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God is infinite, so His universe must be too. Thus is the excellence of God magnified and the greatness of His

kingdom made manifest; He is glorified not in one, but in countless suns; not in a single earth, a single world, but in

a thousand thousand, I say in an infinity of worlds.- Giordana Bruno, 1584, "On the Infinite Universe and

Worlds"

The word Astronomy means “naming the heavens”

Why should we care about Astronomy?

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Why should we care about Astronomy?

Objects in the sky seem remote but there are many reasons we should pay attention to them

Why should we care about astronomy ?

TimekeepingIn the past: •Before watches and written calendars people could tell the time of day and the date from the sky. This was particularly important for farmers in determining when to plant their crops, to know when the spring rains were coming or when winter would soon be setting in.•Stonehenge, pyramids, etc. all have architectural elements that were used for timekeeping•There were pocket sundials made in 1600s which would allow you to tell the time, even at night, using the stars, within 15 minutes of accuracy.

Modern day: If you know your constellations and you know the time of year, you can determine the approximate time by looking at the night sky.

Navigation In the past: Before compasses and GPS, travelers

used the stars to tell direction, especially sailors (using a sextant).

Modern day: Compasses break, GPS batteries lose power, GPS units can’t find satellites, or are simply inaccurate. Stars are always there and with stars and a map you can find your way even in the dark

Why should we care about astronomy ?

Why should we care about astronomy ?

Predicting the future

In the past: The earliest astronomers (Sumerians, Egyptians, Chinese) watched the skies for scientific reasons but also to try and predict events on earth (birth and death of kings, outcomes of battles, etc.). The only known record of this actually working was the Star of Bethlehem. The three wise men were amateur astronomers. Astrology is bunk. The only effect the heavens have on our daily lives is providing light and heat and the occasional news story about a close brush with a space object.

Modern day: Modern astronomers survey the sky for local threats to the Earth such as asteroids and comets with orbits close to us (NEOs – Near Earth Objects), dangerous solar activity (flares), and local supernovae (a star blowing up close to us (within 100 light years) could cause us a lot of trouble)

Why should we care about astronomy ?

Scientific advancement

In the past: Studying the stars helped people learn to practice agriculture, predict seasonal floods, understand the shape of the Earth.

Modern day: Understanding the chemical and physical processes in the stars and other celestial objects can help us understand how things work on Earth.Mapping the universe can help us understand what it looks like and appreciate God’s engineering skill.

Why should we care about astronomy ?There are extremely cool things out there to look at and study

– Manmade: Satellites, ISS– Meteorites and fireballs (these last 4-5 seconds)– Aurorae (if conditions are right)– Details of lunar craters– Other planets– Moons of other planets– Asteroids and comets– Asteroids with moons (Eris, etc. – get from Celestia presentation)– Differently colored stars (you can actually see the colors)– Double stars– Nebulae (Ring nebula, Orion nebula)– Globular clusters– Galaxies by themselves and galaxies that are in the process of colliding with each other– Exploding stars (supernovae – 1987A)– Black holes, white holes, wormholes– Extrasolar planets (with professional equipment)– Views of galactic clusters taken by Hubble telescope in areas of space thought to be blank!– See back in time to the beginnings of the universe (speed of light)– Maybe alien life forms????– And lots more!!

Observing Safety

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Observing Safety – Weather Safety• Weather Safety – exercise the same weather precautions as on a campout or hike.

– When observing, you will be outdoors for long periods of time without moving very much. You can get frostbite just as easily in your backyard as you can on the Arctic tundra. You can get heat exhaustion even at night if it’s hot enough outside. Dress appropriately and take the appropriate precautions for cold or hot weather.

• Heat Exhaustion– Signs – elevated body temp, skin pale and clammy, heavy sweating, nausea, dizziness, fainting, pronounced weakness and

tiredness, headache, muscle cramps.– Treatment – have victim lie down in a cool spot with feet raised. Apply cool damp cloths to skin. Give them water

