About this site

Who is responsible for it

MeteorShowerCal is an independent, self-funded project. Editorial and technical responsibility for everything published here sits with the site's operator, who can be reached at contact@meteorshowercal.com. The operator is not yet named on this page; until they are, treat the site's authority as resting on its published methodology and its cited sources rather than on a byline.

That is a deliberate order of priority. In this subject a name proves very little and a stated formula proves a lot: every number on this site is reproducible from public data using the method on the methodology page, and the sources are cited so you can check them rather than trust us.

What it actually does

Four things determine whether you see meteors, and every site publishes some subset of them. This one combines all four for your coordinates:

1. Radiant altitude, computed from the shower's tabulated radiant position and your latitude and longitude, hour by hour.
2. Moonlight, as a penalty to the limiting magnitude driven by the Moon's altitude and illuminated fraction, not just its phase.
3. Cloud cover, hour by hour, from a licensed forecast source — or an explicit "unknown" when no forecast is available.
4. Sky brightness, which is not connected yet and is therefore reported as missing rather than guessed.

Those four are combined with the International Meteor Organization's rate formula into an expected count and one of four verdicts. The full derivation is on the methodology page.

Where the data comes from

Shower elements — radiant position, drift, geocentric velocity and the solar longitude of maximum — come from the IAU Meteor Data Center's established shower list. Rates, population indices and activity periods were seeded once from the Stellarium project's meteor shower dataset. City coordinates and time zones come from GeoNames. Cloud forecasts come from MET Norway and, in the United States, from NOAA's National Weather Service. Astronomical positions are computed with astronomy-engine.

All 12 showers on the site are the streams that are strong and regular enough to plan around. Full citations and licences are on the methodology page.

How it is paid for

The site currently carries no advertising, no affiliate links and no sponsorship, and it sells nothing. If that changes, the change will be disclosed on the page carrying it and in the privacy notice before it earns anything — not afterwards.

Running costs are edge hosting and a mailing service. There is no venture funding and no paywall planned.

What this site will not do

• Invent data. Missing cloud forecasts read "unavailable". Missing sky-brightness data reads "coming soon". Neither is quietly replaced with a plausible number.
• Predict outbursts. Meteor storms need dust-trail modelling that is outside this engine's scope, and pretending otherwise would make the numbers untrustworthy in exactly the years they matter most.
• Sell you a trip. This is a calculator and a calendar. It does not arrange, book, sell or take payment for travel, accommodation or tours, and it does not collect enquiries for anyone who does.
• Track you. Analytics are cookie-free and aggregate. The only personal data the site stores is what you type into the alert form.

Corrections

If a number here is wrong, that is worth knowing about and the fix is usually quick. Email contact@meteorshowercal.com with the page and what you expected instead. Corrections to computed values are made in the code, so they propagate to every page at once rather than being patched on the page you noticed them on.

The same address handles data-protection requests, licensing questions about the API, and anything else.