By Alice Enevoldsen
Special to West Seattle Blog
Venus. Venus, Venus, Venus, Venus, Venus. Oh, and also Jupiter and then Regulus, but mostly Venus. That’s what we’ve been seeing every night gleaming in the West, so bright I keep thinking it must be an airplane.
(Click image to see it full-size: Looking west from West Seattle at 10:30 pm in mid-June 2015)
Venus will continue to brighten until July 12th before slowly beginning to get dimmer. I highly recommend the article about the difference between Venus’s greatest elongation, greatest illuminated extent, and maximum brightness by Guy Ottewell. As with many things in astronomy and observing there are a number of “best” or “most” moments, and his article clearly illustrates the ones applicable to Venus this month. It continues to be a wonderful observing target for the rest of the month and next month.
Saturday, June 20th, 8:45 pm — Solstice Sunset Watch at Solstice Park, with or without the stone markers.
Sunday, June 21st, 9:38 am — Summer solstice moment.
Wednesday, July 1st, 11:03 am — A few more extremely low tides. Beach Naturalists at Constellation Park from 9:45 am–1 pm
Thursday, July 2nd, 11:45 am — Low tide. Beach Naturalists at Constellation Park 10:00 am–1:30 pm
Friday, July 3rd, 12:27 pm — Lowest tide this year. Beach Naturalists at Constellation Park 10:45 am–2:15 pm
Saturday, July 4th, 1:12 pm — Low tide. Beach Naturalists at Constellation Park 11:45 am–3 pm
(Lincoln Park at low tide 5/5/2012 (c) 2012 Jason Ayres Gift Enevoldsen)
SOLSTICES & LOW TIDES
The lowest tides of the year here in West Seattle are caused by the full and new Moons nearest to the solstices. The low tides in December 2015 and January 2016 will be in the middle of the night, but the summer solstices low tides are in the middle of the day, providing us with an opportunity to view critters and geology usually hidden under water where we see it only through Diver Laura‘s lenses.
Please be exceedingly careful when tidepooling and exploring the exposed intertidal zone. Walk very carefully, observe with your eyes as much as possible, and be gentle when you touch. If you visit Constellation Park south of Alki Point during the hours that Seattle Aquarium’s Beach Naturalists are out, you can ask them all your questions about sea life and protecting the habitat.
ParentMap and the Oregon State Parks have published guidelines on beach etiquette that keeps you and the animals safe.
You remember from elementary school that the Moon causes the tides, but what you probably weren’t taught at that age is that the Sun also helps cause the tides, though less so, which is why we have different tides near the solstices.
Gravity pulls less on things that are farther away, but the difference between the Sun-to-daytime-side-of-the-Earth-distance and the Sun-to-nighttime-side-of-the-Earth-distance is a pretty small percentage of the total distance. That’s why the Sun has less effect than the Moon in general. It is just enough that when the Northern Hemisphere is tilted toward or away from the Sun, as it is on the solstices, we get a little bit extra higher than usual tides. When the Northern and Southern Hemispheres are equidistant from the Sun, as during the equinoxes, those ‘higher-er’ tides would occur closer to the equator.
(A very much not-to-scale diagram of the Sun and Moon’s effect on the tides at the Summer Solstice)
P.S. Don’t confuse Constellation Park (beaches just south of Alki Point Lighthouse) with Solstice Park (earthworks/sunset alignment uphill and inland from Lincoln Park). They’re completely different!
June 24th — First Quarter: The first-quarter moon is ideal for late afternoon and early evening observation (rising in the early afternoon, setting in the middle of the night).
July 1st — Full Moon: The full moon rises at sunset, sets at sunrise and is visible all night.
July 8th — Last Quarter: The week around the last quarter moon, it is visible in the early morning sky (rising in the middle of the night, setting in the early afternoon).
Stellarium: Free planetarium software for your home computer, or Android device. Bring up the sky for anywhere in the world, any time and date in history or the future.
Clear Sky Chart: The astronomer’s forecast for the next couple days. Cloudcover, darkness, and “seeing” which is how nice it is to view the stars, all on one handy chart.
USNO: Dates and times of astronomical happenings.
International Dark Sky Association: How to help your neighbors enjoy the night sky.
Equilibrium Tides from Dr. LuAnne Thompson, Department of Oceanography, University of Washington
WHO IS ALICE?
Alice is many things and works and volunteers for a few notable organizations, but the suggestions and opinions put forth in this article are her own and no one else’s. You can find more about astronomy at alicesastroinfo.com.
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