• Heatstroke– Signs – red, hot dry skin, no sweating, extremely rapid pulse, confusion or disorientation, fainting or unconsciousness,

convulsions– Treatment – place victim in a cool spot with head and shoulders raised, remove outer clothing, sponge bare skin with cool

water, apply cold packs, use fan or place victim in tub of cool water. Obtain medical help immediately.• Hypothermia – when body’s core temperature drops so low it can no longer keep warm.. Can occur even in mild weather. Cool and

windy conditions are particularly dangerous. – Prevention – keep warm and stay dry. Eat plenty of energy foods (nuts, dried fruit, peanut butter)– Signs – Victim may begin shivering, then stop as they get colder. Irritability, sleepiness, incoherence, disorientation, inability

to think clearly.– Treatment – move victim to warm shelter, remove damp clothing, warm person with blankets, cover head with warm hat or

covering, offer hot drinks. Severe hypothermia requires immediate medical attention.• Dehydration –Can happen even in cold weather. Stay hydrated

– If you or someone observing with you begins to have trouble with the weather, remember your first aid and use the same treatments you would use for hypothermia, heat exhaustion, etc. as you would on a scout campout.

• Prepare for bugs (both the biting, stinging kind and the kind that will crawl up your leg and imbed themselves in you) with bug spray, long pants and shirts. Mosquitoes are just as active at night as during the day.

• Most of us can’t see in the dark and when we’re observing, we don’t want to ruin our night vision. This can lead to problems if there are hazards in the area where we’ll be observing

• Check the observing area during the daytime for holes, dropoffs, pipes sticking out of the ground, etc. Make note of them so that you won’t find them accidentally in the dark.

Observing Safety - Location

Observing Safety – Don’ts

• Observing the sun - You don’t look at the sun through a telescope for two primary reasons– Blindness - It will permanently blind you by burning your retina.

The lenses in a telescope are specifically designed to focus light to a small point. The rays of the sun are very powerful and when focused to a point, can create tremendous heat in a small amount of time. Anyone who has lit paper on fire with a magnifying glass knows how this works.

– Telescope Damage - The inside of the telescope is sealed and cannot vent heat. If the inside gets too hot, the lenses can be damaged. The adhesive that secures the lens pieces together can melt and ruin the view. There are special filters that can be used with a telescope for solar viewing, but it is not advisable for an amateur to attempt to do this. Plus, they’re really expensive.

Astronomy Definitions

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Star – a hot glowing ball of gas that produces energy by nuclear reactions in its core.

Planet – large, non-luminescent, sperical body that orbits a starRotate – spin around an axis. Revolve – go around another object (orbit)Meteor terminology

Meteoroid - small rock that orbits the sun. It’s a meteoroid while it’s in space

Meteor – rock from space that hits the earth’s atmosphere and flashes (shooting start, meteor shower)

Meteorite - rock from space that hits the ground and remains intact.Moon – small body that orbits a planet.Asteroid – Large rocky body in space that orbits the sun. In our solar

system, we have a large number of these in the Asteroid beltComet – Icy object from outer solar system. When it comes close to the

sun it grows a tail of steamed off ice.Solar System – Collection of planets, moons, comets, asteroids, etc.

that orbit a star

Astronomy Definitions

Constellation - a pattern of stars in the sky. Early astronomers (Ancient Greeks, Sumerians, Egyptians, etc.) drew imaginary lines between stars to form images of mythological characters or familiar creatures. There are 88 recognized constellations.

Asterism – a portion of a constellation Star Cluster – small group of stars within a galaxyGalaxy – A system of millions or billions of stars, together with gas and

dust, held together by gravitational attraction Milky Way – Not just a chocolate bar - Our own galaxyRed Giant – Old star that has bloated up several thousand times its

original sizeWhite Dwarf – The remnant of a relatively small star that isn’t big

enough to go supernova. Very denseNeutron Star- The highly dense core of a star left over after a

supernova, but not dense enough to form a black hole.Black Hole – Very massive star that has gone supernova and then

collapsed back in on itself and become so dense that even light can’t escape.

Universe – Everything that exists

Astronomy Definitions

All about the Moon

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Where did the moon come from?

• It is believed that our moon resulted from a collision with another body (about ½- ¾ the size of Earth) that combined the two large bodies and kicked off a bunch of molten rock that formed the moon. So the impetus for the moon’s current orbit came from that original collision.

• The orbit of the moon around our planet is elliptical (not a perfect circle) so the distance between Earth and moon can vary.

• Apogee – when the moon is farthest away from Earth• Perigee – when the moon is at its closest to the earth

The Moon – Orbit

How does the Moon stay in orbit?What is an Orbit?

