Celestial Highlights for April 2015
Posted: Wednesday, April 1st, 2015
by Robert Victor and Robert D. Miller
A predawn total lunar eclipse on Saturday, April 4. (For more on that event, see the March issue of CCS). As many as four planets can be seen at dusk. Many bright stars are gathering in the west before their annual departures later in spring.
Few people may choose to arise early to catch the start of the lunar eclipse on Saturday morning, April 4, when the Moon begins to enter the umbra, or dark central core of Earth’s shadow at 3:16 a.m. PDT. For the next 1.7 hours, progressively more of the Moon will be immersed in Earth’s circular dark shadow, until the start of total eclipse at 4:58 a.m. Even before then, the rusty color typical of the Moon in deep eclipse should be noticed, at least in the lower part of the Moon’s disk, closer to the center of Earth’s shadow. Totality lasts less than five minutes, as the northern (upper) edge of the Moon barely passes within the outer edge of Earth’s umbra. There should be a pronounced difference in color and brightness between the top and bottom edges of the Moon. Totality ends by 5:03 a.m., after which the Moon gradually emerges from shadow.
For information on how to estimate the color and brightness of the Moon during totality, refer to the Celestial Highlights article in the March issue of eCCS.
If you prefer to restrict your viewing to just an hour, I recommend 4:30 until 5:30 a.m. PDT, centering on deepest eclipse at 5:00 a.m. At mid-totality, the Moon will be quite dim compared to a normal Full Moon, and observers in dark locations will get a spectacular view of the Milky Way, from Cassiopeia low in NNE, through the Summer Triangle of Vega-Deneb-Altair high in E, and through Sagittarius and Scorpius (with Saturn and Antares) in the southern sky, these two constellations along with Ophiuchus hosting the central bulge of our galaxy.
Spica will be just 10° upper left of the Moon at mid-eclipse on April 4, with golden Arcturus high to their upper right. Next morning, on Easter Sunday April 5, Spica will appear within 4° below the Moon, and on April 8 the Moon will appear within 2° upper right of Saturn and 10° upper right of twinkling Antares, the red supergiant star marking the Scorpion’s heart. The waning gibbous Moon moves through the predawn Milky Way Apr. 9-11, and by Apr. 12 it has passed Last Quarter phase and so appears slightly less than half full. Last easy view of the waning crescent will be low in E an hour before sunup on Apr. 16, with another chance for binocular users half an hour before sunrise on Apr. 17, only 30 hours before New.
The brightest “stars” in Evening mid-twilight in April 2015, in order of brilliance, are: Venus in W to WNW; Jupiter, passing just south of overhead around midmonth; Sirius in SW sky, bluish and twinkling, lower as month progresses; Mercury, emerging from superior conjunction beyond Sun on Apr. 9 to appear very low in WNW to lower right of Venus starting around Apr. 18; Arcturus in ENE to E, higher as month progresses; and Capella, high in NW.
The gap between Venus and Jupiter continues to close, from 84° on April 1 to 51° on April 30, on the way to their spectacular rendezvous on June 30.
This is a good month to follow the motion of Venus against background stars. During Apr. 9-11, Venus passes within 3° S of the Pleiades, or Seven Sisters star cluster, an especially beautiful sight for binoculars! Students can make nightly sketches of the appearance of Venus and surrounding stars around those dates, and during Apr. 16-22 as Venus passes Aldebaran and the Hyades cluster, those stars together comprising the “V”-shaped head of Taurus, the Bull. Venus will pass between the tips of the Bull’s horns on the evening of May 1. Meanwhile Jupiter lingers within 5°-6° east of the Beehive all month. Use binoculars to find that star cluster.
