March/April 2017 – Vol. 29 No. 6

A Predawn Lunar Eclipse, a Transit of Venus, and Other Sky Phenomena in June 2012 and Beyond

Posted: Monday, June 4th, 2012

by Robert C. Victor

We hope you enjoyed the annular or partial solar eclipse of May 20. Perhaps you’ll want to start planning to take in the next two total solar eclipses within the U.S.: On August 21, 2017 (seen as total within a narrow path from Oregon to South Carolina), and on April 8, 2024 (total from Texas to Maine).

Here are some fascinating events to close out the (traditional schedule) school year, and some very striking arrangements of planets, moon and stars to encourage your students to “keep looking up” during the summer months.

June 2012 brings Californians a partial lunar eclipse in the predawn hours on Monday, June 4, and a rare transit of Venus across the face of the Sun on the afternoon of Tuesday, June 5, an event not to happen again for more than a century! Within a week later, and certainly by mid-June, Venus emerges into morning twilight to the lower left of Jupiter. Venus then displays a thin crescent phase, filling out to half full by mid-August while its disk size shrinks as the planet recedes from Earth. Venus will reach peak brilliance in predawn skies in mid-July. In late June and early July, Venus and Jupiter form a brilliant pairing before dawn, an encore of their evening pairing in March. Mars-Saturn remain in the evening sky, the gap between them closing until their trio with Spica in August.

Partial lunar eclipse in predawn on Monday, June 4: moon enters the umbra, or dark central core of Earth’s shadow, around 3:00 a.m. PDT; greatest eclipse (magnitude 37 percent, or 3/8 of the moon’s diameter in dark shadow) occurs at 4:03 a.m. PDT, with moon low in SW, above Antares, heart of the Scorpion. The moon leaves the umbra at 5:06 a.m. PDT. Of all the contiguous 48 states, California has the best view of this eclipse.

On Tuesday, June 5, the transit of Venus will be the last one until December 10, 2117. It begins in the afternoon, at 3:06 p.m. PDT along the U.S. West Coast. The event opens with a ~ 17.6-minute ingress until about 3:23 p.m., as Venus’ disk, 1/32 of the Sun’s apparent diameter, slides onto the solar limb. Venus takes about 6 hours to reach the opposite limb, so for most of North America the transit is still in progress at sunset. For details, including history, safe methods of observing, maps and timetables of visibility, visit:

I plan to have students observe the start of the transit near the close of the school day at Cahuilla Elementary School in Palm Springs, and then visit other locations in the Coachella Valley until the Sun drops below the mountains. Peter A’Hearn, K-12 Science Specialist for Palm Springs Unified School District, plans to host a continuous transit watch in a park adjacent to Vista del Monte Elementary School. We will use solar filters suitable for safe viewing of solar eclipses with unaided eye, and telescopes fitted with front aperture filters for safely viewing the Sun in detail.

The Moon and Planets in June 2012

Morning planets: Jupiter rises in ENE in midtwilight (when Sun is 9° below the horizon) by June 5, and Venus by June 17. These two planets will form a spectacular pair within 5° in late June and early July. Follow Venus until sunrise and observe its crescent, one percent full on June 11, to 5 percent on June 18, and 16 percent on June 30. The planet’s disk, nearly one arcminute (1/60 of a degree) across during transit on June 5, is still 3/4 arcminute across on June 30, enough for 7-power binoculars to resolve the crescent in bright twilight or in daylight.

Mercury, passing superior conjunction May 27 and perihelion May 29, emerges quickly and brightly into WNW, setting after midtwilight by June 4. Binoculars help spot it in bright twilight first few days. Mercury shines at magnitude –1.5 on June 2, then fades, to –1.0 on June 7, –0.5 on June 14, 0.0 on June 22-23, +0.5 on July 1, and +1.0 on July 8.  Mercury passes Venus on June 1, Pollux on June 20, and closely aligns with the Gemini Twins Castor and Pollux on June 23 and 24.

