Solar System 2010Presented by Linder Winter

EVENT DESCRIPTIONThis event will address: The Sun Planets and their satellites Dwarf planets Comets Asteroids and the asteroid belt Meteoroids Oort Cloud Kuiper Belt

EVENT DESCRIPTIONA TEAM OF UP TO: 2

APPROXIMATE TIME: 50 Minutes

EVENT PARAMETERSTeams may bring only one 8.5” x 11” two-sided sheet of notes containing images, graphics and text, plus a basic, non-programmable calculator with a square root function.

THE COMPETITIONParticipants will be presented with one or more tasks, each requiring the use of one or more process skills. Skills may include, but are not limited to, generating inferences, making predictions, problem solving, making and recording observations, formulating and evaluating hypotheses, interpreting data and graphing. The exam may be presented using a thematic approach.

KNOWLEDGE vs.CONCEPTUALLY-BASED LEARNING

Knowledge: Basic information often included in notes for quick reference.Conceptual: Application of “basic knowledge” to tasks requiring reasoning.

Ideally, Science Olympiad activities move from basic knowledge at invitational and regional competitions to more challenging conceptual activities at state and national competitions.

KNOWLEDGE vs.CONCEPTUALLY-BASED LEARNING

Student notes should be a collection of basic knowledge and facts. These may include tables, graphs and graphics.

Preparation for competitions should include numerous opportunities for participants to develop conceptual thinking skills.

During this presentation, numerous examples of conceptual activities will be suggested for use in preparing for competitions.

KNOWLEDGE vs.CONCEPTUALLY-BASED LEARNING

In preparing your team, select relevant images, graphs, charts, tables, etc. and challenge participants to use these in developing their own lists of questions, tasks and activities.

Providing opportunities to develop sound conceptual thinking skills is the most effective type of preparation for SO competitions.

KNOWLEDGE vs.CONCEPTUALLY-BASED LEARNING

Caution participants that the supervisor who actually writes the exam may be a fact-oriented person, so you must prepare them for this possibility also!

Even if the supervisor happens to be a fact-oriented individual, participants who have experienced conceptual learning will have an edge on those whose preparation was primarily based on memorization of facts.

Topics of Study Each of the topics included in the Solar

System event will be introduced in the next series of slides.

This series of slides may be used to introduce the event to students who have expressed a desire to participate in this event.

History and Formation of the Solar System Much of our know-

ledge of how the solar system was formed is gained from direct observations of objects within other galaxies and solar systems – both younger and older.

Image: Northrop Grumman Corporation

History and Formation of the Solar System The planets of the

Solar System formed from a nebula of gas, dust, and ices coalescing into a dusty disk around the evolving Sun.

Within the disk, tiny dust grains and ices coagulated into growing bodies called planetesimals.Image: Pat Rawlings, NASA

Objects of the Solar System: Sun Prominences are

dense clouds of material suspended above the surface of the Sun by loops of magnetic field.

Prominences and filaments are actually the same objects, except that promi-nences are seen projecting out above the limb of the Sun.

Objects of the Solar System: Sun Spicules are small,

jet-like eruptions. Spicules appear as

short dark streaks. Although spicules

last just a few minutes they eject material off of the surface and outward into the hot corona at speeds of 20 to 30 km/s.

Objects of the Solar System: Sun Solar flares are

tremendous explosions on the surface of the Sun.

Solar flares occur near sunspots between areas of oppositely directed magnetic fields.

Objects of the Solar System: Sun Coronal Mass

Ejections or (CMEs) are huge bubbles of gas threaded with magnetic field lines that are ejected from the Sun over the course of several hours.

Objects of the Solar System: Sun Coronal Mass

Ejections disrupt the flow of the solar wind and produce disturbances that strike the Earth with sometimes catastrophic results.

Objects of the Solar System: Sun Coronal mass

ejections are often associated with solar flares and prominence eruptions but they can also occur in the absence of either of these processes.

Objects of the Solar System: Sun The Sun's core is

the central region where nuclear reactions consume hydrogen to form helium.

These reactions release the energy that ultimately leaves the surface as visible light.

Objects of the Solar System: Sun The radiative zone

extends outward from the outer edge of the core to the interface.

The radiative zone is characterized by its method of energy transport - radiation.

Energy generated in the core is carried by light that bounces from particle to particle through the radiative zone.

