Will we Get to See Comet Atlas?

Comets seem to love surprises.  Before astronomers began to make sense of their nature, bright comets would appear without warning, and dominate the night (and sometimes daytime) sky.  Quite often, they were thought to be precursors to disasters.  Some people with a more cheerful outlook would take a comet’s arrival to indicate that a great king was born.

Today, we are not free from fear of these beautiful visitors.  They are large enough and fast enough to devastate any planet that sits in their path.  According to a plausible theory, the dinosaur extinction resulted from climate changes triggered by a comet impact 65 million years ago.

A more recent example happened in 1994, when the fragmented comet Shoemaker-Levy 9 collided with the planet Jupiter.  When large fragments entered Jupiter’s thick atmosphere, they exploded, and created dark spots in the bright clouds.  Many of these spots were larger than Earth!

So much for the scary stuff.  We have just heard that comet C/2019 Y4 (ATLAS) has had a large, sudden increase in brightness.  A comet will warm up as it approaches the Sun, and vapors and dust will escape the surface to form a cloud.  Atlas has suddenly formed an extra large cloud, so it appears much brighter than expected.

So, Atlas has graduated from a “telescopic comet” to one which might be visible to the naked eye.

And here we get to the unpredictability of comets.  Although their orbits are calculated very precisely, their visibility and appearance are very hard to predict.   Based on the brightening of comet Atlas, we may see a very bright comet in May, 2020.  It is possible that it will be visible during daylight; it is also possible that it will disintegrate as it makes its closest approach to the Sun.

Here is a very good article with many details:

https://earthsky.org/space/how-to-see-bright-comet-c-2019-y4-atlas

I will try to keep you posted.  In the meantime…

Keep looking up!