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International Edition Winners - 2013: Pakistan, Target 2, Grade 7-8

International Edition Winners - 2013: Pakistan, Target 2, Grade 7-8


Zahra Khalid
Target 2, Dione
Zahra Khalid
School: Army Public School & College

Grade: 8
City: Sargodha

"Named after the Greek goddess Dione, this moon of Saturn was the fourth of its family to be discovered. It is a part of one of the largest lunar families of the solar system as Saturn has almost 62 confirmed lunar bodies orbiting it in fixed orbits.

Dione was first discovered by astrologist Giovanni Cassini in the Paris observatory in 1648. It is one of the four moons of Saturn discovered by him. The goddess Dione is considered by many as the sister of Zeus. As time went by Dione established her own importance despite her unknown origins. I think this is why the moon has been named Dione. Like the Goddess it has uncertain origins.

Dione is the fourth largest moon of Saturn and fifteenth largest moon in the solar system, having a diameter of 698 metres. It takes 2.74 earth days to complete an orbit around Saturn at a distance of 377,400. Dione also has two co-orbital moons Helene and Polydeuces. Dione has almost 32% the mass of Earth's moon. Dione is the densest of Saturn's moons with the exception of Titan. Dione is 1.48 times as dense as water. It is composed mainly of water ice, but must contain a larger amount of rocky material than Saturn's other ice moons, Tethys and Rhea. Dione is very similar to Rhea in composition, although smaller. Dione is believed to have a rocky core with ice coverage. This causes the same side of the moon to face towards Saturn all the time. Dione's surface consists of heavily cratered areas, moderate and lightly cratered plains, and bright, wispy features. Most of the heavily cratered areas exist on the trailing hemisphere of the moon. Some of these craters can exceed up to 62 miles in diameter while most are less than 18 miles. The largest crater is Amata which is 150 miles in diameter. The origin of the bright, wispy streaks is unknown. The streaks overlay many of the craters, which indicate that they are newer. They may have been formed by ice eruptions through cracks in the surface. This material may have fallen back to the surface as snow or ash. The temperature on the moon averages minus 302 degrees F.

Cassini detected an oxygen atmosphere on Dione. It is very thin; there is just one oxygen ion for every 0.67 cubic inches. Some scientific information also reveals that Dione may have once had a geologically active subsurface ocean. If Dione turned out to have a liquid layer under its crust, that would increase the moon's chances of supporting life.

My interest in Dione is because of the thin envelope of Oxygen on its surface. Oxygen, no matter how less, is still an undeniable hope for new life. It is highly probable that life may once have existed on this lunar body or may again exist one day in the future through natural processes or by human intervention. This makes Dione a very promising subject for further study and research."