The document discusses asteroids, comets, and Pluto. It explains that asteroids formed from leftover material from planet formation and are found mainly in the asteroid belt between Mars and Jupiter due to Jupiter's gravitational influence. Comets formed beyond the frost line and have icy compositions; their tails form when they near the Sun and ice sublimates. Most comets originate from the Kuiper Belt and Oort Cloud. Pluto has properties matching Kuiper Belt objects. An impact likely caused the mass extinction that killed the dinosaurs. While impacts pose a real threat, the likelihood of a major impact within our lifetimes is low. Other planets can affect Earth's impact rates through their gravitational influence on small solar system bodies.
Earth and Life Science - Theories on the Origin of the Solar SystemJuan Miguel Palero
This is a powerpoint presentation that is about one of the Senior High School Core Subject: Earth and Life Science. It is composed of the theories that explains the origin of the Solar System.
Earth and Life Science - Theories on the Origin of the Solar SystemJuan Miguel Palero
This is a powerpoint presentation that is about one of the Senior High School Core Subject: Earth and Life Science. It is composed of the theories that explains the origin of the Solar System.
Beyond The Earth and How The Solar System EvolvedLJAshleyDigamon
This is our PowerPoint Presentation for our report in Science Subject and I want it to share with you. This would be useful for your studies! Hope I can help! Thank you and God Bless!
What is a solar system?
FORMATION OF SOLAR SYSTEM
Components of the SOLAR SYSTEM
Discovery and exploration
Terminology
Description of the Components of the SOLAR SYSTEM
Farthest Regions
Galactic Context
The Solar System is located in the Milky Way galaxy, a barred spiral galaxy with a diameter of about 100,000 light-years containing about 200 billion stars. Our Sun resides in one of the Milky Way's outer spiral arms, known as the Orion Arm or Local Spur. The Sun lies between 25,000 and 28,000 light years from the Galactic Centre, and its speed within the galaxy is about 220 kilometres per second, so that it completes one revolution every 225–250 million years. This revolution is known as the Solar System's galactic year. The solar apex, the direction of the Sun's path through interstellar space, is near the constellation of Hercules in the direction of the current location of the bright star Vega. The plane of the Solar System's ecliptic lies nearly at right angles (86.5°) to the galactic plane.
Origin of the Universe and the Solar SystemNikoPatawaran
The most widely accepted theory of planetary formation, known as the nebular hypothesis, maintains that 4.6 billion years ago, the Solar System formed from the gravitational collapse of a giant molecular cloud which was light years across.
Beyond The Earth and How The Solar System EvolvedLJAshleyDigamon
This is our PowerPoint Presentation for our report in Science Subject and I want it to share with you. This would be useful for your studies! Hope I can help! Thank you and God Bless!
What is a solar system?
FORMATION OF SOLAR SYSTEM
Components of the SOLAR SYSTEM
Discovery and exploration
Terminology
Description of the Components of the SOLAR SYSTEM
Farthest Regions
Galactic Context
The Solar System is located in the Milky Way galaxy, a barred spiral galaxy with a diameter of about 100,000 light-years containing about 200 billion stars. Our Sun resides in one of the Milky Way's outer spiral arms, known as the Orion Arm or Local Spur. The Sun lies between 25,000 and 28,000 light years from the Galactic Centre, and its speed within the galaxy is about 220 kilometres per second, so that it completes one revolution every 225–250 million years. This revolution is known as the Solar System's galactic year. The solar apex, the direction of the Sun's path through interstellar space, is near the constellation of Hercules in the direction of the current location of the bright star Vega. The plane of the Solar System's ecliptic lies nearly at right angles (86.5°) to the galactic plane.
Origin of the Universe and the Solar SystemNikoPatawaran
The most widely accepted theory of planetary formation, known as the nebular hypothesis, maintains that 4.6 billion years ago, the Solar System formed from the gravitational collapse of a giant molecular cloud which was light years across.
This presentation was a school project by me and my friends. It has information about almost everything in the solar system except for planets and stars
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.
About the different dwarf planets their location moons etc. What meteoroids , meteors, comet , asteroids etc. ? what and where oort cloud and Kuiper's belt?
A powerpoint presentation on comets. A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail.
