Experiment
Measure the Distance to the Moon
Use repeated observations and simple geometry to estimate the Earth–Moon distance with a Seestar S50.
ExploreAstronomy Lab
Don't just observe the Universe.
Measure it.
Turn real astronomical observations into experiments. Measure the Moon, investigate planetary motion, identify distant moons and understand the physics behind what you see through a telescope.
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Astronomy you can actually do
Explore hands-on astronomy experiments, interactive tools and practical investigations using real observations and astronomical data.
Using a Seestar S50?
Many of these experiments use real Seestar observations.
Explore the Seestar S50 and what you can do with it
The Moon
Measure our nearest neighbour
Use images, geometry and repeated observations to investigate the Moon's size, distance, phases and eclipses.
Experiment
Measure the Diameter of the Moon
Use angular size and distance to understand how astronomers can estimate the physical diameter of the Moon.
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Interactive
Understand the Phases of the Moon
Explore the current lunar phase and understand the geometry that creates the Moon's changing appearance.
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Observation
The 28 August 2026 Lunar Eclipse
Explore what happened during the deep partial lunar eclipse and how it connects to the solar eclipse earlier that month.
ExploreThe Sun
Use our nearest star as a laboratory
Track sunspots, observe eclipses and connect solar activity with phenomena such as the aurora to understand how the Sun changes over time.
Experiment
Measure the Sun's Rotation
Track sunspots across repeated observations and use their motion to estimate the rotation of the Sun.
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Observation
12 August 2026 Solar Eclipse
Follow a real partial solar eclipse observed and photographed using a Seestar S50.
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Learn
How the Aurora Borealis Forms
Connect activity on the Sun with one of the most spectacular phenomena visible from Earth.
ExplorePlanets & Moons
Use orbital motion to reveal hidden physics
Identify planetary satellites and use their positions and motion to investigate mass, distance and orbital mechanics.
Experiment
Calculate Saturn's Mass
Use observations of Saturn's moons and Kepler's Third Law to estimate the mass of the planet.
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Interactive
Where Are Saturn's Moons Tonight?
Calculate the positions of Saturn's major moons for a chosen date and time.
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Tool
Identify Planetary Moons
Compare a Seestar S50 image with calculated satellite positions to identify planetary moons.
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Experiment
Can a Seestar S50 Photograph Uranus's Moons?
Explore whether a Seestar S50 can capture moons such as Titania and Oberon and how to identify them.
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Learn
Why Venus & Mercury Have Phases
Understand why the inner planets change appearance and what their phases reveal about the structure of the Solar System.
ExploreInteractive Tools
Put the numbers to work
Use interactive calculators and astronomical data to plan observations, test ideas and investigate the sky yourself.
Interactive tool
Telescope Field of View Calculator
Calculate the field of view of a telescope or camera and explore how astronomical targets fit within it.
Open tool
Interactive tool
Angular Size Calculator
Explore how an object's physical size and distance determine how large it appears in the sky.
Open tool
Interactive tool
Solar System Ephemeris
Explore astronomical positions and other useful information for Solar System objects.
Open tool
Interactive tool
Planetary Moons Identification Tool
Compare observations with calculated satellite positions to help identify planetary moons in Seestar S50 images.
Open toolLearn Astronomy
Understand what you're observing
Explore the ideas behind the observations: orbital mechanics, brightness, constellations, asteroids, nebulae and the evolution of stars.
Learn
Celestial Mechanics & Kepler's Laws
Understand the physical laws that describe the motion of planets, moons and other objects in orbit.
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Learn
Apparent & Absolute Magnitude
Learn how astronomers describe brightness and compare objects that lie at very different distances.
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Learn
What Are Constellations?
Discover why stars that appear together in our sky may actually be separated by enormous distances in space.
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Learn
Charles Messier & the Messier Catalogue
Explore the famous catalogue of galaxies, nebulae and star clusters used by observers around the world.
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Learn
The Crab Nebula & the Supernova of 1054
Connect a historical stellar explosion with the remarkable supernova remnant we can observe today.
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Learn
Explore Asteroid Vesta
Discover one of the largest objects in the asteroid belt and what it tells us about the early Solar System.
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