Question 1

How accurate are the pass times?

Accepted Answer

For the ISS and Starlink trains, predictions are computed from orbital element sets that are refreshed continuously, and are typically accurate to within seconds on the day of the pass. Orbits decay and get adjusted, so always re-check the schedule on the day you plan to watch.

Question 2

Why do you need my location?

Accepted Answer

Visibility is hyper-local. A satellite pass that is spectacular from one neighborhood can be below the horizon thirty miles away. Your coordinates let us solve each event against your exact horizon and your local twilight window.

Question 3

What does magnitude mean?

Accepted Answer

Magnitude is the astronomer’s brightness scale, and it runs backwards: lower numbers are brighter. Venus reaches about -4.4, the brightest stars are around -1, and the faintest stars visible to the naked eye are about +6. Every event on TwilightLink carries its predicted magnitude.

Question 4

Do I need a telescope?

Accepted Answer

Almost never. ISS passes, Starlink trains, planets, and meteor showers are all naked-eye events. Comets are the exception — most require binoculars — and each event is labeled with the equipment it needs.

Question 5

Why can’t I see Starlink trains every night?

Accepted Answer

A train is only striking in the first days after launch, while the satellites still fly in tight formation at low altitude. They also have to be sunlit while your ground is dark — the twilight window. When both conditions line up for your location, we put it on your schedule.

Question 6

What is the twilight window?

Accepted Answer

The period after sunset and before sunrise when the ground is dark but satellites hundreds of kilometers up are still in sunlight. It is when almost every visible satellite pass happens — and it is where the name TwilightLink comes from.

Question 7

Does TwilightLink store my location?

Accepted Answer

Your coordinates stay in your browser and are used only to compute your predictions. There are no accounts, no tracking, and nothing to opt out of.

Question 8

Can I get reminders for an event?

Accepted Answer

Yes. Every event page has a Set Reminder button, plus an Add to Calendar export that works with Google Calendar, Apple Calendar, and Outlook.

Questions, answered plainly

01How accurate are the pass times?

02Why do you need my location?

03What does magnitude mean?

04Do I need a telescope?

05Why can’t I see Starlink trains every night?

06What is the twilight window?

07Does TwilightLink store my location?

08Can I get reminders for an event?