July 20
The Anniversary of Landing
Sun Position
The Sun is in Cancer at about +20.0° declination. Northern Hemisphere summer days remain long; Southern Hemisphere winter nights are at their longest and darkest.
Sky Highlight
No named meteor shower peaks on July 20. On this date in 1969, Apollo 11 landed on the Moon, and in 1976, Viking 1 landed on Mars, two of the most significant landings in space exploration history. The Moon is well-placed for evening observation from both hemispheres at some point during the month depending on its phase.
Deep Sky Object
M26 (NGC 6694), an open cluster in Scutum roughly 5,000 light-years away. It is a moderately rich cluster best seen in a small telescope; binoculars show a faint patch. Scutum sits in a dense Milky Way field, making the surrounding star background spectacular on a dark night. Visible from both hemispheres.
Featured Star
Albireo (β Cyg) is 430 light-years away in Cygnus, where its orange giant (K3II) and blue companion (B8Ve) form one of the sky's most-visited telescope objects. The light arriving tonight from Albireo's primary left during the Elizabethan era; from the companion, during the early Victorian period, two different travel times arriving in the same eyepiece.
Around This Date
- July 20, 1944The MW 18014 V-2 rocket reached 176 km altitude, becoming the first man-made object to reach space, two and a half decades before any human followed.
- July 20, 1990Asteroid 5261 Eureka was discovered, becoming the first confirmed Mars trojan asteroid, an object sharing Mars's orbital path around the Sun while staying near one of the Lagrange stability points.
Two landings, seven years apart, on two different worlds. July 20 carries more weight than any other date on the explorer's calendar.