
Moon Phase Finder
Estimate the moon phase and illumination percentage for any calendar date — amateur astronomy tool.
This hub collects free browser-based astronomy and space science tools for enthusiasts, students, and amateur astronomers in 2026: moon phase finders, planetary calculators, telescope tools, and space physics utilities — no signup required.
Updated · Reviewed by The Free AI Tools Editorial Team — Astronomy and space science tools review
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Estimate the moon phase and illumination percentage for any calendar date — amateur astronomy tool.

Compare your Earth weight against gravity on all planets and the moon — space education tool.

Calculate escape velocity from planetary mass and radius — space physics and astronomy education tool.

Compare eyepiece magnification and field-of-view tradeoffs for any telescope setup — astronomy optics tool.

Estimate telescope magnification, true field of view, and exit pupil using aperture, focal length, and eyepiece data. It helps astronomy hobbyists compare setups before a night of observing.
Amateur astronomy has grown significantly as a hobby in 2026, driven by improved telescope accessibility and interest in space exploration generated by commercial spaceflight activity.
Moon phase tracking is one of the most practically useful astronomy tools for both serious observers and casual sky watchers. The moon's phase directly affects the quality of visual observing sessions.
Telescope selection and configuration involve several calculations that benefit from dedicated tools. Magnification is a product of telescope focal length divided by eyepiece focal length.
The planet weight calculator and escape velocity calculator serve an educational function: they make abstract physics concepts tangible by relating them to familiar personal experience.
All 20 free tools related to this topic, organised by category.
Quick answers about the workflow, privacy, and where this tool fits in a broader job.
The moon phase finder shows the current phase of the moon, the date of the next new moon and full moon, the moon's illumination percentage, and its age in the current lunar cycle.
Enter your weight on Earth, and the planet weight calculator shows how much you would weigh on each planet in the solar system, adjusted for their surface gravitational acceleration.
Escape velocity is the minimum speed an object needs to break free from a celestial body's gravitational pull without further propulsion. It depends on the body's mass and radius.
Enter your telescope's focal length and your eyepiece's focal length. The magnification comparator calculates the resulting magnification and compares performance across multiple eyepiece options simultaneously.
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221+ browser-based tools across 13 categories — all free, no sign-up.