hourlyRateAtfunction

How many meteors an ideal watcher at a place would count in an hour under a perfect dark sky, whether or not it is dark there: the sporadic background, a little more on the side that faces the Earth's way and a little less on the other, plus each active shower's rate times the sine of its radiant's height (none where the radiant is below the horizon). The lean towards the morning side (from 0.4 to 1.6 times SPORADIC_HOURLY_RATE) is a simple stand-in for the real daily swing.

import { hourlyRateAt } from "@johnmorrisdotca/chikyu-earth/meteors";

function hourlyRateAt(sky: MeteorSky, place: GeoPoint | readonly [number, number, number]): number

import { hourlyRateAt, meteorSky, pointBeneath } from "@johnmorrisdotca/chikyu-earth/meteors";

const moment = Date.UTC(2026, 11, 14, 8);
const sky = meteorSky(moment);
// Under the Geminids' radiant the rate is the shower's whole rate and the background on top.
console.log(hourlyRateAt(sky, pointBeneath(sky.showers[0]!.shower.radiant, moment)) > 150);

false