Mercury passed through inferior conjunction last month (June 19th). However, it moves fast and only a couple of weeks later is once again in view. On July 1st, the planet appears low down in the morning sky above the northeastern horizon from southern latitudes, remaining visible until about the third week of the month. From northern temperate latitudes, Mercury is not suitably placed for observation this month.
Mercury is best placed around July 12th, the date it reaches greatest western elongation (21 degrees). From latitude 35S (approx. equal to Sydney, Cape Town and Santiago), the nearest planet to the Sun will shine at magnitude +0.4 and appear 8 degrees above the northeastern horizon, 45 minutes before sunrise. It should be noted that once past greatest elongation, Mercury continues to brighten as it draws into the Sun. Finding Mercury is always easier when there's a bright marker nearby. Such an opportunity exists from approx. July 14th to 18th when Mercury can be found about 6 degrees below brilliant Venus (mag. -3.8).
Venus continues to be visible as a brilliant object low down above the northeastern horizon during July, rising about 2 hours before the Sun at the start of July, but less by months end.
As the month progresses, Venus fades marginally from mag. -3.9 to -3.8, which is at the bottom end of its magnitude range. However, it's still far brighter than any other planet. On July 2nd, Venus passes 4 degrees north of Aldebaran (α Tau - mag +0.9) and later in the month (24th) the waning crescent Moon passes 4 degrees south of Venus.
Earth reaches aphelion on July 4th at 1.017 AU (approx. 152.1 million km or 94.5 million miles) from the Sun. This corresponds to the greatest distance of the planet from the Sun during its yearly orbit.
Mars resumed direct motion in May and is currently moving southeasterly through the constellation of Virgo. The rapid motion of the planet against the "fixed" background stars can be easily observed during July. At the start of the month the "Red planet" is positioned 6 degrees northwest of Spica (mag. +1.0). On July 12th, it passes 1.4 degrees north of the star and by months end Mars has moved more than 8 degrees away.
The distance between Earth and Mars increases from 148 to 178 million kilometres (92 to 111 million miles) during July. Hence the planets brightness decreases from mag. 0.0 to +0.4 and its apparent diameter from 9.5 to 7.9 arc seconds.
On July 6th the first quarter Moon passes 0.2 degrees north of Mars, with an occultation visible from South America (1:22 UT).
Jupiter reaches solar conjunction on July 24th. The planet may be glimpsed from southern and equatorial latitudes just after sunset during the first few days of the month, low down above the west-northwest horizon. However, even at magnitude -1.8 it won't be long before the giant planet is lost to the bright twilight glare. From northern temperate latitudes, Jupiter isn't visible at all this month.
Saturn remains a well-placed evening object in Libra. The planet begins the month moving retrograde before reaching its secondary stationary point on July 20th. Following this direct motion is once again resumed. To the naked eye Saturn hardly moves during July, appearing like a "fixed" off-white star positioned 2.5 degrees northeast of beautiful double star Zubenelgenubi (α Lib - mag. +2.75).
The planet is visible as soon as it's dark enough towards the south-southeast from northern temperate latitudes or towards the northeast from southern temperate latitudes. It remains visible until after midnight. Saturn fades slightly from magnitude +0.2 to +0.4 with its apparent diameter shrinking from 17.9 to 17.1 arc seconds as the month progress.
On July 8th, the waxing gibbous Moon passes 0.4 degrees south of Saturn with an occultation visible from Argentina and Chile (2:25 UT).
Uranus (mag. +5.9) is now well placed for observation amongst the stars of Pisces. Although the planet was not discovered until telescopic times it's actually visible to the naked eye, albeit faintly. This is a challenge and if you manage to achieve it, you will join a small select group of people. However, essential for the task is a dark moonless site, good seeing conditions and a good star chart to point to the exact planet location.
At the start of July from northern temperate locations, Uranus rises 4 hours before sunrise and by months end is visible from about midnight. The visibility period from locations further south is even better with Uranus visible before midnight by months end.
The planet is positioned 15 degrees south and 20 degrees east of the centre of the "Great Square of Pegasus" and 2 degrees south of star ε Psc (mag. +4.3).
On July 21st, the waning crescent Moon passes 2 degrees north of Uranus.
