About this 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_at_frostburg.edu

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Frostburg State Planetarium presents

• Spring 2015 Sky Sights for
• Middle School Intermediates by Dr.
  Bob Doyle
• Next Edition July 2015

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Big Topics Treated

• Horizon, Finding directions, Sunrise/Sunset
• How Day Sky Works, Twilight AM PM
• Moon basics, Its 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 15 Moon Schedule Star diagrams
• Spring Talk Show Schedule related info

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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 (1pm in April, May June)
• Sun sets nearly in West, face sunset, right is
  North
• Can use Big Dippers pointers to find N. Star

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Sunrise Sunsets?

• Earths 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

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Lets review these ideas

• What point in sky is farthest from horizon?
• Is it Celestial Pole? Zenith? Nadir?
• Which direction recipe WONT work?
• S Moss side of tree N 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

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Interesting facts about day sky

• Noon sun 400,000 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.

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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 most stars, sun must be 12 degr. below
  hor.
• Arctic Circle cities no darkness in June July
• Equatorial places have shortest twilights
• Our twilights last about 90 min. at dusk dawn

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What about Moon?

• Our moon is 2160 miles across, ¼ Earths 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 Earths 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

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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

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Spring 2015 Moon Schedule

• Early April Full moon 4/4, slow evening exit
• Mid April Evening crescent after 4/19
• Late April 1/2 full evening moon on 4/25
• Early May Full moon 5/3, slow evening exit
• Mid May Evening crescent after 5/21
• Late May ½ full evening moon on 5/25
• Early June Full moon 6/2, slow evening exit
• Mid June Evening crescent after 6/19
• Late June ½ full evening moon on 6/24

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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

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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

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Easy Spring 2015 Planets

• Brilliant Venus is in the western twilight
• Crescent Moon Venus close 4/22, 5/21, 6/20
• Bright planet Jupiter in southwest, Venus to
  right
• Moon Jupiter close on 4/25, 5/23, 6/21
• Venus and Jupiter very close on 6/30 in W. dusk
• Saturn creeps into evening sky, closest on 5/22
• Mercury below Venus, late Apr. early May

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Spring Stars Groups

• Evening Big Dipper upside down, pointers to N.
• Same Dipper point right to sickle of Leo
• Arc of Dippers handle arc to golden Arcturus
• Low in SE is Scorpius, its stars forming J
• In SE is the Summer Triangle, peaked by Vega
• Bright golden star Capella seen briefly low in NW

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Big Dipper N. Star in Spring
Big Dipper
North Star
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Southern sky in Spring 14
Arcturus
Sickle of Leo
Regulus
Spica
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Lets review once more

• Planet NOT prominent in Even.Spring skies15?
  Venus? Mars? Jupiter? Saturn?
• When closest to us, neighbor planet is invisible?
  
• Is it Moon? Mars? Jupiter? Venus?
• Big Dippers handle arcs to what bright star?
• North Star Sirius Capella Arcturus
• Write down your answers
• Answers Mars Venus Arcturus

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Send any questions to.

• Bob Doyle email rdoyle_at_frostburg.edu