Today I saw something that passed like a jet. But am sure it's not so because jet will leave a long track of its passage. It moved in a straight line with sparkling track and what I saw was observed even from 200kms away from my destination. What could it be?
It is most likely a jet contrail. Not all contrails are persistent, and a high altitude jet can be seen over a great distance.
A fireball may leave a trail, but if it does, then it is likely to persist for as long or longer than a jet contrail. A fireball appears to move much faster than a jet, crossing the sky in a few seconds. It also appears to be very bright.
The image and description both point to this being a jet.