Neptune (mag. +7.8) is moving retrograde in Aquarius as it heads towards opposition in August. Although observers may be able to spot Uranus with the naked eye they have no chance do the same with Neptune, it's far too faint. However, the planet is relatively easy to spot binoculars.
Neptune is currently located about 30 degrees southwest of the Great Square of Pegasus and just a few degrees northeast of star sigma (σ) Aqr (mag. +4.8). It rises before midnight from northern temperate latitudes and up to a couple of hours earlier from locations further south.
On July 18th, the last quarter Moon passes 5 degrees north of Neptune.
Solar System Data Table July 2014
|Date||Right Ascension||Declination||Apparent Magnitude||Apparent Size||Illum. (%)||Distance from Earth (AU)||Constellation|
|Sun||5th Jul 2014||06h 55m 18.6s||22d 49m 43.3s||-26.7||31.5'||100||1.017||Gemini|
|Sun||15th Jul 2014||07h 36m 09.8s||21d 35m 57.4s||-26.7||31.5'||100||1.016||Gemini|
|Sun||25th Jul 2014||08h 16m 12.6s||19d 45m 25.3s||-26.7||31.5'||100||1.016||Cancer|
|Mercury||5th Jul 2014||05h 37m 29.5s||19d 09m 33.8s||2.0||09.6"||18||0.699||Taurus|
|Mercury||15th Jul 2014||06h 07m 06.4s||21d 07m 50.3s||0.0||07.5"||43||0.902||Orion|
|Mercury||25th Jul 2014||07h 10m 39.9s||22d 23m 27.1s||-1.0||05.9"||75||1.138||Gemini|
|Venus||5th Jul 2014||04h 49m 01.9s||21d 09m 53.7s||-3.9||11.8"||86||1.414||Taurus|
|Venus||15th Jul 2014||05h 40m 25.6s||22d 30m 42.6s||-3.8||11.4"||89||1.466||Taurus|
|Venus||25th Jul 2014||06h 32m 45.1s||22d 49m 13.3s||-3.8||11.0"||91||1.515||Gemini|
|Mars||5th Jul 2014||13h 12m 11.8s||-08d 15m 53.0s||0.1||09.2"||87||1.015||Virgo|
|Mars||15th Jul 2014||13h 28m 44.4s||-10d 06m 49.5s||0.2||08.7"||87||1.080||Virgo|
|Mars||25th Jul 2014||13h 47m 20.3s||-12d 03m 38.6s||0.3||08.2"||87||1.145||Virgo|
|Jupiter||5th Jul 2014||07h 57m 39.3s||21d 03m 52.8s||-1.8||31.6"||100||6.237||Gemini|
|Jupiter||15th Jul 2014||08h 06m 54.2s||20d 37m 53.5s||-1.8||31.4"||100||6.270||Cancer|
|Jupiter||25th Jul 2014||08h 16m 10.3s||20d 09m 55.7s||-1.8||31.4"||100||6.282||Cancer|
|Saturn||5th Jul 2014||14h 59m 26.6s||-14d 33m 56.6s||0.4||17.8"||100||9.317||Libra|
|Saturn||15th Jul 2014||14h 58m 42.5s||-14d 33m 25.3s||0.4||17.6"||100||9.462||Libra|
|Saturn||25th Jul 2014||14h 58m 36.3s||-14d 35m 42.0s||0.5||17.3"||100||9.618||Libra|
|Uranus||5th Jul 2014||01h 00m 41.2s||05d 44m 43.7s||5.8||03.5"||100||20.056||Pisces|
|Uranus||15th Jul 2014||01h 01m 03.1s||05d 46m 40.6s||5.8||03.5"||100||19.889||Pisces|
|Uranus||25th Jul 2014||01h 01m 07.1s||05d 46m 46.1s||5.8||03.6"||100||19.724||Pisces|
|Neptune||5th Jul 2014||22h 36m 49.1s||-09d 32m 15.5s||7.9||02.3"||100||29.372||Aquarius|
|Neptune||15th Jul 2014||22h 36m 15.1s||-09d 35m 56.4s||7.8||02.3"||100||29.244||Aquarius|
|Neptune||25th Jul 2014||22h 35m 31.7s||-09d 40m 30.1s||7.8||02.3"||100||29.136||Aquarius|