Been thinking - maybe the best way to answer this question is to say what I would say as a GM:
GM - "As you prepare to break orbit, your sensors and comm systems suddenly go wild - energy readings, communications traffic, IFF transponders, etc. Make me a sensor check"
Player A - "I got a 12"
GM - "Good. Ok, as you hunker down over the sensors and try and make sense of the mess, a picture begins to emerge. As you came over the horizon of the world, a large group of ships came into view. Your visual sensors show them as little more than specks of light right now - you'll need to fiddle with the tracking and magnification, but your comm sensors are somewhat telling. There is a ton of encrypted and scrambled communications traffic on a lot of bands, as well as some broadband jamming signals being broadcast. As an ex-Imperial Navy guy, you're thinking the chaos of that traffic indicates some sort of combat."
Player A - "Ok, I'll tell the captain what I'm seeing as try and get my visual sensors calibrated and tracking."
Player B (captain) - "Oh really? How close is our outbound trajectory going to take us to this clusterfudge? Put it on the main screen"
Player C - "I'll make a navigation check to see how close our current course is to them - I got a 10."
GM - "Your navigator informs you that you're apparently headed right into the chaos, captain. Back at the sensors, you've managed to get the optics to begin tacking and magnifiying some of the ships. Still too far away to get clear visuals on everything, you've identified a couple of Sword World's ships, and a couple of Imperial's. Overall, there appears to be a couple dozen ships involved, spread over a pretty big volume of space near the 100d limit. At least one of the Imps is an AZH class cruiser. You've also spotted a lot of fast moving objects too small and quick to positively identify - which really only means one thing - missiles. As you put the visuals up on screen, the computer begins interpreting some other data, and it begins to give you a better idea of what's going on out there. As the computer starts resolving the image of a Sloan class escort on screen, a bright spot appears amidship of it, and suddenly gas begins to vent from there. The pressure of the gas, and angle it's venting at looks like it's going to induce some roll on the ship."
Player B - "Oh crap, we're flying straight into a conflict between the Sword worlder's and the Imperials? Navigator, change our trajectory as best you can to take us to a jump point as far away from that mess as possible. "
Player C - "Aye Aye Captain."
GM - "Well, chances are good that the entire combat would be over, and or have moved well away from your original jump point before you got there, but caution being the better part of valor, your navigator replots your course to include another half orbit of the planet below to head off in the opposite direction. Fortunately, you didn't have too much speed to let the planet do some of the work for you.
As you flee the system, your sensors watch the conflict with interest. Like most space combats, it's pretty long, drawn out, boring and difficult to tell exactly what's going on, but from the sensor data you've picked up, the Sword Worlder's aren't fairing well. At least two of their ships have stopped transmitting and manuevering entirely, and are headed off on fixed trajetories into the outer system. Whether they are dead, dying , or just trying to use stealth to get away you can't tell, but given the fact that you've identified them with your civilian sensors means it's likely the Imperial's have tracked them too. And since they're leaving them alone, you'll guess dead or dying.
One of the other Sword World ships is broke in half and venting gas from the remaining two sections - from the way it split and the power spike on the sensors at the time, you'd guess it was an internal meson hit on the power plant from the spinal mount on the AZH. You've witnessed several missile and laser hits on the other Sword World ships as well.
But the Imperial's haven't gotten off all that easy, either. At one point you witnessed a barrage of fusion or plasma bolts from several of the Sword World ships batter the port side of the AZH - the surface isn't reflecting as much sunlight as it was before, and there is a haze of venting gas along it. Other Imperial ships are similarly damaged."
That's just kind of a basic idea, off the top of my head. If this was something I knew was coming down the pipeline for the players, I'd actually sit down before hand and "play" out the conflict, writing down the sequence of events and everything of interest so that I had a more dramatic script to work from.
In most cases, the players are probably going to be far enough away to simply be witnesses to the events, rather than participants. Even if they happen to run close enough to the combat to have an effect on it, in most cases I'd still keep to the script, and vary only where it affects the players or they affect the combat.