An orbit is falling without hitting the ground

• Place a cannon on a mountain• When the cannon fires, the cannonball will follow its “ballistic trajectory” and hit the ground

• Use more gunpowder and the cannonball will flyfurther before it hits the ground

• If you use enough gunpowder, the cannonball will flyso far that it NEVER hits the ground. The earth curves away at the same rate that the cannonball drops.The cannonball is in orbit!

•The moon orbits the Earth because it’s going fast enough that it falls continuously without hitting the ground.

The Moon – Lunar FeaturesClose Up of Lunar Features with Labels

Naked-eye View(What you see in the

sky)

The Moon – Phases

• Phases of moon:– New moon (moon is between Earth and the sun)– Crescent (waxing when growing, waning when

getting smaller)– First quarter – half of the moon is illuminated. It’s

called first quarter rather than half moon because the moon is ¼ through it’s entire cycle at this point.

– Full Moon (Earth is between moon and the sun)– Gibbous – greater than quarter moon (more than

half illuminated) (waxing and waning)

Lunar Phases• Moon takes 28 days to orbit the

Earth and 28 days to rotate once on its axis so the same side always faces the earth. The Far Side of the moon was never seen until space probes took photos in the 1960s

• Moon moves slowly eastward over successive nights. As it does so, it becomes increasingly illuminated by the sun until it is completely illuminated at the full moon.

• At full moon, it is completely opposite the sun in the night sky.

• Note that the moon also moves higher and lower in the sky through each cycle. This is why it’s possible for the moon to eclipse the sun (or the Earth to eclipse the moon) on occasion, but it doesn’t happen every month.

Lunar Phases – more detail

The outer ring of moon images shows how the moon is seen from Earth. The inner ring of moon images shows the moon’s orientation to Earth and sun

The Moon – Total Solar EclipseTotal solar eclipse – when the moon gets between the sun and the earth and completely blocks the light. This only happens in a small path along the earth’s surface, not the whole planet. The moon is too small and too far away to completely block all light to the earth.

The Moon – Total Solar Eclipse• The last total solar eclipse visible from the

continental U.S.A. occurred on Feb. 26, 1979 (your merit badge counselor remembers this one).

• The next two total solar eclipses visible from the U.S.A. occur on Aug. 21, 2017 and Apr. 8, 2024.

The Moon – Partial solar eclipsePartial solar eclipse – (also called an “annular” eclipse) occurs when the moon is farther from the earth (lunar apogee) and closer to the sun. The moon’s shadow does not completely cover the sun (see picture below for annular eclipse).

The Moon –

The Planets

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• What are the 5 most visible planets? – Mercury– Venus– Mars– Jupiter – Saturn

The Planets

The Planets

• The other planets (Neptune, Uranus, Pluto) are so far away that they are not visible to the naked eye. They weren’t even discovered until the last couple of centuries (Uranus 1780, Neptune 1846, Pluto 1930).

What is an inferior planet? • Any planet between us and the sun

What is a superior planet?• Any planet beyond Earth’s orbit

Name the inferior planets:• Mercury• Venus

Name the superior planets:• Mars• Jupiter• Saturn• Uranus• Neptune• Pluto (unofficially)

The PlanetsInferior vs. Superior planets

Other than their position relative to Earth, what is the difference between Inferior and Superior planets?

Because Inferior planets are closer to the sun than we are, they can get between us and the sun and we can see their “darkside”. This means that the Inferior planets can have phases, much like our moon.

Since Superior planets are farther away from the sun than we are, we can never see their darksides (because the dark side is always facing away from us). As a result, we never see phases on Superior planets.

The PlanetsInferior vs. Superior planets

The Planets

Phases of VenusThis is a photo collage of the planet Venus as it

travels from our side of the sun to the far side. Note

that the planet shows phases similar to our moon.

The crescents at top are very large because Venus was

closer to us at that point. The full disks at bottom are

smaller as Venus gets farther away but more

sun can shine on them so we see a disk.

The Sun

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Layers of the sunCore – center – where reactions take place

The SunCorona

ChromospherePhotosphereConvective Zone

Radiative Zone

Core

Radiative zone – where energy leaves the coreConvective zone – where energy is carried by rising and falling currents of hot gas called convective cells.Photosphere – outer surface Chromosphere – in violent motion, reddish rim during solar eclipses.

Corona (crown) – extends outward from the sun in the form of the solar wind.

What are Sunspots?• Sunspots are temporary phenomena on the

photosphere of the Sun that appear as dark spots. These spots are cooler than the surrounding area, but only by comparison (4500K vs. 5800K).

