According to JonXAmry, comet Atlas is a sign for an upcoming war. He refers to other wars which started every time when a huge comet arrived.
For example the comet of 811, discovered in March 1811. This comet was visible during the New Madrid Earthquakes in December 1811 and in 1812 Napoleon invaded Russia. Or like the Great Comet of 1861 – In 1861 Civil War starts and ends in 1865.
All through time comets, like the comets of 1811 and 1861, were known as the harbingers of war, but what if comet ATLAS or eventually another celestial body is not a sign for an upcoming war but for an upcoming unprecedented natural event that could lead to death, disease and famine.