Calculate Your Age on Another Planet | The Schools' Observatory

Every year, the Earth completes one orbit of the Sun and every year, you have a birthday! And during a year, the Earth rotates 365 times on its axis and we experience 365 sun rises and sun sets. But how old would you be in days or years on another planet?

Do the maths to find out! Then check it with our online calculator.

By the end of this activity you will:

Have calculated how many Earth days old you are
Used data and maths to work out how old you would be on another planet
Have compared your ages on different planets in our Solar System
Have calculated how many days old you would be on another planet

To complete this activity you will need:

To watch the video on this page
To complete the worksheet below
The Planet Data Sheet (below)
Some paper and a pen
A calculator (optional)

Files or Documents

Calculating your Age Worksheet

Approx Duration

15 - 30 mins

Use the video above and the Planet Data Sheet below to complete the worksheet.

You can then check your answers using the age calculator.

Planet Data Sheet

Facts and Figures	Mercury	Venus	Earth	Mars	Jupiter	Saturn	Uranus	Neptune
Orbital Distance (AU)^a	0.38	0.72	1.0	1.52	5.2	9.54	19.2	30.06
Radius (KM)	2,440	6,052	6,378	3,397	71,492	60,268	25,559	24,746
Year Length (Earth Days)	88	225	365.25	687	4,333	10,759	30,687	60,190
Day Length^b (Earth Days)	176	117	1.0	1.03	0.41	0.43	0.75	0.67

^a 1 AU (or Astronomical Unit) = 149,600,000 km and is the mean distance from the Earth to the Sun.

^b Day lengths are sidereal days (time taken to rotate once) except for Mercury and Venus which are given as solar days (time from one sunrise to the next).

If you liked this, why not try

Checking your answers using our calculator

Calculating your weight on another planet

The Electric Orrery

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