• They are caused by intense magnetic activity, which prevents the hotter gases from welling up from underneath.

• Some sunspots are so large they can be viewed from Earth without a telescope (e.g. using a pinhole camera). The Chinese were studying them thousands of years ago, long before telescopes were invented.

Sunspot Cycles• Sunspot appearances fluctuate over a regular 11 year

cycle. Sunspot activity can vary over long periods of time (i.e. there were more sunspots on avg from 1900-1960 and fewer from 1960-present).

• Sunspots were rarely observed during the Maunder Minimum (1645-1715) which coincided with a cooling period called the Little Ice Age. This may suggest that sunspots actually indicate an increase in solar output and can directly affect our weather.

• Sunspots (called starspots) have even been observed on other stars

Sunspots-Effects on Earth• Studies of rock strata (layers) have

suggested that the solar cycles have been active for hundreds of millions of years, if not longer; precambrian sedimentary rock has revealed changes in layer thickness, with a pattern approximately repeating every eleven layers.

• Analysis of tree rings has revealed a detailed picture of past solar sunspot cycles for the last 11,400 years

• Sunspot activity affects weather and plant growth

Why do sunspots last so long?

• Recent observations from the Solar and Heliospheric Observatory (SOHO) using sound waves traveling below the Sun's photosphere have been used to study the internal structure of sunspots. This analysis shows that sunspots behave like terrestrial hurricanes. This explains why they don’t just appear and disappear, but instead, last for weeks at a time.

Solar Flares – What are they?

• A solar flare is a brief eruption of intense high-energy radiation from the sun's surface. This explosion is accompanied by a burst of charged particles.

• Flares occur in active regions around sunspots

• Flares are powered by the sudden release of magnetic energy stored in the corona.

• The background picture shows a solar flare (on left) and the resulting prominence (on right)

Solar Flares• The first solar flare observed by humans was

seen in September of 1859 by astronomers who were observing sunspots. It was so big that it was visible to the naked eye and is considered one of the most powerful on record.

• The flare interrupted electrical telegraph service and caused visible aurorae as far south as Havana, Cuba.

• The background picture shows a massive flare eruption (on right) in filtered light.

Solar Flares• In June of 2011, scientists witnessed the most powerful

solar eruption ever seen. A very large amount of material lofted up, expanded, and fell back down over half the surface area of the sun (as seen in the background picture on this slide).

• When flares occur, they simultaneously launch a large quantity of particles through the solar corona and into space. This is called a coronal mass ejection (CME). It takes 1-2 days for this to reach Earth.

• If one of these powerful flares—and its coronal mass ejection—were to face Earth, the particles would pound satellite components with charged particles, short some out, and potentially cripple them. The particles can also effect telephone and electrical lines.

Earth’s Axial Tilt

• Because of the axial tilt of the Earth, the amount of sunlight reaching any given point on the surface varies over the course of the year. This results in seasonal change in climate.

• Ironically, in the summertime in the Northern hemisphere, the sun is farthest away from us..

Stars and Constellations

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The Zodiac Constellations• What’s special about Zodiac constellations?

They are centered on the plane of the ecliptic which is the path that the sun, moon, and planets appear to follow in the sky. This is basically the plane of the solar system. These constellations have been misused by astrologers to foretell the future and classify people’s personalities based on their birth date. It doesn’t work. Astrology is bunk.

• Trivial note: If you know your Zodiac sign, that is the constellation that the sun is in during your birth month. At least, that was the case about 2500 years ago. Since then, things have shifted around a bit and the sun is now about 1 constellation off from that. Further proof that astrology is bunk because your Zodiac sign is actually one off from what you think it is.

The Zodiac Constellations

Diagram of the Sun’s path through the plane of the ecliptic

Zodiac Constellations and the Plane of the Ecliptic

Zodiac Constellations• Spring: Gemini, Cancer, Leo, Virgo, Libra• Summer: Libra (scales), Scorpius, Sagittarius,

Capricornus, Aquarius• Fall: Capricornus, Aquarius, Pisces, Taurus,

Gemini, Aries• Winter: Gemini, Taurus, Pisces, Aquarius

Let’s take a closeup look at a some of these Zodiac constellations. On the next few slides, you’ll see the outline of a constellation. Click on that and you’ll see a picture that shows you what the ancient astronomers saw in that constellation.

