June 2002 Sky from Keeble Observatory
Last month’s spectacular planetary display is breaking up, victim of the celestial ballet as the planets (Earth included) follow their elliptical courses about the Sun. Recall that early in May we could look west at sunset and see Mercury, Venus, Mars, Jupiter, and Saturn in one view. These are the planets (wanderers) known to the ancient Greeks, so named because of their shifting positions relative to the background constellations. Swift Mercury disappeared into the Sun’s glare at mid-May, and has already pulled past the Sun’s position in the sky, where it will appear in the morning twilight. It will reach 1st magnitude brightness at mid-month, while remaining close to the ENE horizon. For a good view, you’ll need a clean horizon, perhaps looking from a hill.
Venus remains brilliant in the evening, setting over two hours after the Sun. It’s closer to the Sun than we are, and is now catching up to our position (think of a runner on the inside lane of a circular track). Binoculars or a small telescope will show its phase waning towards last quarter by month’s end.
Mars is settling into the horizon glow after sunset, and will be very hard to see by month’s end. We have now pulled about “half a lap” ahead of the Red Planet.
Jupiter is also sinking into the twilight. The largest planet in our solar system begins the month near Venus – you may get them both in a single binocular field of view - but rapidly shifting to the west as we continue around the Sun in a closer, faster orbit.
Saturn is gone from the evening skies, but will re-emerge into the morning by the end of June. Like Mercury, it will be low on the horizon and hard to spot through haze and ground clutter.
Lunar phases for June: Last Quarter on the 2nd, at 8:05 pm; New Moon on the 10th, at 7:46 pm; First Quarter on the 17th, at 8:29 pm; Full Moon on the 24th, at 5:42 pm.
Our mid-month view of the sky at about 9:00 pm finds the “Big Dipper” high and inverted to the north. Remember that the two pointer stars at the end of the “bowl” draw a line towards Polaris. Following the curve of the “handle” past zenith will bring your line of sight to the bright star Arcturus, in Bootes. Continuing the same path towards the south will bring Spica into view, the brightest star in Virgo. Arcturus and Spica can be thought of as marking the base of two triangles. One triangle points southeast, with its apex at Antares, in Scorpio, low on the horizon. The other points west, with Regulus marking its apex, at the heart of the constellation Leo. Castor and Pollux are level to the western horizon, evenly spaced with Venus. Mars lies below, level with Procyon. Turning back to the east, we see Vega and Deneb. Deneb marks the tail of the swan, Cygnus, which “flies” parallel to the plane of the Milky Way Galaxy. Our own path around the center of the Galaxy carries the Sun in the direction of this constellation.