Casual observation: Last night, April 20, 2019, 0330UT-0400 UT, just as an exercise, I tried to image (6478) Gault in blazing moonlight. I think I got it but it is not conclusive by any means. I stacked on a star and not the asteroid itself just see if I could see movement against the starfield. I was happy to see Sextans B galaxy in the field of view. Again, this was not science, just an exercise in possible asteroid finding in full moonlight. This may or may not be the asteroid but maybe others were imaging at the same time who could confirm. C14, Canon 6D, BackyardEOS, 60 second exposures, ISO 12800, stacked in Nebulosity. Fun in any case. New Mexico. - Thomas
PS: The asteroid is only 2.3 miles in diameter. Amazing that it can be seen from Earth.