Mercury's long period of visibility for observers in the tropics and Southern Hemisphere comes to an end in April. The planet remains visible in the morning twilight sky towards the east, but only for the first two weeks of the month.
The best time to look for Mercury is at the start of April, when it appears highest in the sky. The planets altitude then decreases slightly each morning until it's finally lost to the bright twilight sky. During this time, Mercury brightens from magnitude -0.2 to -0.9. For observers at northern temperate latitudes, Mercury remains unsuitably placed for observation this month.
On April 26th, the planet reaches superior conjunction.
Although now fading in brightness, Venus continues to be visible as a brilliant morning object before sunrise. The planet starts the month at magnitude -4.4 and ends it at magnitude -4.1. Even at its faintest Venus is unmistakable; the planet dazzles above the horizon and is so bright that it's often reported as a hovering UFO!!
During April, Venus is best seen from the Southern Hemisphere and equatorial regions. From these locations, it's visible for more than three hours before sunrise. However, from northern temperate latitudes the planet remains low down and visible for only about one hour or so before sunrise.
The phase of Venus increases from 54 to 66% during the month and on April 25th, the waning crescent Moon passes 4 degrees north of the planet.
Mars reaches opposition in Virgo on April 8th and hence is visible all night. At magnitude -1.5, the planet is a wonderful red-orange beacon of light; positioned just a few degrees northwest of the brightest star in Virgo, blue giant Spica (α Vir - mag. +1.0). Not only is the "Red Planet" at its brightest for the year, but also has its largest apparent size, 15.2 arc seconds. Unfortunately, this is not a particularly favourable opposition. At the last great opposition in 2003, Mars reached magnitude -2.9 and displayed an apparent diameter of 25 arc seconds.
Mars can be a frustrating telescope object. When viewed through a 100mm (4-inch) telescope it appears small but under good seeing conditions it's possible to spot the polar cap as well as other major surface features such as Syrtis Major and various dusty shadings. Larger telescopes fair better with more subtle details visible.
On April 14, Mars is closest to Earth at 0.6176 AU (92.4 million kilometres or 57.4 million miles) distant and on the same day, the almost full Moon passes 3.5 degrees south of the planet.
Jupiter remains a beautiful early evening object during April. The "King of the Planets" is visible as soon as it's dark enough in the constellation of Gemini. Despite fading from magnitude -2.2 to -2.0 during the month, the planet is still brighter than Mars despite the latter reaching opposition in April.
With a current declination of 23 degrees north of the celestial equator, Jupiter favours observers located in the Northern Hemisphere. For example, from latitudes of northern Europe and North America, it remains visible until well after midnight at months end. However, from the Southern Hemisphere the visibility period is considerably less.
On April 6th, the first quarter Moon passes 5 degrees south of Jupiter.
Saturn is now moving retrograde among the faint stars of the constellation of Libra. The stunning "Ringed Planet" is heading towards next month opposition and is visible from early evening, remaining so for the rest of the night. During the month, Saturn brightens slightly from magnitude +0.4 to +0.2 with it apparent size increasing marginally from 18 to 19 arc seconds.
To the naked eye Saturn appears yellowish. Through a telescope the planets rings are a beautiful sight, visible with just a small instrument and currently wide open (tilted at 21.7 degrees). A medium sized telescope of 150mm (6-inch) or 200mm (8-inch) aperture will show a wealth of details including subtle planet formations, divisions in the rings as well as up to half a dozen of Saturn's satellites.
On April 17th, the waxing crescent Moon passes 0.4 degrees south of Saturn and an occultation is visible from South America.
Uranus reaches solar conjunction on April 2nd and the distant planet is unsuitably placed for observation throughout April from northern temperate latitudes. However, those located at southerly latitudes may be able to spot Uranus (mag. +5.9) with binoculars, low down towards the east just before sunrise at the end of the month.
The planet is located in Pisces and on April 27th the thin waning crescent Moon passes 2 degrees north of Uranus.
Neptune, magnitude +8.0, is currently located in Aquarius. Like Uranus, it remains unsuitably placed for observation from northern temperate latitudes during April, but can be seen in the early morning sky from tropical and southern latitudes. By months end it rises up to four hours before the Sun from such locations.
