Astrosphere for July 31, 2007

Today’s astrophoto is brought to you by bloodhound31, it’s a photo of the Triffid Nebula.

Centauri Dreams is reporting on an interesting theory to explain mass extinctions in the past: the Sun’s rise and fall above the galactic plane.

The Space Review has a cool article about the potential for using space guns to access space.

Here’s a cool 6-part series of articles about how to get started in amateur astronomy from Helium. And another 8-part series on how telescopes work.

Pamela Gay is attending the American Association of Physics Teachers, and has this great article about the challenges of both doing and popularizing science.