All About Comets - More to Come This Spring
Comets have long fascinated humanity. These mysterious glowing orbs in the night sky have inspired everything from panic to poetry, and the more we learn the more intriguing them get!
We now know that comets are just chunks of ice, gas and dust, but they exhibit some peculiar behaviors that distinguish them from the background sky. Most famous of course are the long tails that follow the comets, almost like a wake through space.
But if there's nothing in space to push through, like a boat through the water, then what causes the tail?
The Sun emits a stream of charged particles called the solar wind, and when a comet gets close enough into our solar system to start passing through this invisible charged stream, it reacts with the gases that are latent in the comet's core.
As it reacts, these gases begin emitting from the core and are pushed away in the solar wind. The closer it gets to the Sun, the stronger the effect. What this means visually is that whenever you see a tail on a comet, it will always point directly opposite the Sun, in the same way a boat's wake is always pointing opposite the direction of travel.
Perhaps the most famous comet is Halley's Comet (1P/Halley), which is a "periodic" comet that keeps returning after a set interval. The good news is that it's always a magnificent showpiece that steals the show. The bad news is that it won't be back until 2061, as it makes a return every 75-76 years, a truly once in a lifetime event.
However there are many pleasant surprises, such as Hale-Bopp and others that were more brilliant than predicted, but only visit once before leaving our solar system forever, or others who make a periodic return over several hundred years, and we may not know about them until they get close!
We'll talk more about comets over the coming months, but for now you can read more about Halley's Comet here:
Stay well, and clear skies!