Leo the Lion (Spring)

Libra:The Scales(Summer)

Scorpius:The Scorpion(Summer)

Taurus (the Bull)

(Fall/Winter)

Gemini:The Twins(Winter)

Non-Zodiac Constellations

• Spring: Big Dipper, Little Dipper, Cassiopeia, Cepheus, Draco, Corona Borealis, Bootes, Hercules, Auriga, Perseus, Coma Berenices

• Summer: Big Dipper, Little Dipper, Cassiopeia, Bootes, Lyra, Cygnus, Aquila, Hercules

• Fall: Big Dipper, Little Dipper, Cassiopeia, Pegasus, Andromeda, Perseus, Pleiades

• Winter: Orion

Corona Borealis – Northern Crown(Spring)

Cepheus - the King(Spring Constellation)Cassiopeia’s HusbandLooks like a house

Bootes – the Shepherd(Summer Constellation)Chases the Big Bear around the North StarLooks like a broken kite

Cygnus – the Swan(Summer Constellation)Also known as the Northern Cross

Pegasus-the flying horse(Fall Constellation)

Orion the Hunter(Winter)

Non-Zodiac ConstellationsYear Round Constellations

While most constellations are only visible to us for part of the year, the following constellations are visible all year because they are positioned close to the polar axis (around Polaris):

• Ursa Major (Big Dipper)• Ursa Minor (Little Dipper) • Cassiopeia (The Queen)• Draco (The Dragon)

Year Round Non-Zodiac Constellations

Big Dipper/Ursa Major/Big Bear

Year Round Non-Zodiac Constellations

Little Dipper/Ursa Minor/Little Bear

Year Round Non-Zodiac Constellations

Cassiopeia – The Queen

Finding the North Star

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Finding the North Star

• Find Right pan of dipper• Find Right pan of dipper

Finding the North StarFinding the North Star

• Find Right pan of dipper

Finding the North StarFinding the North StarFinding the North Star

• Draw line to closest bright star

Finding the North StarFinding the North StarFinding the North Star

• Find open W of Cassiopeia

Draw line to brightest star

Spring and Summer Triangles

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Knowing how to identify the Spring and Summer Triangles can help you find your way around in the night sky

Spring TriangleComposed of the

brightest stars in 3 constellations:

• Arcturus (Bootes)• Denebola (Leo)• Spica (Virgo)

Summer Triangle

Composed of the brightest stars in 3 constellations:

• Deneb (Cygnus)

• Vega (Lyra)

• Altair (Aquila)

All About Stars

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Star Brightness

– A stars apparent magnitude (how bright it looks to us on Earth) does not necessarily indicate it’s actual brightness. A fairly dim star may seem very bright to us if it’s very close to us (dependent on proximity). Sirius looks very bright to us, but it’s only 9 ly away. Rigel is much brighter, but it’s 800 ly away.

– Big stars are not necessarily brighter than smaller stars. Hot stars are not necessarily brighter than cooler stars.

Stars and heatStars in order of heat: • Blue – hottest (Rigel in Orion)• White – Canis Major• Yellow – our own sun (Sol)• Orange - Arcturus• Red – coolest – Betelgeuse in Sagittarius

Magnitude• Star Magnitude is the measure of how luminous

(bright) a star is.• There are two different kinds of magnitude:

– Apparent Magnitude – Absolute Magnitude

• Apparent Magnitude="The brightness of a star or other celestial body as viewed by the unaided eye.“

• Absolute Magnitude= " The magnitude of a star as it would appear to a hypothetical observer at a distance of 32.6 light years."

Magnitude – Brightness Scale

Negative numbers indicate greater brightness

1st Magnitude StarsThese stars are visible in constellations you know: • Arcuturus (Bootes – base of kite)• Spica (Virgo)• Vega (Lyra – star that joins parallelogram and

triangle)• Altair (Aquila)• Antares (Scorpius)• Capella (Auriga)• Betelgeuse (Orion)• Rigel (Orion)• Sirius (Canis Major)• Aldebaraan (Taurus)

Stars Dimmer than 1st Magnitude

• Deneb (Cygnus – tail of the swan)

• Polaris (North star in Little Dipper)

• Castor and Pollux (Gemini – Pollux is brighter twin, stars make up their heads)

• Mizar and Alcor (visual binary in handle of Dipper – 2nd star from the end of the handle)

What reduces the magnitude of Stars?

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Light Pollution• What is it?

