Alert F-16s out of California scrambled to hunt down mysterious targets over Nevada and California twice on Sunday.

A distant star dimmed by 97% for nearly 200 days. Astronomers say giant rings around a brown dwarf or super-Jupiter may explain it.

In other instances, cyclists may find themselves pedaling hard to progress down an obvious slope, as if gravity is pushing them in the opposite direction. The rest of this article is behind a paywall.

Astronomers have analyzed the data from long-term radio observations of a binary pulsar known as PSR J1906+0746. Results of the new study, published February 5 on the arXiv pre-print server, deliver ...