Tuesday, 12 June 2012

Dolphin

Dolphin Jumping and playing Dolphins occasionally leap above the water surface, and sometimes perform acrobatic figures (for example, the spinner dolphin). Scientists are not certain about the purpose(s) of the acrobatics. Possibilities include locating schools of fish by looking at above-water signs like feeding birds, communicating with other dolphins, dislodging parasites or simple amusement. Play is an important part of dolphin culture. Dolphins play with seaweed and play-fight with other dolphins. At times they harass other local creatures, like seabirds and turtles. Dolphins enjoy riding waves and frequently surf coastal swells and the bow waves of boats, at times “leaping” between the dual bow waves of a moving catamaran. Occasionally, they playfully interact with swimmers. Captive dolphins have been observed in aquariums engaging in complex play behavior which involves the creation and manipulation of bubble rings.




Monday, 4 June 2012



Moon

The Moon is the only natural satellite of the Earth,[nb 4][7] and the fifth largest satellite in the Solar System. It is the largest natural satellite of a planet in the Solar System relative to the size of its primary, having a quarter the diameter of Earth and 1⁄81 its mass.[nb 5] The Moon is the second densest satellite after Io, a satellite of Jupiter. It is in synchronous rotation with Earth, always showing the same face; the near side is marked with dark volcanic maria among the bright ancient crustal highlands and prominent impact craters. It is the brightest object in the sky after the Sun, although its surface is actually very dark, with a similar reflectance to coal. Its prominence in the sky and its regular cycle of phases have, since ancient times, made the Moon an important cultural influence on language, calendars, art and mythology. The Moon's gravitational influence produces the ocean tides and the minute lengthening of the day. The Moon's current orbital distance, about thirty times the diameter of the Earth, causes it to appear almost the same size in the sky as the Sun, allowing it to cover the Sun nearly precisely in total solar eclipses.