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Home , Astrological sign, Celestial sphere, Zodiac

Today Rover Is NASA's Mars in rover Curiosity Space Frozen in Place News: Following had an attitude Software Error problem. (But it's fine now.)

https://www.space.com/mars-rover-curiosity-attitude-glitch.html Study Points • Predict the approximate time of /night you should look for first quarter , full moon, last quarter moon. • Explain how think the Moon formed and give evidence. • What causes a solar ? What causes a lunar eclipse? What phase is the moon for each? • Explain why the undergoes . Explain why it is hot in the summer. Explain why the appears high in the during the summer but low in winter? • What is included in the area of the sky known as the ? What does the word zodiac mean? How many are in the zodiac according to ? • What is the ? Where is the Sun in this plane? the Moon? the ? the ? • What is meant by “the Sun is in ”? Explain why you only see some of the constellations of the zodiac at a given time. • What is meant by the Earth’s ? Is Earth’s precession a long or a short time? • Explain why Polaris is the North ? Explain why the stars appear to revolve around the North Star? • Explain why the Sun is not in the say it is in when you are born. • What distinguishes science from non-science? Give an example. • Name the five North Circumpolar Constellations. Why are these important to us in MN? • Define and ? Sketch the Sun, Earth, and Earth’s orbit. Draw Earth with the axis tilt and label the location of Earth at the and . Cycles of the Sky: Part 2 • Moon – Moon Phases, Motions, Formation – Lunar and Solar • Zodiac, Ecliptic • Precession • North Circumpolar Constellations • Seasons Moon Phases

Orerry with light Moon Phases*

Moon Position at Sunset* Horizons textbook Moon Phases Continued*

Moon Position at Sunrise* Moon rises ~50 minutes later every day

Horizons From Last Moon Lecture

Conclusion on Moon’s motion: • Minute to minute the Sun, Moon, & stars appear to rise in east and set in west due to Earth’s spin (). • Day to day, Moon moves west to east due to Moon’s orbit (revolution) around Earth. (Also generally true for other planets, due to the ’s orbit.) Origin of Moon* • Early Earth and Mars-size object collide* • Moon formed out of particles orbiting around the new collided Earth* – Best explanation we have, but isn’t perfect. • Moon is made up of materials found in Earth’s crust (outer layer) • How the Moon was formed https://www.youtube.com/watch?v=mQAdYWcA7ig (1:56) • Evolution of the Moon (after it formed) https://www.youtube.com/watch?v=UIKmSQqp8wY (2:41)

Image: http://www.seti.org/node/1458 Lunar Eclipses – only at Full Moon*

•If the Moon passes through Earth’s shadow, we see a lunar eclipse.* •Lunar Eclipse – Earth blocks the sunlight from the Moon* • If the entire surface of the Moon enters the umbra, the lunar eclipse is total.

© Cengage Learning 2014 Orerry with light Total Lunar Eclipse

• A total lunar eclipse can last up to 1 hour and 40 minutes. • During a total eclipse, the Moon has a faint, red glow, reflecting sunlight scattered in the Earth’s atmosphere. Lunar Eclipse Dates • 1 – 2 lunar eclipses per year usually • Next one in MN: 16, 2022 Size of the Sun & Moon from Earth

• From Earth the size of the Moon and Sun are about the same!

The angular diameter of the Moon (~0.5o) is almost exactly the same as that of the Sun. This is a pure coincidence. The Moon’s linear diameter is much smaller than that of the Sun. Solar Eclipses – only at New Moon*

Orerry with light

Due to the equal angular diameters, the Moon can cover the Sun completely when it passes in front of the Sun, causing a total solar eclipse.* Solar Eclipse – Moon blocks Sunlight from Earth* Solar Eclipses

The Moon’s shadow sweeps across the Earth, over points from where we can see a solar eclipse. Total Solar Eclipse

During a total solar eclipse, the solar chromosphere, corona, and prominences can be seen.

Diamond Ring Effect Solar Eclipse Types

1. Total 2. Annular 3. Partial

4. Hybrid (both total and annular) • Types are due to the changing (angular) size of the Moon and Sun seen from Earth because the orbits are not perfect circles (they are ellipses). Wikipedia.com Solar Eclipse Dates

• About 1 per year; max time is ~7 minutes. • Next Total Solar Eclipse in USA (Texas to Maine): 8, 2024 (2033 Alaska, 2044 MT & ND) • Last Total Solar Eclipse across USA – 21, 2017 – Best Pictures website link

Very Important Warning: Never observe the Sun directly with your bare eyes, not even during a partial solar eclipse!