– Too much artificial light which dims the night sky.• How to combat it

– Cover your head down to your shoulders with a dark cloth so that stray light doesn’t interfere with your vision

– Observe later at night as businesses close down and people go to sleep

– Look for bright objects – Sirius, Vega, Spica, Aldebaraan, Arcturus, etc.

– Head away from the cities. Even just a few miles into the country can make a huge difference.

• Turbulent air can also affect viewing. (Think of shimmery hot air over a road or sidewalk in summer)

– Look for:• No wind• Cooler nights• Lower humidity

Galaxies

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Galaxies

Galaxy – Very large groups of stars with great distances between them.

Milky Way - Milky river of dust that can be seen under very dark skies in the summer. It runs directly overhead in July. It is made up of stars and lots, and lots of stardust. So much stardust that we can’t see the center of our galaxy. Which might be a good thing for us if the center of the galaxy really is a super black hole like scientists believe. Radiation from that black hole would be deadly, even at this distance.

Our Galaxy – The Milky Way

Our galaxy is considered a barred spiral. Each arm of the galaxy is named after the constellation in which it can be seen in our sky. The arm in which our sun is located is marked on the diagram.

Our Galaxy – Overhead View

Andromeda Galaxy (M31) - spiralOur closest galactic neighbor

The Andromeda Galaxy is the closest galaxy to us in the universe. It’s so close, that it is the only galaxy that is actually visible with the naked eye (if you know where to look). Andromeda is a very large galaxy, possibly 1.5-2 times as big as our own Milky Way.Andromeda is a spiral galaxy.

Sombrero Galaxy (M104) – lenticular: A galaxy having a central bulge surrounded by a flattened disk with no pattern of spiral arms. 

Whirlpool Galaxy (M51) - spiral

Here’s a view of a spiral galaxy from above. This galaxy has a companion (bright object at far right).

Feeling Small

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The Nearest SuperclustersBeyond the local supercluster is a large collection of other superclusters stretching all across the visible univers. This graphic is a map of the universe within 500 million light years. It shows most of the major galaxy superclusters that surround the Virgo supercluster. These superclusters are not isolated in space but together with many other smaller concentrations of galaxies they form parts of extensive walls of galaxies surrounding large voids. Three of the biggest walls near us are marked on the map as well as several of the largest voids. There are several hundred thousand large galaxies within 500 million light years, so even on this scale our galaxy is a very insignificant object.

Hubble Deep FieldIn December 1995, the Hubble Space Telescope was pointed at a blank area of the sky in Ursa Major for ten days. It produced one of the most famous astronomy pictures of modern times. Almost every object in this image is a galaxy typically lying 5 to 10 billion light years away.

Tools of the Trade

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Why are telescopes and other astronomical tools important?

• Because they significantly increase the amount of light that our eyes can gather and more light means that more detail is visible to us (use example of standing far away from a TV set and how the picture gets clearer the closer you get (or the bigger it is)).

• This even holds true for instruments that detect radiation in non-visible wavelengths such as infrared, ultraviolet (show rainbow to explain this), radio waves, gamma rays, x-rays, etc. We can’t see any of these things with our naked eyes, but these instruments can see them and allow us to see them.

• This is important because all of these sources of electromagnetic radiation provide us a ton of information about the astrophysical objects out in space. We’re trapped in a very small area in the universe (at least on a cosmological scale – even our farthest probe hasn’t left our solar system yet), yet because we have these tools, we know a lot of information about objects and phenomena that are very far away and existed a very long time ago.

Binoculars• Allow “binocular vision” which provides depth of

field. This is particularly important for comet hunting, lunar observing, Milky Way, star clusters.

• Light travels through thelarge objective lensthen through theporro prism lensesand then through the eyepiece lenses.

Big Binoculars• These are 25x100

binoculars (25x magnification at eyepieces, 100mm objective lenses at the ends of the barrels). These are much bigger than the 7x35s and 10x50s that you usually buy in the store.

Bigger Binoculars

Some binoculars can be very large, basically two refractors next to each other on a tripod or mount.

How to Care for BinocularsLens Care• Always replace the lens caps on both the objective

and eyepiece lenses when finished. This will keep dust and scratches off of the lenses.

• Always store binoculars in their case in a cool, dry location. Attics are not a good place to store any optical device. Heat can destroy lenses.

• Only clean binocular eyepieces and objectives when absolutely necessary and only with microfiber cloths (e.g. eyeglass cleaning cloth).

