The cover of the May 2021 issue

Stellar Nurseries, Giovanni Cassini, and Biosignatures

In the May 2021 issue of Sky & Telescope, we’re discussing the hunt for cosmic rays and the massive telescope and detector arrays trying to track down their sources. Good thing we’ll only need one telescope to spot incredible stellar nurseries in faraway galaxies — but we may need a couple of eyepieces, so we’re exploring a few recent innovations and how to select the best ones for your observing needs. However, even the best eyepieces won’t help us find life on other planets unless we know what we’re looking for. Astrobiologists are looking for chemical compounds that could signal life if found in the atmospheres of other planets.


Cosmic Power Rangers

Scientists are deploying vast arrays to search for the origin of the most energetic particles in the universe.

By Govert Schilling

 Star-forming Regions in Faraway Galaxies

Test your skills by spotting stellar nurseries in distant galaxies.

By Scott Harrington

Building a Better Biosignature

Finding signs of alien life requires more prep work than you might think.

By Arwen Rimmer

Giovanni Domenico Cassini and the Birth of Big Science

Innovations from an under-appreciated 17th-century astronomer still reverberate today.

By Gabriella Bernardi

Some Thoughts About Today’s Eyepieces

Eyepieces are just as important as telescopes when it comes to visual observing, but some of the conventional wisdom about them has changed.

By Dennis di Cicco

Beyond the Printed Page:

Exoplanet Watch

Help NASA and the American Association of Variable Star Observers observe planets outside our solar system.

Adventures in Deep Space

Check out this collection of challenging observing projects.

Spotting Mercury

Learn more about observing and photographing this elusive planet from the Association of Lunar and Planetary Observers.

Free Software for Planetary Observers

Use the free WinJUPOS program to identify specific features of the planets in your astrophotos or sketches.


Anatomy of the Amazing Big Dipper

There’s more to this distinctive collection of stars than meets the eye.

By Fred Schaaf

A Brief Total Lunar Eclipse

Get ready to watch the Moon pass through Earth’s shadow.

By Bob King  

Spurious Shadows

Don’t be fooled by these Jovian moon mirages.

By Thomas Dobbins  

Big Bear Pair

Exploring M81 and M82 is double the fun in more ways than one.  

By Ken Hewitt-White

Table of Contents

See what else May's issue has to offer.


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