Astronomers have argued for years over whether massivegalaxies form from scratch, or by chunking together smaller galaxies. Lately, evidence is building for the latter theory, and anew study adds to ...

Some regions in space are especially good at creating massive stars. Astronomers know the recipe for creating a star in one of these stellar nurseries calls for hydrogen gas, dust, and some amount of ...

This spectacular, multi-hued formation of lenticular clouds was observed soon after the sun set over Rocky Mountain National Park near Estes Park, Colo., on Jan. 5. Professional photographer Richard H ...