Cosmic Studio
Reference data for the cosmos. Calculate your weight on other worlds and visualize the scale of the universe.
| Name | Symbol | Value | Description |
|---|---|---|---|
Astronomical Unit | au | 149,597,870,700 m | Average distance from Earth to Sun |
Light Year | ly | 9.4607 × 10¹⁵ m | Distance light travels in one year |
Parsec | pc | 3.0857 × 10¹⁶ m | 3.26 light years |
Solar Mass | M☉ | 1.9885 × 10³⁰ kg | Mass of the Sun |
Solar Radius | R☉ | 6.957 × 10⁸ m | Radius of the Sun |
Solar Luminosity | L☉ | 3.828 × 10²⁶ W | Energy output of the Sun |
Earth Mass | M⊕ | 5.972 × 10²⁴ kg | Mass of the Earth |
Earth Radius | R⊕ | 6,371 km | Mean radius of the Earth |
Moon Mass | M☾ | 7.342 × 10²² kg | Mass of the Moon |
Moon Distance | - | 384,400 km | Average distance to Moon |
Measuring the Immeasurable
In everyday life, a measuring tape is enough. In space, the numbers get so big they break our calculators. That's why astronomers invented their own system of units.
The Three Scales of Space
Planetary
Scale: Kilometers
For moons and planets.
Earth Radius: 6,371 km
Moon Distance: 384,400 km
Solar System
Scale: AU
Distances between planets.
1 AU: Earth to Sun (150M km)
Jupiter: ~5.2 AU away
Interstellar
Scale: Light Years
The void between stars.
Light Year: ~9.46 Trillion km
Nearest Star: 4.24 ly away
Gravity: The Glue of the Universe
Gravity isn't just what keeps your feet on the ground; it's the engine of the cosmos. It crushes hydrogen atoms together to ignite stars (M☉) and binds galaxies together.
Use our Weight on Worlds tab to see how different gravity feels. On Mars, you'd feel like a superhero, jumping 3x higher. On Jupiter, you'd be crushed by your own weight.
Frequently Asked Questions
Why do we use Astronomical Units (AU)?
Space is too big for kilometers! 1 AU is the average distance from Earth to Sun (~150 million km). It's the perfect 'inch ruler' for measuring distances within our Solar System.
How much would I weigh on the Sun?
If you could stand on the Sun without burning up, you would weigh about 28 times more than on Earth! A 70kg person would feel like they weigh nearly 2 tons (1953kg).
What is the difference between a Light Year and a Parsec?
A Light Year is the distance light travels in one year. A Parsec (3.26 light years) is a unit derived from trigonometry (parallax) used by astronomers to measure distances to nearby stars.
How do we weigh the Earth and Sun?
We don't use a scale! We use gravity. By observing how fast the Moon orbits Earth, or Earth orbits the Sun, we can use Newton's version of Kepler's Third Law to calculate the mass of the central body.
Is gravity the same everywhere on Earth?
Not exactly. Gravity is slightly stronger at the poles and weaker at the equator due to Earth's rotation and shape (it's slightly flattened). Use 9.81 m/s² as a reliable average.
What is a Solar Mass (M☉)?
It's the standard unit for weighing stars. Because stars are huge numbers in kilograms (2 x 10³⁰ kg), saying 'Observation A is 5 Solar Masses' is much easier than writing 30 zeros.