On December 6, 1997, James V. Scotti the University Of Arizona’s Spacewatch Project discovered the asteroid 1997 XF 11. When first discovered by Scotti, it was initially thought that the asteroid would pass as close to the earth as the moon’s orbit. After observing the arch of the asteroid’s path for 88 days, it was announced by Peter Shelus at the McDonald Observatory in Texas that the asteroid would pass by the earth on October 26, 2028 at a distance of only 30,000 miles, which would be between the earth and moon. An asteroid passing that close to the earth could cause catastrophic events. After locating pre-discovery photos, or photos taken of the portion of the sky being observed prior to the discovery of 1997 XF 11, further observations and computations have determined that the asteroid will pass by earth much further away, approximately 600,000 miles in 2028.
When the asteroid was first seen or discovered, scientists observed its path over a period of time to determine if there were hazards associated with an asteroid nearly one mile wide, passing extremely close to earth. This illustrates the difference between discovery and observation. In the case of asteroid 1997 XF 11, the act of discovering came before the act of observing, or did it? The process of observing deep space is how James Scotti discovered asteroid 1997 XF 11.
By now you may be wondering which came first, the chicken or the egg and that would be a very good question. The distinction is the amount of time involved. An observation of a process is done over a period of time. It could be hours, days, weeks or months before the result of the observation is determined or discovered.
The Messenger spacecraft, launched in 2004, while performing the planned mission to do a roundabout of the planet Mercury, has made it possible for scientists to observe the characteristics of the planet Mercury. By observing the planet from the cameras on-board Messenger it is hoped that scientists can discover the composition of the exosphere of Mercury. While on its journey, Messenger will fly by the planet Venus and scientists will be able to observe Venus through the lenses of Messenger’s cameras. Scientists are hoping to make significant discoveries by observing both planets during the mission.
Throughout human history, mankind has observed the earth and the sky and made discoveries which have been the basis for the knowledge that we possess today. By continuing to observe, we will continue to discover the wonders of the universe that we are a part of.