San Francisco-based museum of science, technology and arts, The Exploratorium has a website that calculates the age of users on any planet in the solar system as per their date of birth on Earth.
The age calculator also tells users when they can celebrate their next birthday on a different planet. The age is calculated based on the planet’s rotation and revolution around the sun.
Thus for a person, who is born on July, 1989 and aged 30 years on Earth, the calculator computes their age to be 126.6 years on Mercury, 49.5 years on Venus, 16.2 years on Mars, 0.122 years on Pluto and so on, so forth.
The calculator also reveals when a person on Earth can celebrate their birthday on the other planets as well. Thus for someone who was born on July 1, 1989, on Earth, they will celebrate their next birthday sometime on January 4, 2020, on Mercury, Jan 31, 2023, on Jupiter and Feb 6, 2236, on Pluto among others.
The difference in age on different planets was calculated on Earth’s rotation and revolution.
The website defines, “The top-like rotation of the earth on its axis is how we define the day. The time it takes the earth to rotate from noon until the next noon we define as one day. We further divide this period of time into 24 hours, each of which is divided into 60 minutes, each of which is broken into 60 seconds.”
There are no rules that govern the rotation rates of planets and it depends on how much “spin” there was in the “original material” that went into forming each one. The website reveals that subsequently, Jupiter turns once on its axis every 10 hours, while Venus takes 243 days to spin once.
The calculator relies on the works of noted astronomer Johannes Kepler, best known for his laws on planetary motion.
Kepler briefly worked with Danish observational astronomer Tycho Brahe. After Brahe’s death, Kepler obtained his observations and used them to discover that planets do not move in circles, but rather in ellipses which have two diameters, both short and long.
Kepler found that when the planets were nearer the sun in their orbits, they move faster than when they were farther from the sun. Kepler established that farther a planet was from the sun, longer it took for it to make one complete revolution, leading to the formation of the three Kepler’s Laws of Orbital Motion.
Of these Kepler’s third law states precisely that the period of time a planet takes to go around the sun squared is proportional to the average distance from the sun cubed forms the basis of the birthday calculator.