Mercury is at superior conjunction with the Sun on 7th February. At the time of conjunction, the planet will be on the opposite side of the Sun, some 1.40 AU (209 million km or 131 million miles) distant from Earth. During the last week of February, Mercury is visible as a very low down difficult evening star (mag –0.8), only a few degrees above the western horizon shortly after sunset. The view is better for northern hemisphere observers compared to their southern counterparts.
Venus is a brilliant evening object in Pisces, visible towards the west shortly after sunset. With an apparent magnitude of –4.1, it is unmistakable and by months end will set up to 4 hours after the Sun. On the evening of 9th February, Venus and Uranus (mag. 5.9) will be less than half a degree apart. Later in the month (25th) a thin crescent Moon will pass 3 degrees north of Venus.
Mars is now moving in a westerly retrograde motion, beginning the month in Virgo before heading swiftly back into Leo. The red planet rises well before midnight and with an apparent magnitude of -1.0 is nearly as bright as Sirius. Telescopically, the apparent diameter of Mars is increasing nicely, from 11.8 arcseconds at the start of the month to 13.8 arcseconds at the end.
An almost full Moon will pass about 10 degrees south of Mars on 10th February. At the end of the month, Mars will be approx. 15 degrees from Regulus (mag. 1.35), the brightest star in Leo.
Jupiter is in Aries and still reasonably placed for observation as an evening object during February, although now well past opposition. The giant planet sets a little earlier each night as the month progresses. At the end of February it sets about 2 hours later than at the beginning of the month. During this time the apparent Jovian disk size shrinks from 39 to 36 arcseconds.
A crescent Moon will be a few degrees north of Jupiter on 27th February. The gap between Jupiter and Venus is continuing to close; at the end of February Jupiter is only 12 degrees north of Venus.
Saturn is located in Virgo, about 7 degrees from bright star Spica (mag. 1.0). The rings are wide open and well situated for observation. Saturn is now moving towards opposition and at the start of the month rises about half way through the night. At the end of the month it appears an hour or two earlier.
On February 8th Saturn is stationary before proceeding westerly in retrograde motion. However, the position of Saturn will change little during the month; only about half a degree in relation to the fixed stars. The night of 12/13th February will see the Moon pass within a few degrees of both Saturn and Spica.
During February the apparent diameter of Saturn is a healthy 18 arcseconds.
Uranus is located in Pisces and visible as an evening object, best seen during the first part of the month. However, it won't be long before the planet is lost to the evening twilight. A good time to look for this distant world is on the evening of 9th February when mag 5.9 Uranus is just half a degree south of Venus (mag. -4.0).
Neptune is in conjunction with the Sun and not observable during the month.
Solar System Data Table - February 2012
|Date||Right Ascension||Declination||Mag.||Size||Illum. (%)||Distance (AU)||Constellation|
|Sun||5th Feb 2012||21h 12m 08.8s||-16d 09m 53.9s||-26.7||32.4'||100||0.9858||Capricornus|
|Sun||15th Feb 2012||21h 51m 49.1s||-12d 57m 12.3s||-26.7||32.4'||100||0.9875||Capricornus|
|Sun||25th Feb 2012||22h 30m 18.0s||-09d 23m 23.4s||-26.7||32.3'||100||0.9897||Aquarius|
|Mercury||5th Feb 2012||21h 07m 45.7s||-18d 39m 57.7s||-1.2||4.8"||99||1.4063||Capricornus|
|Mercury||15th Feb 2012||22h 17m 20.3s||-12d 26m 34.5s||-1.1||5.0"||98||1.3362||Aquarius|
|Mercury||25th Feb 2012||23h 23m 27.9s||-04d 16m 28.6s||-0.8||5.8"||83||1.1681||Aquarius|
|Venus||5th Feb 2012||23h 47m 00.5s||-02d 10m 10.2s||-4.0||15.5"||73||1.0799||Pisces|
|Venus||15th Feb 2012||00h 29m 10.1s||+03d 03m 51.7s||-4.1||16.5"||70||1.0127||Pisces|
|Venus||25th Feb 2012||01h 10m 42.9s||+08d 11m 29.7s||-4.2||17.7"||66||0.9428||Pisces|
|Mars||5th Feb 2012||11h 37m 28.6s||+06d 42m 55.9s||-0.7||12.2"||97||0.7676||Leo|
|Mars||15th Feb 2012||11h 29m 43.0s||+07d 46m 00.0s||-0.9||13.1"||98||0.7165||Leo|
|Mars||25th Feb 2012||11h 17m 38.7s||+09d 08m 21.1s||-1.1||13.7"||99||0.6842||Leo|
|Jupiter||5th Feb 2012||02h 05m 08.2s||+11d 33m 34.3s||-2.2||38.7"||99||5.0972||Aries|
|Jupiter||15th Feb 2012||02h 10m 27.4s||+12d 04m 14.4s||-2.1||37.5"||99||5.2513||Aries|
|Jupiter||25th Feb 2012||02h 16m 39.3s||+12d 38m 38.6s||-2.1||36.5"||99||5.3970||Aries|
|Saturn||5th Feb 2012||13h 53m 24.9s||-08d 53m 18.1s||0.6||17.7"||100||9.3830||Virgo|
|Saturn||15th Feb 2012||13h 53m 19.1s||-08d 49m 56.9s||0.5||18.0"||100||9.2282||Virgo|
|Saturn||25th Feb 2012||13h 52m 33.7s||-08d 43m 05.6s||0.5||18.3"||100||9.0864||Virgo|
|Uranus||5th Feb 2012||00h 08m 17.0s||+00d 07m 53.6s||5.9||3.4"||100||20.7421||Pisces|
|Uranus||15th Feb 2012||00h 09m 57.6s||+00d 19m 04.3s||5.9||3.4"||100||20.8571||Pisces|
|Uranus||25th Feb 2012||00h 11m 48.2s||+00d 31m 17.1s||5.9||3.4"||100||20.9494||Pisces|
|Neptune||5th Feb 2012||22h 09m 18.8s||-11d 58m 01.2s||8.0||2.2"||100||30.9547||Aquarius|
|Neptune||15th Feb 2012||22h 10m 45.0s||-11d 50m 08.4s||8.0||2.2"||100||30.9850||Aquarius|
|Neptune||25th Feb 2012||22h 12m 12.2||-11d 42m 10.0s||8.0||2.2"||100||30.9864||Aquarius|