June 4

June 4

Sting at the Tail

Sun Position

The Sun is in Gemini, declination near +22.5°. Days in the Northern Hemisphere are at their longest and still lengthening; the southern winter is settling in.

Sky Highlight

No major shower peaks today. The Scorpius-Sagittarius region of the Milky Way is rising in the south after dark, offering a rich sweep of star clouds, clusters, and nebulae best enjoyed from southern and subtropical locations.

Deep Sky Object

M6 (Butterfly Cluster), an open cluster about 1,600 light-years away. M6 in Scorpius is a loose open cluster whose brightest members trace a rough butterfly shape; it contains the variable orange supergiant BM Scorpii, which shifts noticeably in color compared to its blue-white neighbors. Best from southern latitudes and the tropics; northern observers see it low in the south in June evenings.

Featured Star

Shaula (λ Sco) is a triple system about 700 light-years away, led by a blue subgiant (B1.5IV) that marks the very tip of the scorpion's curved tail; its Arabic name means 'the raised tail.' Three stars masquerade as one sharp blue point at the most recognizable hook in the summer sky.

Around This Date

  • June 4, 1974Mariner 10 completed its second flyby of Mercury, the first spacecraft to visit the planet and the only one to conduct multiple flybys during its mission.
  • June 5, 1989Voyager 2 completed a trajectory correction burn in preparation for its Neptune flyby, the last planetary encounter of the Voyager program.

Seven hundred light-years of travel, and the sting still looks sharp from here.