A presentation on the planet Venus. Designed for 5th grade students. Contains basic facts, including the space probes that helped us learn about Venus. Includes quiz questions at the end.
A comet is an icy small Solar System body (SSSB) that, when close enough to the Sun, displays a visible coma (a thin, fuzzy, temporary atmosphere) and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust and small rocky particles. Comets have been observed since ancient times.
Comets have a wide range of orbital periods, ranging from a few years to hundreds of thousands of years. Short-period comets originate in the Kuiper belt, or its associated scattered disc,[1] which lie beyond the orbit of Neptune. Longer-period comets are thought to originate in the Oort cloud, a hypothesized spherical cloud of icy bodies in the outer Solar System. Long-period comets plunge towards the Sun from the Oort cloud because of gravitational perturbations caused by either the massive outer planets of the Solar System (Jupiter, Saturn, Uranus, and Neptune), or passing stars. Rare hyperbolic comets pass once through the inner Solar System before being thrown out into interstellar space along hyperbolic trajectories. Exocomets, comets beyond our solar system, have also been detected and may be common in the Milky Way Galaxy.[2]
Comets are distinguished from asteroids by the presence of a coma or a tail. However, extinct comets that have passed close to the Sun many times have lost nearly all of their volatile ices and dust and may come to resemble small asteroids.[3] Asteroids are thought to have a different origin from comets, having formed inside the orbit of Jupiter rather than in the outer Solar System.[4][5] The discovery of main-belt comets and active centaurs has blurred the distinction between asteroids and comets (see asteroid terminology).
As of January 2011 there are a reported 4,185 known comets[6] of which about 1,500 are Kreutz Sungrazers and about 484 are short-period.[7] This number is steadily increasing. However, this represents only a tiny fraction of the total potential comet population: the reservoir of comet-like bodies in the outer Solar System may number one trillion.[8] The number visible to the naked eye averages roughly one per year, though many of these are faint and unspectacular.[9] Particularly bright or notable examples are called "Great Comets".
A PowerPoint presentation designed for 5th graders that teaches facts about Mercury, including the Mariner 10 and MESSENGER probes that NASA sent to study it. This is Part 1 of the inner planets.
A presentation on the planet Venus. Designed for 5th grade students. Contains basic facts, including the space probes that helped us learn about Venus. Includes quiz questions at the end.
A comet is an icy small Solar System body (SSSB) that, when close enough to the Sun, displays a visible coma (a thin, fuzzy, temporary atmosphere) and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust and small rocky particles. Comets have been observed since ancient times.
Comets have a wide range of orbital periods, ranging from a few years to hundreds of thousands of years. Short-period comets originate in the Kuiper belt, or its associated scattered disc,[1] which lie beyond the orbit of Neptune. Longer-period comets are thought to originate in the Oort cloud, a hypothesized spherical cloud of icy bodies in the outer Solar System. Long-period comets plunge towards the Sun from the Oort cloud because of gravitational perturbations caused by either the massive outer planets of the Solar System (Jupiter, Saturn, Uranus, and Neptune), or passing stars. Rare hyperbolic comets pass once through the inner Solar System before being thrown out into interstellar space along hyperbolic trajectories. Exocomets, comets beyond our solar system, have also been detected and may be common in the Milky Way Galaxy.[2]
Comets are distinguished from asteroids by the presence of a coma or a tail. However, extinct comets that have passed close to the Sun many times have lost nearly all of their volatile ices and dust and may come to resemble small asteroids.[3] Asteroids are thought to have a different origin from comets, having formed inside the orbit of Jupiter rather than in the outer Solar System.[4][5] The discovery of main-belt comets and active centaurs has blurred the distinction between asteroids and comets (see asteroid terminology).
As of January 2011 there are a reported 4,185 known comets[6] of which about 1,500 are Kreutz Sungrazers and about 484 are short-period.[7] This number is steadily increasing. However, this represents only a tiny fraction of the total potential comet population: the reservoir of comet-like bodies in the outer Solar System may number one trillion.[8] The number visible to the naked eye averages roughly one per year, though many of these are faint and unspectacular.[9] Particularly bright or notable examples are called "Great Comets".
A PowerPoint presentation designed for 5th graders that teaches facts about Mercury, including the Mariner 10 and MESSENGER probes that NASA sent to study it. This is Part 1 of the inner planets.
What is Earth and space science about?
