Meteors and more

Meteoroid

While in space, a meteorite is called a meteoroid

Meteorite

a small rock or rocky grain that strikes Earth’s surface

Meteor

\-sometimes called a shooting star

\- it is when a meteorite enters Earth’s atmosphere and friction causes it to burn up, producing a streak of light

where do they come from and how big are they?

\-come from pieces if rock that broke off of other objects

\-sizes range from as small as a pebble or as big as a boulder

Are these rocks dangerous?

\-most disintegrate before reaching thee earth by burning up in the atmosphere

\-some leave a trail that lasts several minutes

\-meteoroids that reach earth are called meteorites. Large ones can cause damage

Flagstaff, Arizona (meteor shower)

\-49,000 years ago

\-meteorite about 30-50 feet in diameter

\-weighed about 650 pounds

\-energy= 2.5 million tons of dynamite

\-impact 4000 feet wide, 650 feet deep

\-still visible today

what is a meteor shower?

\-usual rate= 6 meteors per hour

\-during a meteor shower, rate may be as high as 60 meteors per hour

\-they occur when Earth pases through the tail or debris of a comet

\-presides (mid-august)

\-leonides (mid-november)

Comets

bodies in space made up of ice, dust, and small gritty particles

\-sometimes called dirty snowballs

\-when they are 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

Where do comets come from?

\-many originate in a region called the oort cloud which is located beyond the orbit of the dwarf planet Pluto

\-others originate in the Kuiper belt beyond the orbit of Neptune

\-this region is filled with billions of comets

Famous comets

\-comet hale-bopp

\-halley’s comet

\-comet kohoutek

asteriods

an irregularly shaped rocky object in space ( like a space potato)

\-may be the shattered remains of object left over from the time when the planets were formed

how big are asteroids?

\-larger than meteoroids (main difference between the two types of space rock)

\-size ranges from 10 feet across to bigger than a mountain

how many asteroids are there, and where are they?

\-approx. 150,000 asteroids in the solar system

\-most are in a band that orbits the sun between Mars and Jupiter (asteroid belt)

Near-Earth Asteroids (NEAs)

\-at least 1000 asteroids orbit outside of thee asteroid belt- these could be a danger to Earth

\-asteroids that cross Earth’s orbit are called Near-Earth or NEAs

\-a near-earth asteroid and earth collision is unlikely

\-the impact would depend on the size of the asteroid

large asteroid hits earth

\-65 million years ago

\-catastrophic collision

\-6-12 miles in diameter

\-Near the Yucatan Peninsula in the Gulf of mexico

\-Produced an explosion equivalent to 100 trillion tons of dynamite

\-gouged out a crater about 60 miles in diameter

what do scientists think happened?

\-forests were wiped clean for a distance of 300-600 miles in all directions

\-300 foot wave struck the coast of Texas

\-powerful earthquakes

\-landslides destroyed long stretches of coastline

\-explosion threw huge amounts of debris into the air, covering large parts of North America

More predictions

\-poisonous gases and dust soared high into the Atmosphere, spread over most of the earth, and then fell back onto the surface

\-sunlight was blocked from reaching the earth’s surface for many months

\-temperatures plummeted to the freezing point in normally warm areas

\-not enough sunlight for photosynthesis

\-plants and animals died

\-many animals became extinct including many types of dinos

is the Earth in danger of a large asteroid impact?

not that we know of

\-none of the asteroids or comets we have discovered so far are on a collision course with earth.

\-we cannot speak for the undiscovered, and it is possible (but unlikely) to collide at any time