"The comet is a swift-moving object and currently is easily visible in the northeastern skies during pre-dawn hours, showing a pretty distinct tail and large coma (head or halo, caused by the emanation of gases and other materials as the comet warms up on its approach to the sun). The tail appears to be slightly less than one-half degree and several spikes in this tail have been recorded (on December 15) by imagers in New Mexico," Sherrod said. The jury is still out regarding just what kind of show Kudo-Fujikawa would provide Earth-based viewers when it is closest to the sun, but there is a prospect that it would be a "textbook comet," Sherrod said. "However, the visibility during its greatest brilliancewill be greatly hampered because of the comet's angle of approach to the sun and the Earth-sun-comet positioning during that period." Towards the end of January, the comet will be approaching the sun and swinging behind it from Earth's vantage point, thus getting lower and lower each successive morning into early February. "In February the comet will be more favorably placed for observers in the southern hemisphere, and there are some estimates that suggest that the comet could attain a brightness equal to the bright planet Venus (a magnitude of less than 4)," Sherrod said. Magnitude is a measure of brightness used by astronomers. The lower the magnitude value of an object, the brighter that object is.Objects that shine with a magnitude of less than 6 are usually visible with the naked eye. Kudo-Fujikawa is currently being seen at a magnitude of between 7 and 8. Much of what Earth will be able to see of Kudo-Fujikawa is contingent on the activity that occurs when it is closest to its pass by the sun (perihelion) on January 28, 2003, Sherrod said. At that point it will be only 16 million miles (25 million kilometers) from the sun. The average distance of the Earth from the sun is 93 million miles (150 million kilometers). "The retrograde orbit (meaning the comet is coming in at an opposite direction in relation to the orbits of the primary planets) of this comet and its close pass from the sun at that time have suggested to many, myself included, that the comet might potentially break up from solar radiation and solar wind. If this does indeed occur, then we might expect more volatile activity from this object than if it passes perihelion totally intact and unscathed. "Now, if this does happen, then we might expect an incredible comet to be visible as the inner, more volatile and rare gases are exposed to solar radiation," Sherrod said. For more precise instructions of how to find the cometand Sherrod's regular updates on its progressplease visit the Arkansas Sky Observatory. News Alerts From the National Geographic News Desk Receive regular e-mail alerts about breaking National Geographic news. Send an e-mail to the news desk with the word "Subscribe" in the header field. We'll let you know whenever we publish an interesting story. |