On December 21 about an hour before sunset, the planets Jupiter and Saturn will appear very close together low in the western sky in a celestial event called a conjunction.¹ In fact, the two planets will be so close together that they should appear as a “double planet” to the naked eye.

An exoplanet 260 light-years away is being described as the first of its kind ever detected.^1,2 This exoplanet, catalogued as LTT 9779b, is called an “ultra-hot Neptune” because of its large size and nearness to its host star.

A letter to the editor in Nature Geoscience notes that this year marks the 100-year anniversary of Milutin Milankovitch’s (Milanković’s) book explaining how slow changes in Earth’s orbital and astronomical motions could affect its climate.¹ This book, entitled Mathematical Theory of Heat Phenomena Produced by Solar Radiation, laid the mathematical groundwork for wh