no one tries to raise the alarm

Because the asteroid sheers the comms tower off the ship as they avoid it. It's gimmicky as a plot device but it's still sensible why they don't warn anyone.

Edit: further to that, when this happens it's only Carmen and the guy pilot on the bridge at the time because of shifts. Carmen even mentions how much she dislikes what is essentially a night shift on an expected milk run. So when they suddenly find themselves confronted by an out of place gravity well/shadow they don't have much time to do anything except not get crushed like a drinks can.

no one tries to raise the alarm

Because the asteroid sheers the comms tower off the ship as they avoid it. It's gimmicky as a plot device but it's still sensible why they don't warn anyone.