June 2005 Skies

The month of June completes the season of Spring and ushers in Summer, bringing longer days and shorter nights (until June 21st), then progressively shorter days again until December.

June also brings two spectacular planetary conjunctions involving Mercury, Venus and Saturn: Both occur in the early evening sky late in the month and will be interesting for ALL to observe!  (More below).

Lastly, Mars continues to brighten and move away from the Sun in the morning sky, in preparation for a close – and very bright – approach to the Earth this Autumn.

In early June, only a few early evening Summer stars and constellations will be visible. Also, the Milky Way wraps around our horizon and is invisible.  Later in June, or if you observe later at night, the easily recognizable Summer constellations will be more visible along with the Summer Milky Way.

The SUN begins June in the Zodiac constellation of TAURUS the Bull, where it remains until June 21st. This year, the Sun reaches its most northerly point in the sky (marking the beginning of Summer) at 11:44p.m. on the evening of June 20th.  It will be just inside Taurus on its border with Gemini and the northern border of Orion.  A few hours later on the morning of June 21st the Sun moves into GEMINI the Twins for the remainder of June.

The earliest sunrise of the year occurs just before 5:21a.m. on June 10th.  The latest sunset of the year is a few seconds after 7:36p.m. on June 30th.  In between, the longest day of the year (14 hours, 13 minutes, and a few seconds) happens on June 21st.  It may seem surprising that the earliest sunrise and the latest sunset do NOT occur on June 21.  Why is this?

The Evening Sky
Essentially, all June sunsets happen at the same time: They range only between 7:27p.m. on June 1st to 7:36p.m. on June 30th.  In fact, between June 23rd and July 2nd all sunsets occur within a few seconds of 7:36p.m.

The Moon:
June’s NEW MOON occurs the afternoon of June 6th in Taurus.  The 1st QUARTER MOON happens on June 14th in VIRGO.  June’s FULL MOON is on June 21st in SAGITTARIUS.  On that evening, moonrise will be shortly after sunset and you will notice the Moon never reaches very far above the horizon all night.  Finally, the Moon marks its 3rd QUARTER phase near midday on the 28th in CETUS the Whale.  (Wait! How can the Moon NOT be in a Zodiac constellation? See this link!)

The June Moon passes near five naked-eye planets:
MERCURY, very difficult to see in the post-sunset glare the evening of the 7th
VENUS (not particularly close to the Moon) the evenings of the 7th and 8th in Taurus
SATURN, close to the Moon the evening of the 9th in Gemini
JUPITER, close to the Moon overnight on the 15th in VIRGO
MARS on the morning of the 29th in PISCES

After sunset on June 7, look for the 1 ½ day old Crescent Moon if you have a clear view down to the Western horizon.  It will be about 6 degrees below and right of Venus.  (Venus is the very bright “star” low in the Northwest after sunset.)  Mercury will then be below the crescent Moon, but binoculars are a must to see Mercury, as the planet sets only 27 minutes after sunset.

After sunset on June 9th, the Moon will be above and to the right of Saturn in the darkening sky.

Overnight June 15th- 16th the Moon approaches within 1 ½ degrees of the bright planet Jupiter.  It will be even more impressive in binoculars, as, Jupiter’s 4 brightest moons should be visible near the planet and below the Moon.

(The farther South one travels, the closer to Jupiter the Moon appears.  The Moon eclipses Jupiter tonight as viewed from the South Pacific, New Zealand, and Australia.)

Moon & Prominent Stars:
Crescent Moon near Castor & Pollux in GEMINI on the 9th.
Waxing Moon near Regulus in LEO on the 12th.
Gibbous Moon near Spica in VIRGO overnight on the 16th.
Nearly-Full Moon near Antares in Scorpio overnight June 19th and 20th.

Evening Planets. VENUS, SATURN, JUPITER, and (beginning early in the month) Mercury.
MERCURY should be far enough from the Sun to become easily visible about June 15th, when it sets more than an hour after the Sun.  Begin to look for the planet low in the sky near the sunset point about 45 minutes after sunset. It will appear to brighten as the sky darkens, but this may be offset by its proximity to the horizon.  For the rest of the month, Mercury chases and “catches up with” Saturn and Venus.  These three planets will form a rare “triple conjunction” in the Western sky on the evenings of June 24 – 26.

Also taking place is a rare extremely close Mercury-Venus conjunction!  These two planets remain close together for the rest of June. Between June 24 – 28 they will appear closer than the angular width of the Moon.  Mercury is closer to the Sun and so appears to move faster than Venus.  Mercury swings counterclockwise around the brighter planet and starts to rush back toward the Sun by month end. By the middle of July, it will again be deep in the Sun’s glare.

