1911 Apofibs

I have a natural skepticism about pronouncements from science. I guess because I admire the scientific method. Which basically says, entertain theories only until new facts prove otherwise.
So I was a little worried recently when scientists announced the asteroid Apophis posed absolutely no threat in 2029, when it is scheduled to come within 23,000 miles of us. The moon, incidentally, orbits at about 239,000 miles. So 23,000 miles is kind of close in astronomical terms.
Far from the "absolutely no threat" section of my mind. A couple of dirt clods could change the orbit a mere 23,000 miles. Which could happen.
Because recently the scientific folks determined they had origianlly underestimated the size of Apophis. Turns out it's about 20% larger than they thought. About 1066 feet in diameter as opposed to 885 feet. Doesn't seem like much, I know, but that much extra diameter translates into far greater mass. Like a 75% increase over earlier estimates.
A bit more than a couple of dirt clods.
So all I'm saying, if they messed up once...
How could they screw up so badly? It has to do with albedo. Albedo is how much light a body reflects. And surprisingly, this really pasty white teacher I had in high school. Mr. Bedo, or Al as we called him, looked a lot bigger in a swimsuit then us tanned teens because he reflected so much light.
Apophis the asteroid is the opposite. It's far darker, so from a distance it looked smaller. Therefore, its mass was estimated as far less.
Mass, by the way, is not just what they use to calculate things like orbital arcs and whatnot. It's also a word they use in mass hysteria.
I'm checking the new Mayan calendar for any mentions of asteroids now.
America, ya gotta love it.