Include the Moon in your sketches when it appears. On Apr. 19, 40 min. after sunset, the thin young crescent, age 32 hours past New, will be low in W to WNW. Binoculars may show Mercury within 8° to Moon’s lower right, and dim Mars within 4° upper left of Mercury and within 5° lower right of Moon. This is the same night Venus passes closest north (7° upper right) of Aldebaran. On Apr. 20, the lovely crescent Moon will be almost directly below Venus, within 9° lower right of Aldebaran, and 9° lower left of the Pleiades. On Apr. 21, the Moon climbs to 5° upper left of Aldebaran, while Venus shines within 8° to their upper right. Far to their lower right, dim Mars glows only 1.5° to upper left of bright Mercury.
On Apr. 22, Betelgeuse, shoulder of Orion, is 10° S (lower left) of the crescent Moon, while Mercury-Mars appear closest to each other, 1.3° apart, with fainter Mars to lower left. This is the first evening emerging Mercury is higher than sinking Mars. They’ll be 2.0° apart on Apr. 23, while Moon is midway between Betelgeuse and Pollux, brighter of Gemini twins. On Apr. 24, the fat crescent (42%) Moon exits Winter Hexagon nearly halfway from Procyon to Pollux. On Apr. 25, the First Quarter Moon, half full, is 9° lower right of Jupiter.
On Apr. 26, the Moon is in waxing gibbous phase, 8° to Jupiter’s lower left, and on the next night, Apr. 27, it appears 4° S of Regulus, heart of Leo, the Lion.
On Apr. 30, Mercury passes within 2° S of the Pleiades (use binoculars to see the cluster). During Apr. 30-May 8 Mercury stays 22° lower left of Venus as both planets move eastward against the star background.
At dusk on May 1, the Moon, not quite Full, appears 5° above Spica, and on the next evening, 8° to the star’s lower left. Full Moon will occur on the evening of May 3, with the Moon 21° to the lower left of Spica.
Mid-April is a good time for students to start keeping a checklist of bright stars seen each evening, within the first hour after sunset. Many bright stars are gathered in the western sky, including the huge Winter Hexagon. Striking changes in the visibility of stars will occur in the next several weeks, as a result of the Earth’s revolution around the Sun. Students can list their sightings of the planets, too! An observer’s log is provided here.
For related classroom and desktop activities for students to explain these observations, go to this link:
and then scroll down to “Modeling seasonal visibility of stars and visibility of the planets.” Includes planet orbit charts, a data table for plotting planets, and an activity sheet with 15 questions on visibility of stars and planets in 2015-2016.
For more information on sky events in 2015, see these articles and activities:
(A selection of twilight sky charts for use during months of the best planet gatherings.)
Links to related activities on the changing visibility of stars and planets, a selection of sky maps for northern California (exact for lat. 40° N), and a preview of Comet Halley’s next appearance in 2061, are now available at www.abramsplanetarium.org/msta/
Robert D. Miller, who provided the twilight charts, did graduate work in Planetarium Science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.
Posted: Wednesday, October 12th, 2016
by Jessica Sawko
In June 2016 California submitted a waiver application to discontinue using the old CST (based on 1998 standards) and conduct two years of pilot and field tests (in spring 2017 and 2018, respectively) of the new science assessment designed to support our state’s current science standards (California Next Generation Science Standards (CA-NGSS) adopted in 2013). The waiver was requested because no student scores will be provided as a part of the pilot and field tests. The CDE received a response from the U.S. Department of Education (ED) on September 30, 2016, which provides the CDE the opportunity to resubmit a revised waiver request within 60 days. The CDE will be revising the waiver request and resubmitting as ED suggested.
