Moab Happenings Archive
Return to home

SKY HAPPENINGS

Moab UT (at City Hall)
38O34’ N Latitude 109O33’ W Longitude
4048 ft - 1234 m

The Sky for March 2011
By Faylene Roth

 

March
Sunrise and Sunset

DATE

SUNRISE

SUNSET

1

6:51am

6:11pm

2

6:49am

6:12pm

3

6:48am

6:13pm

4

6:46am

6:14pm

5

6:45am

6:15pm

6

6:43am

6:16pm

7

6:42am

6:17pm

8

6:40am

6:18pm

9

6:39am

6:19pm

10

6:37am

6:20pm

11

6:36am

6:21pm

12

6:34am

6:22pm

13

7:33am

7:23pm

14

7:31am

7:24pm

15

7:30am

7:25pm

16

7:28am

7:26pm

17

7:27am

7:27pm

18

7:25am

7:28pm

19

7:24am

7:29pm

20

7:22am

7:30pm

21

7:20am

7:31pm

22

7:19am

7:32pm

23

7:17am

7:33pm

24

7:16:am

7:34pm

25

7:14am

7:35pm

26

7:13am

7:36pm

27

7:11am

7:37pm

28

7:10am

7:38pm

29

7:08

7:39pm

30

7:06

7:40pm

31

7:05

7:40pm

DAYLENGTH
Daylight outpaces darkness this month. March 18 marks the day when the period from sunrise to sunset exceeds 12 hours. In addition, the change to Daylight Savings Time on March 13 shifts the period of daylight forward one hour, which allows an extra hour of daylight each afternoon. Civil twilight extends the useful period of daylight another half hour before sunrise and after sunset. Nautical twilight continues through the next half hour during which the overhead sky fades to darkness. The horizon fades to black during the final 30 minutes of astronomical twilight. (The reverse progression occurs at sunrise.) The time of sunrise and sunset assumes a flat horizon. Actual time may vary depending upon the landscape.

MOON HAPPENINGS
March 4 – New Moon occurs at 1:46pm March 12 – First Quarter Moon sets after midnight March 19 – Full Moon rises at 7:55pm March 26 – Last Quarter Moon rises after midnight
(The time of moonrise and moonset assumes a flat horizon. Actual time may vary.)

VERNAL EQUINOX
Spring officially arrives in the northern hemisphere March 20 at 5:21pm MDT. That marks the moment when the sun’s path along the ecliptic crosses the celestial equator in the constellation Pisces. Watch the sun rise and set on this day to determine due east and due west. To find the celestial equator in the night sky trace a line through the three stars of Orion’s Belt eastward and parallel to the horizon. The celestial equator passes between Procyon (bright star of Canis Minor) and Sirius (very bright star in C. Major) and extends to Spica (bright star in Virgo). The ecliptic crosses the celestial equator at two points. On September 23 at the autumnal equinox, the sun’s path along the ecliptic crosses the celestial equator in Virgo about 20 degrees west of Spica. On the vernal equinox the two lines cross in Pisces.

ZODIACAL LIGHT
Turn your gaze towards the western horizon during the first week of March just as astronomical twilight ends. As the rosy glow of sunset fades to darkness, look for a whitish beam of light shooting up into the sky from the region where the sun disappeared below the horizon. The zodiacal light appears before and after each equinox. At this time of year the sun is rising and setting nearly due east and due west which shoots the last rays of the sun in a nearly perpendicular line that can be seen 50-60 degrees above the horizon under dark sky conditions. The zodiacal light illuminates a section of the huge cloud of interplanetary dust and debris that encircles the sun. After the equinox look for the zodiacal light in the morning sky before astronomical twilight lightens the eastern sky. The beam of light becomes visible about an hour before morning twilight and continues up to an hour after evening twilight ends.

LOCAL STAR COUNT
Join Red Rock Astronomers for an evening of stargazing and telescope viewing at 8:30pm on Sunday, March 27, at Old City Park and to participate in the annual INTERNATIONAL GLOBE AT NIGHT STAR COUNT. Meet at the southwest corner of the grassy field below the bandstand. If cloudy skies or inclement weather cancels the event, we will gather the following Sunday, April 3, at the same time. Dress warmly and bring a chair or blanket if desired. A red light or flashlight wrapped in red cellophane is advised. This event is sponsored by WabiSabi and is free and open to all ages. Call 259-4743 or 259-3313 for more information.

