2011 Sky Calendar

2011 Sky Calendar

Seasons and the Sun

Monday, January 3    
Earth at Perihelion (closest to the Sun – distance =91,422,023 miles or 147,098,036 km)

Sunday, March 20
Vernal Equinox at 1:21pm HST – This is the official beginning of the season of Spring. On equinox days the Sun rises directly East and sets directly West.  There is twelve hours of daylight and twelve hours of night – hence it’s meaning, equal night.  From here forward to the Summer Solstice the length of daylight hours increase, and nights get shorter.

Tuesday, June 21
Summer Solstice at 7:16am HST – First day and official beginning of Summer.  This day has the northernmost sunrise and sunset, highest noon position of the Sun.  On this day we have the longest amount of daylight and shortest amount of night.

Monday, July 4
Earth at Aphelion (farthest from the Sun – distance =94,528,559 miles or 152,096,452 km)

Thursday, September 22
Autumnal Equinox at 11:05pm HST – The season of Fall officially begins.  On equinox days the Sun rises directly East and sets directly West.  There is twelve hours of daylight and twelve hours of night – hence it’s meaning, equal night.  From here forward to the Winter Solstice daylight hours decrease, and nights get longer.

Wednesday, December 21
Winter Solstice at 7:30 HST – Winter officially begins. This day has the southernmost sunrise and sunset, lowest noon position of the Sun.  On this day we have the longest night, and shortest amount of daylight.

HST = Hawaiian Standard Time (GMT – 10h or 10hours behind Greenwich Mean Time)
Note: Hawaii does NOT observe Daylight Savings Time

For details on the night sky for the month of January click here, for February click here, and for March skies, click here.

Phases of the Moon – 2011

Eclipses in 2011

 Eclipses in 2011
Total Solar Eclipse occurs when the New Moon passes precisely between the Sun and the Earth, blocking the Sun from our view along a narrow path. This year there is NOT a total solar eclipse anywhere in the world.  The next one takes place November 13, 2012!  

December 10 – Total Lunar Eclipse
A Total Lunar Eclipse takes place when the Full Moon passes through the Earth’s shadow.  This causes the Moon to dim in appearance and often it turns a coppery red, or dark brown color during the event at totality.  Lunar eclipses are easier to see as they are visible from half of the Earth at one time, unlike Solar eclipses where you need to be in a specific location.  Partial phase of the eclipse will begin at 2:45am HST.  This phase will last 62 minutes and the Moon will continue to dim until totality which is at 4:06am HST.  Totality will last 51 minutes.  The color during totality depends on the Earth’s atmosphere and ranges from bright orange to the deep brown depending on dust and aerosols suspended in it.  The more of this material, the darker it will appear.  Totality ends at 4:57am HST and the partial phase will then continue until 6:17am HST.  Lunar eclipses are completely safe to view with the unaided eye!

Major Meteor Showers in 2011

Meteor showers occur when the Earth passes through the debris left over by comet tails or other objects that orbit the Sun. Meteors appear as flashes of light and are sometimes called "shooting or falling stars" even though they really are not stars at all. Viewing meteors is best with the unaided eye on a moonless night at a dark location. 

*The Zenith Hourly Rate is the maximum rate per hour at the peak of the shower. While the meteor showers peak on specific dates, meteors are often visible for a few days prior to and after the peak date. 

Planet Viewing for 2011

Mercury is a challenging planet to see as it never is far from the Sun.  Look for it at sunset the third week in March, the third week in July, and the second week of November.  For morning glimpses of the planet try the second week of January, the first week of May, first week of September, and the third week of December.

Venus starts the year high in the morning sky and rises over three hours before the Sun in early January. It remains a nice morning object for the first half of 2011. It will disappear into the glow of sunrise in July and August, and then reappear very low in the evening sky in September of 2011. Venus will stay very low in the western sky in late 2011.

Mars starts the year very close to the Sun after sunset and will be difficult to see.  It will disappear into the glow of sunset by mid-month and re-emerge in the morning sky around the beginning of March. It will slowly get higher throughout the year. Throughout 2011 it is relatively faint.


Jupiter starts 2011 high in the west-southwest at sunset. Its four Galilean Moons are always easily visible in binoculars. It will sink lower each day and by late March Jupiter is lost in the glare of sunset.  It will re-emerge in the morning sky around the beginning of May.
By July, Jupiter is rising three hours prior to the Sun. In early August, it will around midnight.
Jupiter will be in opposition October 29th and will rise at sunset, be highest in the sky at midnight, and set at sunrise. Jupiter rises a few minutes earlier each night thereafter and be well placed for observing in the evening sky for the rest of 2011.

Saturn starts the year as a morning object rising about 1 am. It will be well positioned for observing high in the early morning sky during the early part of 2011.  It is in opposition on April 3rd being visible from sunset to sunrise this evening.  By early August, it will be low in the southwest as they sky gets dark. It will disappear into the glow of sunset in mid-September and re-emerge in the morning sky in late October. By early December, Saturn is rising three hours before sunrise.  This year the rings will continue to open up and our view of them in small telescopes will improve.
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The Days of the Week

The origins of our days of the week come from the five planets visible to the unaided eye together with the Sun and the Moon. Monday or Moon Day, Sunday or Sun Day, Saturday or Saturn Day are very apparent and are Old English adaptations of the Roman names. Tuesday was named in honor of Mars (Tiw's Day was an Old English adaptation of the Norse god of war). Wednesday was in honor of Mercury (Woden’s Day from the Germanic god of wisdom). Thursday was in honor of Jupiter (Thor's Day to the Norse god of thunder associated with Jupiter). Friday was in Honor of Venus (Frige’s Day from Germanic god of beauty and love associated with Venus).