Moon Phase Finder
Estimate the moon phase and illumination percentage for any calendar date , amateur astronomy tool.
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Astronomy & Space Tools
Explore moon phases, escape velocities, planet weights, and telescope optics with browser-based space calculators.
Escape Velocity Calculator
Calculate escape velocity from planetary mass and radius , space physics and astronomy education tool.
Planet Weight Calculator
Compare your Earth weight against gravity on all planets and the moon , space education tool.
Telescope Magnification Comparator
Compare eyepiece magnification and field-of-view tradeoffs for any telescope setup , astronomy optics tool.
Telescope Field of View Calculator
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.
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