VENUS continues to move farther Eastward away from the Sun all month and will dominate the Western sky by month end.  Venus orbits closer to the Sun than Earth. As it passes Earth, it alternately appears as our “Evening Planet” for about 10 months and then as the “Morning Planet” for about another 10 months. Now into its 2nd month as an Evening Planet, Venus will remain the brightest object in the evening sky (after the Sun and Moon), through the rest of the year.  Through a telescope, Venus displays the same phases as the Moon, and now shows a nearly “Full” phase.

JUPITER and SATURN can be observed all month in the evening sky as the next brightest objects (after the Sun, Moon and Venus).

SATURN remains in GEMINI until June 30th, when it moves into CANCER.  Saturn can be viewed low in the West after sunset, especially as part of the Triple Conjunction with Mercury and Venus on the evenings of June 24th, 25th, and 26th.  By month end, Saturn will be very difficult to see in the sunset glare.  In early July, Saturn moves past the Sun and becomes a Morning Planet.

JUPITER remains in VIRGO all month and is still visible most of the night.  It sets at about 2a.m. on June1st but only a bit after midnight at month end. A pair of binoculars should show Jupiter’s four brightest satellites Io, Europa, Ganymede, and Callisto close to the planet.  Between June 17th and 27th a telescope will show slowly moving Jupiter pass south of the 7th magnitude star HD109756.

What Else to See?
Spring’s prominent constellations set earlier each evening as Summer approaches.  Still, the sky will be dark by 9:30p.m.  A moonless evening in the month will be a fine time to view Ursa Major (the familiar “Big Dipper”) high in the Northern Sky.  Follow through the Dipper’s “handle” stars in a curve over to bright Arcturus (high overhead in Bootes) and on to Spica (near Jupiter) in Virgo.  Beneath the Big Dipper and toward the West is Leo the Lion.  Beneath and to the West of Virgo is Corvus the Crow. As high as Virgo and more to the East, is Hercules.

Northeast of Hercules the brilliant star Vega rises higher each evening.  Vega is the brightest star of summer.  It marks the position of Lyra the lyre.  Below Vega is Cygnus, the Swan (or Northern Cross), anchored by the blue-white star Deneb.  To the South of Deneb is yellow Altair in Aquila the eagle.  Vega, Deneb and Altair form the “Summer Triangle” of bright summer stars.

Rising in the June Southeast sky after dark is the long “body” of Scorpio the zodiac scorpion.  By 10:30p.m. on early June evenings Scorpio’s whole “tail” and “stinger” stars will be above the horizon, followed by Sagittarius the archer aiming his arrow at the scorpion.  In Scorpio’s heart is the bright red supergiant star Antares, a star many believe will one day die as a dazzling supernova.

The Moon eclipses (“occults”) two stars of 6th magnitude or brighter on the evening of June 19th , beginning shortly before 8p.m. A small telescope will be needed to watch this event. See details here.

Saturn, in the Milky Way this month, passes so close to a faint star that it will appear as an “extra” moon in a telescope,.  If you have a small telescope, be sure to watch Saturn the evening of June 17th, when the magnitude 6.8 star HD64351 passes very close to both Saturn’s moon Dione and the planet itself.

The Morning Sky
June sunrises occur at nearly the same time all month: From 5:24a.m. on June1st to 5:21a.m. on June 10th, and then later again to 5:25a.m. on the 30th.

The crescent MOON appears in morning June skies through the 5th and again from the 21st through the end of the month.  The Moon lies near MARS on the morning of June 29th.

Morning Planet: MARS.
MARS begins June in AQUARIUS, moves into PISCES on June 7th, moves into CETUS (Mars’ orbit is also inclined several degrees to Earth’s orbit) on June 20th, and moves yet again into Pisces on the 30th.  The Red Planet is now quite easy to observe as it moves into more Northerly constellations and becomes closer to Earth (and brighter).  By month end, Mars will be as bright as Vega and will continue to brighten throughout the summer.

Mars rises at about 1:35a.m. on June 1st, and at about 12:30a.m. on the 30th.

Seen through a telescope, Mars grows larger in size, enroute to a close approach (“opposition”) to the Earth later in the year.

What Else to See? The Summer Milky Way is best positioned to observe after midnight, so morning observers are most fortunate in June.  Those with binoculars or a small telescope can pick out many star clusters, star clouds and gas clouds (nebulae) by sweeping along the arch of the Milky Way from Cygnus to Sagittarius.

The Moon will either occult or approach very close to stars of 6th magnitude or brighter on the mornings of June 23rd, 24th and 25th.

Specific times for these events are given here.

Good Luck Observing!