2004 AS1

near-Earth asteroid, first discovered on January 13, 2004, by the LINEAR project.

Although rather ordinary, it caused some controversy in astronomical circles due to initial projections posted on the web by the Minor Planet Center suggesting an imminent collision with Earth on or about January 15 with a likelihood of 1:4. These projections came from very early observations, and turned out to be quite inaccurate (which is an ordinary occurrence in astronomy, as new observations refine the projected path of an object). In fact, the poster at the MPC had not realised that the data he had posted was essentially an impact prediction.

The general media did not get hold of the story at the time.

The asteroid passed in a distance of 12 million km (or 32 times the distance from the Earth to the Moon), posing no threat. It turned out to have a diameter of about 500m. It is an Apollo asteroid, with perihelion at 0.88AU, a rather low eccentricity of 0.17, an inclination of 17° and a orbital period of 1.11 years.