PULLMAN, Wash. — A group of researchers, including Washington State University’s Scott Hudson, have published an article in the journal Science that predicts that an asteroid may be heading for a collision with earth. Fortunately, there are 878 years to prepare, and the actual probability of a collision is only one-third of one percent.

The scientists are predicting that Asteroid 1950 DA, about 1-kilometer in size, could hit earth in a 20-minute interval in March 2880. Previous to this work, scientists have been unable to accurately predict asteroid collisions with planets more than a few decades ahead and within a 10-day interval.

Although Asteroid 1950 DA was initially discovered in 1950, researchers lost track of it, re-discovering it on New Year’s Eve 2000. Its potentially nefarious nature and its close approach to Earth were discovered in the course of a recent radar experiment. Upon understanding the possibility for such an event, the researchers worked to gain a more accurate prediction of the asteroid’s orbit, examining factors normally ignored in looking at the potential hazard from incoming asteroids, including things like computational noise and orbital perturbations from gravity when asteroids encounter other objects in the solar system.

The scientists, including researchers from Jet Propulsion Laboratory and the California Institute of Technology and the University of California at Santa Cruz, were then able to consider the trajectory of the asteroid over a much longer time frame than usual and estimate the probability of a collision.

Hudson, professor of electrical engineering and computer science, has worked to better understand the exact shape and orientation of asteroids and to develop computer models that more accurately predict their orbits. He worked for 15 years to develop the computationally intensive computer software to look at scattering of radiowaves, from which he can then determine the shape and orientation of asteroids. Such work has been made possible by advances in computing power in the past decade, and it has made it easier for scientists to know exactly how distant asteroids look.

Before anyone panics, Hudson is quick to mention that no human being has ever been killed by an asteroid collision, and there are numerous other natural and manmade hazards of more concern. Nevertheless, the possibility of a collision remains an intriguing question for scientists because of its potentially catastrophic effects. The work also is of interest because asteroids can provide valuable clues to the origin and evolution of our solar system.