The Solar System's most distant planet is never bright enough to be visible to the naked eye but can be spotted with binoculars and small telescopes. Finding Neptune is currently made easier since brilliant Venus (mag. -4.3) is nearby; the two planets reached their closest point on April 12th when separated by just 0.7 degrees.
Later on April 24th, the waning crescent Moon passes 5 degrees north of Neptune.
Solar System Data Table April 2014
|Date||Right Ascension||Declination||Apparent Magnitude||Apparent Size||Illum. (%)||Distance from Earth (AU)||Constellation|
|Sun||5th Apr 2014||00h 55m 00.7s||05d 53m 02.4s||-26.7||32.0'||100||1.000||Pisces|
|Sun||15th Apr 2014||01h 31m 43.8s||09d 35m 15.5s||-26.7||31.9'||100||1.003||Pisces|
|Sun||25th Apr 2014||02h 09m 01.1s||13d 01m 36.1s||-26.7||31.8'||100||1.006||Aries|
|Mercury||5th Apr 2014||23h 46m 48.0s||-04d 03m 43.1s||-0.3||05.6"||81||1.211||Aquarius|
|Mercury||15th Apr 2014||00h 50m 58.7s||03d 24m 28.1s||-0.9||05.2"||92||1.302||Pisces|
|Mercury||25th Apr 2014||02h 04m 43.1s||12d 02m 51.4s||-2.2||05.1"||100||1.331||Aries|
|Venus||5th Apr 2014||22h 03m 17.8s||-11d 18m 06.7s||-4.4||21.4"||56||0.781||Aquarius|
|Venus||15th Apr 2014||22h 45m 13.9s||-08d 11m 00.5s||-4.3||19.4"||60||0.859||Aquarius|
|Venus||25th Apr 2014||23h 27m 23.1s||-04d 32m 34.9s||-4.2||17.8"||64||0.936||Aquarius|
|Mars||5th Apr 2014||13h 18m 32.6s||-05d 30m 30.2s||-1.4||14.9"||100||0.627||Virgo|
|Mars||15th Apr 2014||13h 03m 56.1s||-04d 21m 18.9s||-1.4||15.2"||100||0.618||Virgo|
|Mars||25th Apr 2014||12h 50m 22.0s||-03d 22m 25.0s||-1.3||14.9"||99||0.628||Virgo|
|Jupiter||5th Apr 2014||06h 44m 38.7s||23d 17m 00.9s||-2.4||41.9"||99||4.702||Gemini|
|Jupiter||15th Apr 2014||06h 45m 09.4s||23d 17m 13.3s||-2.3||40.6"||99||4.853||Gemini|
|Jupiter||25th Apr 2014||06h 47m 02.6s||23d 15m 50.0s||-2.3||39.3"||99||5.011||Gemini|
|Saturn||5th Apr 2014||15h 21m 49.3s||-15d 56m 56.1s||0.4||18.3"||100||9.087||Libra|
|Saturn||15th Apr 2014||15h 19m 32.3s||-15d 47m 06.5s||0.3||18.5"||100||8.999||Libra|
|Saturn||25th Apr 2014||15h 16m 52.3s||-15d 36m 07.4s||0.2||18.6"||100||8.937||Libra|
|Uranus||5th Apr 2014||00h 46m 43.8s||04d 18m 50.9s||5.9||03.4"||100||21.027||Pisces|
|Uranus||15th Apr 2014||00h 48m 49.5s||04d 32m 05.9s||5.9||03.4"||100||21.008||Pisces|
|Uranus||25th Apr 2014||00h 50m 52.2s||04d 44m 56.3s||5.9||03.4"||100||20.962||Pisces|
|Neptune||5th Apr 2014||22h 33m 13.5s||-09d 50m 23.1s||8.0||02.2"||100||30.751||Aquarius|
|Neptune||15th Apr 2014||22h 34m 20.6s||-09d 44m 04.7s||8.0||02.2"||100||30.636||Aquarius|
|Neptune||25th Apr 2014||22h 35m 18.9s||-09d 38m 38.5s||7.9||02.2"||100||30.502||Aquarius|