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.

Bell Work 1-20-16 Explain in your own terms how the “radial velocity technique” for finding exoplanets works. This bar timer, will start when anywhere on the slide is clicked. The bar will move from left to right and the word ‘End’ will appear at the end, accompanied by a ‘Deep Gong’ sound. It is possible to change the duration of this timer to any time, by entering the animation settings, and changing the timing for ‘rectangle 3’. Note the time has to be entered as a number of seconds – so if you want 2mins & 30secs – this is entered as 150 (60X2 + 30 = 150).

3. Gravitational Microlensing: Light from a distant star is bent and focused by gravity as a planet passes between the star and Earth Light in a Gravity Lense http://planetquest.jpl.nasa.gov/system/intera ctable/11/index.html

Pros: Cons: You can detect exoplanets! Sometimes, free-floating planets in space, ones that don't orbit a star, will cause quick microlensing events that astronomers will record. These events give us an idea of how common these so-called 'rogue' planets are in the galaxy Cons: You can’t predict where they will happen, so they have to watch large parts of the sky over long periods of time

4. Astrometry: The orbit of a planet can cause a star to wobble around in space in relation to nearby stars in the sky Miniscule Movements http://planetquest.jpl.nasa.gov/system/interact able/11/index.html

Astronomeristery…er…Astronometery Con Pro Extremely hard to do Doesn’t work well with Earth based telescopes because of our atmosphere We find very few stars this way Requires precise, expensive optics (Pick one to write down) Dancing Stars!

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

Account of Jeremiah Horrock’s observations of the transit of Venus This is an account of the first known observation of a transit of Venus. Johannes Kepler predicted the transits of Venus and Mercury, but did not live to see them occur. For additional information on Jeremiah Horrocks, see page 14 of the “Transit Tracks” lesson.

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…

Taken from space http://eoimages.gsfc.nasa.gov/images/imagerecords/78000/78196/sdo_transit_201206_sd.h264..mov

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. 17

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. 18

Graphing Transits In your notebook, graph change in brightness v. time for book and light Change in brightness 0% 50% 100% 0 1 2 3 4 5 time in seconds

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

How can we find exoplanets? In your notebook, graph change in brightness v. time for “planet” and light (orbiting planet) Change in brightness 0% 50% 100% 0 1 2 3 4 5 time in seconds

What would the transit of a planet look like if you made a graph brightness vs time? BRIGHTNESS Demonstrate a transit, using the same lamp as above, and “orbiting” a bead on a dark thread around the lamp (bulb). Ask the students to move about to see the bead cross the lamp. Ask the students to graph the light from the lamp as several transits occur. Again, this could be drawn on the board for discussion of what light curves look like, and what they tell you. Key point: the light output does not drop to zero as the bead never covers the entire lamp (bulb). Discussion questions: 1) What does the depth of the “dip” tell us? The size of the bead (planet) because bigger beads block more light, and smaller beads block less. 2) What do the repeated transits tell us? The time it takes for the bead to repeat a transit. For a planet, this is the orbital period, or year length. Repeat the demonstration to emphasize that the orbital period is one revolution about the star (aka lamp), and that equals one year. 3) What’s the orbital period of the Earth? About 365.25 days (hence, leap year once every 4 years). 22

This is a “light curve.” How are the planet’s size and orbital period shown in the light curve? 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 period (time for one orbit)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

The fifth and final way we find exoplanets? Transits demonstration What differences do you notice between the 2 planets? (there are at least 4!) Size Color Period Distance from star write in notebook What is a transit? A transit is an event where one body crosses in front of another, based on the point of view of the observer (ex: planet in front of star)

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 http://planetquest.jpl.nasa. gov/system/interactable/11 /index.html Searching for Shadows Single Planet

5. Transit Method: When a planet passes directly between its star and an observer, it dims the star’s light by a measureable amount http://planetquest.jpl.nasa. gov/system/interactable/11 /index.html Searching for Shadows Different Planet Sizes

5. Transit Method: When a planet passes directly between its star and an observer, it dims the star’s light by a measureable amount http://planetquest.jpl.nasa. gov/system/interactable/11 /index.html Searching for Shadows Multiple Planets

Pros You can determine size, period, distance from star, number of planets, temperature, 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

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

http://kepler.nasa.gov/images/videos/transitAnimation2.mov http://kepler.nasa.gov/images/videos/transitAnimation1.mov