Types of Telescopes

Three main types of visible light scopes:

• Refracting (lenses)

• Reflecting (mirrors)

• Catadioptric (multiple mirrors)

Telescopes - Refractors

Refractor• Uses lenses to gather

and focus light• Same type as original

Galileo telescope

Telescopes - Refractors

What Galileo saw with his refractor:Saturn has been known since prehistoric times because it is easily visible to the naked eye. Not until the invention of the telescope, however, did people observe Saturn's magnificent rings.Galileo Galilei was the first to observe Saturn with a telescope in 1610. Because of the crudeness of his telescope, he couldn't determine what the rings were. He incorrectly guessed that there were two large moons on either side of Saturn. Two years later when he viewed Saturn again, the "moons" had disappeared. We know now this is because Galileo was viewing the rings edge-on so that they were invisible. After another two years, Galileo viewed Saturn again and found that the "moons" had returned. He concluded that the rings were "arms" of some sort.

                                                                                    

                                                                                          

Telescopes-Early Use

What Galileo drewWhat Galileo saw Galileo

Telescopes - Reflectors

Reflector• Uses a mirror to gather

and focus light• Also called Newtonian

after inventor Isaac Newton• Modern Newtonians work

much like Isaac’s original (replica at right)

Telescopes - ReflectorsReflector• Parabolic primary mirror gathers and reflects light to

secondary mirror(diagonal)

Secondary mirror reflects

light into focuser and

through eyepiece into eye

Telescopes - CatadioptricCatadioptric (or compound)• Uses mirrors and lenses

to gather and focus light• Lots of power in a compact

form factor• You pay a lot for that power.

Much more expensive than refractors and reflectors

• Most common types are:– Schmidt-Cassegrain– Maksutov-Cassegrain

Telescopes - CatadioptricCatadioptric (or compound)• Parabolic primary mirror gathers and reflects light to

large secondary mirror

Secondary mirror reflects

light into focuser and

through eyepiece into eye

How to Care for Optical Telescopes• Always replace the lens caps on both the

objective and eyepiece lenses when finished. This will keep dust and scratches off of the lenses.

• Always store telescopes in a cool, dry location. Attics are not a good place to store any optical device. Heat can destroy lenses.

• Only clean telescope eyepieces and objectives when absolutely necessary and only with microfiber cloths (e.g. eyeglass cleaning cloth).

How to Care for Optical Telescopes• Cover the telescope when not in use.

• Store extra eyepieces and lenses in sealed plastic bags or food containers to protect from dust

• Avoid touching the lens or mirrors with your fingers at all times. The dirt and oils from your skin can damage them.

Telescopes - Radio

• Radio Telescopes– Pick up radio waves emitted by objects in

space (planets, stars, galaxies, etc.)– Reveal temp and composition of objects in

space

Telescopes - Radio• Radio telescopes can be very large

The Arecibo telescope (shown on this page) is built into a crater and is 1000 feet wide

• See the inset picture in the lower left of this slide for an aerial view of the telescope.

Telescopes – X-Ray

X-Ray Telescopes• Good for finding hot spots in galaxies• Cosmic x-rays (emitted from very hot objects) can be

used to study dying stars, colliding galaxies, and quasars (extremely bright starlike objects that give off enormous amounts of energy)

• Captures X-rays from the edge of the observable universe

• Orbital X-ray scopes capture rays that are normally absorbed by Earth’s atmosphere (Chandra?)

Space Probes

• Helios- Sun-scope that tracks solar flares, sunspots, radiation from near the sun

• Mercury Probe

• Mars Probes

• Cassini (Saturn)

Special tools

• Spectroscope – shows spectrum of starlight – what it’s burning (chemical composition)– Frauhofer lines, etc.

• Filar micrometer – used for gauging distance between double-stars.

• Photometer – measures magnitude of stars• CCD – much like consumer digital devices. First digital

cameras were used for astrophotography back in the 80’s and earlier. More sensitive than standard consumer models.– Astrophotography – basic example – set digital camera for timed

photo (longest time), set light sensitivity to highest level, set photo mode to B/W, set on tripod facing North star and get a photo of star tracks (show example).

• Night vision instruments – can capture 2-3 times more light than your scope alone.

