March 20 5:48 UTC March 19 Wed, 11:48PM http://aa.usno.navy.mil/data/docs/EarthSeasons.php See also sundial activities on March 19 at 1:40pm. NASA Solar Week activities 3/17 to 3/21 http://www.solarweek.org/ NASA Sun-Earth Day: March 20 http://sunearthday.gsfc.nasa.gov/2008/index.php March 2006 equinox activities version http://members.csolutions.net/fisherka/astronote/notes/Springequinoxteachers... Simple sun science activities using the Gallivan Center sundial http://members.csolutions.net/fisherka/astronote/observed/ALSSundial/html/Ac... Gnomon shadows move in a straight line on the equinox: Gallivan Center sundial illustration: http://members.csolutions.net/fisherka/astronote/observed/ALSSundial/img/pix... Animation: http://members.csolutions.net/fisherka/astronote/observed/ALSSundial/img/pix...
From the activities page for the equinox equinox:
Observe a sunset equinox using the 300 South Street, just north of the Gallivan Center sundial: On the date of the equinoxes, the Sun rises at due East (azimuth 90°) and sets due West (azimuth 270°). As intended by the plaza developers, the Gallivan Center Sundial is shaded by building interference at sunrise and sunset on the equinoxes. However, the street system in Salt Lake City, Utah is laid-out in a rectilinear grid oriented to the compass points. 300 South Street, directly north of the Gallivan Center Plaza, is aligned on a due east-west line. On the equinoxes, the Sun rises and sets down the center line of this street. The sunsets on the day of the spring (April 21) and autumnal (September 23) equinoxes are particularly striking. A pedestrian crossing, with a concrete protected barrier, allows the visitor to stand near the centerline of 300 South Street without exposing oneself to traffic hazards. After the spring equinox and until the autumnal equinox, the Sun spends part of each day directly illuminating the north sides of buildings. This has implications for building design and for the cooling loads of buildings during the summer. After the autumnal equinox, across the winter solstice, and until the spring equinox, the north sides of buildings spend six months in shade. This has implications for building heating loads. Other places to watch an equinox: Robert Peerless Utah Sundagger at the Utah Valley State College - Wasatch Campus - in Heber http://www.perless.com/sundagger.html Getting to the UVSC Wasatch campus - http://www.uvsc.edu/wasatch/contactus/index.html http://maps.yahoo.com/&q3=40.54474%2C-111.413645#mvt=h&lat=40.54474&lon=-111... Parowan gap - sunset in gap: http://www.parowangap.org/ Nancy Holt's 1976 Utah Sun Tunnels http://ludb.clui.org/ex/i/UT3126/ Gallivan Center http://www.slcgov.com/PublicServices/Gallivan/default.htm http://www.slcgov.com/PublicServices/Gallivan/map.html JPL Horizons Empheris data for SLC, UT March 20, 2008 -6 hrs for MDT or on Mar. 19, 2008 (UT) Az Elev ObsEcLon ************************************** 04:48 306.1626 -34.4210 359.9565895 04:58 308.6076 -35.9239 359.9635412 05:08 311.1457 -37.3752 359.9704949 05:18 313.7820 -38.7703 359.9774507 05:28 316.5210 -40.1038 359.9844084 05:38 319.3667 -41.3703 359.9913678 05:48 322.3220 -42.5640 359.9983289 05:58 325.3887 -43.6788 0.0052916 06:08 328.5670 -44.7086 0.0122556 06:18 331.8552 -45.6472 0.0192210 06:28 335.2495 -46.4883 0.0261875 06:38 338.7437 -47.2260 0.0331550 06:48 342.3292 -47.8546 0.0401234 On March 19 around 1:40pm MDT, the Sun transits at about elevation equal to 90 - Salt Lake City's latitude: JPL Horizons Empheris data for SLC, UT March 19, 2008 -6 hrs for MDT ******************************************************************************* Date__(UT)__HR:MN Azi_(a-appr)_Elev **************************************** 2008-Mar-19 19:10 * 170.4516 48.6697 2008-Mar-19 19:20 * 174.2282 48.9249 2008-Mar-19 19:30 * 178.0342 49.0555 2008-Mar-19 19:40 *t 181.8506 49.0602 2008-Mar-19 19:50 * 185.6580 48.9389 2008-Mar-19 20:00 * 189.4374 48.6927 Date__(UT)__HR:MN Azi_(a-appr)_Elev **************************************** 2008-Mar-20 19:10 * 170.4886 49.0709 2008-Mar-20 19:20 * 174.2960 49.3245 2008-Mar-20 19:30 * 178.1329 49.4523 2008-Mar-20 19:40 *t 181.9800 49.4532 2008-Mar-20 19:50 * 185.8172 49.3271 2008-Mar-20 20:00 * 189.6252 49.0753 - Kurt ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