Visible to the naked eye
Visible with binoculars
Visible with a telescope2°April 25, 11 P.M. EDTENORION
TAURUS
GEMINI
¡cd
+iMars
M35
NGC 215832 ASTRONOMY • APRIL 2021
Planet viewing this
month is limited to
the evening and morning
hours, with a broad stretch
of nighttime devoid of major
planets. Mars drifts through
Taurus and into Gemini, while
Mercury and Venus make a
late April appearance. Jupiter
and Saturn start the month in
Capricornus, now appearing
in the predawn sky. They
climb higher as the month
progresses.
Mercury passes through
superior conjunction on the far
side of the Sun April 18 and
appears in the evening sky
along with Venus, whichpassed through superior con-
junction in late March. Both
planets are slow to climb away
from the Sun’s glow.
On the last day of April,
both planets hang very low in
the western sky 30 minutes
after sunset. Venus is most
challenging at only 2° in eleva-
tion and sinking fast, but at
magnitude –3.9 you can catch
it perhaps 10 minutes earlier. If
you do spot Venus, it’s a useful
guide to find fainter Mercury
4.5° above it. Mercury stands
6° high 30 minutes after sunset
and glows at magnitude –1.2. It
sets just after 9 P. M. local time.
The visibility of both planetsMars cozies up to two star clusters (^)
Mars rules the night
APRIL 2021
THE SOLAR SYSTEM’S CHANGING LANDSCAPE AS IT APPEARS IN EARTH’S SKY.
BY MARTIN RATCLIFFE AND ALISTER LING
SKY THIS MONTH
Grab your binoculars April 25, when Mars passes 0.5° north of M35. Nearby is
NGC 2158. ALL ILLUSTRATIONS: ASTRONOMY: ROEN KELLY
A crescent Moon and
three planets peek out
from the early morning
clouds above Bursa,
Turkey. Most planetary
observing this month is
best done in the hours
before sunrise. TUNÇ TEZEL