Use specially designed solar viewing shades, solar filters, or a projection technique. Constellations

• Imaginary memory aids to describe sky • 88 total constellations named in Earth’s celestial (previously 48 from about 350 BC) • Currently used like stellar zip codes • Other versions around – Chinese, , Hindu, Native American

Celestial Sphere Zodiac Constellations and the Ecliptic

Zodiac means circle of little animals* http://lifeng.lamost.org/courses/astrotoday/CHAISSON/AT301/HTML/AT30103.HTM Constellations of the Zodiac

• Seen throughout the year because of Earth’s revolution • The zodiac constellations are located along the Sun’s path on Earth (Ecliptic Plane).* • Ecliptic Plane – the plane of Earth’s path around the Sun.* • The zodiac region includes the Earth’s path around the Sun, our Moon’s path, & planets’ paths across Earth’s sky.* Annual Motion of the Sun

• The Sun is in on 1 (sign of Sagittarius) • The Sun is in on 1 (sign of Aquarius) • The Sun is in Leo on 1 (sign of Leo)* • During the days of a given zodiac sign, that constellation isn’t visible because it is behind the Sun, as viewed from Earth* Orerry with Sagittarius Two Versions of Zodiac Constellations • 13 Astronomical Constellations of the Zodiac (used by astronomers) and includes * • 12 Astrological Constellations of the Zodiac • All 13 are in the ecliptic plane; Babylonians removed 1 to fit the 12 calendar (and pretended they were One constellation missing from the traditional zodiac signs. the same size) http://spaceplace.nasa.gov/starfinder2/en/ Precession of Earth • Earth’s Precession – slow movement of Earth’s axis because Earth is spinning* (traces out a circle as it changes) • The Earth’s North pole currently points to Polaris so we call Polaris our North Star, but the North Star will change.* – Earth’s axis of rotation points to the North Star and stars move around that as the Earth rotates • 3000 BC: North star = Thuban (5000 years ago) – origin of astrology about 1000 BC, different sign dates (3000 years ago) • 14,000 AD: North star = • 26,000 year cycle (long time)* Parke Kunkle’s precession video (watch if you miss lecture) Precession wheel demo What Sign Are you?

• Astrology is based on the locations of the constellations from about 3000 years ago when the constellations were visible at different times of the year than they are now.* • Astrology is not a science; it is a belief system – not testable or repeatable (science hallmarks: natural, testable & simple)* • Astronomy uses the same names of constellations and uses all 13 constellations in the ecliptic • You can look up your astrology sign based on the 13 sidereal constellations and accurate north star here: http://www.livescience.com/4667-astrological-sign.html • More about this from NASA here: http://spaceplace.nasa.gov/starfinder2/en/ North Circumpolar Constellations • Constellations visible year-round (mid- & north)* – Minnesota and further north to the North Pole • Don’t rise or set; Visible all year and all night • 5 North Circumpolar Constellations: Ursa Major (Big Dipper), Ursa Minor (Little Dipper), Cassiopeia, Draco, Cepheus*

http://antwrp.gsfc.nasa.g http://www.captureminnesota.com/ & ov/apod/ap040911.html Seasons on Earth • Caused by Earth’s tilt which is about 23 degrees

Northern summer = Northern winter = Southern winter Southern summer

Globe Seasons • When the is tilted toward the sun, it also experiences longer daylight. – Longer daylight is the cause of higher temperatures in summer* • The Earth’s tilt causes longer daylight in one hemisphere – Show longer daylight with globe & Sun is higher in the sky

Northern Hemisphere • Equinox: equal night and Seasons day* • Equinox is when the Sun Fall Summer is crossing Earth’s * • Solstice: daylight is longest in each Winter hemisphere* Spring • Solstice is when Earth’s axis is tilted toward the Sun in one hemisphere*

Orerry www.faculty.edfac.usyd.edu.au Explanation with a friend

• Explain why the Earth undergoes seasons. Explain why it is hot in the summer. Explain why the Sun appears high in the sky during the summer but low in winter?

• Write your own explanation with the help of a classmate. Write 2-4 sentences to explain.

• This will help you understand what you learned today. Observation Projects

• Earth-Sun Scaling • Moon Phases Due: TODAY! • Start Jan. 23 • Due March 5 • (10 pts) – Start: Today • Sunset – Part 1 – Due: May 12 • Start Jan. 21 – Easiest way: Come with the • Due Feb. 18 class on Feb. 4 • Star Gazing • Start Jan 21 • Due May 12 Homework • Complete permission slip and return to me.

• Continue STUDY POINTS • Lab – arrive this week with the necessary materials • Complete D2L Quiz 2 (due Thursday) • Test 1 in 2 weeks: Tues, Feb. 11 – To prepare: study points & 4 D2L quizzes – About 40 multiple choice questions. Bring a pencil. – Optional – bring a calculator (not graphing), some will be in the room to use – writing assignment