If the original poster is reading this, coudl you describe the
apparent speed better? Perhaps hold out your hand at arms length
and spread your fingers wide - about how long did the sat take
to pass that span? How spans across the sky was the sat visible?

Is it concerning the iridium flase I saw or the asteroid during the
night?

If it's the second one, it drew a line of about 80° and lasted no more
than 10 seconds.