Saturn, shining at mag. +0.5 to +0.7, drifts through S and SSW at dusk in course of June, staying within 5° of +1.0-mag. Spica. (Saturn ends retrograde June 25.) Through a telescope, rings reach a temporary minimum of 12.5° from edgewise, owing to motion of Earth around Sun. In the longer term, as Saturn orbits the Sun, the rings will “max out” at 27° from edgewise in 2017.

Mars in June fades from mag. +0.5 to +0.9 in SW to WSW at dusk, while shifting east 0.4° to 0.5° daily against stars of Leo-Virgo. On June 25-26, Mars is midway between Regulus and Saturn, 26°-27° from each. On Aug. 13-14, Mars will pass between Saturn and Spica, forming a striking compact, nearly straight-line trio in the WSW at dusk. In surrounding days, from August 7 to 20, the three objects will form a triangle no more than 5° on a side.

Moon near planets, June through August

Sun. June 17 at dawn: Waning crescent old moon low in ENE, between Jupiter to its upper right, and Venus rising to its lower left.

Thurs. June 21 at dusk: First easy waxing crescent young moon low in WNW. To moon’s upper right, locate Mercury, Pollux, and Castor.

Mon. & Tues. June 25 and 26 at nightfall: moon near Mars. Moon passes First Quarter phase (half full and 90° or one-quarter circle east of Sun) on June 26.

Wed. & Thurs. June 27 and 28 at nightfall: Waxing gibbous moon near Saturn and Spica. Saturn is the higher and brighter of the two “stars” near the moon.

Sun. July 15, about 1-1/2 hours before sunrise: Spectacular gathering of waning crescent moon, Venus, Jupiter, the star Aldebaran, and the Hyades star cluster, with the Pleiades or Seven Sisters star cluster not far above. Wonderful views for unaided eye and binoculars.

Mon.-Wed. July 23-25 at nightfall: Fat waxing crescent moon, approaching First Quarter phase, slips past Mars, Saturn, and Spica. On the middle date, Saturn-Spica are 4.5° apart, with Mars 12° to their west (lower right), forming a nearly isosceles triangle.

Sat. August 11, about 1-1/2 hours before sunrise: moon near Jupiter, Aldebaran, and the Hyades. The waning crescent moon will interfere little with the peak of the Perseid meteor shower in the predawn hours of Sunday.

Mon. August 13, about 1-1/2 hours before sunrise: moon near Venus. A perfect day for using the moon to follow Venus long into daylight hours! The moon will occult Venus between 1 p.m. and 2 p.m. PDT from West Coast. For a map and timetable of disappearance and reappearance of Venus, go to

Wed. August 15, about one hour before sunrise: Mercury very low in ENE, to lower left of old crescent moon. On Thursday, look about 45 minutes before sunrise to catch an even older crescent moon rising to lower right of Mercury.

Tues. August 21, one hour after sunset: Waxing crescent moon about 4-1/2 days after New, is low in WSW below a compact triangle of Saturn, Mars, and Spica. Four bodies within a 6.5° field! Can you fit all four within the field of view of 7-power binoculars?

Robert C. Victor was Staff Astronomer at Abrams Planetarium, Michigan State University. He is now retired and enjoys providing skywatching opportunities for school children in and around Palm Springs.


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Written by Robert Victor

Robert Victor

Robert C. Victor was Staff Astronomer at Abrams Planetarium, Michigan State University. He is now retired and enjoys providing skywatching opportunities for school children in and around Palm Springs, CA. Robert is a member of CSTA.

One Response

  1. Thanks for keeping us up to date on the celestial occurrences. I am looking forward to looking at the transit this afternoon.

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CSTA Endorses March for Science

Posted: Monday, March 27th, 2017

The California Science Teachers Association (CSTA) stands with our science and science education colleagues in endorsing the March For Science and its associated activities.

