We were driving south on 395 from Tahoe to Mammoth and my son saw a bright green ball in the sky to our left. Then we (four of us) all saw it for at least 3 seconds. It disappeared for a second and then reappeared (behind a cloud?) again for several seconds before disappearing behind the mountains. It was much larger than any asteroid any of us have seen and was moving much faster than any plane. It was larger than Mars, probably twice the size. The main color was green or greenish blue with pink or magenta around it. It was bright enough to leave an after image but did not seem to have a real trail.