Earth and space science (ESS) connects systems
Earth and space science explores the interconnections between the land, ocean, atmosphere, and life of our planet. These include the cycles of water, carbon, rock, and other materials that continuously shape, influence, and sustain Earth and its inhabitants.
ESS also explores the cyclical interactions between the Earth system and the Sun and Moon.
ESS explores how New Zealand has been shaped by its location
New Zealand straddles the boundary between two major tectonic plates. ESS scientists – and students who study ESS – investigate how this precarious location has impacted (and continues to impact) on New Zealand’s geology and landforms, sometimes in dramatic ways.
ESS investigates the major ocean currents that flow past New Zealand and the impact these and other factors have on our weather and climate.
ESS explores the solar system and beyond
Planet Earth is dynamically linked with the solar system and the wider universe. ESS investigates the structure and composition of these systems and develops understanding of the vast distances and times involved.
What is the Nature of Science strand about?
Why study Earth and space science?
Key concepts: Earth and space science
What is biology | physics | chemistry about?
Interpreting the Nature of Science in an ESS context
Understanding about science
Students learn how understanding of the Earth system, the solar system, the universe, and the interactions between them has developed over time. For example, how:
Wegener and other scientists came to understand that the surface of the earth is broken into tectonic plates that move and interact at their boundaries
Pluto was discovered in 1930 because of disturbances in the orbits of Uranus and Neptune and became the ninth planet, only to be declared a dwarf planet in 2006 after the discovery of Kuiper Belt objects of similar sizes
technologies such as space telescopes and probes have facilitated a build-up of knowledge and understanding about planets, moons, and the rest of the universe
attempts by humans to travel in space have been influenced by the politics of the day
satellites that can measure such factors as the temperature of the surface of the ocean make it possible to build computer models that can be used to accurately monitor changes in the Earth system
the cumulative work of many scientific teams has led to such breakthroughs as understanding the mechanisms of climate change and ocean acidification.
Investigating in science
Students investigate aspects of the Earth system, the solar system and the universe. For example:
Investigating the exchange of carbon dioxide between the ocean and atmosphere by undertaking practical investigations and processing and interpreting secondary data.
Investigating the Sun, Moon and Earth cycles by exploring and developing different models.
useful student materials reference for basic education. Asteroids, comets, and meteors are chunks of rock, ice, and metal left over from the formation of our solar system 4.6 billion years ago. They are a lot like a fossil record of our early solar system. There are about 1.3 million known asteroids, and more than 3,800 known comets. If we take a complete inventory of the entire contents of the Solar System, we find that there are many small, rocky bodies ranging in size from similar to grains of sand up to the size of small moons or comets. The smallest rocky objects that are found in space are referred to as meteoroids. There are three different classifications of meteoroids, depending on how they are observed:
Meteoroid: A chunk of rock orbiting the Sun inside the Solar System.
Meteor: When a meteoroid encounters the Earth's atmosphere, it interacts with the gases in the atmosphere and all or most of it gets vaporized. The streak of light that we see as the rock penetrates the atmosphere is called a meteor, which many people refer to as "a shooting star."
Meteorite: If some of the material that makes up a meteoroid survives the trip through the atmosphere and is found on Earth, we refer to the remnant as a meteorite. If you want help identifying candidate meteorites you can see the following page:
University of New Mexico: How to Identify a Meteorite(link is external)
There are many meteorites that have been recovered on Earth. We find that there are several types of meteorites that can be separated based on their composition. Some meteorites are almost entirely made up of iron and nickel. These chunks of metal are very easy to find when they land on the Earth because they are so dense and are essentially chunks of metal. There are also stone and stony-iron mix meteorites that land on the Earth (these are more common), but since they appear to the untrained eye more like the naturally occurring rocks on the Earth, without extensive testing they are more difficult to identify as meteorites. During its mission, the Mars Rover Opportunity discovered an iron meteorite on Mars. It just happened to be lying on the planet's surface right near where the Rover's heat shield landed after the spacecraft jettisoned it. This is an iron meteorite, making it stand out among the other rocks the Rover has studied intensively during its trip around the surface of Mars.
5. Masses - determined through observing the gravitational
effect of the planet on some nearby object (moons, nearby
planets, satellites)
Density - divide mass by volume
• Planets orbit
the sun
counter-
clockwise as
seen from the
North Celestial
Pole.
