From how galaxies form to the beginnings of the universe, the images from the space telescope are giving cosmologists new data to explore—and theories to build out.

From how galaxies form to the beginnings of the universe, the images from the space telescope are giving cosmologists new data to explore—and theories to build out.

Three species that lived about 308 million years ago challenge the idea that the first land vertebrates underwent amphibian-like metamorphosis.