How do you know that the sun is going to rise at approximately 6:37 AM on a given morning? You know this because you take observations, and you take measures. How do you know how many miles you must walk on a familiar trip? You can count the steps, or measure the distance, and you can verify this against maps drawn by other. You observe, and take measures. We know that the 12th Planet will make its passage in late spring or early summer of the year 2003 [Note: see 2003 Date explanation] because we are observing the planet approaching your solar system. We were present when it came through last. This is as known to us as the setting of the sun and the rising of the sun is to you. We see this, laid out before us, and we watch each day as the comet approaches and calculate any variance from our last plot. Therefore this is not something uncertain that we have to morph up out of calculations and call the best estimate or our speculation. This is not speculation, this is observation, and we are telling you what we are observing.