Astronomy & Space Science Directory

Calculate the energy and crater size of a hypothetical asteroid impact from mass and velocity.

Calculate maximum exposure time before star trailing from focal length and sensor using the 500 rule.

Calculate the useful range and field of view for binoculars by magnification and aperture.

Calculate blackbody peak wavelength with inputs, formulas, and instant results.

Estimate your sky darkness on the Bortle scale based on naked-eye limiting magnitude.

Calculate the total delta-v budget needed for a space mission between two bodies.

Estimate the number of communicable civilizations in our galaxy using the Drake equation.

Calculate the dates and visibility of upcoming solar and lunar eclipses for your location.

Calculate escape velocity with inputs, formulas, and instant results.

Calculate field of view with inputs, formulas, and instant results.

Plot a star on the H-R diagram using its luminosity and surface temperature.

Calculate delta-v requirements for a Hohmann transfer orbit between two circular orbits.

Calculate the Hubble time and estimated age of the universe from the Hubble constant.

Calculate the locations of the five Lagrange points for a two-body gravitational system.

Calculate how long light takes to travel between astronomical objects in the solar system and beyond.

Calculate limiting magnitude with inputs, formulas, and instant results.

Calculate the current moon phase and upcoming full and new moon dates.

Calculate orbital period with inputs, formulas, and instant results.

Calculate parallax distance with inputs, formulas, and instant results.

Calculate your weight on any planet in the solar system based on surface gravity.

Calculate redshift with inputs, formulas, and instant results.

Convert cosmological redshift to distance using Hubble law and standard cosmological parameters.

Calculate the Roche limit — the minimum distance before a satellite is torn apart by tidal forces.

Calculate delta-v from the Tsiolkovsky rocket equation using mass ratio and exhaust velocity.

Calculate the orbital speed of a satellite at any altitude above Earth.

Calculate when and where to look for ISS and satellite passes from your location.

Calculate the Schwarzschild radius (event horizon) of a black hole from its mass.

Calculate scaled distances and sizes for a solar system scale model at any chosen scale.

Estimate space mission costs from payload mass, orbit, and launch vehicle selection.

Calculate breathable air supply duration for EVA from tank pressure, volume, and consumption rate.

Calculate the distance to a star from its parallax angle in parsecs and light years.

Calculate brightness ratio between two stars from their apparent magnitude difference.

Calculate a star luminosity from its radius and surface temperature using Stefan-Boltzmann law.

Calculate sunrise, sunset, and daylight hours for any location and date on Earth.

Compare telescope value by calculating cost per inch of aperture across models.

Calculate the true field of view for your telescope and eyepiece combination.

Estimate the faintest star your telescope can detect based on aperture diameter.

Calculate telescope magnification with inputs, formulas, and instant results.