Astronomy March 2009

Is there something we don't know about gravity?
Spacecraft flybys and the Moon's orbit aren't following predictions. Whatever is causing this could usher in a new theory of gravity.
By John D. Anderson


Scientists rule out some explanations for these strange occurrences.
By Liz Kruesi


Surprises from MESSENGER's historic Mercury flyby
The MESSENGER spacecraft flew past Mercury in October, revealing landscapes never seen up close before.
By Richard Talcott


The MESSENGER spacecraft flew past the innermost planet October 6, giving scientists their second close look at Mercury in 2008.
By Richard Talcott


Cassini flies through Enceladus' geysers
The Cassini spacecraft flew past Saturn's moon Enceladus twice in October, diving into its water-rich plume and imaging its dynamic surface.
By Richard Talcott


The Cassini spacecraft flew past Enceladus once in August and twice in October, returning some of the sharpest images of the active moon yet.
By Richard Talcott


How the Spitzer Space Telescope unveils the unseen cosmos
NASA's flagship infrared eye in the sky has probed hidden corners of the universe for 5 years. Spitzer chief scientist Michael Werner shares some of the telescope's greatest discoveries.
By Michael Werner


The structure of star-forming regions, the recipe of a grand design spiral galaxy, and the look of the Milky Way's center all made the list.
By Daniel Pendick
Discover galaxy groups and clusters
With an 8-inch or larger scope and a dark sky, go after these distant citizens of the cosmos.
By Steve Coe



Add another 10 to the list from "Discover galaxy groups and clusters."
By Michael E. Bakich


How to build a backyard observatory
A permanent telescope setup gives you fast and easy access to the sky.
By Michael E. Bakich


Download Contributing Editor Mike D. Reynold's article about three ready-made domes to help you with your observatory purchase.
By Michael E. Bakich