Sky & Telescope - October 2021 - 4

SPECTRUM by Peter Tyson
Perish the Thought
EXTINCTION IS NOT SOMETHING we commonly think of when we
direct our attention to the night sky. I'm not talking about that of
light - the atmospheric extinction that paints gorgeous sunsets,
for instance - but of life. Why would we? For all we know, species
extinction may be, like life itself, unique to down here.
Many of us suspect there's life beyond Earth, though, and if that's true, it
only follows that its snuffing-out happens elsewhere, too. One merely has to
visualize supernovae to convince oneself of that notion. If shockwaves from
the 1987A supernova in the Large Magellanic Cloud reached nearby planetary
systems, they might well have instantly extinguished any and all life there.
Here on Earth, mass extinctions in particular can be regenerative events.
As Shannon Hall reminds us in her cover story on page 18, the end of the
non-avian dinosaurs at the close of the Cretaceous Period 66 million years ago
cleared the way for the Age of Mammals. That opportunity
eventually led to the evolution of us, Homo sapiens,
the only species that can contemplate its own demise.
Just how that long-ago extirpation occurred is the subject
of Hall's piece - the fabled asteroid might not have
been the half of it, it turns out.
Mass extinction might even have struck elsewhere in
pRemnant of Supernova
1987A as seen in
light of several different
wavelengths
our own solar system. Venus today has surface temperatures
hot enough to melt lead, and it's hard to imagine
any mortal beings thriving there now, except possibly
high in the atmosphere (S&T: Jan. 2021, p. 10). But if,
as some scientists conjecture, our sister world had water
oceans billions of years ago, could it have once sustained organisms that died
out after a runaway greenhouse effect scalded the entire surface? Earth hosted
life as early as 3.5 billion years ago; why not Venus?
As Paul Byrne points out in his article on page 12, it's possible that the
second planet from the Sun has always been as hellish as it is now, but if not,
extraterrestrial extinction might have transpired right next door to us, as it
were. Three new missions to Venus will seek to determine if that broiling orb
had a more habitable environment in its distant past (see page 17).
To ponder the most massive extinction of all, have a look at Nicole Nazzaro's
review of The End of Everything (Astrophysically Speaking) on page 67. Written by
astrophysicist Katie Mack, the book, as its title reveals, considers the annihilation
of everything - the universe and all it contains.
With all this in mind, I guess it's fair to say that extinction
could be something we think about every time we
stargaze. Just don't let it ruin your evening.
Editor in Chief
Editorial Correspondence
(including permissions, partnerships, and content
licensing): Sky & Telescope, One Alewife Center,
Suite 300B, Cambridge, MA 02140, USA. Phone:
617-500-6793. E-mail: editors@skyandtelescope.org.
Website: skyandtelescope.org. Unsolicited
proposals, manuscripts, photographs, and
electronic images are welcome, but a stamped,
self-addressed envelope must be provided to
guarantee their return; see our guidelines for
contributors at skyandtelescope.org.
Advertising Information:
Tim Allen: 773-551-0397
E-mail: tallen@skyandtelescope.org
Web: skyandtelescope.org/advertising
Customer Service: Magazine customer
service and change-of-address notices:
skyandtelescope@emailcustomerservice.com
Phone toll-free U.S. and Canada: 800-253-0245
Outside the U.S. and Canada: 386-597-4387
4 OCTOBER 2021 * SKY & TELESCOPE
Visit shopatsky.com
Shop at Sky customer service:
shopatsky.com/help
Subscription Rates:
U.S. and possessions: $54.95 per year (12 issues)
Canada: $69.95 (including GST)
All other countries: $84.95, by expedited delivery
All prices are in U.S. dollars.
The Essential Guide to Astronomy
Founded in 1941 by Charles A. Federer, Jr.
and Helen Spence Federer
EDITORIAL
Publisher Kevin B. Marvel
Editor in Chief Peter Tyson
Senior Editors J. Kelly Beatty, Alan M. MacRobert
Science Editor Camille M. Carlisle
News Editor Monica Young
Associate Editor Sean Walker
Observing Editor Diana Hannikainen
Consulting Editor Gary Seronik
Editorial Assistant Sabrina Garvin
Senior Contributing Editors
Dennis di Cicco, Richard Tresch Fienberg,
Robert Naeye, Roger W. Sinnott
Contributing Editors
Howard Banich, Jim Bell, Trudy Bell, Monica Bobra,
John E. Bortle, Ronald Brecher, Greg Bryant, Thomas
A. Dobbins, Alan Dyer, Tom Field, Tony Flanders, Ted
Forte, Steve Gottlieb, David Grinspoon, Shannon Hall,
Ken Hewitt-White, Johnny Horne, Bob King, Emily
Lakdawalla, Rod Mollise, James Mullaney, Donald W.
Olson, Jerry Oltion, Joe Rao, Dean Regas, Fred Schaaf,
Govert Schilling, William Sheehan, Mathew Wedel, Alan
Whitman, Charles A. Wood, Richard S. Wright, Jr.
Contributing Photographers
P. K. Chen, Akira Fujii, Robert Gendler,
Babak Tafreshi
ART, DESIGN & DIGITAL
Art Director Terri Dubé
Illustration Director Gregg Dinderman
Illustrator Leah Tiscione
Webmaster Scilla Bennett
ADVERTISING
Advertising Sales Director Tim Allen
AMERICAN ASTRONOMICAL
SOCIETY
Executive Officer / CEO, AAS Sky Publishing, LLC
Kevin B. Marvel
President Paula Szkody, University of Washington
President Elect Kelsey Johnson, University of Virginia
Senior Vice-President Geoffrey C. Clayton, Louisiana
State University
Second Vice-President Stephen C. Unwin, Jet Propulsion
Laboratory, California Institute of Technology
Third Vice-President Adam Burgasser, UC San Diego
Treasurer Doris Daou, NASA Planetary Science Division
Secretary Alice K. B. Monet, U.S. Naval Observatory (ret.)
At-Large Trustees Hannah Jang-Condell, University of
Wyoming; Edmund Bertschinger, MIT; Jane Rigby, NASA
Goddard Space Flight Center; Louis-Gregory Strolger,
Space Telescope Science Institute
Newsstand and Retail Distribution:
Marisa Wojcik, mwojcik@i-cmg.com
Comag Marketing Group
The following are registered trademarks of
AAS Sky Publishing, LLC: Sky & Telescope and
logo, Sky and Telescope, The Essential Guide to
Astronomy, Skyline, Sky Publications, skyandtelescope.org,
skypub.org, SkyWatch, Scanning the
Skies, Night Sky, SkyWeek, and ESSCO.
ALMA (ESO / NAOJ / NRAO) / A. ANGELICH. VISIBLE-LIGHT IMAGE: NASA / ESA HUBBLE SPACE TELESCOPE. X-RAY IMAGE: NASA CHANDRA X-RAY OBSERVATORY

http://www.shopatsky.com http://www.shopatsky.com/help http://www.skyandtelescope.org/advertising http://www.skyandtelescope.org http://skyandtelescope.org http://skyandtelescope.org http://www.skypub.org http://www.skyandtelescope.org

Sky & Telescope - October 2021

Table of Contents for the Digital Edition of Sky & Telescope - October 2021