A slender crescent Moon and the brilliant star cluster the Pleiades may be glimpsed just before sunrise this morning.

Venus, rising before the Sun, reaches its greatest distance west of the Sun, 46 degrees away. In a small telescope, it appears as a perfect half “moon,” exactly 50% illuminated.

The narrow crescent Moon will be close to both Venus and Mars, which are only 2 degrees apart this morning.

Venus, rising before the Sun, reaches its greatest distance west of the Sun, 46 degrees away. In a small telescope, it appears as a perfect half “moon,” exactly 50% illuminated.

This is an event worth staying up to watch, if you have a telescope with at least 90mm aperture. Here’s the play-by-play:

2:38 a.m. The shadow of Jupiter’s bright moon Ganymede enters the limb of the planet.
4:05 a.m. The shadow of Jupiter’s innermost bright moon Io enters the limb of the planet.
5:20 a.m. Io (the moon itself) begins to transit in front of Jupiter.
5:45 a.m. Great Red Spot rotates into sight on limb of Jupiter.
6:15 a.m. Shadow of Ganymede leaves Jupiter.
6:21 a.m. Shadow of Io leaves Jupiter.
6:45 a.m. Great Red Spot central on Jupiter.
7:36 a.m. Io leaves disk of Jupiter.
7:45 a.m. Great Red Spot rotates out of sight.
People in eastern North America will miss the end of the event because of daylight flooding the sky, but people in western North America should see the full show (1:05 to 3:15 a.m. PDT).

A slender crescent Moon and the brilliant star cluster the Pleiades may be glimpsed just before sunrise this morning.

Venus, rising before the Sun, reaches its greatest distance west of the Sun, 46 degrees away. In a small telescope, it appears as a perfect half “moon,” exactly 50% illuminated.

The narrow crescent Moon will be close to both Venus and Mars, which are only 2 degrees apart this morning.

This is an event worth staying up to watch, if you have a telescope with at least 90mm aperture. Here’s the play-by-play:

2:38 a.m. The shadow of Jupiter’s bright moon Ganymede enters the limb of the planet.
4:05 a.m. The shadow of Jupiter’s innermost bright moon Io enters the limb of the planet.
5:20 a.m. Io (the moon itself) begins to transit in front of Jupiter.
5:45 a.m. Great Red Spot rotates into sight on limb of Jupiter.
6:15 a.m. Shadow of Ganymede leaves Jupiter.
6:21 a.m. Shadow of Io leaves Jupiter.
6:45 a.m. Great Red Spot central on Jupiter.
7:36 a.m. Io leaves disk of Jupiter.
7:45 a.m. Great Red Spot rotates out of sight.
People in eastern North America will miss the end of the event because of daylight flooding the sky, but people in western North America should see the full show (1:05 to 3:15 a.m. PDT).

Mercury is at greatest elongation west from the Sun on June 13, 23 degrees away from the Sun. This makes it a “morning star,” but this is not a favorable apparition for observers in the northern hemisphere, the ecliptic being at a very small angle to the horizon. It is a better apparition for observers in the southern hemisphere

Venus shines with a magnitude of -4.2 in the pre-dawn sky. It is at greatest elongation west on June 5, 46 degrees away from the Sun.

Mars is low in the predawn eastern sky. It is paired with Venus for the whole month, approaching within 2 degrees on June 19.

Jupiter is now well clear of the Sun and shining brightly in the southeastern sky in the early morning.

Saturn is still well placed for observation in Leo, south of the main body of the lion. Saturn is brighter than any nearby star and doesn't tend to twinkle, which should help in identifying it. In a telescope, its rings have begun to close, now tilted at 3.7°. With its nearly edge-on rings, Saturn continues to look like a cocktail onion with a toothpick stuck through it. Its moons are more obvious than usual because they form an east-west line through Saturn’s equator. Observers in western North America will have a chance to see the shadow of Saturn’s largest moon Titan cast on the globe of Saturn on June 15.