Tension at the Heart of Cosmology

Astronomers have found two different – and mutually exclusive – values for the expansion rate of the universe.

New Horizons swings past Ultima Thule

The historic encounter gave us our first close-up look at a Kuiper Belt object, the most distant body we have ever explored.

The Outer Limits universe

Objects briefly seen on television over 50 years ago make terrific targets for today’s amateur astronomers.

The paper trail of astronomy

Transient treasures of word and art show that our science has a rich and colorful past. 

Mission complete for Opportunity rover

After 15 years exploring the Red Planet, the Mars Exploration Rover mission has ended.

The story behind Stellarvue

From the start, this company’s goal was the perfect telescope.

In Every Issue

Web Talk
Advertiser Index
Final Frontier
Astro News
New Products
Reader Gallery