The news is not all bad: five inspiring science stories to lift your mood

While recreational cannabis laws have significantly reduced arrests for cannabis possession and sales, racial disparities in arrests still exist, according to a new study from Weill Cornell Medicine, Instituto Tecnológico Autónomo de México and The University of Texas at Austin. The authors suggest that recreational cannabis laws do not fully resolve underlying systemic inequities.

When you're looking for signs of extraterrestrial intelligence, it helps to know what you're looking for and to go about it in the most efficient way. But work so far has generally not done so, writes Benjamin Zuckerman, an astrophysicist and emeritus professor in the Department of Physics & Astronomy at the University of California at Los Angeles (UCLA).