On Earth, determining the exact time is almost trivial. The planet uses a sophisticated global system that combines atomic clocks, GPS satellites and ultra-fast communications networks to keep everything perfectly aligned.
However, that precision does not automatically transfer outside of Earth. Albert Einstein showed that time does not flow at the same pace everywhere in the universe. The clock’s ticking speed depends on gravity: in a stronger gravitational field, time flows more slowly, and in a weaker one, faster. Even coordinating weather on Earth is a complex task, and extending that system to the entire solar system is far more demanding. For future explorers planning to live and work on Mars, one basic question must first be answered: What time is it on Mars?
Physicists from the National Institute of Standards and Technology (NIST) have now provided a precise answer for the first time. Their calculations show that clocks on Mars, on average, tick 477 microseconds faster per day compared to clocks on Earth. This difference is not constant. Due to the elongated orbit of Mars and the gravitational influences of other bodies, the deviation can vary by up to 226 microseconds per day during a year on Mars.
Understanding the passage of time on Mars is critical for future missions. As NASA prepares for more advanced phases of exploration of the Red Planet, accurate timing will be critical for navigation, communication and coordination at interstellar distances.
How scientists accurately calculated the time on Mars for the first time
Mars already differs from Earth in basic weather cycles. A Martian day is about 40 minutes longer than an Earth day, while a year on Mars lasts 687 Earth days, compared to 365 on Earth. In addition to these obvious differences, scientists had to determine whether a second on Mars lasts the same as a second on Earth.
An atomic clock placed on Mars would work perfectly normally. The problem arises when that clock is compared to the one on Earth. Over time, there is a divergence, and the scientists’ task was to calculate exactly how much that shift is, similar to defining the time zone between two planets.
Scientific AmericanAccording to the theory of relativity, gravity affects the flow of time. Mars has about five times weaker surface gravity than Earth, but that wasn’t enough to explain the entire difference. The Sun, which contains more than 99 percent of the total mass of the Solar System, has a dominant gravitational influence. Additionally, the presence of the Earth, Moon, Jupiter, and Saturn makes Mars’ orbit more elongated and irregular compared to the relatively stable orbits of the Earth and Moon.
That is why time on the Moon always flows about 56 microseconds faster per day than on Earth, while the changes on Mars are much more pronounced. After the gravity of Mars, orbital motion and the influences of the Sun, Earth and Moon were included in the calculations, the researchers arrived at the final result.
The difference of 477 millionths of a second seems negligible – it is about a thousandth of the time it takes to blink an eye. However, in modern technology, such differences have enormous significance. For example, 5G communication systems require time precision within a tenth of a microsecond.
Today, signals between Earth and Mars take anywhere from four to 24 minutes to arrive, and sometimes longer. Scientists compare this situation to communication before the telegraph, when letters traveled across oceans for weeks or months.
The development of a reliable system for synchronizing time between planets could one day enable synchronized communications networks throughout the solar system. Although such systems, as well as permanent human settlements on Mars, are still a long way off, research into these issues now helps scientists anticipate the challenges ahead.
In addition to practical application, these researches also contribute to basic science. Measuring the passage of time on other worlds provides new tests of Einstein’s theories of special and general relativity, deepening understanding of the very foundations of how time works in the universe, writes Science Daily.