Schmidt-Cassegrain

Hobby-based Q&A

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…

Astronomy Questions & Answers

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…

Astronomy Questions & Answers

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,…

Hobby-based Q&A

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…

M87

Science-based Q&A

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.…

Astronomy Questions & Answers

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…

Advertisement
Advertisement
Advertisement
Advertisement