dibbern2 - 4:22 am on Aug 19, 2011 (gmt 0)
In solar system terms, 35 million km is a very close call.
We travel 2.6 million km per day around the Sun, so if the comet orbit intersects the Earth's orbit and the comet had arrived at that point 13.8 days before or after the actual arrival date, it would have been on a course to slam into Earth.
Stuff like this keeps me coming here every day. Amazing minds hang out here.