You are hereTHIS MONTH'S SKY - January 2011

THIS MONTH'S SKY - January 2011

Celestial Events -- January 2011




Jupiter will pass closely by Uranus on January 2nd.  The two planets had passed on June 6 and September 22.  The triple conjunction (as it is called) occurs because both planets moved forward, then retrograde, then back to forward during this period.  (Jupiter's retrograde loop being much larger than Uranus's).

This is the last opportunity for awhile to easily find Uranus  (The next conjunction of Jupiter and Uranus will be in 2024). Because bright Jupiter is easy to spot, and Uranus is nearby, a star chart like the one to the right can be used to star-hop fro Jupiter to sixth-magnitude Uranus.  For scale, on January 2 the two planets will be 33' (arc minutes) or just over ½° apart.  Be careful not to mistake the fifth-magnitude star 20 Piscium  nearby (Uranus will be upper right from Jupiter; 20 Piscium below Jupiter.).


Jupiter and Uranus in January
(5-day intervals)


The morning sky is still the best place to see planets.  Saturn rises just after midnight on New Year's Day and two hours earlier at the end of January.  The best time to see it is when it is highest -- just before dawn.  In Virgo, Saturn's rings are easy to see with a scope, 10° from edge-on..  On January 27 Saturn begins retrograde motion (reversing its motion with respect to the stars)..

Well below Saturn but easy to spot is brilliant Venus.  As January begins it rises at 4 AM, over three hours before the Sun, and can be seen in a dark sky if you get up early enough.  Venus is at greatest elongation from the Sun, 47°, on January 8.

Mercury is also having a good appearance for most of January.  Look for it lower left of Venus early in the month.  On January 9, it is at greatest elongation (23°) from the Sun.

Finally, the Moon joins the party at the beginning and end of January.  On the 1st it is above Antares, the bright star in Scorpius.  The following day it is near Mercury.  After making a trip around the sky, the Moon is positioned between Venus and Antares on the 29th, and below Venus the next day.

Saturn, Venus, Moon, Mercury
(plus Spica, Antares)
7 AM January 1

Saturn, Venus, Mercury
(plus Spica, Antares)
7 AM January 15

Saturn, Venus, Moon, Mercury
(plus Spica, Antares)
7 AM January 31




Click to get sky charts and a description of the sky for this month.



MERCURY has a good appearance in the evening sky.  In the first 10 days of January it is up well before sunrise.  It begins the month in Ophiuchus, but enters Sagittarius on the 6th. Though it slowly falls back towards the Sun during the next few weeks, it can be seen for most of the month. .

VENUS (magnitude -4.6 to -4.3, diameter 27.1" to 19.8", phase 46% to 61% lit) rises almost four hours before the Sun in early January.  Beginning the month in Libra, on the 10th it enters Scorpius and on the 14th goes into Ophiuchus.  Venus is at greatest elongation on the 8th. Although Venus remains almost the same distance from the Sun all month (46° - 47°), it is moving toward the southernmost part of the ecliptic.  By the end of January it will be only three hours ahead of the Sun.

MARS is too close to the Sun to be seen this month.  It is in conjunction with the Sun on February 4.

JUPITER (magnitude -2.3 to -2.2, diameter 38.7" to 35.8") in Pisces, continues to dominate the western sky in the evening hours.

SATURN (magnitude +0.8 to +0.7, diameter 17.2" to 18.1") in Virgo rises about 12:30 AM at the start of January and about 10:30 AM at month's end.  Its rings continue to open, 10° from edge on.

URANUS (magnitude +5.9, diameter 3.4") in Pisces, is very close to Jupiter early in the month distance closes to 36' (0.6).

NEPTUNE (magnitude +8.0, diameter 2.2") moves from Capricornus to Aquarius on January 23.

PLUTO (magnitude +14.1, diameter 0.1") is still in western Sagittarius.  Its nearness to the Sun makes it an impossible target .

On the morning of January 1 the MOON passes the bright star Antares.  The next evening it is below right of Mercury.  New Moon occurs on the 4th.  On the 9th and 10th the Moon passes Jupiter.  First Quarter Moon occurs on the 12th and Full Moon seven days later.  On January 25, look for the Moon grouped with Saturn and the star Spica.  Last Quarter Moon is the following evening.  On the 29th a pretty crescent Moon is near Venus and Antares, and the following morning a smaller crescent Moon is near Venus.


(Times in EST)

January 1 The crescent Moon is 4°  above the star Antares this morning.
January 2 The Moon, now very thin, is 4⅔°  below right of Mercury this morning.
January 3 Earth is at perihelion, its closest to the Sun.  It is "only" 91,407,000 miles from the Sun.
JANUARY 3 - 4 JUPITER IS ½° FROM URANUS THESE EVENINGS.  Look for Uranus to Jupiter's upper right.  (Don't confuse it with the star 20 Piscium to Jupiter's lower right.)
January 4 The Quadrantid meteor shower peaks.
  New Moon at 4:03 AM.  There is a partial solar eclipse for parts of Europe, Africa and Asia.
January 8 Venus is at greatest elongation west from the Sun (47°).
January 9 Mercury is at greatest elongation west from the Sun (23°).
  The waxing crescent Moon is 9° to Jupiter's right this evening.
January 10 The Moon is now 9° above Jupiter.
January 12 First Quarter Moon at 6:31 AM.
January 19 Full Moon at 4:21 PM.
January 25 The waning Moon forms a pretty grouping with Saturn and the star Spica.  Through the night it approaches Spica, with Saturn poised above both.
January 26 Last Quarter Moon at 7:57 AM.
January 27 Saturn is stationary, beginning retrograde movement.
January 29 The crescent Moon is between Venus and Antares this morning.
January 30 The Moon is 6° below Venus this morning.