Sky & Telescope - January 2021 - 12

NEWS NOTES
ASTRONOMY & SOCIETY

Wildﬁres Threaten
Observatories
TWO HISTORIC OBSERVATORIES, Lick

and Mount Wilson, have survived the
worst U.S. wildﬁre season on record.
The ﬁres also threatened amateur observatories in the region - and devastated
one of them.
The Santa Clara Unit (SCU) Lightning Complex Fire swept across the
area east of San Francisco Bay, coming
dangerously close to the Lick Observatory domes on August 19-20.
"We are tremendously thankful to
the ﬁreﬁghters from all over California,

whose courageous actions saved Lick
Observatory," says director Claire Max.
The observatory, founded in 1876,
escaped major damage, and no one
was injured. However, a few residences
- including the home of astronomer
Edward Emerson Barnard - were lost.
Then in September, the massive Bobcat wildﬁre bore down on the historic
Mount Wilson Observatory, founded in
1904 by George Ellery Hale. Local radio
and television transmission towers,
located on the peak and worth $1 billion, were also at risk. On the afternoon
of September 15th, the ﬁre approached
within 150 meters (500 feet) of the
observatory complex. By nightfall the

Fire rages near Mount Wilson. The
150-foot solar tower is visible in
the foreground.

worst had passed, though the ﬁre took
several more weeks to contain.
Fires also affected amateur observatories. Some escaped with smoke damage, such as the Sierra Remote Observatories. Others were not so lucky: The
Tri-Valley Stargazers, an astronomy
club in Livermore, California, lost their
main observatory building to the same
SCU Lightning Complex wildﬁres that
came so close to Lick.
The Hidden Hill Observatory,
donated to the club in 1983, was used
for observing, research, astrophotography, and outreach events. Recently, the
Tri-Valley Stargazers had even ﬁnished
a two-year renovation project, including improvements to the building and
equipment upgrades. When ﬁre swept
through the area, the club lost almost
everything, including most structures
and two custom-built telescopes.
However, the landowners made it
out safely, and their home escaped
the blaze. A small dome also survived
unscathed. And within a month the TriValley Stargazers had raised more than
$30,000 to rebuild the observatory,
likely another two-year project.
"I am overwhelmed by the support
we've received so far from the community and from fellow stargazers
throughout the world," says club president Roland Albers.

THE SUN

The Solar Activity Cycle Has Stabilized
SOLAR CYCLE 25 IS HERE, and predictions suggest that the next decade of the
Sun's activity will mimic the last one -
halting a four-decade downward trend.
The historical sunspot record shows
an 11-year cycle, as the number of sunspots (and other solar activity) increases
and then decreases again over that
timeframe. While the timing is steady,
the cycle varies in strength, and the
Sun's behavior the last couple of decades
has puzzled astronomers.
In September, NASA and the
National Oceanic and Atmospheric

JANUARY 2 021 * SK Y & TELESCOPE

Administration (NOAA) cosponsored
the Solar Cycle 25 Prediction Panel.
The international group of scientists
declared December 2019 to be solar
minimum, which in turn marks the
beginning of Cycle 25. The scientists
must average the sunspot number over
13 months to smooth out the Sun's
variability, hence the delay between
solar minimum and the announcement.
The panel also announced a consensus on forecasts for Cycle 25 - unlike
the panel for Cycle 24, which was split.
The current panel predicts the next

peak in activity will come in July 2025,
with 115 sunspots. That prediction,
while weaker than average, is almost
exactly the same as what actually
occurred in Cycle 24: Activity peaked in
April 2014 with 114 sunspots.
Cycle 25 should thus interrupt the
trend of decreasing activity that has
been going on for more than 40 years.
Cycle 24 was the weakest cycle in
100 years (S&T: Nov. 2013, p. 10), and
some had even speculated that the Sun
could be approaching a largely sunspotless period. But the Cycle 25 forecast
contradicts the notion that we are
headed for a more profound change in
solar magnetic activity.

HPWREN / M OUN T WILSON OBSERVATORY

■ DAVID DICKINSON & SABRINA GARVIN

Sky & Telescope - January 2021

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