• All planets are
in the same
orbital plane
EXCEPT
Mercury and
Pluto.
6. Terrestrial Planets
Mercury, Venus, Earth
and Mars
•Close to Sun
•Small masses, radii
•Rocky, solid surfaces
•High densities
•Slow rotation
•Weak magnetic field
•No rings
•Few moons
Jovian Planets
Jupiter, Saturn,
Uranus, and Neptune
•Far from Sun
•Large masses and
radii
•Gaseous surface
•Low densities
•Fast rotation
•Strong magnetic field
•Many rings
•Many moons
7. Asteroids - rocks with sizes greater than 100m across
Most asteroids remain in the Asteroid belt between
Mars and Jupiter but a few have orbits that cross
Earth’s path.
Three asteroids
hit the Earth
every 1 million
years!
9. Asteroid sizes range from 100m to about 1000km
They are composed of carbon
or iron and other rocky
material.
The Asteroid belt is a group of
rocks that appear to have never
joined to make a planet. Why do
we think this?
•Too little mass to be a planet
•Asteriods have different chemical
compositions
10.
11. Meteoroids –
interplanetary rocky
material smaller than 100m
(down to grain size).
•called a meteor as it burns
in the Earth’s atmosphere
•if it makes it to the ground,
it is a meteorite
Most meteor showers are
the result of the Earth
passing through the orbit of
a comet which has left
debris along its path
12. Meteor crater near
Winslow, AZ - the
culprit was
probably 50 m
across weighing
200,000 tons!
Meteors are rocky - mainly iron and nickel
Some contain carbonaceous material - rich in organic material
Meteors are old - 4.5 billion years - based on carbon dating
Meteor showers:
Orionid – Oct 21/22
Leonid – Nov 18/19
Geminid – Dec 14/15
13. Comets
Dirty snowballs - dust and rock in methane, ammonia and ice
Halley’s Comet in 1986
All light is reflected from the Sun - the comet makes no light of its own
The nucleus is a few km in diameter
14. •Cometary orbits take them far beyond Pluto
•Many take up to 1 million years to orbit the Sun once!
•Short period comets (< 200 years) (like Halley’s comet)
•Short period comets may have originated in the Kuiper belt
•Kuiper belt comet gets “kicked” into an eccentric orbit, bringing
it into the solar system
•These long period comets probably originate in the Oort cloud
15. Formation of the Solar System
Any theory to describe the formation of our Solar System
must adhere to these facts:
1. Each planet is isolated in space
2. The orbits are nearly circular
3. The orbits of the planets all lie in roughly the same plane
4. The direction they orbit around the Sun is the same as the
Sun’s rotation on its axis
5. The direction most planets rotate on their axes is the same as
that for the Sun
6. The direction of a planet’s moon orbits is the same as that
planet’s direction of rotation
7. The Terrestrial planets are very different from the Jovian
planets
8. Asteroids are different from both types of planets
9. Comets are icy fragments that don’t orbit in the ecliptic plane
16. Our sun and the planets began from a cloud of dust and gas (nebula)
As the cloud contracts under its own
gravity, the Sun is formed at the
center.
The cloud starts to spin and the
smaller it contracts, the faster it spins.
Conservation of angular momentum
Cloud forms a flattened, pancake shape.
Nebular Theory for Solar System formation
18. Condensation Theory for Planet Formation
The gas in the flattened nebula would never eventually
clump together to form planets.
Interstellar dust (grain-size particles) lies between stars -
remnants of old, dead stars.
These dust grains form
condensation nuclei -
other atoms attach to
them to start the
“collapsing” process to
form the planets in the
gas cloud.
19. What happened next…..
A flattened solar nebula disk exists
after cloud spins and contracts
Condensation nuclei form clumps
that grow into moon-size
planetesimals
Solar wind from star formation (Sun
forming) blow out the rest of the gas
Planetesimals collide and grow
Planetesimals form the basic planets
over hundred million years
20. Why the difference between inner and outer planets?
•Rocky inner planets: The
type of the material that
condensed out of the nebular
cloud at these higher
temperatures was rocky in
nature.
•Gaseous, Bigger outer
planets: Both rock and gas
could condense out of the
cloud at lower temperatures
where these planets formed.
Why are they gaseous? - gas is present
Why are they bigger? - accretion onto the planet starts sooner
because they are further from the Sun, less effected by solar wind
TEMPERATURE!
