How do scientists calculate the mass of a distant planet?
Measuring a planet's weight is impossible with a scale, so astronomers rely on gravity and light. This video explores the ingenious methods used to determine the mass of worlds, from Earth-bound experiments to observing distant, starless planets.
Calculating a planet's mass requires observing how its gravity affects its surroundings. Scientists have employed diverse techniques, such as hanging a plumbob near a Scottish mountain to observe gravitational effects. Beyond our solar system, researchers can identify the mass of starless worlds by watching them act as planet-sized lenses when viewed from two different vantage points simultaneously.
Source: How to Weigh a Planet