Michael SeedsDana BackmanChapter 8Origin of the So.docxARIV4
Michael Seeds
Dana Backman
Chapter 8
Origin of the Solar System and Extrasolar Planets
*
The solar system is our home in the universe. As humans are an intelligent species, we have the right and the responsibility to wonder what we are. Our kind has inhabited this solar system for at least a million years. However, only within the last hundred years have we begun to understand what a solar system is.
*
You are linked through a great chain of origins that leads backward through time to the first instant when the universe began 13.7 billion years ago.The gradual discovery of the links in that chain is one of the most exciting adventures of the human intellect.
The Great Chain of Origins
*
Earlier, you have studied some of that story:Origin of the universe in the big bangFormation of galaxiesOrigin of starsProduction of the chemical elementsHere, you will explore further and consider the origin of planets.
The Great Chain of Origins
*
By the time the universe was three minutes old, the protons, neutrons, and electrons in your body had come into existence. You are made of very old matter.
The History of the Atoms in Your Body
*
Although those particles formed quickly, they were not linked together to form the atoms that are common today.Most of the matter was hydrogen and about
25 percent was helium. Very few of the heavier atoms were made in
the big bang.
The History of the Atoms in Your Body
*
Although your body does not contain helium, it does contain many of those ancient hydrogen atoms that have remained unchanged since the universe began.
The History of the Atoms in Your Body
*
During the first few hundred million years after the big bang, matter collected to form galaxies containing billions of stars. You have learned how nuclear reactions inside stars combine low-mass atoms, such as hydrogen, to make heavier atoms.
The History of the Atoms in Your Body
*
Generation of stars cooked the original particles, fusing them into atoms such as carbon, nitrogen, and oxygen. Those are common atoms in your body.Even the calcium atoms in your bones were assembled inside stars.
The History of the Atoms in Your Body
*
Most of the iron in your body was produced by:Carbon fusion in type Ia supernovae Decay of radioactive atoms in the expanding matter ejected by type II supernovae
The History of the Atoms in Your Body
*
Atoms heavier than iron, such as iodine, were created by:Rapid nuclear reactions that can occur only during supernova explosions
The History of the Atoms in Your Body
*
Elements uncommon enough to be expensive—gold, silver, and platinum in the jewelry that humans wear—also were produced: during the violent deaths of rare, massive stars.
The History of the Atoms in Your Body
*
Our galaxy contains at least
100 billion stars, of which the sun is one.The sun formed from a cloud of gas and dust about 5 billion years ago.The atoms in your body were part of that cloud.
Th ...
Professor’s Questions Set 5Provide comprehensive answers to th.docxwkyra78
Professor’s Questions Set 5
Provide comprehensive answers to the following questions. Remember to support your arguments where necessary by websites and pictures.
Chapter 7 and 8 Readings
1. Why is Jupiter so much richer in hydrogen and helium than Earth?
2. Why do astronomers conclude that none of the Jovian planets’ rings can be left over from the formation of the planets?
3. How can Jupiter have a liquid interior and not have a definite liquid surface?
4. Why are Uranus and Neptune respectively green-blue and blue?
5. What evidence indicates that catastrophic impacts have occurred in the solar system’s past?
6. Why do astronomers refer to carbonaceous chondrites as unmodified or “primitive” materials?
7. What evidence indicates that the asteroids are mostly fragments of larger bodies?
8. What is the difference between condensation and accretion?
9. Why does the solar nebula theory predict that planetary systems are common?
10. Why is the evidence of “hot Jupiters” puzzling? What is the current hypothesis of how they formed?
Michael Seeds
Dana Backman
Chapter 8
Origin of the Solar System and Extrasolar Planets
*
The solar system is our home in the universe. As humans are an intelligent species, we have the right and the responsibility to wonder what we are. Our kind has inhabited this solar system for at least a million years. However, only within the last hundred years have we begun to understand what a solar system is.
*
You are linked through a great chain of origins that leads backward through time to the first instant when the universe began 13.7 billion years ago.The gradual discovery of the links in that chain is one of the most exciting adventures of the human intellect.
