Go Stargazing: April Edition

Saturn dominates April 2011 skies because yesterday, on April 3, the Earth passed between the sun and Saturn.  This alignment, called opposition, puts Saturn in the sky all night long; it rises in the east at dusk and sets in the west at dawn.

Venus’ apparition as a dazzling morning star is coming to an end.  It is getting lower and lower in the sky each morning as the angle between the solar system plane and the horizon gets shallower.  Face southeast at dawn, and you can’t miss it of you have a clear horizon.

Jupiter is directly behind the sun from our perspective on April 6 and therefore invisible all month.

Mars also remains lost in the sun’s glare all month.

A swath of brilliant winter stars continues to dominate evening skies.  These stars are now high in the west at dusk and set in late evening.  Orion, the Hunter, is in the southwest as April begins.  His two dogs, represented by Sirius and Procyon, are to his left.  Beside Orion in the west is Taurus, the Bull with Aldebaran as its eye. Gemini, the Twins, are above Orion.  The Big Dipper is to the upper right of the North Star, with its handle pointing down and to the right.  From that handle, you can ‘arc to Arcturus’ and then ‘speed on to Spica’; those stars are low in the east at dusk.  Leo, the Lion, passes almost overhead in late evening.

Below Sirius, just above the southern horizon in late twilight, is a star second only to Sirius in brightness.  This is Canopus, which marks the keel (bottom) of the legendary ship Argo Navis.  Canopus is so far south, in fact, that most Americans never see it.  From the Gulf Coast, however, Canopus does rise.  In early April, you can still see it in the evening just after dusk.

Creative Commons License photo credit: ComputerHotline

Moon Phases in April 2011:

New Moon                      April 3, 9:32 a.m.

1st Quarter                     April 11, 7:05 a.m.

Full Moon                       April 17, 9:43 p.m.

Last Quarter                  April 24, 9:46 p.m.

Sunday, April 24, is the first Sunday after the first Full Moon of spring.  Therefore, this is Easter Sunday.  This happens to be the second latest possible date for Easter.  Easter will fall on April 25, the absolute latest date, in 2038.

Go Stargazing! April Edition

 Creative Commons LicensePhoto Credit: myyorgda

Saturn was up all night last month, and will remain well placed in the evening sky this month.  You can spot it in the east at dusk.  Mercury is briefly visible at dusk in late April.  Mercury is nowhere near as dazzling as Venus, but is bright enough to appear in twilight while most stars aren’t.  Look low in the west northwest at dusk, right over the point of sunset, beginning mid-month.  Mercury appears farthest from the Sun on April 26; the crescent moon that night will help you find it. 

Jupiter, in the southeast at dawn, is the brightest thing in that part of the sky (Venus is brighter but is located due east) unless the Moon is nearby (as it is on April 19).  Mars remains close to the horizon at dawn much of the spring, and takes longer to fully emerge into the morning sky.  Venus can help you find Mars towards the end of the month.  Beginning about mid-month, Mars appears to the lower left of the much brighter Venus.  Mars appears under Venus (between Venus and the horizon) on April 27.

Venus enters the morning sky in dramatic fashion this month.  Look due east right as day begins to break for the brightest thing there except for the Moon.  You’ll see Venus noticeably higher in the sky each passing day.   On the morning of April 22, the crescent Moon is very close to Venus.  In fact, the Moon actually occults (blocks) Venus shortly after sunrise that morning.  Venus remains the ‘morning star’ for the rest of 2009.  

Dazzling Orion shifts westward now that spring is underway.  His belt now points up right Aldebaran, the eye of Taurus, the Bull, which sets with Orion in the west.  The Dog Stars Sirius and Procyon are also found in the west, to Orion’s left.  Sirius is the brightest star we ever see at night.  Now above Orion are two stars of similar brightness less than five degrees apart.  These are Castor and Pollux, marking the heads of Gemini, the Twins. 

 Creative Commons LicensePhoto Credit: myyorgda

Look in the east at dusk for stars in the shape of a backwards question mark, with a right triangle below that.  These stars are in the constellation Leo the Lion.  Saturn rises in Leo.  The Big Dipper is highest on spring evenings.  From the Big Dipper’s handle, you can ‘arc to Arcturus.’  Arcturus, in the east at dusk, is the fourth brightest star we ever see at night and will be the brightest one in the sky once Sirius sets. Continuing the curve of the Big Dipper’s handle past Arcturus, you can ‘speed on to Spica, a star low in the southeast at dusk.  Spica represents a stalk of wheat held by Virgo, the Virgin, who is in fact the harvest goddess.

Moon Phases in April 2009:

First Quarter                     April 2, 9:33 am
Full Moon                          April 9, 9:55 am
Last Quarter                     April 17, 8:38 pm
New Moon                         April 24, 10:23 pm

Easter is the first Sunday after the Paschal Full Moon, which is the first moon whose 14th day is on or after March 21 (the  “vernal equinox“).