The decision by the CSTA Board of Directors to support the March for Science was based on the understanding that this is an opportunity to advocate for our mission of high quality science education for all and to advance the idea that science has application to everyday life, is a vehicle for lifelong learning, and the scientific enterprise expands our knowledge of the world around us. The principles and goals of the March for Science parallel those of CSTA to assume a leadership role in solidarity with our colleagues in science and science education and create an understanding of the value of science in the greater community. CSTA believes that the integrity of the nature of science and that the work of scientists and science educators should be valued and supported. We encourage your participation to stand with us.

There are over 30 satellite marches planned for the April 22, 2017 March for Science in California (to find a march near you, click on “marches” in the upper right of the main page, select “satellite marches” and use the search feature). We encourage members who participate in the March for Science to share their involvement and promotion of science and science education. Feel free to promote CSTA on your signs and banners. For those on social media, you may share your involvement via Twitter, @cascience and our Facebook groups.

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

California Science Curriculum Framework Now Available

Posted: Tuesday, March 14th, 2017

The pre-publication version of the new California Science Curriculum Framework is now available for download. This publication incorporates all the edits that were approved by the State Board of Education in November 2016 and was many months in the making. Our sincere thanks to the dozens of CSTA members were involved in its development. Our appreciation is also extended to the California Department of Education, the State Board of Education, the Instructional Quality Commission, and the Science Curriculum Framework and Evaluation Criteria Committee and their staff for their hard work and dedication to produce this document and for their commitment to the public input process. To the many writers and contributors to the Framework CSTA thanks you for your many hours of work to produce a world-class document.

For tips on how to approach this document see our article from December 2016: California Has Adopted a New Science Curriculum Framework – Now What …? If you would like to learn more about the Framework, consider participating in one of the Framework Launch events (a.k.a. Rollout #4) scheduled throughout 2017.

The final publication version (formatted for printing) will be available in July 2017. This document will not be available in printed format, only electronically.

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

Call for CSTA Awards Nominations

Posted: Monday, March 13th, 2017

The 2017 Award Season is now open! One of the benefits of being a CSTA member is your eligibility for awards as well as your eligibility to nominate someone for an award. CSTA offers several awards and members may nominate individuals and organizations for the Future Science Teacher Award, the prestigious Margaret Nicholson Distinguished Service Award, and the CSTA Distinguished Contributions Award (organizational award). May 9, 2017 is the deadline for nominations for these awards. CSTA believes that the importance of science education cannot be overstated. Given the essential presence of the sciences in understanding the past and planning for the future, science education remains, and will increasingly be one of the most important disciplines in education. CSTA is committed to recognizing and encouraging excellence in science teaching through the presentation of awards to science educators and organizations who have made outstanding contributions in science education in the state and who are poised to continue the momentum of providing high quality, relevant science education into the future. Learn More…

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

Call for Volunteers – CSTA Committees

Posted: Monday, March 13th, 2017


CSTA is now accepting applications from regular, preservice, and retired members to serve on our volunteer committees! CSTA’s all-volunteer board of directors invites you to consider maximizing your member experience by volunteering for CSTA. CSTA committee service offers you the opportunity to share your expertise, learn a new skill, or do something you love to do but never have the opportunity to do in your regular day. CSTA committee volunteers do some pretty amazing things: Learn More…

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

A Friend in CA Science Education Now at CSTA Region 1 Science Center

Posted: Monday, March 13th, 2017

by Marian Murphy-Shaw

If you attended an NGSS Rollout phase 1-3 or CDE workshops at CSTA’s annual conference you may recall hearing from Chris Breazeale when he was working with the CDE. Chris has relocated professionally, with his passion for science education, and is now the Executive Director at the Explorit Science Center, a hands-on exploration museum featuring interactive STEM exhibits located at the beautiful Mace Ranch, 3141 5th St. in Davis, CA. Visitors can “think it, try it, and explorit” with a variety of displays that allow visitors to “do science.” To preview the museum, or schedule a classroom visit, see Learn More…

Written by Marian Murphy-Shaw

Marian Murphy-Shaw

Marian Murphy-Shaw is the student services director at Siskiyou County Office of Education and is CSTA’s Region 1 Director and chair of CSTA’s Policy Committee.