April 12
Gagarin Day
Sun Position
The Sun is in Aries near +15° declination. Northern hemisphere evenings are long and warming; southern hemisphere observers are heading deeper into autumn's longer nights.
Sky Highlight
April 12 is Yuri's Night, the annual celebration of the first human spaceflight, Gagarin's 108-minute orbit on April 12, 1961. It is also the anniversary of the first Space Shuttle launch, Columbia, on April 12, 1981. No recurring sky event, but the date is one of the most significant fixed points on the human spaceflight calendar.
Deep Sky Object
Omega Centauri (NGC 5139), globular cluster in Centaurus, about 17,000 light-years. Omega Centauri is the largest and most massive globular cluster associated with the Milky Way, containing roughly 10 million stars and spanning 150 light-years; it is a naked-eye object from the southern hemisphere and a spectacular binocular sight. Northern hemisphere observers need a clear southern horizon; it is best from latitudes south of 40°N.
Featured Star
Hadar (β Cen) is a blue B1III giant 390 light-years away, actually a triple system, with the primary pair separated by only a few AU and a third star in a wider orbit, all presenting as a single blue point to the naked eye. It serves as one of the two Pointer stars toward the Southern Cross, a function as practical today as it was for ancient Polynesian and Indigenous Australian navigators.
Around This Date
- April 12, 1961Yuri Gagarin, aboard Vostok 1, became the first human to travel to space, completing one orbit of Earth in 108 minutes before landing in the Soviet Union.
- April 12, 1981Space Shuttle Columbia lifted off from Kennedy Space Center on STS-1, the first orbital test flight of the shuttle program, with John Young and Robert Crippen aboard.
On this date in 1961, a man left the atmosphere for the first time; the stars he briefly shared the sky with had no idea anything had changed.