Spring 2012 Sky Sights Presentation

1. About this presentation…. • Is free to be used by students, teachers & public. Please acknowledge it is from FSU. It can also be copied and downloaded. • Is written in Microsoft Power Point that can be read by a number of computer systems. • If you find any needed changes, please contact Dr. Doyle at rdoyle@frostburg.edu

2. Frostburg State Planetarium presents Spring 2012 Sky Sights for Middle School & Intermediates by Dr. Bob Doyle Next Edition: July 2012

3. Big Topics Treated • Horizon, Finding directions, Sunrise/Sunset • How Day Sky Works, Twilight AM & PM • Moon basics, It’s Origin Why has varying shapes? • Bright points seen at night? Easy Spring Planets • Best Stars & Groups Seen on Spring Evenings • 3 Built in Mini Quizzes with answers supplied • Spring ‘12 Moon Schedule & Star tables • Spring Sky Show Schedule & related info

4. Horizon & Directions • When looking at sky, we may view ½ of universe! • Horizon surrounds us, the sky/ground boundary • At top of sky is zenith, 90 degrees from horizon • From North rightward, East, then South and West. • Sun rises in East, face sunrise, left is North • Midday shadow N (1p in April, May & June) • Sun sets nearly in West, face sunset, right is North • Can use Big Dipper’s pointers to find N. Star

5. Sunrise & Sunsets? • Earth’s daily rotation makes it look as if sun rises each morning & sets each afternoon • Time of sunrise, sunset varies thru year • Earliest sunrise & latest sunset in late June • Latest sunrise & earliest sunset in late Dec. • Longest days when sun highest, farthest N • Shortest days when sun lowest, farthest S • Change in sunrise/sunset reduced closer to equator • Change in sunrise/sunset increased near poles

6. Let’s review these ideas • What point in sky is farthest from horizon? • Is it Celestial Pole? Zenith? Nadir? • Which direction recipe WON’T work? • S. Side of tree with moss? Shadow in mid day? • Place where biggest changes with seasons? • Polar Regions? Mid Latitudes? Equator? • Write down your answers for these questions. • Answers: Zenith, Mid day shadow, Polar regions

7. Interesting facts about day sky • Noon sun million x brighter than full moon • Day Sky max. polarization 90 deg. from sun • Maximum sunlight energy in early summer • Sun peaks around 1 pm when Daylight time • Minimum sunlight energy in late Dec. • To find North, face where sun goes down and extend your right arm out, points North.

8. Twilight or Dusk? • When sun disappears from our view, the air overhead is still ‘seeing’ sun and glowing. • Sun 6 degr. below horizon, turn on lights • Sun 18 degr. below horizon, sky darkest • To see faint stars, sun must be 12 degr. below hor. • Arctic Circle cities have no darkness in June • Equatorial places have shortest twilights • Our twilights last about 90 min. at dusk & dawn

9. What about Moon? • Our moon is 2160 miles across, ¼ Earth’s width • Moon ¼ as big as Earth; if Earth a regular globe (1 ft.wide), moon is a tennis ball. • If Earth-moon distance about 30 x Earth’s width. • As Earth, Moon lit by sun with day & night halves • As Moon orbits Earth, see varying part of day side • After line up with sun, moon waxes (grows) 14 d • After full moon, moon wanes (shrinks) 14 days • Moon phase cycle 29.5 dy, approx. month length

10. Just a little bit more about Moon • Moon rocks reveal moon matter from Earth! • Moon due to planets colliding, debris hurled • Moon formed from ring of orbiting debris • Early moon closer, much stronger tides • Moon slowly spiraling out, lengthen our day • Earth has 1st natural moon from sun, 6th largest moon in solar system

11. Half full moon shows craters near its straight edge where sun there is rising or setting. Dark areas are lava plains – few craters there

