The Sun in Our Sky

Lab Objectives:

  • Students will understand the Sun is a Star
  • Students will know size of the Sun in comparison to the Earth
  • Students will be introduced to the various structures of the Sun.
  • Students will be introduced to the Sun’s role in changing seasons
  • Students will know the Earth and other planets in the solar system revolve around the Sun.

Benchmark(s) Addressed:

  • SC.05.PS.03.01 Recognize and describe the motion of an object in terms of one or more forces acting on it.
  • SC.05.ES.04 Describe the Earth's place in the solar system and the patterns of movement of objects within the solar system using pictorial models.
  • SC.05.ES.04.01 Describe Earth's position and movement in the solar system.
  • SC.05.ES.04.02 Recognize that the rotation of the Earth on its axis every 24 hours produces the night-and-day cycle.
  • SC.05.SI.01 Make observations. Ask questions or form hypotheses based on those observations, which can be explored through scientific investigations.
  • SC.05.SI.03 Collect, organize, and summarize data from investigations.
  • SC.05.SI.04 Summarize, analyze, and interpret data from investigations.

Materials and Costs:

List the equipment and non-consumable material and estimated cost of each

Item $

  • Drinking Straws (100 straws).…………………………………….$1.50
  • Copies of Lab (free)
  • Scissors (amazon.com) 12 pack $34.62 x 3….…………..$103.86
  • Flashlights (amazon.com) 2 pk w/batteries teacher demo…..$11.97

Estimated total, one-time, start-up cost: $117.33

List the consumable supplies and estimated cost for presenting to a class of 30 students

Item $

  • Drinking Straws (100 straws) ………………...…………………..$1.50
  • Copies of Lab (free)

Estimated total cost each year: $1.50

Time:

Initial prep time: 30min (at home)

Preparation time: 5 min (set-up at school)

Instruction time: 10 min (lecture), 10 min (activity)

Clean-up time: 5 min

Assessment:

-Sun Worksheet

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-Verbal questions

  • Consider these questions

-Where does its heat come from (hydrogen to helium)?

-How do we get heat?

-Why do we orbit the sun (gravity)

-How do we keep the heat?

The Background

“The Sun” information provided by:

THE SUN

The Sun is the most prominent feature in our solar system. It is the largest object and contains approximately 98% of the total solar system mass. One hundred and nine Earths would be required to fit across the Sun's disk, and its interior could hold over 1.3 million Earths.

The Sun's outer visible layer is called the photosphere and has a temperature of 6,000°C (11,000°F). This layer has a mottled appearance due to the turbulent eruptions of energy at the surface.

Solar energy is created deep within the core of the Sun. It is here that the temperature (15,000,000° C; 27,000,000° F) and pressure (340 billion times Earth's air pressure at sea level) is so intense that nuclear reactions take place. This reaction causes four protons or hydrogen nuclei to fuse together to form one alpha particle or helium nucleus. The alpha particle is about .7 percent less massive than the four protons. The difference in mass is expelled as energy and is carried to the surface of the Sun, through a process known as convection, where it is released as light and heat. Energy generated in the Sun's core takes a million years to reach its surface. Every second 700 million tons of hydrogen are converted into helium ashes. In the process 5 million tons of pure energy is released; therefore, as time goes on the Sun is becoming lighter.

The chromosphere is above the photosphere. Solar energy passes through this region on its way out from the center of the Sun. Faculae and flares arise in the chromosphere. Faculae are bright luminous hydrogen clouds, which form above regions where sunspots are about to form. Flares are bright filaments of hot gas emerging from sunspot regions. Sunspots are dark depressions on the photosphere with a typical temperature of 4,000°C (7,000°F).

The corona is the outer part of the Sun's atmosphere. It is in this region that prominences appear. Prominences are immense clouds of glowing gas that erupt from the upper chromosphere. The outer region of the corona stretches far into space and consists of particles traveling slowly away from the Sun. The corona can only be seen during total solar eclipses.

images/sun.earth.lrg.jpg

The Sun appears to have been active for 4.6 billion years and has enough fuel to go on for another five billion years or so. At the end of its life, the Sun will start to fuse helium into heavier elements and begin to swell up, ultimately growing so large that it will swallow the Earth. After a billion years as a red giant, it will suddenly collapse into a white dwarf -- the final end product of a star like ours. It may take a trillion years to cool off completely

History of Sundials

“History of Sundials” provided by:

inside/sundial.jpg

The earliest sundials known from the archaeological record are obelisks (3500 BC) and shadow clocks (1500 BC) from ancient Egypt and Babylon. Presumably, humans were telling time from shadow-lengths at an even earlier date, but this is hard to verify. In roughly 700 BC, the Old Testament describes a sundial — the "dial of Ahaz" mentioned in Isaiah 38:8 and II Kings 20:11 — which was likely of Egyptian or Babylonian design. Sundials are believed to have existed in China since ancient times, but very little is known of their history.

The Romans adopted the Greek sundials, so much so that Plautus complained in one of his plays about his day being "chopped into pieces" by the ubiquitous sundials. Writing in ca. 25 BC, the Roman author Vitruvius listed all the known types of dials in Book IX of his De Architectura, together with their Greek inventors.[57] All of these are believed to be nodus-type sundials, differing mainly in the surface that receives the shadow of the nodus.

Sundials are associated with the passage of time, and it has become common to inscribe a motto into a sundial, often one that prompts the viewer to reflect on the transience of the world and the inevitability of death, e.g., "Do not kill time, for it will surely kill thee." A more cheerful popular motto is "I count only the sunny hours." Various collections of sundial mottoes have been published over the past few centuries.

Fun Facts

“Fun Facts” provided by:

-Comets' tails point away from the Sun at all times. So, when a comet is moving away from the Sun, its tail is actually leading. Comet tails are caused by dust and gas being lost from the comet and then pushed away from the Sun by the solar wind (charged particles moving out from the Sun) and by radiation pressure from the Sun.

-Lightning is 5 times hotter than the Sun.

-The Earth is actually closer to the Sun during the Northern hemisphere's winter (when the weather is colder), and further away during the warm summer months!

-Our sun is expected to last about 5 billion more years. It has already been in existence about 4.5 billion years.

-The sun is 93 million miles from earth, yet it's 270,000 times closer than the next nearest star.

-The sun contains 99% of all the mass in our solar system.

-During a total solar eclipse, local temperatures can drop up to 20F degrees.

-A cosmic year is the amount of time it takes the Sun to revolve around the center of the Milky Way, about 225 million years.

The Activity

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