Objects of the Solar System: Sun The interface layer

lies between the radiative zone and the convective zone.

The fluid motions found in the convec-tion zone slowly disappear from the top of this layer to its bottom where the conditions match those of the calm radiative zone.

Objects of the Solar System: Sun It is now believed

that the Sun's magnetic field is generated by a magnetic dynamo in the interface layer.

Changes in fluid flow velocities across the layer can stretch magnetic field lines of force and make them stronger.

Objects of the Solar System: Sun The convective zone

is the outermost layer of the solar interior.

It extends from a depth of about 200,000 km right up to the visible surface.

Convective motions carry heat to the surface.

These motions are visible at the surface as granules and super-granules.

Objects of the Solar System: PlanetsAccording to the International Astronomical Union (IAU), a planet is a celestial body that:

Is in orbit around the Sun, Has sufficient mass to

assume a hydrostatic equilibrium (nearly round) shape, and

Has “cleared the neighbor-hood” around its orbit.

This definition does not apply outside the solar system.

http://www.ccastronomy.org/tour_of_universe_tour.htm

Objects of the Solar System: Dwarf PlanetsAccording to the IAU, a dwarf planet:

Is in orbit around the Sun Has sufficient mass for its

self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape,

Has not “cleared the neighbor-hood” around its orbit, and

Is not a satellite of a planet, or other nonstellar body.

http://www.ccastronomy.org/tour_of_universe_tour.htm

Objects of the Solar System: Dwarf Planets There are currently

five official dwarf planets. Pluto was demoted to dwarf planet status. Ceres, the largest asteroid in the main asteroid belt between Mars and Jupiter, was also declared a dwarf planet. Images courtesy of NASA, ESA,

JPL, and A. Feild (STScI).

Objects of the Solar System: Dwarf Planets The three other dwarf

planets are Eris, Make-make and Haumea.

Pluto, Makemake and Haumea orbit the Sun on the frozen fringes of our Solar System in the Kuiper Belt.

Eris, a Trans-Neptunian Object, is located even further from the Sun.Images courtesy of NASA, ESA,

JPL, and A. Feild (STScI).

Objects of the Solar System: Dwarf Planets Haumea is a large Kuiper

Belt Object (KBO). It is an icy world that

orbits far from the Sun on the frozen fringes of our Solar System.

Because it is so far away, Haumea takes 285 years to orbit the Sun once!

Haumea is usually a bit further from the Sun than Pluto.Images courtesy of NASA, ESA,

JPL, and A. Feild (STScI).

Objects of the Solar System: Dwarf Planets What, do you suppose,

causes this dwarf planet’s strange shape?

Which arrow, red or blue, represents the object’s most likely spin axis? Explain.

Images courtesy of NASA, ESA, JPL, and A. Feild (STScI).

Objects of the Solar System: Dwarf Planets What, do you suppose,

causes this dwarf planet’s strange shape? Its rapid rotation.

Which arrow, red or blue, represents the object’s most likely spin axis? Explain. Blue. It bulges outward at right angles to the spin axis.Images courtesy of NASA, ESA,

JPL, and A. Feild (STScI).

Objects of the Solar System: Satellites Planetary rings are

thought to have been created when small moons collided with others, or ventured too close to their parent planet.

The resulting fragments gradually spread out into concentric orbits, breaking into ever smaller fragments through repeated collisions, eventually forming a ring system.

Objects of the Solar System: PlanetsSeasons

Extraterrestrial seasons are hardly noticeable on some planets (Venus), extreme on others (Uranus), and in some cases impossible to define (Mercury).

Planetary seasons result from two factors: (1) axial tilt (2) variable distance from the sun

(orbital eccentricity)

Objects of the Solar System: PlanetsClimates

Effects of atmospheres Composition Density Orbital eccentricity Distance from the Sun Rotational rate Axial tilt Presence of surface liquids Planetary size Albedo Solar wind

Objects of the Solar System: PlanetsTidal Effects The gravity of

Jupiter and its large moons yank Io every which way.

Io’s "solid ground" tides are more than five times as high as Earth’s highest ocean tides!

Objects of the Solar System: Asteroids The heaviest concen-

tration of asteroids is in a region lying between the orbits of Mars and Jupiter called the asteroid belt.

