Silly question

[Tzitzis]

I was traveling yesterday night and I saw what I think was an iridium flare from a satellite. But then it strook me; how can I know if it's a satellite or a "shooting star"?

I know it may be a dumb question but I'm curious and relatively new to astronomy, so any feedback would be helpful (the answer may be too obvious but haven't thought anything yet)

Clear skies!

[DeepSkyBagger]

An Iridium flare stays in the same place and lasts for maybe a couple of seconds. A meteor (shooting star) moves very quickly, and again can last for a couple of seconds.

You can check whether what you saw was an Iridium flare by using this website: http://heavens-above.com/IridiumFlares.aspx

[Dave In Vermont]

Finding Iridium-flares in advance with a satellite-tracking program is an aspect of astronomy (and related) that many people enjoy - judging by the number of downloads for good software-programs that can give you dates & times for watching a flare. That aspect likely appeals to those of us who enjoy watching peoples' expressions by correctly pointing up at the sky - and telling them one is going to happen anytime now!  

If you'd like to be able to do this, or just know what that thing was you just saw going by through your eyepiece (more often than most people realize, it's quite crowded up there), my favorite software-program is Previsat, coming from France. And it's totally free-of-charge to download and run. Brought to us by SourceForge, the same group as Stellarium uses. Loads of other free software-programs, too. Here's Previsat:

https://sourceforge.net/projects/previsat/?source=directory

And your question wasn't a dumb one at all!

Have fun!

Dave

[Stu]

6 hours ago, Tzitzis said:

I was traveling yesterday night and I saw what I think was an iridium flare from a satellite. But then it strook me; how can I know if it's a satellite or a "shooting star"?

I know it may be a dumb question but I'm curious and relatively new to astronomy, so any feedback would be helpful (the answer may be too obvious but haven't thought anything yet)

Clear skies!

It's a speed thing really. Iridium flares are slow moving satellites which brighten to an intense white flare and then fade over a period of 10 seconds or so. You can often see them before and after the flare as a very dim point of light.

Shooting stars, or meteors, travel much faster and generally streak across the sky very fast (maybe in a second or two). They sometimes leave a trail and are not always  pure white depending upon the chemical makeup of the meteor.

[Tzitzis]

Thanks guys! I saw a meteorid then. Cool. Alas, I don't remember in which part of the sky it was 

[LukeSkywatcher]

Stu summed up the visual difference very nicely. Its all about the speed and the "fade in/fade out"...so to speak. Ive seen 3 satellite flares (Iridium or not) purely by chance. 2 of them were side by side within seconds of each other.