Trans-Neptunian objects (TNOs) are icy bodies that vary widely in size, from large dwarf planets like Pluto and Eris—each ...

Astronomers have discovered what seems to be a star racing through the Milky Way at 1.2 million mph, dragging a Neptune-sized planet along for the ride.

It was, of course, a great joy for me when we could confirm the planet’s existence,” said Dr. Cretignier. “It was also a ...

In this mind-bending series, Jim Al-Khalili explores the vast range of size in the universe, from tiny atoms to gigantic, interconnected galaxies.