Objects of the Solar System: Asteroids Some 7000 asteroids

have been identified so far.

It is likely that the origin of the asteroid belt lies in the gravitational perturbation of Jupiter, which kept these planetisimals from coalescing into larger bodies.

The figure above shows the asteroid Gaspra which was investigated by the Galileo spacecraft

Objects of the Solar System: Asteroids Asteroid orbit distributions

show evidence for Kirkwood Gaps, which are certain orbital radii within the asteroid belt for which there are few asteroids.

These gaps are associated with orbital radii that lead to orbital periods that are ratios of integer multiples of Jupiter's orbital radius.

They result from resonance interactions with Jupiter that tend to eject asteroids from such orbits.

The Galileo spacecraft found a surprise when it flew by the asteroid Ida: Ida has a tiny moon, which has been named Dactyl! The small dot to the right of Ida is Dactyl.

Objects of the Solar System: Meteoroids A meteoroid is matter revolving around the

sun or any object in interplanetary space that is too small to be called an asteroid or a comet.

Unofficially the size limit for an asteroid has been set at 50 meters; anything smaller than that is simply called a meteoroid.

Objects of the Solar System: CometsInformation participants should know about comets: Composition: water, carbon dioxide, ammonia, and

methane ices, with mixed-in dust Origins of short-period vs. long-period comets Parts: head, coma and tails: ion (gas) tail, dust tail Why they glow: reflection of light and gases being

excited by sunlight emitting electromagnetic radiation

Disturbances that cause comets to leave their home in the Kuiper belt or Oort Cloud … passing star, etc

Influence of Jovian planets on their orbits

Objects of the Solar System: Comets

The center of a comet's head is called its nucleus. The nucleus is a few kilometers across and is surrounded by a diffuse, bright region called the coma that may be a million kilometers in diameter. The coma is formed from gas and dust ejected from the nucleus as it is heated by the Sun. The coma is bright both because it reflects sunlight and because its gases are excited by sunlight and emit electromagnetic radiation.

Objects of the Solar System: Comets

Short-period comets are the most common. They have only mildly elliptical orbits that carry them out to a region lying from Jupiter to beyond the orbit of Neptune. Illustrated: Location of Halley’s Comet in the year 2024

Facts about the Asteroid Belt The total weight of

all the asteroids in the asteroid belt is about 1/35th of that of our moon!

Ceres, the largest asteroid, is about 1/3 the total weight of all the asteroids!

Even though there are a lot of asteroids, the asteroid belt is mostly empty space.

Traveling through the asteroid belt in a space ship would not be very much like what you see in a science fiction film.

In addition to the belt asteroids, there are others based upon their location and orbit in the solar system: Apollo, Amors, Atons, Trojan and Centaurs.

Kuiper Belt The Kuiper Belt is

made up of millions of icy and rocky objects that orbit our Sun beyond the orbits of Neptune and Pluto.

Scientists think the gravity of big planets like Jupiter and Saturn swept all these icy leftovers out to the edge of our solar system.

Missions to Kuiper Belt: New HorizonsAfter it flies past Pluto and Charon, New Horizons will head into the Kuiper Belt. It will be the first spacecraft to explore this mysterious region.

Oort Cloud The Oort Cloud is an

immense spherically-shaped cloud surround-ing our Solar System.

The vast distance of the Oort cloud is considered to be the outer edge of the Solar System.A diagram comparing the

size of the Oort Cloud to the orbits of Uranus and Pluto.

Lunar Eclipse

1. Penumbral Lunar Eclipse: The Moon passes through Earth's penumbral shadow. This type of eclipse is difficult to detect.2. Partial Lunar Eclipse: A portion of the Moon passes through Earth's umbral shadow. 3. Total Lunar Eclipse: The entire Moon passes through Earth's umbral shadow.

Solar Eclipses A solar eclipse occurs

when the moon passes in a direct line between the Earth and the Sun.

The moon's shadow travels over the Earth's surface and blocks out the Sun's light as seen from Earth.

Image courtesy of NASA

Solar Eclipses During a total solar

eclipse the entire central portion of the Sun is blocked out.

During a total solar eclipse, the Sun's outer atmosphere, the corona, is visible.

Image Courtesy of NASA

Solar Eclipses If the penumbra

passes over you, only part of the Sun's surface will be blocked out.

