Transcript Comets - Net Start Class

Space!
Comets
Asteroids
Meteors
Inertia
• The tendency of a moving object to
continue in a straight line or a stationary
object to remain in place
• The more mass an object has, the more
inertia it has. The more inertia an object
has the harder it is to start/stop it.
• Inertia keeps the planets moving forward
Gravity
• A force that pulls objects towards
each other.
• Gravity from the sun keeps the
planets from floating out into space
• Strength of gravity depends on the
masses and distance between the
objects.
Gravity and Inertia
Gravity and Inertia work together
to keep the planets in orbit
around the sun
Law of Universal Gravitation
In Newton's
equation, F is the
gravitational force, G
is a constant of
proportionality, M
and m are the two
masses exerting the
forces, and r is the
distance between the
two objects.
Comets
Chunks of ice & space dust flying
through space.
* Elliptical Orbit around the Sun.
* Part of our Solar System that
orbits in and out. We can see it
coming and going for
days/weeks/months.
* Solar wind burns off tail. Tail
points away from the Sun.
http://cse.ssl.berkeley.edu/SegwayEd/lessons/cometstale/frame_orbits.html
“On April 20, 2007, the comet (Encke) had just dipped inside the orbit of Mercury,
perilously close to the sun, when a solar eruption struck and literally tore the comet's tail
off. This surely has happened to comets before, but for the first time in history a
spacecraft was watching. NASA's STEREO-A probe recorded a fantastic movie of the
collision. “
http://science.nasa.gov/science-news/science-at-nasa/2007/01oct_encke/
http://www.windows.ucar.edu/tour/link=/comets/comets.htm
l
This image of the Hale-Bopp comet was taken on March 7, 1997. The comet is currently
as far away from the Sun as our Earth is (1 astronomical unit). The yellow lines show
where the comet has extensive outbursts of dust from its center or nucleus. This is very
unusual because comets normally don't spew out this much dust at this distance. The
image was taken by H Fukushima, M Takata, and D Kinshita.
National Astronomical Observatory of Japan
Asteroids
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Chunks of Rock floating in space.
Not spherical (ball-shaped like a planet).
No volcanic activity
Some large enough to have gravity.
Most orbit the Sun between Mars &
Jupiter – Asteroid Belt
26 asteroids are 200 Km long!
Most more than 100 Km long!
Most is empty space. Put all the asteroids
together, they would still be smaller than
Earth’s Moon.
About 40,000 asteroids are more than
½ mile long!
http://en.wikibooks.org/wiki/Wikijunior:Solar_System/Asteroid_belt
Stoney asteroid 243 Ida and
its satellite Dactyl (more information and orbit).
Meteoroid
• Chunks of Rocks & Metals that
float around in space
• Come from Asteroid Belt (broken
from asteroids)
• Broken off from planets or comets
• Size: small rock or pebble.
http://www.solarviews.com/eng/meteor.htm
Meteors
• Chunks of Rocks & Metal that fall
into Earth’s atmosphere & burn up
• Meteoroids that are pulled in by
E’s gravity
• Burn up when hit Earth’s
atmosphere
• We see as “falling stars” – Meteor
http://www.star-bits.com/ID.htm
Showers
http://www.moonglow.net/ccd/picture
s/meteors/index.html
A detailed shot of a meteor,
taken during the Leonid
meteor shower in midNovember.
Image Showing Meteors of the
Leonid Meteor Shower, taken from
Space.
Meteorite
• Meteoroid that does not burn up all
the way.
• Hits the E’s surface.
• Very small, hit very fast.
• Most hit water, some land – causes
craters
• Craters on Moon – from Meteorites
The Barringer Impact Crater in Arizona, USA.
Note that it is 1.2km in diameter and has a
maximum depth of 183 meters. It was created by
a meteorite of 40 meters in diameter impacting at
a speed of 11 km/second.
Meteoroid – rock still in space
(Android phone satellite is in space)
Meteor – rock that burns up in
Earth’s atmosphere
(OR it could burn up)
Meteorite – rock that lands on
Earth (“Are you alright?” “you have
the right to keep it!”)
• http://cse.ssl.berkeley.edu/SegwayEd/lessons/
CometsTale/com.html
• Comet Game
• http://cse.ssl.berkeley.edu/SegwayEd/lessons/c
ometstale/frame_gallery.html
• Comet history pics