So these asteroids are *always* between the earth and the sun? Otherwise, if the sun is say at 12 o'clock and the earth is at 6, wouldn't the asteroids at some

So these asteroids are *always* between the earth and the sun? Otherwise, if the sun is say at 12 o'clock and the earth is at 6, wouldn't the asteroids at some point be at say 3 and 9? If we can see Mercury and Venus what makes the sun's glare a factor for these asteroids?