12. Spring 2012 Moon Schedule • Early April: Full moon 4/6 (grey lava plains) • Mid April: Moon in AM sky, ½ full on 4/13 • Late April : ½ even. moon 4/28 (craters) • Early May: Full 5/5 (Gr. Plains, White Highlands) • Mid May : Moon in AM sky, ½ full on 5/13 • Late May: ½ Even. Moon 5/28 (craters) • Early June: Full moon 6/3 (low sky path & bright) • Mid June: Moon in AM sky, ½ full on 6/10 • Late June; ½ Even. Moon 6/26 (craters)

13. Another review of ideas.. • As you face sunset, what points North? • Back of Head? Right arm (out)? Left ear? • If Earth 1 ft. wide, how far away is moon? • Is it 10 feet? 30 feet? 100 feet? 300 feet? • How long does moon ‘grow’ or ‘shrink’? • Is it A week? A half month? A month? • Write down your answers to above 3 questions. • Answers: Right arm (out), 30 feet, A half month

14. Bright points we see at night? • Even the nearest planets appear as * (points) as we see them with our eyes; for even these objects far away Venus at closest 100x farther than our moon • To tell a planet from a star, all night stars twinkle and planets usually shine steady. • Also satellites (especially Space Station) shine steadily as creep eastward across sky • Night stars are distant suns, really, really far away compared to our planet neighbors. • If Earth penny size, moon 22” away, sun 730 ft. away (6.3 ft. wide), nearest star is 37,000 mi.away

15. Easy Spring 2012 Planets • Venus is brilliant point in SW dusk (Apr. & May) • Crescent Moon & Venus close 4/24 & 5/22 • Bright Jupiter seen in April below Venus • Crescent Moon & Jupiter near on 4/22 • Orange Mars fades & drifts westward in spring • Moon & Mars close on 4/3, 5/28, 6/25 • Saturn near * Spica, near moon on 4/6, 5/4, 6/25 • Mercury W dusk from mid June on, moon 6/21 • Venus passes in front of sun after 6 p.m. on 6/5

16. Spring Stars & Groups • Evening: Big Dipper upside down, pointers to N.* • Same Dipper * point right to sickle of Leo • Arc of Dipper’s handle arc to golden “Arcturus” • Low in SE is Scorpius, it’s stars forming ‘J’ • In SE is the Summer Triangle, peaked by * Vega • Bright golden star Capella seen briefly low in NW

17. Big Dipper & N. Star in Spring Big Dipper North Star

18. South on Spring Evenings 2012 Arcturus Sickle of Leo Regulus Saturn Mars Spica

19. Let’s review once more… • Planet NOT prominent in Spring‘12 evening sky? • Is it Venus? Mars? Jupiter? Saturn? • When closest to us, neighbor planet is invisible? • Is it Venus? Mars? Jupiter? Saturn? • Big Dipper’s handle arcs to what bright star? • North Star Sirius Capella Arcturus • Write down your answers • Answers: Jupiter Venus Arcturus

20. Sky Shows Schedule – April & May • Free Sunday Public Shows at 4 pm • Sky Shows in Compton 224 • April Show: “Predators of Africa”, no Easter show • May Show: “Savannah Grazers” 5/6, 5/13, 5/20 • Come about 10 min.early as no late admissions • Call (301) 687-7799 for spoken road directions

21. Frequently asked questions • What are shooting or falling stars? • Pea sized space grit impacting upper atmosphere and bursting into flame. • What if planets aligned (as beads on string)? • They can’t as orbits are not in 1 plane. But even if they could, their pull very weak compared to our moon. • Why study other worlds? won’t ease our problems • By understanding other worlds, better know Earth • Your questions are welcome at our public programs.

22. Send any questions to…. • Bob Doyle email rdoyle@frostburg.edu • Be sure that questions involve basics about sky, moon, planets and stars • For questions about 2012, Pluto, Asteroids, Comets – see Sunday shows, talk to Dr. Doyle • Sunday programs are free on Sundays at 4 p.m.and change monthly at FSU To arrange program for special group, club, call below number and state your date and hour. • Call (301) 687-7799 to request free planetarium bookmark, schedule sent to you through mail