Callisto Rotation

Go to this link to see an animation of Callisto Rotating.

http://www.solarviews.com/raw/jup/vcallis1.mpg

Life.....?

Could there possibly be life on Callisto? According to astronomers a body in space has to have certain characteristics in order to possibly support life. A planet needs a liquid water, an oxygen atmosphere, and a magnetic field minimum in order to support life. Callisto does not really have these characteristics. Although there is water on Callisto, it is not liquid, it is frozen. Although, Callisto has an atmosphere it is comprised mostly of carbon dioxide, and is very very thin, and some astronomers think it even disappears and comes back often. Callisto does not have an internally generated magnetic field. Although Callisto does not have any of the characteristics necessary to support life, I still think, like scientists that there could be one celled organisms below its ice and rock surface.

Alien Organism :)

Although Callisto does not have the characteristics to support life, scientists have come up with a few bodies that can possibly support life. One of them is Mars. Mars is the fourth planet away from our sun and is classified as a terrestrial planet. The reason some scientists believe there is life on it is because in 1997 a small robotic rover named Sojourner found abundances of water on mars. A more recent reason is that in a meteor that supposedly came from mars had life on it. I agree with the astronomers and scientists on this one, because it is quite possible that there could be life outside of earth.

Mars: The Red Planet

Sources:
http://science.nasa.gov/newhome/headlines/ast22oct98_2.htm
http://www.windows.ucar.edu/tour/link=/jupiter/moons/callisto_atmosphere.html&edu=high
http://www.solstation.com/stars/jupiter.htm
http://www.solarviews.com/cap/jup/callist1.htm
http://www.nature.com/nature/journal/v387/n6630/abs/387262a0.html
http://seds.org/~spider/spider/Mars/mmetlife.html
http://seds.org/~spider/spider/Mars/mmetlife.html

Distance.....

There are a few ways space can be measured within our solar system, Km (kilometer), Au (astronomical unit), and Ly (light year). Kilometer is the smallest form of measurement, spanning only 3,280 ft. One astronomical unit spans 150 million kilometers and shows the distance between the sun and earth. Light travels at 186,00 mi/sec., so in one light year we could travel 6,000,000,000,000m. We can use the form of measurement, Km to measure a state to a state. We could use the form of measurement AU to measure the distance from the sun and earth. And we can use the form of measurement, Ly to measure between galaxies.

Earth is approximately 628,743,036 km from Jupiter's moon Callisto. In order to actually get to Callisto it would take about 6 years if the spacecraft you were traveling in went thousands of miles per hour. Humans can get to Callisto and have.


This picture shows one AU.

Orion Nebula

The Orion Nebula

Scientific Vocabulary

Accretion: A process where small objects in space collide and stick together to form larger bodies in space.

Fusion: A process in which atoms join together to produce power.

Supernova: A supernova occurs when a supergiant star stops fusion in it's core, collapses then explodes.

Planetesimals: One of the small celestial bodies that were fused together.

How Callisto Formed

There are two ways for a moon to form: accretion and gravity or impact. Jupiter's moon, Callisto formed using accretion and gravity. The Six steps Callisto took towards forming are as follows: First a supernova occurred, then came a nebula. Hot gas and dust left over from the Supernova's explosion swirled around in space. As the cloud cooled atoms started to move slower, therefore clumping together. Then Planetesimals formed and accretion began. Callisto gathered together using the gas and dust that surrounded Jupiter. Then Callisto became a proto Planet and grew to it's full size, however because Callisto did not have enough mass in order to 'clear its neighborhood' of debris. The final step of Callisto's formation was to get caught inside Jupiter's orbit, Where it is even today.

What makes a planet

In order for a planet to be a planet they need to meet the three requirements required by the International Astronomical Union. 1) It needs to orbit around a star. 2) It needs to have enough gravity to pull itself into a spherical shape. 3) It needs to be able to clear its orbit of debris. This makes Pluto, a dwarf planet. Although Pluto has two out of the three characteristics needed in order to be a planet it does not have enough gravitational pull to clear its orbit of debris. My heavenly body, Callisto is a moon and not a planet because it does not revolve around a star, it revolves around Jupiter. Callisto also cannot clear its 'neighborhood' of debris. However Callisto is defiantly big enough to be a planet, Callisto is almost as big as the planet Mercury!


The Dwarf Planet Pluto