The instrument bay
Space maths,
done for you.
Small, exact calculators for study and work. Type a number, get the answer, and see the method behind it.
Tool 01
Weight on other worlds
Moon 11.6 kg
Mercury 26.5 kg
Venus 63.4 kg
Mars 26.5 kg
Jupiter 177.0 kg
Saturn 74.5 kg
Method. Your Earth weight multiplied by each world's surface gravity relative to Earth (for gas giants, at the cloud tops).
On the launch pad
Planned
Telescope calculator
Magnification, field of view and limiting magnitude.
Planned
Orbital period
Kepler's third law, worked step by step.
Planned
Escape velocity
How fast you must go to leave any world.
Frequently asked questions
- Your weight on any world equals your mass multiplied by that world's surface gravity. We use gravity ratios from NASA's Planetary Fact Sheets. For example, Mars has a surface gravity of 3.72 m/s² — about 38% of Earth's 9.807 m/s² — so a 70 kg person weighs roughly 266 N there.
- One AU is the mean distance from the Earth to the Sun: exactly 149,597,870.7 km, as defined by IAU 2012 Resolution B2. It is the standard unit for distances within our Solar System.
- Light travels at 299,792.458 km/s in a vacuum (NIST CODATA value). From the Sun to Earth takes about 8 minutes 20 seconds. From the Sun to Neptune — roughly 30 AU — light takes about 4 hours 10 minutes. Use the Light Travel Time tool to calculate any distance.
- Mars orbits the Sun in 1.8808 Earth years, so a Martian year is about 687 Earth days. To find your Mars age, divide your age in Earth years by 1.8808. The Age on Planets tool does this for all eight planets automatically, using orbital periods from NASA's Planetary Fact Sheets.