You will see a partial solar eclipse, and the sky may dim slightly depending upon how much of the Sun's disc is covered. Partial Solar Eclipse

Solar Eclipses In some cases, the

moon is far enough away in its orbit that the umbra never reaches the Earth at all. In this case, there is no region of totality, and what you see is an annular solar eclipse.

In an annular eclipse, only a small, ring-like sliver of light of the Sun’s disk is visible. ("annular" means "of a ring").Annular Eclipse

Courtesy of NASA

Lunar Phases

Lunar Phases

Planetary Phases

Inferior Planets Explanation The planets, as

viewed in the sky, exhibit characteristic aspects and phases. "Aspects" refers to the location of the planet with respect to our overhead sky reference;"phases" refers to the fact that the planets, through a telescope, exhibit phases.

Planetary Phases

Superior Planets Explanation The aspects and

phases of the superior planets differ from those of the inferior planets because of geometry: their orbits are outside that of the Earth.

Planetary Phases

Possible Comparison Activity

http://csep10.phys.utk.edu/astr161/lect/celestial/aspects.html

Planetary Motions: Rotation The time the Earth takes to make a complete

rotation on its axis varies by about a millionth of a second per day.

While some days are shorter than average, the planet’s rotation shows a long-term slowing trend, ultimately leading to a longer day.

Planetary Motions: Precession The Earth's

rotation axis is not fixed in space. Like a rotating toy top, the direction of the rotation axis executes a slow precession with a period of 26,000 years.

Planetary Motions: Precession Pole Stars are

Transient. Thus, Polaris will not always be the Pole Star or North Star. The Earth's rotation axis happens to be pointing almost exactly at Polaris now, but in 13,000 years the precession of the rotation axis will mean that the bright star Vega in the constellation Lyra will be approximately at the North Celestial Pole, while in 26,000 more years Polaris will once again be the Pole Star.

Planetary Motions: PrecessionBecause of the precession of the equinoxes, the vernal equinox moves through all the constellations of the Zodiac over the 26,000 year precession period. Presently the vernal equinox is in the constellation Pisces and is slowly approaching Aquarius.

Kepler’s First Law of Planetary Motion The path of the

planets about the sun are elliptical in shape, with the center of the sun being located at one focus. (The Law of Ellipses)

Kepler’s Second Law of Planetary Motion The line joining a

planet to the Sun sweeps out equal areas in equal times as the planet travels around the ellipse.

Kepler’s Third Law of Planetary Motion The square of the

total time period (T) of the orbit is proportional to the cube of the average distance of the planet to the Sun (R). (The Law of Harmonies)

Newton’s First Law of Motion Every object in a

state of uniform motion tends to remain in that state of motion unless an external force is applied to it.

This law is recognized as Galileo's concept of inertia, and is often termed simply as the "Law of Inertia".

Newton’s Second Law of Motion The relationship

between an object's mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector.

This is the most powerful of Newton's three Laws, because it allows quantitative calculations of dynamics: how do velocities change when forces are applied.

Newton’s Third Law of Motion For every action

there is an equal and opposite reaction.

This law is explains the flight of a rocket.

Newton’s Law of Gravitation: The Legend What Really Happened with the Apple?

Newton, upon observing an apple fall from a tree, began to think along the following lines: The apple is accelerated, since its velocity changes from zero as it is hanging on the tree and moves toward the ground. Thus, by Newton's 2nd Law there must be a force that acts on the apple to cause this accelera-tion. Let's call this force "gravity", and the associated acceleration the "acceleration due to gravity". Then imagine the apple tree is twice as high. Again, we expect the apple to be accelerated toward the ground, so this suggests that this force that we call gravity reaches to the top of the tallest apple tree.

Newton’s Law of Gravitation Newton reasoned

that if the force of gravity reaches to the top of the highest tree, might it not reach even further;

In particular, might it not reach all the way to the orbit of the Moon!

Newton’s Law of Gravitation Then, the orbit of

the Moon about the Earth could be a consequence of the gravitational force, because the acceleration due to gravity could change the velocity of the Moon in just such a way that it followed an orbit around the earth.

Newton’s Law of Gravitation This can be illustrated

with the thought experi-ment shown in the figure to the left. Suppose we fire a cannon horizontally from a high mountain; the projectile will eventually fall to earth, as indicated by the shortest trajectory in the figure, because of the gravitational force directed toward the center of the Earth and the associated acceleration.

