Astronomy
Your Age on Other Planets
How old would you be on Mars, Jupiter or Pluto? Calculated from each planet's orbital period.
Open toolAstronomy tools to calculate your age and weight on other planets, follow the phases of the Moon and simulate solar and lunar eclipses.
Interactive astronomy
Astronomy Tools to Study the Solar System, the Moon and Eclipses
Astronomy tools to calculate your age and weight on other planets, follow the phases of the Moon and simulate solar and lunar eclipses.
Astronomy
Your Weight on Other Planets
How much you would weigh on each planet, the Moon and the Sun. Teaches the difference between mass and weight.
Open toolAstronomy
Moon Phases and Lunar Calendar
The Moon today, upcoming main phases and a month-by-month lunar calendar with Moon visualization.
Open toolAstronomy
Eclipse Simulator
Simulate solar and lunar eclipses. See the Sun–Earth–Moon geometry in real time.
Open tool4 of 4 tools
Articles and study paths
Use these routes as study guides. They connect theory, examples and related tools.
Age on other planets
Understand why a year changes with each planet’s orbital period.
Weight on other planets
Compare mass and weight using the gravity of planets, the Moon and the Sun.
Moon phases today
See the current phase, the upcoming main phases and the lunar calendar.
How eclipses happen
Visualize the Sun–Earth–Moon alignments in solar and lunar eclipses.
Solved exercises
Exercise 1
Why does a person have fewer birthdays on Jupiter?
Because Jupiter takes about 11.86 Earth years to go around the Sun once.
Practice with the toolExercise 2
If your mass is 60 kg, does it change on Mars?
No. Your mass stays 60 kg; your weight changes because it depends on local gravity.
Practice with the toolExercise 3
Are the phases of the Moon caused by Earth’s shadow?
No. Lunar phases depend on the illuminated portion of the Moon as seen from Earth. Earth’s shadow only appears in a lunar eclipse.
Practice with the toolCommon mistakes in Astronomy
- Confusing mass with weight when comparing planets.
- Thinking age changes because of gravity; it changes because of the planet’s orbital period.
- Explaining the phases of the Moon as Earth’s shadow, which only happens in a lunar eclipse.
- Believing there should be an eclipse every month, ignoring the tilt of the Moon’s orbit.
Recommended pairings
To study better, follow these pairs of tools: