The impact will be strong enough to alter the comet's orbit, and there has been some public concern over whether humanity's impact of a comet might alter its orbit enough to cause it to threaten Earth. No such retribution is possible, A'Hearn said. Pristine target The point of the impact, of course, is to learn about comets. But comets never sit still. At least not until they crash into a planet or something.
Some comets travel a fifth of the way to the next nearest star.
And then there's the fact comets hoard a vault of pristine information about the formation of the very planets they like to smash into. The recent breakup of a comet provided researchers with an unprecedented view of its nucleus, and scientists were thrilled at what they learned . Along with ground-based observations, a camera and an infrared spectrometer on the Deep Impact mother ship will watch the action. A'Hearn said that after the mother ship has transmitted all the data back to Earth, which will take about two days, the craft is slated to be abandoned to wander through the solar system. Comet Tempel 1, the target, was discovered in 1867.