The idea of a “New Year” on Mars came about as scientists needed a way to keep track of Mars’s seasonal cycles and weather patterns, especially as more missions began exploring the planet. In 1955, scientists at the Jet Propulsion Laboratory (JPL) chose a specific date to mark “Mars Year 1,” which became a reference point for Mars’s seasonal changes. They set the Martian calendar by designating a particular moment in Mars’s orbit as the start of a new year, choosing the spring equinox in the northern hemisphere, when sunlight is evenly distributed across the planet.
NASA and ESA recognized that Martian exploration needed a timeline that reflected the natural rhythms of Mars. Just as Earth has seasons based on its orbit around the Sun, Mars also has its seasonal cycles. The Mars New Year began as a way to track the planet’s cycles, highlighting scientific events and discoveries along the journey. Because Mars takes about 687 Earth days to orbit the Sun, a year on Mars is nearly twice as long as ours. Today, Mars begins its 38th year since the official calendar was started in 1955.
This specific starting point allowed scientists to coordinate observations better, measure seasonal changes, and track atmospheric conditions across different missions and studies. Having a calendar like this on Mars makes it easier for researchers to compare data over multiple Martian years, noting how conditions change and building a complete understanding of Martian weather, climate, and potential for future human settlement.
There was some debate among scientists over what date to designate as the start of the Martian year, primarily because Mars has different orbital dynamics compared to Earth. Unlike Earth’s relatively consistent and near-circular orbit, Mars has a more eccentric orbit, which means its distance from the Sun varies significantly. This variation affects the length and characteristics of each season, making it harder to choose a single “natural” start date.
Some researchers proposed using the northern spring equinox (as JPL eventually did), while others considered starting the year at different points in Mars’s orbit, like the northern autumn equinox or a point closer to perihelion (when Mars is closest to the Sun). The spring equinox won out because it provided a natural midpoint for seasonal observations and aligned with the start of Mars’s growing season in its northern hemisphere, where many early Mars missions focused their attention.
The final choice standardized Mars’s calendar for all researchers, so everyone studying Mars – from weather to atmosphere to surface exploration – could operate on the same timeline, eliminating confusion across missions and studies. This decision has since been widely accepted and used for Mars missions by both NASA and ESA.
What is an Equinox?
The Mars New Year aligns with an equinox, a time when the Sun shines equally on both Martian hemispheres, marking the start of spring in Mars’s northern hemisphere. Like Earth’s equinoxes, when day and night are of equal length, the Martian equinox helps scientists observe seasonal changes. Tracking these changes is critical for understanding Mars’s climate, surface conditions, and how the planet’s atmosphere interacts with solar radiation – all essential knowledge for future missions and possibly even human habitation.
Connecting Mars and Earth Through New Year Celebrations
On Earth, New Year celebrations mark transitions, reflect cultural traditions, and emphasize renewal. The Mars New Year brings a similar sense of renewal to space exploration. Each Martian New Year inspires new research goals, mission milestones, and the human drive to explore the unknown. ESA and NASA use the Mars New Year as a reminder of our shared journey to expand human knowledge, seeing Mars not just as a distant planet but as part of our larger story.
The first observed birthday on Mars – Curiosity’s Birthday
NASA’s Curiosity rover celebrated its Martian birthday on August 5 (PDT), the day it landed on Mars. In honour of this special occasion, Goddard Space Flight Center engineers used the Sample Analysis at Mars (SAM) instrument to “sing” Happy Birthday to Curiosity.
Why the Mars New Year Matters for Science and Humanity
Mars exploration connects to our own history, echoing the way ancient people used the skies to mark seasons, navigate the world, and connect with the cosmos. The Mars New Year is more than just a scientific milestone; it’s a cultural bridge between our planet and Mars. With every new year on Mars, we expand our knowledge of planetary science, test our technological limits, and explore what it means to be human in the vast cosmos.
By sharing the Mars New Year with students, we can show them how scientific curiosity fuels progress and remind them that they are part of an unfolding story that stretches beyond Earth.
More resources
To learn more about Mars’s unique calendar and our journey to explore it, visit NASA’s Mars New Year resources here and ESA’s resources here.
https://www.scientificamerican.com/article/happy-martian-new-year
https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Happy_New_Year_on_Mars
