Knowledge: meeting the learning goals and expectations. Complex Knowledge: demonstrations of learning that go aboveand above and beyond what was explicitly taught. Knowledge: meeting the learning goals and expectations. Foundational knowledge: simpler procedures, isolated details, vocabulary. Limited knowledge: know very little details but working toward a higher level. Understand how our view of the solar system has changed over time and how discoveries made have led to our changing our view of the solar system. Learn planetary characteristics such as number of moons, size, composition, type of atmosphere, gravity, temperature and surface features. Understand the movement of planetary bodies. Understand which planetary characteristics are more important than others when it relates to our understanding of other worlds. Understand how proximity to the sun influences planets. Understand the methods and tools scientists use to learn about other planets and moons in our solar system. Understand the conditions needed for a habitable world and determine if there are habitable worlds in our solar system or outside the solar system. Understand how we look for and study solar systems other than our own.

You have a current event due AT MIDNIGHT ON FRIDAY!

How do we find them? 1. Direct Imaging: Astronomers can take pictures of exoplanets by removing the overwhelming glare of the stars they orbit

2. Gravitational Microlensing: Light from a distant star is bent and focused by gravity as a planet passes between the star and Earth

3. Astrometry: The orbit of a planet can cause a star to wobble around in space in relation to nearby stars in the sky

4. Radial Velocity Technique: Orbiting planets cause stars to wobble in space, changing the color of the light astronomers observe

What’s this? Write down what you think it is…. A transit is seen when planet is seen to cross in front of a star. This requires that the observer (on Earth in this case), the planet (Venus or Mercury), and the Sun all line up. The Sun’s apparent size is ½ degree, and so this is a rare event. The orbits of the Earth, Venus, and Mercury are all tilted with respect to each other. With respect to Earth’s orbit (aka, the ecliptic), Venus’ orbit is tilted by 3.4 degrees and Mercury’s is tilted 7 degrees. As a consequence, the Venus and Mercury do not often transit the Sun as see from Earth. Transits across the face of the Sun can only occur when the planet is crossing the plane of the ecliptic at same the time it lies between the Earth and the Sun. Mercury’s orbit is complex, and the transits occur every few years. For Venus, transits come in pairs, about 8 years apart, and then more than a century goes by before the next pair. The next transit of Mercury is on May 9, 2016 , and the last transit of Venus was June 5/6, 2012 and the next is December 1011, 2117. For further information on transits, go to: http://eclipse.gsfc.nasa.gov/transit/venus0412.html Or see: “Transit of Mercury”: http://en.wikipedia.org/wiki/Transit_of_Mercury “Transit of Venus”: http://en.wikipedia.org/wiki/Transit_of_Venus

Read the article at MrHyat.rocks Then answer this question: “Who is Jeremiah Horrocks and what did he do?”

What’s this? Write down what you think it is…. A transit is seen when planet is seen to cross in front of a star. This requires that the observer (on Earth in this case), the planet (Venus or Mercury), and the Sun all line up. The Sun’s apparent size is ½ degree, and so this is a rare event. The orbits of the Earth, Venus, and Mercury are all tilted with respect to each other. With respect to Earth’s orbit (aka, the ecliptic), Venus’ orbit is tilted by 3.4 degrees and Mercury’s is tilted 7 degrees. As a consequence, the Venus and Mercury do not often transit the Sun as see from Earth. Transits across the face of the Sun can only occur when the planet is crossing the plane of the ecliptic at same the time it lies between the Earth and the Sun. Mercury’s orbit is complex, and the transits occur every few years. For Venus, transits come in pairs, about 8 years apart, and then more than a century goes by before the next pair. The next transit of Mercury is on May 9, 2016 , and the last transit of Venus was June 5/6, 2012 and the next is December 1011, 2117. For further information on transits, go to: http://eclipse.gsfc.nasa.gov/transit/venus0412.html Or see: “Transit of Mercury”: http://en.wikipedia.org/wiki/Transit_of_Mercury “Transit of Venus”: http://en.wikipedia.org/wiki/Transit_of_Venus

Jeremiah Horrocks Made First Observation of the Transit of Venus (1639)

Cook's drawing shows the Transit of Venus as it appeared on June 3, 1769, from Tahiti.

Transits of Venus Occur in pairs separated by more than a hundred years. there have been 53 transits since 2000 B.C. only 6 have been observed since the invention of the telescope in 1608. The next opportunity to see a transit is 12/10/2117. The last one was in 2012. Womp Womp…

Imagine you have a light sensor aimed a lamp Imagine you have a light sensor aimed a lamp. What would the graph of brightness vs time look like? (sketch this graph) TIME BRIGHTNESS Demonstration: Turn off classroom lights. Turn on a bare, 25W lamp (frosted) as the light source. Move a book, or other large opaque object across the lamp between the class and the lamp. Ask the students to draw in the air a graph of the light from the lamp as the book is moved. A student could draw this on the board for discussion about graphing. 17

Imagine you have a light sensor aimed a lamp Imagine you have a light sensor aimed a lamp. In your notebook, graph change in brightness v. time for book and light TIME BRIGHTNESS Demonstration: Turn off classroom lights. Turn on a bare, 25W lamp (frosted) as the light source. Move a book, or other large opaque object across the lamp between the class and the lamp. Ask the students to draw in the air a graph of the light from the lamp as the book is moved. A student could draw this on the board for discussion about graphing. 18

