THE FAR REACHES OF THE UNIVERSE

By Isabel and Nora

PART 1: COMETS

Water Comets are partly made of ice When comets go near the sun, some of the ice

melts and the comet gets smaller This is how most comets die, they get smaller

and smaller

Tools for Discovery and Investigation Spaceguard is a program that tracks any big

objects in space like comets, asteroids or meteors that could hit us

The Hubble telescope was launched by NASA and takes pictures in space

It was originally inaccurate, but they sent people into space to fix it

Satellites and traveling probes can also help us discover things about the solar system

Scale Comets are about 5-10 kilometers wide Comet tails are usually 100,000 kilometers The larger the comet, the larger the tail Two recent Oort Cloud comets were Hyakutake

and Hale-Bopp Hyakutake was average in size and came 15

million kilometers close to earth Hale-Bopp was unusually big, but it didn’t

aproach closer than 1.32 AU* to earth Bright comets can be seen every 5-10 years

*Note: 1 astronomical unit is 149,598,000 kilometers

Comet Tails Dust tails shed comet materials from the nucleus Ion tails are made of ions, electrically charged

atoms, and always face away from the sun The solar wind helps cause the ion tails Solar radiation ionizes the material in comets Comets only have tails when they are near the

sun Ion tails always face away from the sunBlack=nucleusTan=coma Yellowish=head of comet Blue=dust

tailRed=ion tail

Head of comet

PART 2: THE OORT CLOUD

States of Matter, Materials and Densities

The Oort Cloud has a dense core 1/6 of the icy objects in the Oort cloud are in

the dense core A giant molecular is a cloud that is far more

massive than the sun. It is the birthplace of stars and solar systems. When encountered it can redistribute comets in The Oort Cloud

Tools For Discovery and Investigation The Oort cloud is named after Jan H. Oort

Gravity, Orbiting and Centripetal Forces Stars in The Milky Way affect The Oort Cloud’s

gravity The Oort Cloud can sometimes be the source of long

period comets Sometimes long period comets in The Oort Cloud

are pulled by planets gravity and turned into short period comets

Scale The total mass of all the comets in The Oort Cloud is

40 times that of earth**Note: Earth is 5.7 times 10 to the 24th power The Oort cloud is 3 light years long and 3 light years

away from the sun Comets are usually tens of millions of kilometers

apart within The Oort Cloud

Bibliography

Rosanna, H. (2011, February 3). The oort cloud. Retrieved from http://www.solarviews.com/eng/oort.htmRosanna, H. (2011, February 3). Comet introduction. Retrieved from http://www.solarviews.com/eng/oort.htmDavies, J. (2001). Beyond pluto. Cambridge, United Kingdom: Cambridge University Press.University of Washington. "Crashing Comets Not Likely The Cause Of Earth's Mass Extinctions." ScienceDaily 31 July 2009. 3 February 2011 <http://www.sciencedaily.com /releases/2009/07/090730141552.htm>.Harvey, S. (2011, February 4). Deep impact. Retrieved from http://solarsystem.nasa.gov/deepimpact/index.cfm

The Comet/Oort Cloud Movie