Careers in Astronomy

Astronomy Merit Badge

Careers in Astronomy

What astronomers do

• Design and carry out observing programs with a telescope or spacecraft

• Don’t spend all of their time looking through telescopes. They spend a lot more time analyzing data from telescopes and spacecraft

Careers in Astronomy

• To be an astronomer you must be:– Observant– Logical– Imaginative– Intutive– Curious

Careers in AstronomyAstronomers:• Are typically good at math and science, skilled with

computers• Need to take calculus, physics, chemistry in school.• Reading, writing and speaking skills are important• Are usually found teaching at colleges and

universities• Usually do research in a particular area of

astronomy– Planetary science– Solar astronomy– Stars and galaxies

• Some have careers in government, others in aerospace industry

Careers in Astronomy• Other careers

– Science teacher– Science writer– Planetarium or science museum directors and staff– Observing techs or assistants– Telescope operators– Optical engineers

• Related careers– Computing– Image processing– Instrument design and building (for telescopes or

spacecraft)

Amateur AstronomyWhat can Amateur Astronomers do?• Astronomy is one of the few scientific disciplines where

amateurs can make a big contribution. An amateur with a $150 telescope and a star map can find a sky object that nobody else has ever seen.– NEO finding and tracking (most of this is done by amateurs)– Comet hunting (mostly done by amateurs)– Spending time looking at things that professionals can’t spend time

on.• Amateur was able to photograph energy jets radiating from a black hole

and helped solve a mystery about the effect of those jets on the surrounding nebula

– Galaxy Zoo – classifying galaxies that have been found by the Hubble deep sky project. Too many for scientists to classify. You can help classify them with your smartphone or computer.

– Map storms on Mars and Jupiter– Get to look at actual stars (Most professionals don’t)– Still contribute to the field while pursuing other professions

Observation Requirements

Astronomy Merit Badge

Observation RequirementsIn order to really understand astronomy (and complete this badge), you’ll have to do some of the same things that professional astronomers do - You’ll watch the sky and record what you see.

1) In order to do that, you’ll have to know when the things you want to look at in the sky are visible, so you’ll make a planet chart for 2012.2)Then you’ll track a planet over the course of several weeks, sketching it’s position so you can see how it moves through the sky. 3)You’ll sketch the position of the Big Dipper over the course of several hours so you can observe the visible rotation of the earth. 4)And you’ll sketch the moon’s phases and note some of its landmarks. You won’t believe how much you can see once you know what you’re looking at.

You don’t have to be a great artist to do these things, just sketch what you see to the best of your ability, with special attention to location and position of objects in the sky.

Observation Requirements

4c) Make two sketches of the Big Dipper. In one sketch, show the Big Dipper’s orientation in the early evening sky. In another sketch, show its position several hours later. In both sketches, show the North Star and the horizon. Record the date and time each sketch was made.

Observation Requirements

5b) Find out when each of the five most visible planets that you identified in requirement 5a will be observable in the evening sky during the next 12 months, then compile this information in the form of a chart or table. Update your chart monthly to show whether each planet will be visible during the early morning or in the evening sky.

Planet Chart-2012Use the planet chart at right to find the times when planets are visible in the night sky for 2012. You can determine this by looking for the straight lines that refer to planets transiting (e.g. “Mars transits”, “Neptune transits”, etc.). These lines indicate when a planet is most visible in the night sky for the Northern Hemisphere. Create a table that lists the planets and what months they will be visible in the night sky. Or . . .

Planet Chart - 2012You can also visit the following website to find when planets are visible throughout 2012 and make your chart from this information: http://www.telescope.com/Articles/Current-Articles/Astronomy/Notable-2012-Celestial-Events/pc/9/c/192/sc/199/p/101857.uts?utm_source=120103&utm_medium=email&utm_campaign=CelestialEvents

Observation Requirements6) At approximately weekly intervals, sketch

the position of Venus, Mars or Jupiter in relation to the stars. Do this for at least four weeks and at the same time of night. On your sketch, record the date and time next to the planet’s position. Use your sketch to explain how planets move.

See the sample sketches on the next slide for an example.

Sketch a Planet’s movementWeek #1

Week #2

Week #3

Week #4

Observation Requirements7) Do the following:a) Sketch the face of the moon and indicate at least

five seas and five craters. Label these landmarks.

Note: Review the moon information in this presentation as it lists the most visible craters and seas.

b) Sketch the phase and the daily position of the Moon at the same hour and place, for a week. Include landmarks on the horizon such as hills, trees, and buildings. Explain the changes you observe.