40 seconds or 40 arc seconds? 40 arc seconds is "less than one degree." A lot less.

Are they talking about time or about angles?

More importantly, why am I drawn back to this pointless discussion?

Because inquiring minds want to know. :lol:

Iridium satellites can be seen in pairs but it is rare.

Most Iridium satellites have similar orbital parameters so they are usually well separated. The Iridium satellites are groups of satellites spaced around the same orbit. A few Iridium satellites have orbits at a slightly different altitude. There used to be spare satellites in orbit at a different altitude, so if one satellite died there was a ready replacement already in orbit. Now I think that's no longer the case, but there are a few Iridium satellites that have different orbital periods to the rest. In either case, what happens is the lower satellite orbits faster than the higher one. Every now and again two satellites will pass each other. If you are lucky enough to be in the right spot it is possible to see twin flares.

I witnessed a twin Iridium flare about 3 or 4 years ago, after it was predicted on heavens-above.com. Two very bright satellites visible simultaneously is really an amazing sight.