Mercury is one of the most difficult visible planets to spot, always close to the glare of the sun. In the week ahead there is a rare opportunity to see Mercury. The planet is low in the west southwestern sky, above the bright planet Jupiter, soon after sunset. The two are a pair amid the light of twilight. They are less than 2 degrees apart tonight.

Temperature: Precip.

Day Max. Min. Inches.

Fº Fº

Dec. 19 41 27 .00

Dec. 20 37 31 1.08*

Dec. 21 36 31 Trace

Dec. 22 47 19 .62*

Dec. 23 24 18 .00

Water temperature in Edgartown harbor: 38º F.

The nights ahead this weekend are moonless. New Moon is tomorrow. The moon appears only briefly on Sunday night, when it is right under the bright planet Jupiter and Mercury. All three are close to the horizon and tough to see.

Temperature: Precip.

Day Max. Min. Inches.

Fº Fº

Dec. 12 59 41 1.64

Dec. 13 58 27 Trace

Dec. 14 33 19 .00

Dec. 15 52 32 .02

Dec. 16 59 40 .21

Dec. 17 44 33 .42

Dec. 18 53 31 .07

Water temperature in Edgartown harbor: 46º F.

For those up really late tonight there is an astronomical event worth noting. Tonight’s last quarter moon appears close to the ringed-planet Saturn. Both are in the zodiacal constellation Virgo. Saturn is the brightest “star” in the area and has a yellowish tint. Find the moon and the solar system’s second largest planet is nearby.

Extreme tides are taking place this week, the most tonight and this weekend. The reason is astronomical. The moon is both full and close, closer than at any time since 1993.