While checking the 2MASS asteroid processing, Roc and I discovered that we have observed 10 Hygiea, the lowest-numbered asteroid we have seen as far as we know. It was seen in scan 066 of 971205n; the calibrated photometry is:

          (J,H,Ks) = 9.117 0.019   8.805 0.023   8.710 0.029 

Roc put together a jpg image in all three bands which you can see by clicking here. 10 Hygiea is near the top of the image marked with green cross-hairs. The 2MASS source was within about 0.1" of the predicted position of Hygiea.

For the five RTB nights, there were 265 asteroids predicted to be within the areas covered by scans. Of those, 148 had 2MASS sources positionally associated with the predicted asteroid position. A number of those will be spurious associations, of course, but 95 of the associated 2MASS sources have 3 band detections. A GIF plot of the color-color diagram may be seen by clicking here.