About how many asteroids are estimated to be in the asteroid belt separating Mars and Jupiter?

skysmom65

Some scientists were seriously concerned about the possible high density of objects in the asteroid belt, which lies between the orbits of Mars and Jupiter, when the first robotic spacecraft were scheduled to be sent through it. The first crossing of the asteroid belt took place in the early 1970s, when the Pioneer 10 and Pioneer 11 spacecraft journeyed to Jupiter and beyond. The danger lies not in the risk of hitting a large object. In fact, such a risk is minuscule because there is a tremendous amount of space between Mars and Jupiter and because the objects there are very small in relation. Even though there are perhaps a million asteroids larger than one kilometer in diameter, the chance of a spacecraft not getting through the asteroid belt is nearly negligible. MORE: http://www.sciam.com/askexpert_question.cfm?articleID=00032640-7CEA-1C72-9EB7809EC588F2D7&catID=3&topicID=2 Feb 20 07, 4:06 PM