Magazine | Page 120 of 278 | Astronomy.com

Telescopes and Equipment

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If the light from a galaxy traveled 13.3 billion years to reach Earth, does that mean the light left this galaxy when the universe was 500 million years old? Was the galaxy 13.3 billion light-years away from Earth then?

Deep-Sky Objects

California dreamin’

Exoplanets, Planets, Solar System, The Moon

Jupiter’s evening return

It’s about time

In my astronomy studies decades ago, we used the “Roche limit” to determine when a smaller body is too close to survive a larger object’s gravitational force. Do astronomers still use that term?

Astrophotography

Using masks, part 2

Web Extra: Exploring the pulsar zoo

Web Extra: What about Eta Carinae?

Why do we see a flash instead of a constant signal from a millisecond pulsar, which spins 20-700 times per second? Is that not fast enough to maintain a steady beam of light?

Web Extra: A comet’s nucleus laid bare

Astrophotography

Using masks, part 1