I just ran into my first Alien contact. The ship is so weak it could not destroy a civilian civilian transport, on the other hand, it opened fire on a unarmed civilian transport.
It shoots 13 nuclear missiles at a time, has 10 to 15 launches of those said rockets. All of them are launched as one group.
Thermal contact is 1440 and observed top speed is 1537.
It is not armed with anything but missiles.
*EDIT*
Never mind, the civilian ship is dead. It just took it a LONG time and many many volleys to do it.