This was really faint. Very close, and very faint means very small. 10 meters, I estimated. Not time to panic yet. We put the asteroid's motion into the computer to track the asteroid instead of the stars, and took an exposure.
Some close asteroids leave trails half that long in twice the time.
I had never seen anything like this. We quickly took a whole pile of images to make an animation out of. This was just phenomenal. We kept coming back to this one, even though we had enough data because it was so spellbinding. Friday it was cloudy, but we got a few more images Saturday after that.