Note: Hold your hand at arm’s length to measure apparent distances in the sky. The width of the little finger approximates 1.5 degrees. Middle, ring, and little finger touching represent about 5 degrees. The width of a fist is about 10 degrees. The fist with the thumb extended at a right angle equals 15 degrees. The hand stretched from thumb to little finger approximates 20-25 degrees. The diameter of both the full moon and the sun spans only 0.5 degree. Adjust for the size of your hand.

Primary Sources: USGS; U.S. Naval Observatory; Your Sky at http://www.fourmilab.ch/yoursky/
To find out when the space shuttle and International Space Station are visible from your location,
go to: http://spaceflight.nasa.gov/realdata/sightings/index.html and click on Sighting Opportunities.


VISIBLE PLANETS
Jupiter - Our second brightest planet continues to dominate the evening sky. Look for it low on the western horizon in evening twilight for the first three weeks of March. Jupiter then disappears into the sun’s glare as its orbit takes it beyond the sun as seen from Earth. It reappears in late summer. On March 6 a slender waxing crescent moon appears six degrees to the right of Jupiter, which is in the constellation Pisces. (Magnitude -2.1)

Mercury - The most elusive planet of our solar system presents itself this month to those who make an effort to gain a high enough vantage point to get a clear view of the western horizon. Mercury sets within a few minutes of Jupiter (both in Pisces) on March 13-16. On March 13, Mercury appears below and to the right of Jupiter (brighter of the two planets.) On March 15, Jupiter is directly to its left; only two degrees separate the planets. By March 16, Mercury is above and to Jupiter’s right. Mercury continues to be visible on the western horizon after sunset even after Jupiter has been consumed by the sun’s glare. It remains in the sky more than an hour after sunset. However, its brightness fades radically during this period which makes it more difficult to see without binoculars. (Magnitude -1.3 fading to -0.2)

Saturn - Soon after Jupiter sets in the early evening sky, Saturn claims its prominence in the eastern sky. It rises about two hours after sunset in early March, then rises a few minutes earlier each evening. By month’s end it is rising as twilight darkens the sky. Saturn remains in the sky all night, appearing directly overhead around midnight. Look for it low on the western horizon in morning twilight. It sets soon after sunrise. On March 19 the Full Moon moves across the sky with the ringed planet, which is in the constellation Virgo. Saturn’s bright yellow glow contrasts with the slightly fainter blue light of Spica (Virgo’s brightest star), below and to the left of Saturn. (Magnitude +0.5)

Venus -
The brightest of our planets still dominates the eastern sky during morning twilight. At the beginning of March it rises about two hours ahead of the sun, just before astronomical twilight lightens the eastern sky. By month’s end, it appears about an hour ahead of the sun as nautical twilight brightens the sky. On March 1 a slender waning crescent moon trails Venus by less than two degrees into the morning sky. Venus is in the faint constellation Capricorn. (Magnitude -4.1)

Note: Apparent magnitude values range from -4 to +6 for most planets and visible stars. The lower the value the brighter the object. A decrease of 1.0 magnitude is 2.5 times brighter.

MAJOR CONSTELLATIONS this MONTH

Overhead
Cancer
Canis Minor
Gemini

Northward
Cassiopeia
Cepheus
Perseus
Ursa Major
Ursa Minor

Eastward
Bootes
Corona Borealis
Leo
Virgo

Southward
Canis Major
Corvus
Hydra

Westward
Auriga
Orion
Taurus

 

Bright stars of winter and the Milky Way move from the overhead sky to the western horizon during March. The eastern sky provides a view perpendicular to the flattened plane of our galaxy—less densely populated than the winter view through the plane of our galaxy towards the spiral edge.

Hold the star chart high above your head and match the compass directions to the direction you are facing. Adjust the star chart by orienting Ursa Major (Big Dipper) to match its position in the sky.

The star chart approximates the sky from astronomical twilight to midnight. As the night and month progresses, the constellations shift toward the northwest. The celestial equator is measured in hours (h).
The ecliptic is measured in degrees.

Moab sky chart

 
Return to home

© 2002-2011 Moab Happenings. All rights reserved.
Reproduction of information contained in this site is expressly prohibited.