SUNSET: 
Is obstruction of less consequence for photography than for visual observing?
Some of the best images of planets are taken with Schmidt-Cassegrain telescopes, yet people often say that the large central obstruction makes this design ill-suited for planetary observing. Is the obstruction of less consequence for photography than for visual observing? Do CCDs and digital cameras make the central obstruction less…
Will meteor showers be enchanced if you fly 3,000 feet above the ground in an airplane?
I recently got my pilot license. Will meteor showers be enhanced at all for my girlfriend and me in a low-winged Tomahawk airplane, flying 3,000 feet above the ground?There are several tradeoffs to consider. True, you’ll be 1 kilometer closer to the meteors overhead. But most of them flash into…
What is the unfamiliar star in Johnny Horne's image of the Horsehead Nebula?
While looking at Johnny Horne's recent image of the Horsehead Nebula (September issue, page 65), I glanced up at my own picture mounted on the wall and suddenly noticed a "star" in Johnny's image that does not exist in this part of the sky. It must be a passing asteroid,…
With an associate's degree in electronics and computer technology, what are your chances of getting a job in astronomy?
I've been an active amateur astronomer for more than 10 years and would like to turn my hobby into a career. With an associate's degree in electronics and computer technology, what are my chances of reaching this goal?If you define a career in astronomy broadly enough, and if you want…
What's the density of the black hole in galaxy M87?
On page 20 of the March 2004 issue, you say the 3-billion-solar-mass black hole in the center of the galaxy M87 has an average density about that of air. I would love to understand how this makes any sense. The diameter of a black hole scales directly with its mass.…
Four Galilean moons shadows
Can all four Galilean moons cast their shadows on Jupiter ’s disk at the same time?No. A triple shadow transit is as good as it gets (S&T: July 2004, page 94). The motions of the three inner moons are gravitationally locked so that, as English astronomer George B. Airy wrote…