July 2012: the moon and planets

Posted: June 30, 2012 in Moon, Observing, Planets

Here’s a brief run down of where the planets are going to be in July.  Check out my planetary elongation chart to see when conjunctions are going to happen in 2012.

The Moon

The principal phases of the moon this month are:

Full moon

Last quarter

New moon

First quarter

 July 5th  July 11th  July 19th  July 26th
The Planets

Mercury is an evening sky object and it reaches greatest elongation east of the Sun on July 1st at 26°E.  However, it sets shortly after sunset so is not likely to be seen by UK astronomers.

Venus is a brilliant object, at magnitude -4.5, in the morning sky among the stars of Taurus.  During the first week of July it lies not far from Jupiter and the Hyades star cluster.  Telescopes show Venus to be a waxing crescent and the angular diameter is decreasing as the planet recedes from Earth.

Looking northeast on July 7th at 3.10am. Aldebaran, Venus, Jupiter and the Pleiades make an almost perfect line in the sky.

Earth is at aphelion – the furthest distance from the Sun of the year – on July 5th.  The distance between our planet and the Sun will be just over 94½ million miles that day.

Mars is an evening sky object in the constellation Virgo.  The Red Planet is a fading first magnitude star and it is visible low in the western sky for a few hours after twilight has fallen.  Mars is now so distant that high magnifications on well collimated telescopes will be required to see the gibbous disk of the planet.

Jupiter is shining at magnitude -2.1 in the morning sky before dawn.  It will rise a little earlier each successive morning.  Look for Jupiter near the northeast horizon near the more brilliant Venus.  On the morning of July 15th the Moon will pass very close to Jupiter.  From the south of England the moon will graze [PDF] or completely cover the distant planet.  From Northumberland we’ll get the kind of view shown below.

Crescent moon and Jupiter at 3.10am on July 15th as seen from Northumberland.

Saturn is visible in the evening sky, in the west, for a few hours after dark.  Saturn is marginally brighter than Mars, also in the constellation Virgo.  Saturn is to be found 5 degrees north of Spica, the brightest star in Virgo and about the same magnitude as Saturn.

Uranus and Neptune are best seen in the morning sky.  Uranus shines like a star of magnitude +5.8 in the constellation Pisces.  From exceptionally dark skies Uranus is a naked eye object for keen sighted observers.  Binoculars will show it easily enough.  Neptune resides in the constellation Aquarius and telescopes are required to see this 8th magnitude planet.  The positions of both worlds are shown in the chart below:

Positions of Uranus and Neptune at 2am on July 15th 2012.


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