Newton’s Law of Gravitation But as we increase the

muzzle velocity for our imaginary cannon, the projectile will travel further and further before return-ing to earth. Finally, Newton reasoned that if the cannon projected the cannon ball with exactly the right velocity, the projectile would travel completely around the Earth, always falling in the gravitational field but never reaching the Earth, which is curving away at the same rate that the projectile falls.

Newton’s Law of Gravitation That is, the cannon

ball would have been put into orbit around the Earth. Newton conclud-ed that the orbit of the Moon was of exactly the same nature: the Moon continuously "fell" in its path around the Earth because of the accelera-tion due to gravity, thus producing its orbit.

Newton’s Law of Gravitation By such reasoning,

Newton came to the conclusion that any two objects in the Universe exert gravitational attraction on each other, with the force having a universal form:

Newton’s Law of Gravitation The constant of proportionality G is

known as the universal gravitational constant. It is termed a "universal constant" because it is thought to be the same at all places and all times, and thus universally characterizes the intrinsic strength of the gravitational force.

To continue your studies, go to: http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html

Effects of Planets and Their Satellites upon each other: Tidal Lock Tidal locking (or tidal

coupling) occurs when the gravitational gradient makes one side of an astronomical body always face another.

A tidally locked body takes just as long to rotate around its own axis as it does to revolve around its partner.

This synchronous rotation causes one hemisphere constantly to face the partner body.

Effects of Planets and Their Satellites upon each other: Tidal Lock Usually, only the

satellite becomes tidally locked around the larger planet, but if the differ-ence in mass between the two bodies and their physical separation is small, both may become tidally locked to the other, as is the case between Pluto and Charon.

Effects of Planets and Their Satellites upon each other: Tidal Coupling and Gravitational Locking

As a consequence of tidal interactions with the Moon, the Earth is slowly decreasing its rotational period and eventually the Earth and Moon will have exactly the same rotational period, and these will also exactly equal the orbital period.

Thus, billions of years from now the Earth will always keep the same face turned toward the Moon, just as the Moon already always keeps the same face turned toward the Earth.

Effects of Planets and Their Satellites upon each other: Shepherding

Cordelia and Ophelia, a pair of shepherding satellites on each side of Epsilon ring of Uranus keeps the ring particles in place through resonant gravitational forces.

Effects of Planets and Their Satellites upon each other: Resonance

Hyperion and Titan are in a 4:3 orbital reso-nance, which means that Titan orbits Saturn 3 times for every 4 times Hyperion orbits. As a result, Hyperion gets periodic "shoves" from Titan's gravity as their orbits match up.

Constellations Identification of the constellations containing

all planets visible on the evening of the day of the competition, either with the unaided eye or a telescope.

REPRESENTATIVE ACTIVITYParticipants will attempt to identify and to place in sequential order the series of events in the geologic history of one or more small areas on the surface of a planet or satellite.

REPRESENTATIVE ACTIVITY

This is an imaginary scene on Earth’s Moon. Using the concept of super-position, list the events as they occurred, by letter and in order, from oldest to most recent.

REPRESENTATIVE ACTIVITY

1. B, A, CEvent B is the oldest as it is overlapped by event A.Event C is the most recent because it overlaps Event A.

RESOURCES http://www.tufts.edu/as/wright_center/

products/sci_olympiad/sci-olympiad_astro_geo.html

http://www.tufts.edu/as/wright_center/products/sci_olympiad/sci_olympiad_geo.htm.

RESOURCES http://www.tufts.edu/as/wright_center/

products/sci_olympiad/sci-olympiad_astro_geo.html

http://www.tufts.edu/as/wright_center/products/sci_olympiad/sci_olympiad_geo.htm.

NATIONAL SCIENCE EDUCATION STANDARDS

Earth and Space Science, Content Standard D: Structure of the Earth System; Earth’s History; Earth in the Solar System.

Physical Science: Content Standard B: Motions and Forces; Transfer of Energy

Recommended Websites Astronomy 161: The Solar System http://csep10.phys.utk.edu/astr161/lect/index.html Solar Physics: The Sunhttp://solarscience.msfc.nasa.gov/interior.shtml Kepler’s Lawshttp://www.wwu.edu/depts/skywise/a101_kepler.html