At its October 2016 North/South Assessment meetings CDE confirmed that there will be no administration of the old CST in the spring of 2017. (An archive of the meeting is available at http://www.cde.ca.gov/ta/tg/ai/infomeeting.asp.) Learn More…
Posted: Thursday, September 22nd, 2016
by Carol Peterson
1) To celebrate the 100th anniversary of the National Park Service, Google has put together a collection of virtual tours combining 360-degree video, panoramic photos and expert narration. It’s called “The Hidden Worlds of the National Parks” and is accessible right from the browser. You can choose from one of five different locales, including the Kenai Fjords in Alaska and Bryce Canyon in Utah, and get a guided “tour” from a local park ranger. Each one has a few virtual vistas to explore, with documentary-style voiceovers and extra media hidden behind clickable thumbnails. Ideas are included for use in classrooms. https://www.engadget.com/2016/08/25/google-offers-360-degree-tours-of-us-national-parks/. Learn More…
Posted: Thursday, September 22nd, 2016
CSTA is pleased to announce the winners of the 2016 CSTA Awards for Distinguished Contributions, Margaret Nicholson Distinguished Service Award, 2014 and 2015 PAEMST-Science recipients from California, and the 2016 California PAEMST Finalists. The following individuals and organizations will be honored during the 2016 California Science Education Conference on October 21- 23 in Palm Springs. This year’s group of awardees are truly outstanding. Please join us in congratulating them!
Margaret Nicholson Distinguished Service Award
The Margaret Nicholson Distinguished Service Award honors an individual who has made a significant contribution to science education in the state and who, through years of leadership and service, has truly made a positive impact on the quality of science teaching. This year’s recipient is John Keller, Ph.D. Dr. Keller is Associate Professor, Cal Poly San Luis Obispo and Co-Director, Center for Engineering, Science, and Mathematics Education, Cal Poly San Luis Obispo. In her letter of recommendation, SDSU science education faculty and former CSTA board member Donna Ross wrote: “He brings people together who share the desire to make a difference in the development and implementation of programs for science teaching. Examples of these projects include the Math and Science Teaching Initiative (MSTI), Noyce Scholars Program, Western Regional Noyce Initiative, and the Science Teacher and Researcher (STAR) program.” Through his work, he has had a dramatic impact on science teacher education, both preservice and in-service, in California, the region, and the country. He developed and implemented the STEM Teacher and Researcher Program which aims to produce excellent K-12 STEM teachers by providing aspiring teachers with opportunities to do authentic research while helping them translate their research experience into classroom practice. SFSU faculty member Larry Horvath said it best in his letter:“John Keller exemplifies the best aspects of a scientist, science educator, and mentor. His contributions to science education in the state of California are varied, significant, and I am sure will continue well into the future.” Learn More…
Posted: Tuesday, September 20th, 2016
by Peter A’hearn
NGSS is a big shift. Teachers need to learn new content, figure out how this whole engineering thing relates to science, and develop new unit and lesson plans. How could NGSS possibly make life easier?
The idea that NGSS could make our lives easier came to me during the California State NGSS Rollout #1 Classroom Example lesson on chromatography. I have since done this lesson with high school chemistry students and it made me think back to having my own students do chromatography. I spent lots of time preparing to make sure the experiment went well and achieved the “correct” result. I pre-prepared the solutions and organized and prepped the materials. I re-wrote and re-wrote again the procedure so there was no way a kid could get it wrong. I spent 20 minutes before the lab modeling all of the steps in class, so there was no way to do it wrong. Except that it turns out there were many. Learn More…
Posted: Tuesday, September 20th, 2016
by Robert C. Victor. Twilight sky maps by Robert D. Miller. Graph of evening planet setting times by Dr. Jeffrey L. Hunt
Our evening twilight chart for September, depicting the sky about 40 minutes after sunset from SoCal, shows brilliant Venus remaining low, creeping from W to WSW and gaining a little altitude as the month progresses. Its close encounter within 2.5° N of Spica on Sept. 18 is best seen with binoculars to catch the star low in bright twilight. The brightest stars in the evening sky are golden Arcturus descending in the west, and blue-white Vega passing just north of overhead. Look for Altair and Deneb completing the Summer Triangle with Vega. The triangle of Mars-Saturn-Antares expands as Mars seems to hold nearly stationary in SSW as the month progresses, while Saturn and Antares slink off to the SW. Learn More…