The Planets this Month - February 2017

Mercury

Mercury is now heading towards superior conjunction, which it reaches on March 6th. From southern and tropical regions, the planet is visible in the morning sky during the first half of February. However, it remains low down above the eastern horizon. For example, on February 1st, Mercury shines at mag. -0.2 and will be 7 degrees high, one hour before sunrise from mid-southern latitudes. Each subsequent morning, it falls slightly back towards the Sun until finally lost to the bright twilight glare during the second week of the month. From mid-latitude northern locations, it's not observable.

On February 7th, Mercury reaches aphelion when it will be 0.467 AU (approx. 69.9 million kilometres or 43.4 million miles) from the Sun.

Venus

Venus remains a brilliant evening object throughout the month. The planet shines as an unmissable beacon of light above the western horizon. On February 17th, greatest illumination occurs when it peaks at mag. -4.9, which is about as bright as it ever gets. Positioned about 6 degrees east of Venus is Mars (mag. +1.2).

From northern temperate latitudes, Venus sets 4 hours after the Sun at the start of February, decreasing to 3 hours by months end. Southern Hemisphere observers don't have it so favourable; the visibility period is about 2 hours shorter.

On February 20th, Venus reaches perihelion at 0.718 AU (approx. 107 million kilometres or 66.7 million miles) from the Sun. The apparent size of the planet increases this month from 31 to 46 arc seconds with its illuminated phase decreasing from 40 to 18 percent. On the last day of the month, the waxing crescent Moon passes 10 degrees south of Venus.

Mars

Mars is now long past its best but remains visible in the evening sky, towards the west. The Red planet is moving direct in Pisces and as previously mentioned is positioned a few degrees from Venus. During February, its brightness fades slightly from mag. +1.1 to +1.3. Telescopically, Mars spans only 5 arc seconds in diameter and therefore too small for serious observational work.

On February 1st, the waxing crescent Moon passes 2 degrees south of Mars, providing nice evening viewing. Later on the 27th, Mars passes 0.6 degrees north of Uranus with both objects visible in the same binocular field of view.

Jupiter

Jupiter is located in Virgo and continues to increase in brightness and apparent size as it heads towards opposition in April. At the start of February, the Solar System's largest planet is a brilliant morning object, rising before midnight. By months end, it's visible during mid-evening.

This month, Jupiter brightens from mag. -2.1 to -2.3 with its apparent size improving from 39 to 42 arc seconds. On February 2nd, the planet reaches its first stationary point, which signals the start of this year's opposition period. Afterwards retrograde motion commences. First magnitude Spica, the brightest star in Virgo, is positioned 4 degrees south of Jupiter.

On February 15th, the waning gibbous Moon passes 3 degrees north of Jupiter. The following day, Jupiter reaches aphelion for the first time since 2005, when it moves out to 5.45 AU (approx. 816 million kilometres or 507 million miles) from the Sun. The planet then heads back towards perihelion, which it reaches on January 20, 2023. On this day, Jupiter will be located 4.95 AU (approx. 740 million kilometres or 460 million miles) from our star.

Jupiter during February 2017 - pdf format (credit:- freestarcharts)

Jupiter offers something for all types of optical instrument. Binoculars reveal a small off-white coloured disk, without detail. Also visible are the four large Galilean moons (Io, Europa, Ganymede and Callisto), which continuously change position as they orbit the planet. Occasionally all four are visible, but often some are hidden from view as they pass in front of, or behind the giant planet's disk.

When viewed through a telescope, Jupiter is a stunning sight. Even a small 80mm (3.1 inch) refractor shows the main equatorial cloud belts. Larger telescopes reveal much more details, including smaller belts, ovals, festoons, dark regions and the Great Red Spot.

Saturn

Saturn, mag. +0.6, is an early morning object moving direct. It starts the month in Ophiuchus, before crossing the constellation boundary and into Sagittarius on February 23rd. With a declination of 22 degrees south, the planet is better placed from southern and tropical latitudes, where it rises over 3 hours before the Sun at the beginning of February. The visibility period continues to improve as the month progresses and by months end, Saturn can be seen just after midnight. From northern temperate locations, the planet remains low down, rising around 4am local time on February 28th.

Through a telescope, Saturn's most famous feature is of course its spectacular rings. Even a small telescope will show them and they are currently displayed wide open at a 26-degree tilt. In addition, small scopes also show some of the larger Moons, including Titan.

The waning crescent Moon passes 4 degrees north of Saturn on February 20th.

Saturn during February 2017 - pdf format (credit:- freestarcharts)

Uranus

Uranus, mag. +5.9, remains an early evening binocular object during February. The seventh planet from the Sun and the first to be discovered in the telescope era is moving slowly direct in Pisces. It's visible towards the west as soon as dark enough. Positioned about 1.5 degrees west of Uranus is zeta Psc (ζ Psc - mag. +4.9). Located in the same region of sky as Uranus are Mars and Venus. Of course, there is no comparison in brightness. Mars is 70x brighter than Uranus with Venus 19,000x brighter! As previously mentioned, Mars passes 0.6 degrees north of Uranus on February 27th.

For those located at mid-northern latitudes, Uranus can be seen for some 5 hours on February 1st, reducing to around 3 hours by months end. From southern locations its visibility period is only about half as much.

At the beginning of the month, the thin waxing crescent Moon passes 3 degrees south of Uranus (Feb 2nd).

Venus, Mars and Uranus during February 2017 - pdf format (credit:- freestarcharts)

Neptune

Neptune is located in Aquarius. The distant blue planet is heading towards solar conjunction, which it reaches on March 2nd. Consequently, it's positioned inconveniently close to the Sun throughout the month and not suitably placed for observation.

Solar System Data Table February 2017