How Planetary Years Work
We measure time based on Earth's movement. A "day" is one rotation of Earth on its axis, and a "year" is one revolution of Earth around the Sun (approx. 365.25 days).
However, every planet in our solar system moves at a different speed and distance from the Sun. Kepler's laws of planetary motion describe how planets closer to the Sun orbit faster, while those further away orbit much slower.
Inner Planets (Fast Years)
- Mercury: The fastest planet, zipping around the Sun in just 88 days. You age roughly 4 times faster here!
- Venus: Takes about 225 days to orbit. Interestingly, its day is longer than its year!
Outer Planets (Slow Years)
- Mars: The Red Planet takes nearly 2 Earth years (687 days) to complete an orbit.
- Jupiter: The gas giant takes almost 12 Earth years. If you're 24 on Earth, you're only 2 on Jupiter.
- Saturn: Takes about 29.5 years. Many people relate this to the "Saturn Return" in astrology.
- Uranus: A lifetime on Earth (84 years) is just one year here.
- Neptune: Takes a whopping 165 years. It hasn't even completed one orbit since its discovery in 1846 until 2011!
Related Space Tools
- Birthday Moon Phase - See the moon on your birthday
- Zodiac Sign Calculator - Find your astrological sign
- Age in Seconds - See how many seconds you've been alive