The Great Chain of Origins
*
Earlier, you have studied some of that story:Origin of the universe in the big bangFormation of galaxiesOrigin of starsProduction of the chemical elementsHere, you will explore further and consider the origin of planets.
The Great Chain of Origins
*
By the time the universe was three minutes old, the protons, neutrons, and electrons in your body had come into existence. You are made of very old matter.
The History of the Atoms in Your Body
*
Although those particles formed quickly, they were not linked together to form the atoms that are common today.Most of the matter was hydrogen and about
25 percent was helium. Very few of the heavier atoms were made in
the big bang.
The History of the Atoms in Your Body
*
Although your body does not contain helium, it does contain many of those ancient hydrogen atoms that have remained unchanged since the universe began.
The History of the Atoms in Your Body
*
During the first few hundred million years after the big bang, matter collected to form galaxies containing billions of stars. You have learned how nuclear reactions inside stars combine low-mass atoms, su ...
b) Explain how the three debris fields (i-e-- Main Asteroid Belt- Kuip.docxbickerstaffinell
b) Explain how the three debris fields (i.e., Main Asteroid Belt, Kuiper Belt, and Oort Cloud) formed in the Solar System. c) Explain the planetary accretion process whereby the planets in the Solar System formed.
Solution
Solution B)
Asteroid Belt : The Asteroid Belt consists of hundreds of thousands of rocks, with all kinds of different shapes, ranging in size from the Dwarf Planet Ceres at 950 Km in Diameter, down to small bits the size of dust particles. It lies between Mars and Jupiter.
Formation - when our solar system was being formed, a tenth planet tried to form between Mars and Jupiter. However, Jupiter s gravitational forces were too strong, so the material was unable to form a planet. Even if a planet had formed it wouldnt have been anything write about . It is estimated that if you put all the asteroid into the solar system into one body thwy would form an object less than half the size of moon.
Kuiper Belt : The Kuiper Belt (pronounced Kai-per) consists of Icy rocks, and it a major source of short-period Comets in the Solar system. Extending beyond the planet Neptune, Pluto was discovered to be one of the largest objects in the belt.
Formation - When the solar system formed, much of the gas, dust and rocks pulled together to form the sun and planets. The planets then swept most of the remaining debris into the sun or out of the solar system
Oort Cloud : Oort cloud is a collection of Comets, thought to extend far beyond the planets of the Solar System. the Oort comets are distributed spherically about the Sun, possibly extending as far as half way to the next star. The Oort orbits are not regular or planar like the Asteroid and Kuiper belts, and are often perturbed through gravitational interactions during their long journeys on highly eccentric orbits.
Formation : The Oort Cloud is roughly spherical, and is thought to be the origin of most of the long-period comets that have been observed. This cloud of particles is theorized to be the remains of the disc of material that formed the Sun and planets.
.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
2. 9.1 Asteroids and Meteorites
Our Goals for Learning
• Why is there an asteroid belt?
• How are meteorites related to asteroids?
3. Asteroid
Facts
• Asteroids are rocky leftovers of planet formation.
• Largest is Ceres, diameter ~1,000 km
• 150,000 in catalogs, and probably over a million with
diameter >1 km.
• Small asteroids are more common than large asteroids.
• All the asteroids in the solar system wouldn’t add up
to even a small terrestrial planet.
7. Why are there very few asteroids
beyond Jupiter’s orbit?
A. There was no rocky material beyond Jupiter’s
orbit.
B. The heaviest rocks sank towards the center of the
solar system.
C. Ice could form in the outer solar system.
D. A passing star probably stripped away all of
those asteroids, even if they were there at one
time.
8. Why are there very few asteroids
beyond Jupiter’s orbit?
A. There was no rocky material beyond Jupiter’s
orbit.
B. The heaviest rocks sank towards the center of the
solar system.
C. Ice could form in the outer solar system.
D. A passing star probably stripped away all of
those asteroids, even if they were there at one
time.
9. Which explanation seems to be
the most plausible?
A. The belt is where all the asteroids
happened to form.
B. The belt is the remnant of a large
terrestrial planet that used to be between
Mars and Jupiter.
C. The belt is where all the asteroids
happened to survive.
10. Which explanation seems to be
the most plausible?
A. The belt is where all the asteroids
happened to form.
