Aziz Kemal Burkay...
Prepared and Translated By Cheng Hung Yousuf Ma, PhD, March 1st 2006.
Ice Exists on Surface of Comet, But Most Lies Deeper
By analyzing data and images taken prior to impact, Deep Impact scientists have detected water ice in three small areas on the surface on comet Tempel 1. This is the first time ice has been detected on the nucleus, or solid body, of a comet. The findings are published on February 2, 2006 in the online version of the journal Science.
Volume of Earth's Water:
Water is continually moving around, through, and above the Earth as water vapor, liquid water, and ice. In fact, water is continually changing its form. The Earth is pretty much a "closed system," like a terrarium. That means that the Earth neither, as a whole, gains nor loses much matter, including water. Although some matter, such as meteors from outer space, are captured by Earth, very little of Earth's substances escape into outer space. This is certainly true about water. This means that the same water that existed on Earth millions of years ago is still here. Thanks to the water cycle (view a graphic of the water cycle), the same water is continually being recycled all around the globe.
The Earth has approximately 1.3 billion cubic kilometers of water, meaning that a sphere with all of that water in it would have a diameter of 1354 kilometers (841 miles).
Based on the diameter of 1,354 km, the total volume of water on Earth is about 1.299725033 billion cubic kilometers.
Asteroids are rocky and metallic objects that orbit the Sun but are too small to be considered planets. They are known as minor planets. Asteroids range in size from Ceres, which has a diameter of about 1000 km, down to the size of pebbles. Sixteen asteroids have a diameter of 240 km or greater. They have been found inside Earth's orbit to beyond Saturn's orbit. Most, however, are contained within a main belt that exists between the orbits of Mars and Jupiter. Some have orbits that cross Earth's path and some have even hit the Earth in times past.
Asteroids are material left over from the formation of the solar system. One theory suggests that they are the remains of a planet that was destroyed in a massive collision long ago. In fact, if the estimated total mass of all asteroids ware gathered into a single object, the object would be less than 1,500 kilometers (932 miles) across -- less than half the diameter of our Moon.
Of all the meteorites examined, 92.8 percent are composed of silicate (stone), and 5.7 percent are composed of iron and nickel; the rest are a mixture of the three materials. Stony meteorites are the hardest to identify since they look very much like terrestrial rocks.
The following picture depicts where and how asteroids are distributed in the Solar System.
Based on the diameter of 1,500 km, the total volume of asteroids in our solar system is about 1.767133125 billion cubic kilometers.
Largest Asteroid Might Contain More Fresh Water than Earth
The largest known asteroid could contain more fresh water than Earth and looks like our planet in other ways, according to a new study that further blurs the line between planets and large space rocks.
Ceres has long been considered one of the tens of thousands of asteroids that make up the asteroid belt between Mars and Jupiter. At 930 km (580 miles) in diameter – about the size of Texas – it’s the largest asteroid (see picture) in the belt, accounting for about 25 percent of the belt’s total mass.