A new trail in this southern Arizona city plots the most visitor-friendly astronomy stops—and there are plenty to choose from ...

A new trail in this southern Arizona city plots the most visitor-friendly astronomy stops—and there are plenty to choose from ...

The planet’s elusive aurorae are much colder than expected, which is how they evaded detection for so long.

This is a still from an animation showing asteroid 2024 YR4 as it passes by Earth and heads toward its potential impact with the Moon. This 3D shape of the asteroid was determined from data obtained ...