It's highly unlikely the interstellar comet 3I/ATLAS is an alien spacecraft. However, here are things scientists would look for to detect an alien probe.
Astronomers have discovered a long-period radio transient with theory-defying properties. It's incredibly polarized, and its spin appears to be speeding up.
A fossil of an ancient reptile shows a distinct crest that is made neither of feathers, scales or hair. It's forcing scientists to rethink reptilian evolution.
Astronomers have found evidence for a newborn planet 440 light-years away, sculpting spiral arms in the disk of gas and dust around its young parent star.
Cutting-edge gravitational wave detectors have found most massive black hole merger yet. Discoverers say it defies our understanding of how black holes form.
Members of the EarthSky community - including scientists, as well as science and nature writers from across the globe - weigh in on what's important to them.