B. The belt is the remnant of a large
terrestrial planet that used to be between
Mars and Jupiter.
C. The belt is where all the asteroids
happened to survive. But WHY didn’t they
form a little planet?
11.
12. Rocky planetesimals
survived in the asteroid
belt between Mars and
Jupiter because they did
not accrete into a planet.
Jupiter’s gravity, stirs
up the asteroid orbits
and prevents their
planet formation.
17. Pieces of Asteroids:Meteorite
Types
1) Primitive: Unchanged in composition
since they first formed 4.6 billion years
ago.
2) Processed: Younger, have experienced
processes like volcanism or
differentiation.
20. What do we learn from
meteorites?
• primitive meteorites tell us when solar
system formation began.
• Processed meteorites tell us what asteroids
are like on the inside.
• Processed meteorites provide direct proof
that differentiation and volcanism happened
on asteroids.
21. Meteorites from Moon and Mars
• A few meteorites arrive from the Moon and Mars
• Composition differs from the asteroid fragments.
• A cheap (but slow) way to acquire moon rocks and
Mars rocks.
• One Mars meteorite generated a stir when scientists
claimed evidence for microscopic life in it.
22. What have we learned?
• Why is there an asteroid belt?
• Orbital resonances with Jupiter
disrupted the orbits of
planetesimals, preventing them
from accreting into a planet.
Those that were not ejected
from this region make up the
asteroid belt today. Most
asteroids in other regions of the
inner solar system accreted into
one of the planets.
• How are meteorites related to
asteroids?
• Most meteorites are pieces of
asteroids. Primitive meteorites
are essentially unchanged since
the birth of the solar system.
Processed meteorites are
fragments of larger asteroids
that underwent differentiation.
23. 9.2 Comets
• Our Goals for Learning
• How do comets get their tails?
• Where do comets come from?
25. Comet Facts
• Formed beyond the frostline, comets are icy
counterparts to asteroids.
• “Dirty snowballs” = the nucleus
• Most comets do not have tails.
• Most comets remain perpetually frozen in
the outer solar system. Only a few enter the
inner solar system, where they can grow
tails.
26. When a comet nears the Sun, its ices can sublimate into
gas and carry off dust, creating a coma and long tails.
31. Kuiper belt:
On orderly orbits
from 30-100 AU in
disk of solar
system
Oort cloud:
On random orbits
extending to about
50,000 AU
Only a tiny number
of comets enter the
inner solar system -
most stay far from
the Sun
32. How did they get there?
• Kuiper belt comets align with the plane of
planet orbits
• Oort Cloud Comets were kicked out of the
solar system by the gravity from jovian
planets: random orbits
33. What have we learned?
• How do comets get their tails?
• The vast majority of comets do
not have tails. Only those few
comets that enter the solar
system grow tails. As the comet
approaches the Sun its nucleus
heats up. Some of the comet’s
ice sublimates into gas, and the
escaping gases carry along
some dust. The gas and dust
form a coma and two tails: a
plasma tail of ionized gas and a
dust tail. Larger particles can
also escape, becoming the
particles that cause meteors and
meteor showers on Earth.
34. What have we learned?
• Where do comets come from?
• Comets that enter the solar
system come from one of two
reservoirs in the outer solar
system: the Kuiper belt and the
Oort cloud. The Kuiper belt
comets still reside in the region
beyond Neptune in which they
formed during the birth of the
solar system. The Oort cloud
comets are thought to have
formed in the region of the
jovian planets, and were kicked
out to the great distance of the
Oort cloud by gravitational
encounters with the planets.
35. 9.3 Pluto: Lone Dog
or Part of a Pack?
• Our Goals for Learning
• What is Pluto like?
• Is Pluto a planet or a Kuiper belt comet?
36. Pluto: the exception
• Not a gas giant like the other outer planets.
• Has a very elliptical, inclined orbit.
• By far the smallest planet, and smaller than
several moons.
• Has a surprisingly large moon Charon, probably
formed by a huge comet collision with Pluto.
37. Pluto will never collide with Neptune because
of a 3:2 orbital resonance.
38. What is Pluto like?
• 1978 discovery of Pluto’s moon Charon:
Pluto’s mass from Newton’s orbital law.
