Hey, did you realise it's only been a little over a year since we last had a serious discussion about this? https://www.trekbbs.com/threads/moving-slow-at-warp-speed.297708/#post-12755895 The perfect time to dive back in, I say! At which point I'm going to withdraw my assertion that the mass-reduction power of the nacelles was still in operation - your subsequent posts show that this is simply not necessary What we are talking about now is Newtonian physics which I usually avoid in Trek talk because let's be honest; starships do not operate according to those principles! The amount of fuel required for a thruster style engine to push a vessel to even 10% of lightspeed alone is MASSIVE - probably far more than the mass of the ship itself! Owing to that I think the presence of sub-spacey mass-reduction units (likely housed in the nacelles) is a foregone conclusion - at least under normal circumstances. In this episode, the Enterprise could easily have spent a certain portion of her impulse fuel in matching the asteroid - a tiny percentage of lightspeed true, but without the mass reduction field of the nacelles it would nonetheless be a major drain on the fuel supply. However, since we are dealing with Newtonian physics for a change, this would be the most economical solution available. I assume enough fuel was kept in reserve to slow the ship down again once it reached the planet. For an asteroid to become a meteor requires it to hit a planet though, which is why the speed can vary so much (depending on the angle of attack). https://www.amsmeteors.org/meteor-showers/meteor-faq/#3 In open space, the fastest asteroid on record is the recently discovered "2019 AQ3", zipping round the sun at a whopping 13,975 mph! https://www.space.com/43263-fastest-orbiting-asteroid-found-2019-aq3.html https://www.spacereference.org/asteroid/2019-aq3 This is a speed of approx 38.8KM/S or 0.00013% of lightspeed A typical asteroid moves at 25KM/S or 0.00008% of lightspeed The issue of speed is a crucial one and was discussed at some length in this old thread https://www.trekbbs.com/threads/killer-asteroid.292243/page-4 Spock states that they have been en route to the asteroid for "several" hours, at least part of which was done at Warp 9. Assuming that local gravitational anomalies limited the Enterprise's total average speed to that of a mere 300,000KM/S then we can calculate that 3 hours at lightspeed would take the Enterprise 3,240,000,000 KM (slightly further out than Uranus). If the asteroid then takes 59.223 days to travel that same distance, it is going at 633 KM/S which is only 0.002% of lightspeed but still 16 times faster than the fastest known asteroid in our real world. I really can't see how we make the objects any slower I don't mind this - it reinforces the fact that space is really, really BIG. A portable repair shop probably arrived 5 minutes after the credits rolled, anyway. Certainly there is none of the usual doom and gloom associated with the Enterprise being severely broken which was seen in other episodes.