2What makes up our Solar System? The sunPlanetsMoonsAsteroid belt (between Mars and Jupiter)Lots of spaceAll sorts of bits and pieces of rock
3Meteorite, Meteoroid, Meteor? What’s the difference?
4Meteorite vs. Meteoroid Meteoroid = while in space a meteorite is called a meteoroidMeteorite = a small rock or rocky grain that strikes Earth’s surfaceSo the difference is just based on where the rock is when you are describing it
5Meteor Sometimes called a “Shooting Star” When a meteorite enters Earth’s atmosphere, friction causes them to burn up, producing a streak of light
6Where do they come from? How big are they? Pieces of rock that broke off other objectsSizes range from as small as a pebble or as big as a huge boulder
7Are they dangerous?Most meteoroids disintegrate before reaching the earth by burning up in Earth’s atmosphereSome leave a trail that lasts several minutesMeteoroids that reach the earth are called meteorites. Large ones can cause damage
8Flagstaff, Arizona 49,000 years ago Meteorite about 150 feet in diameterWeighed 650 poundsEnergy = 2.5 million tons of dynamite4000 feet wide, 650 feet deepStill visible todayBarringer Meteorite Crater
9What’s a “Meteor Shower”? Usual rate = six meteors per hourDuring a Meteor Shower = rate may be as high as 60 meteors per hourOccur when Earth passes through the tail or debris of a cometPresides (mid-August)Leonids (mid-November)
10Comets Bodies in space made up of ice, dust, small gritty particles Sometimes called “dirty snowballs”When close to the sun, ice vaporizes, producing a spectacular streak of gas, referred to as a “tail”Many in a regular orbit around the sun
12Where do comets come from? Many ordinate in a region called the Oort cloud which is located beyond the orbit of the dwarf planet PlutoOthers originate in the Kuiper Belt beyond the orbit of NeptuneThis region is filled with billions of comets
15AsteroidsAn irregularly shaped rocky object in space (like a space potato)May be the shattered remains of objects left over from the time when the planets were formed
16How big are asteroids? Larger than meteoroids (In fact, the main difference between meteoroids and asteroids is their size.)Size ranges from 10 feet across to bigger than a mountain
17Asteroids Approx. 150,000 asteroids in the Solar System Most are in a band that orbit the sun between Mars and Jupiter (Asteroid Belt)Why are there all of those asteroids between Mars and Jupiter and not another planet?
18Near-Earth Asteroids (NEAs) At least 1000 asteroids orbit outside of the Asteroid Belt – these could be a danger to EarthAsteroids that cross Earth’s orbit are called Near-Earth Asteroids or NEAsNEA / Earth collision not likelyBut if it did, the affect of the impact would depend on the size of the asteroid
19Large Asteroid hits Earth 65 Million Years Ago Catastrophic CollisionAsteroid 6 to 12 miles in diameterNear the Yucatan Peninsula in the Gulf of Mexico
20Large Asteroid hits Earth 65 Million Years Ago Collision produced an explosion = trillion tons of dynamiteGouged out a crater about 60 miles in diameterHow would an event like this affect Earth?
21What do Scientists Think Happened? Forests were wiped clean for a distance of 300 to 600 miles in all directions300 foot wave struck the coast of TexasPowerful EarthquakesLandslides destroyed long stretches of coastline
22What do Scientists Think Happened Explosion threw huge amounts of debris into the air, covering large parts of North AmericaPoisonous gases and dust soared high into the atmosphere, spread over most of the Earth, and then fell back onto the Earth’s surface
23What do Scientists Think Happened Sunlight was blocked from reaching the Earth’s surface for many monthsTemperatures plummeted to the freezing point in normally warm areasNot enough sunlight for photosynthesisPlants died Animals diedMany animals became extinct (including many types of dinosaurs)
24The Rise and Fall of Life on Earth See the dip around 65 Million years ago?This represents the extinction of about 75% of all the species alive at that time.
25Is the Earth in danger of a large asteroid impact? Not that we know of!None of the asteroids or comets discovered so far is on a collision course with Earth.However, we can't speak for those that are not yet discovered. In principle, one of those could hit any time, but statistically the chances are very small.
26Torino ScaleA system used to rate the hazard level of an object moving toward Earth
27ReviewQ: What is the difference between a meteoroid, meteororite, and a meteor?Meteoroid = while in space a meteorite is called a meteoroidMeteorite = a small rock or rocky grain that strikes Earth’s surfaceMeteor = “Shooting Star”
28Review Q: What is the difference between an asteroid and a meteoroid? The main difference is the size of the object.Q: Which is larger, asteroid or meteoroid?Asteroids are larger than meteoroids.
29ReviewQ: Why is it important to study smaller bodies in our Solar System such as comets or asteroids?They help us learn about the history of our Solar System.
30ReviewQ: Why do planets and moons with atmospheres have less impact craters than those without atmospheres?The atmosphere slows and burns smaller objects like meteorites, thus many do not reach the surface to create an impact.
31ReviewBright streaks of light that result when rocky bodies burn up in the atmosphere are called ___________.Frozen bodies made of ice, rock, and dust, sometimes called “dirty snowballs” are called _____________.Small, rocky bodies that revolve around the sun are called ______________.
32ReviewBright streaks of light that result when rocky bodies burn up in the atmosphere are called meteors.Frozen bodies made of ice, rock, and dust, sometimes called “dirty snowballs” are called comets.Small, rocky bodies that revolve around the sun are called asteroids.
33ReviewQ: Discus what could happen if the Earth experienced another large asteroid impact. How would it affect life on Earth?Forests flattened for many milesIf asteroid landed in water, it would cause giant waves and landslidesPowerful Earthquakes
34The devastation continues… Poisonous gases and dust fills the atmosphere, blocks out the sunTemperatures drop drasticallyNo photosynthesis = plants die = animals dieSome animals become extinct
35Review Q: Where is the Asteroid Belt? Asteroid Belt is between Mars and JupiterQ: What is the Torino Scale?A system used to rate the hazard level of an object moving toward Earth