• It has a thin nitrogen atmosphere that will
refreeze onto the surface as Pluto’s orbit
takes it farther from the Sun.
• Pluto is the largest Solar System object that
has not been visited by spacecraft.
42. Is Pluto a planet or a Kuiper Belt
comet?
• Pluto is well beyond Neptune, in the Kuiper
Belt.
• Inclined orbit is typical of Kuiper Belt
comets.
• Composition is typical of Kuiper Belt
comets, but not any of the other planets.
43. Is Pluto a planet or a Kuiper Belt
comet?
• Kuiper Belt objects have been found that
approach Pluto’s size.
• Kuiper Belt comets have similar orbital
resonances with Neptune.
• Kuiper Belt comets can have moons.
• Triton (a captured moon) is even larger than
Pluto.
44. What have we learned?
• What is Pluto like?
• Pluto is much smaller than
any other planet, with an orbit
more elliptical and more
inclined to the ecliptic plane
than that of any other planet.
It is made mostly of ices and
has a very thin atmosphere of
gases that are expected to
freeze onto the surface as
Pluto moves farther from the
Sun in its 248-year orbit. It
has a moon, Charon, with a
slightly lower density than
Pluto, suggesting that Charon
may have been formed in a
giant impact.
• Is Pluto a planet or a Kuiper
belt comet?
• Whether Pluto should be
called a “planet” is a matter
of opinion, but its properties
suggest that it is a Kuiper belt
comet. Its composition and
orbital properties match those
of other Kuiper belt comets
and do not fit in with the
other planets. It is the largest
known Kuiper belt comet
today, but there may be
larger ones still awaiting
discovery.
45. 9.4 Cosmic Collisions: small
bodies vs. the planets
Our Goals for Learning
• Have we ever witnessed a major impact?
• Did an impact kill the dinosaurs?
• Is the impact threat a real danger or just media
hype?
• How do other planets affect impact rates and life
on Earth?
47. Comet SL9 caused a string of
violent impacts on Jupiter in 1994,
reminding us that catastrophic
collisions still happen.
Tidal forces tore it apart during
previous encounter with Jupiter
56. Mass Extinctions
• Large dips in total species diversity in the
fossil record.
• The most recent was 65 million years ago,
ending the reign of the dinosaurs.
Was it caused by an impact?
How would it have happened?
57. Dinosaur fossils
in lower rock
layers
No dinosaur
fossils in these
rock layers
Thin layer
containing iridium
from impactor
58. Iridium - evidence of an impact
• Iridium is very rare in Earth surface rocks
but often found in meteorites.
• Luis and Walter Alvarez found a worldwide
layer containing iridium, laid down 65
million years ago.
64. An iridium-rich
sediment layer and
an impact crater on
the Mexican coast
65 million years
ago.
shows that a large
impact occurred
at the time the
dinosaurs died out,
66. Facts
• Asteroids and comets have hit the Earth.
• A major impact is only a matter of time: not IF but
WHEN.
• Major impact are very rare.
• Extinction level events ~ millions of years.
• Major damage ~ tens-hundreds of years.
67. Tunguska, Siberia: June 30, 1908
The ~40 meter object disintegrated and exploded in the
atmosphere
69. An object 1km in size would produce a mile-high tidal wave
This slide is placeholder in case you would like to
download and show the movie noted below (notes
field).
70. Impacts will certainly occur in the future, and while the
chance of a major impact in our lifetimes is small, the
effects could be devastating.
71. The asteroid with our name on it
We haven’t seen it yet.
Deflection is more probable with years of
advance warning.
Control is critical: breaking a big asteroid into
a bunch of little asteroids is unlikely to
help.
We get less advance warning of a killer
comet…
72. What are we doing about it?
• Stay tuned to
http://impact.arc.nasa.gov
73. How do other planets
affect impact rates
and life on Earth?
74. Gravity from
Jovial planets
can influence
the path of
comets and
Asteroids.
They could
protect us or
steer one in
our direction
Fig 9.20
75. Was Jupiter necessary for life
on Earth?
Impacts can extinguish
life.
But were they
necessary for ‘life as
we know it’?
76. What have we learned?
• Have we ever witnessed
a major impact?