Imagine you have a light sensor aimed a lamp Imagine you have a light sensor aimed a lamp. What would the transit of a book look like if you made a graph of brightness vs time? (sketch this graph) TIME BRIGHTNESS Demonstration: Turn off classroom lights. Turn on a bare, 25W lamp (frosted) as the light source. Move a book, or other large opaque object across the lamp between the class and the lamp. Ask the students to draw in the air a graph of the light from the lamp as the book is moved. A student could draw this on the board for discussion about graphing. 19

Like this? TIME BRIGHTNESS Key outcome: all of the lamp (bulb) is covered at some point, and so the lamp’s output goes to zero. The slope of the ingress and outgress of the book is slanted as the book covers and then reveals the lamp. TIME 20

Imagine you have a telescope aimed at a planet What would the transit of a planet look like if you made a graph of brightness vs time? (sketch this graph) TIME BRIGHTNESS Demonstration: Turn off classroom lights. Turn on a bare, 25W lamp (frosted) as the light source. Move a book, or other large opaque object across the lamp between the class and the lamp. Ask the students to draw in the air a graph of the light from the lamp as the book is moved. A student could draw this on the board for discussion about graphing. 21

This is a “light curve.” TIME BRIGHTNESS BRIGHTNESS The depth of the “dip” provides information on the size of the planet. The deeper the “dip,” the larger the planet. For a planet the diameter of Jupiter, the dip is between 1-2% of the starlight. For a planet the size of Earth, the dip is around 0.01%. The time between “dips” is the time between transits. The time between “dips” is the orbital period, or the “year” for the planet. An animation of a transit can be downloaded at: http://kepler.nasa.gov/multimedia/animations/ Select “Transit Graph” 22

This is a “light curve. ” What does this depth of the dip tell us This is a “light curve.” What does this depth of the dip tell us? What does the interval between the dips tell us? The size of the planet The orbital period of the planet TIME BRIGHTNESS The depth of the “dip” provides information on the size of the planet. The deeper the “dip,” the larger the planet. For a planet the diameter of Jupiter, the dip is between 1-2% of the starlight. For a planet the size of Earth, the dip is around 0.01%. The time between “dips” is the time between transits. The time between “dips” is the orbital period, or the “year” for the planet. An animation of a transit can be downloaded at: http://kepler.nasa.gov/multimedia/animations/ Select “Transit Graph” 23

Is there a relationship between the planet’s orbital period and its distance from its star? Why yes there is….Keplers Third Law!  This is a discussion question: Is there a relationship between the planet’s period (time for on orbit) and its distance from its star? Again, the lamp-bead can be used with a variety of thread lengths, and the relationship between year length an distance will become more obvious. The longer the year, the greater the distance from the Sun/star. Note: This is not a linear relationship. For direct instruction, use the slides on Kepler’s three laws, go to. slides 56,57,58. These slides link to an online website with animations of Kepler’s Laws that allow the user to change the parameters and animate the systems. Depending upon your teaching strategies, you may wish to re-arrange the slides to introduce all three laws before the students begin to work on the light curves, or use the Kepler’s three laws slides to wrap up the lesson and provide the formal instruction for your students on Kepler’s three laws. 24

From just this light curve, we already know the planets: -Size -Orbital Period -Distance from parent star TIME BRIGHTNESS The depth of the “dip” provides information on the size of the planet. The deeper the “dip,” the larger the planet. For a planet the diameter of Jupiter, the dip is between 1-2% of the starlight. For a planet the size of Earth, the dip is around 0.01%. The time between “dips” is the time between transits. The time between “dips” is the orbital period, or the “year” for the planet. An animation of a transit can be downloaded at: http://kepler.nasa.gov/multimedia/animations/ Select “Transit Graph” 25

This is the actual light curves for Kepler 4b This is the actual light curves for Kepler 4b. The upper light curve shows the “dips” on a period of 3.2135 days. The lower chart shows the transit in detail. Kepler 4b transits it star in about 5 hours, from beginning to end of the transit. Note that the upper curve is scaled against “DAYS” (HJD = Heliocentric Julian Days, a precise way in which astronomers measure time, counting days), hence the transits are sharp, pointed dips because they last less than one day. The lower curve is “stretched out” into “HOURS” so that the shape of the transit looks different. The sloping sides show that the light diminishes slowly as the planet begins to block some of the star’s light. It’s flat on the bottom when the planet is entirely in front of the disk of the star, and then sloped again when the transit ends as the planet is exiting from in front of the star. For each Kepler system, these plots are available in the scientific literature. They are also posted on the Kepler website via the “Discoveries” table. Go to: http://kepler.nasa.gov/Mission/discoveries/ Click on the individual planet name (e.g., Kepler-4b) to go to a page with an animation of the system (based on real data), and excerpts from the scientific publication like the plots on this slide.

5. Transit Method: When a planet passes directly between its star and an observer, it dims the star’s light by a measureable amount

What does the slope of the dip tell us? http://kepler.nasa.gov/images/videos/transitAnimation2.mov

We are probably missing most planets that exist… http://planetquest.jpl.nasa.gov/video/24

Pros You can determine size, period, distance from star, number of planets, temperature, size of planet, planet composition Very successful – found thousands this way Cons: Tricky if there is more than 1 planet Works best with telescopes in space. Everything has to line up or we can’t detect anything at all

Sketch Go back to your notes, and make a sketch depicting each method of finding exoplanets that we have discussed so far.