More than five years ago there was an event that reminded us of a comparison of comets and cats. The media proclaimed comet ISON “the comet of the century.” Experts predicted that it would outshine the full moon. Some said that it would be visible in daylight. Astronomy magazine predicted that it could “become the brightest comet ever seen by anyone now alive.” Excitement was in the air as people waited to see this remarkable comet in the fall of 2013. What happened to it?
Comets have been described as dirty snowballs in space. They consist of water ice, other frozen gasses, and rocks orbiting through the solar system. When they pass near the Sun, the solar radiation vaporizes the solids, and the vapor reflects the sunlight creating a visible ball called a coma. The solar wind causes the appearance of a tail pointing away from the Sun.
The comet that brought such excitement was named ISON after the International Scientific Optical Network based in Russia that initially discovered it. Because its perihelion (closest passage to the Sun) was going to be only 1.8 million kilometers in November of 2013, astronomers expected it to be a rare and “dazzling” sight. However, as the comet came close to the Sun, it disintegrated. What was left instead of being “fifteen times brighter than the full moon” was almost, or entirely, invisible to the naked eye. Star-gazers were disappointed.
Famed comet hunter David Levy made the statement: “Comets are like cats. They have tails, and they do precisely what they want.” Yes, comets and cats are unpredictable. However, one thing we know is that the design of our solar system makes it unlikely that one will collide with Earth. What the Sun doesn’t stop, the “comet sweeper” giant outer planets will—especially Jupiter which captured one of the comets that David Levy discovered. Although Levy said that comets do what they want, it might be more accurate to say that comets do what God wants.
–Roland Earnst ©2019