Sky & Telescope - April 2023 - 50

APRIL 2023 OBSERVING
Celestial Calendar
April 22
About 10 p.m.
CORONA
BOREALIS
10°
DRACO
HER C ULES
tWith an early moonset, conditions for the
2023 Lyrid meteor shower couldn't be better.
You can begin your meteor watch as early as
10 p.m. local daylight time on the evening of
April 22nd, when twilight has fully faded and
the radiant stands above the northeastern
horizon. However, the best time to observe
will be in the predawn hours of the 23rd when
the radiant is nearly overhead for observers at
mid-northern latitudes.
Lyrid
radiant
Vega
LYRA
Deneb
Facing Northeast
Looking
for Lyrids
CIRCUMSTANCES COULDN'T BE
better this year for the annual Lyrid
meteor shower. The 9%-illuminated
crescent Moon sets before midnight on
the peak night of April 22-23, creating
optimal conditions for this modest
display. Shower members stream from
a point in the constellation Hercules,
some 8° southwest of the bright star
Vega, in Lyra.
While Lyra will be visible in the
northeast around 10 p.m. local daylight
time, the Lyrid display is best viewed
between 2:00 a.m. and 4:30 a.m. on
April 23rd, when the radiant stands
highest and before twilight begins to
noticeably brighten the sky.
Under dark conditions you can
expect to see about 15 meteors per hour.
Spot a Very Young Moon
Outbursts with increased activity occur
whenever Earth encounters denser
streams of debris, as it did in 1803 and
1982. However, no similar enhancement
is expected this year. Lyrid
meteors generally don't have lingering
trails, though the display is known for
producing fireballs. The Lyrids originate
from dust released by Comet C/1861 G1
(Thatcher), a long-period comet that
circles the Sun every 415 years. It last
reached perihelion in 1861 and will do
so again in 2276.
One remarkable aspect of the Lyrids
is that the display has been observed
for more than 2,700 years. Although
the radiant wasn't determined until
the 1803 outburst, it's likely Chinese
astronomers first recorded the shower
as far back as 687 BC. I plan to set my
alarm both for the pleasant show and
to keep the chain unbroken. And if the
display fizzles, at least I got to preview
the summer sky.
ARE YOU CHARMED by the razor-thin
lunar crescent? If you are, then face westnorthwest
half an hour after sunset on April
20th to catch a very young Moon. From
the East Coast it will be a little less than
20 hours old and 0.7% illuminated; from
the Midwest it's 21 hours old and 0.8% lit;
and from the West Coast, it's 23 hours old
and 1.0% lit. Since the crescent will hover
just a few degrees above the horizon, find a
location with an unobstructed view (looking
over water is ideal) and use binoculars or a
small telescope to help locate the Moon and
to enhance the delicate scene.
tMars reappears from behind the limb of a paperthin
lunar crescent as seen from De Soto, Kansas,
shortly after the occultation of December 6, 2010.
The Moon's age at the time was just 1.3 days. Lowaltitude
air turbulence distorts its fragile outline.
50 APRIL 2023 * SKY & TELESCOPE
DOUG ZUBENEL
Sky & Telescope - April 2023

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