical role of the Mars Reconnaissance Orbiter in capturing such dramatic scenes, crediting the orbiter’s nearly two decades of observations for providing invaluable insights into the planet’s dynamic springtime activities. A specific photo taken in 2015 exemplifies the orbiter’s ability to document the awe-inspiring geologic events unfolding on Mars.
Another captivating phenomenon observed during Mars’ spring season is the eruption of explosive geysers, captured in striking blackish fan shapes in images taken from the orbiter’s perspective above. When sunlight penetrates the carbon dioxide ice, heating the ground below, the ice sublimates into gas, building pressure until a sudden eruption propels a mix of carbon dioxide, sand, and dust into the Martian atmosphere.
The best opportunity to witness these dark, fan-shaped geysers in their full glory is anticipated around December 2025, coinciding with the arrival of spring in Mars’ southern hemisphere, where larger and more visible geysers are prevalent.
Spidery Landforms and Wind-Carved Canyons
As the Martian landscape transitions from winter to spring, the melting of frozen carbon dioxide reveals intricate marks known as “araneidoform terrain,” resembling spider-like formations when viewed from space. These intriguing landforms, some spanning over a kilometer and featuring hundreds of legs, often cluster together in swarms, adding a distinct visual allure to Mars’ surface.
The mysterious processes behind the creation of these spider-like formations continue to intrigue scientists at JPL, who are diligently working to replicate Mars-like conditions to unlock the secrets of these enigmatic structures. Additionally, the Martian northern polar ice cap, equivalent in size to Texas, offers a vast canvas for studying seasonal transformations on Mars.
Spring’s arrival on Mars also heralds the emergence of strong winds, shaping the iconic spiral pattern of Mars’ north polar cap over centuries. The Coriolis effect, a result of the planet’s rotation, influences the wind flow, sculpting deep canyons like Chasma Boreale, a spectacular feature comparable in length to the Grand Canyon and reaching depths of up to 2 kilometers.
Lastly, the resilient sand dunes on Mars, adorned with frost during the winter months, showcase the dynamic interplay between wind and ice as temperatures rise in spring. The frost surrounding the elevated dunes gives way to movement as the ice melts, setting the stage for a mesmerizing dance of sand particles driven by Martian winds.
Reflecting on the vibrant and tumultuous spring season on Mars, Diniega paints a vivid picture of a planet in flux, with a cacophony of cracking and exploding phenomena punctuating the arrival of a new season. The dynamic interplay of ice, wind, and geological forces on Mars serves as a poignant reminder of the ever-changing nature of our neighboring planet, inviting further exploration and discovery.
This captivating narrative of Mars’ explosive springtime transformations originally appeared on WIRED Japan, offering a glimpse into the mesmerizing world of Martian geology and seasonal dynamics.