• In 1994, we observed
the impacts of comet
Shoemaker–Levy 9 on
Jupiter. The comet had
fragmented into a string
of individual nuclei, so
there was a string of
impacts that left
Jupiter’s atmosphere
scarred for months
77. What have we learned?
• Did an impact kill the
dinosaurs?
• We are not certain whether an
impact was the sole cause, but
a major impact clearly
coincided with the mass
extinction in which the
dinosaurs died out, about 65
million years ago. Sediments
from the time show clear
evidence of an impact, and an
impact crater of the right age
has been found near the coast
of Mexico.
78. What have we learned?
• Is the impact threat a
real danger or just
media hype?
• Impacts certainly pose
a threat, though the
probability of a major
impact in our lifetimes
is fairly low.
79. What have we learned?
• How do other planets affect impact rates and life
on Earth?
Impacts of asteroids and comets are always linked in at
least some way to the gravitational influences of
Jupiter and the other jovian planets. These
gravitational influences have shaped the asteroid belt,
the Kuiper belt, and the Oort cloud, and sometimes
still help determine when an object is flung our way.
Editor's Notes
Fun clip: the trailer from the movie Armageddon, if you can find it. The file was called armageddon.mov in Feb 2004 but it’s scarce now for some reason.
See also http://www.badastronomy.com/bad/movies/armageddon.html for Phil Plait’s review
Thought question: were these pictures taken from Earth?
One of these has a satellite (Ida is orbitted by Dactyl, lower left)
Rocky material condensed everywhere.
B. The students often get confused by the differentiation ideas they’ve just
heard about in planet formation.
D. If a passing star ripped off asteroids, it would have stripped away comets
and planets too. (That may be one explanation for the truncation of the
Kuiper belt…)
Discussion: A -- planetesimals formed EVERYWHERE in the solar system.
B--there’s not enough mass in the asteroid belt to be the remnant of even
a small terrestrial planet.
If you covered Chapter 8, orbital resonances are covered in the context with the jovian moons and Saturn’s rings.
Really useless terminology: “Meteroid” - the rock before it hits the Earth’s surface.
A movie of this meteorite flying through the Earth’s atmosphere is available for public use at
http://impacts.arc.nasa.gov/gallery/comet2.mpg Other meteors/meteorite events available on
The web include the March 26, 2003 Park Forest IL event; August 10, 1972 Grand Tetons, WY (a BIG one skipping off the atmosphere.)
Simple rocks and metal, occasionally carbon compounds and water.
Shiny bits are metal flakes, first to condense.
White features are solidified dropletsof material that splashed out during impacts during accretion
News update: Sedna was discovered Nov 14, 2003. It is 3 times farther away than Pluto, it is about 75% the size of Pluto. It may have a moon. It will continue to brighten for the next 72 years. It has a 10,500 year orbit. It might be a representative of the inner Oort cloud. It has a reddish color for unknown reasons.
Smithsonian (SITES) and the Space Telescope Science Institute produced a marvelous minidocumentary of the Shoemaker Levy coverage and real scientist commentary.
http://hubblesource.stsci.edu/exhibits/videos/kiosk Download “Comet Crash”
QT movie (21 MB), broadcast quality mpeg-2 file (124 MB)
Chain of craters on Callisto, of another comet torn apart by tidal forces from Jupiter.
Map of variable gravity strength; white lines show the outlines of land masses
and the Mexican regions.
Several atomic bombs worth of energy.
Crater is 1 km in diameter.
Impact was 20 megatons
Privately owned National Landmark.
A simulation movie is available for public use at
http://www.lanl.gov/worldview/news/tsunami.gov
The description is at:
http://www.lanl.gov/worldview/news/releases/archive/02-064.shtml
The impact scene in the Hollywood movie from 1998’s Deep Impact is actually pretty good.
Chance of death by asteroid: About one in 100,000
From 7-April-2004 congressional testimony of Astronaut Ed Lu, B612 Foundation: 10% chance during our lifetime of a 70 m asteroid, impacting with energy of 10 megatons or 700 Hiroshima bombs. (Senate Subcommittee on Science, Technology, and Space.) Note that 50 meters was the size of the object that created Meteor Crater.