Monday, January 28, 2008


Earth is the third planet on or after the Sun and the fifth largest of the planet. Earth is the only planet whose English forename does not originate from Greek/Roman mythology. The name derives from Old English and Germanic.

Earth, for sure, can be studied exclusive of the aid of spacecraft. However it was not until the twentieth century that we had maps of the complete planet. Pictures of the planet taken from space are of significant importance; for example, they are a huge help in weather prediction and especially in tracking and predicting hurricanes, they are amazingly beautiful. The Earth's magnetic field and its relationships with the solar wind also generate the Van Allen emission belts, a pair of doughnut shaped rings of ionized gas (or plasma) trapped in orbit just about the Earth. The on the outside belt stretches from 19,000 km in altitude to 41,000 km; the inner belt lies involving 13,000 km and 7,600 km in altitude.

Sunday, January 20, 2008

Venus and Earth

Venus is by the side of times regarded as Earth's sister planet. In some ways they are particularly similar:

* Venus is only a bit of smaller than Earth (95% of Earth's diameter, 80% of Earth's mass).

* Both have a small number of craters representing relatively young surfaces.

* Their densities and chemical compositions are in a similar way.

Because of these similarities, it was measured that below its dense clouds Venus might be very earthlike and power even have life. However, unfortunately, more detailed study of Venus reveals that in plenty of important ways it is radically different from Earth. It may be the smallest amount hospitable place for life in the solar system.

The strength of Venus' atmosphere at the surface is 90 atmospheres (about the same as the pressure at a deepness of 1 km in Earth's oceans). It is collected generally of carbon dioxide. There are numerous layers of clouds many kilometers bulky composed of sulfuric acid. These clouds entirely incomprehensible our view of the surface. This thick atmosphere creates a run-away greenhouse effect that raises Venus' face temperature by about 400 degrees to over 740 K (hot enough to melt lead). Venus' surface is truly hotter than Mercury's in spite of creature nearly twice as far from the Sun. The oldest terrains on Venus appear to be regarding 800 million years old. Extensive volcanism at that time wiped out the in move ahead surface counting any large craters from early in Venus' history.

Monday, January 07, 2008

The facts about Venus

Venus (Greek: Aphrodite; Babylonian: Ishtar) is the goddess of feel affection and beauty. The planet is so named the majority likely because it is the brightest of the planets recognized to the ancients. Venus has been identified since prehistoric times. It is the brightest thing in the sky not including for the Sun and the Moon. Like Mercury, it was generally thought to be two part bodies: Eosphorus as the morning star and Hesperus as the sunset star, but the Greek astronomers knew better.

Venus' rotary motion is rather unusual in that it is both very slow (243 Earth days per Venus day, somewhat longer than Venus' year) and retrograde. Moreover, the periods of Venus' rotary movement and of its orbit are synchronized such that it for all time presents the same face in the direction of Earth when the two planets are at their neighboring approach.

Tuesday, January 01, 2008

Mercury's dense iron core

Mercury is to a great extent denser than the Moon (5.43 gm/cm3 vs. 3.34). Mercury is the second densest mainly important body in the solar system, after Earth. Actually Earth's density is outstanding in part to gravitational density; if not for this, Mercury would be denser than Earth. This signifies that Mercury's dense iron core is reasonably larger than Earth, probably comprises the greater part of the planet. Mercury therefore has only a comparatively thin silicate mantle and crust.

Mercury's inner is under enemy control by a big iron core whose radius is 1800 to 1900 km. The silicate on the outside shell (analogous to Earth's mantle and crust) is just 500 to 600 km thick. At least several of the core is perhaps molten. Mercury truly has an enormously thin atmosphere consisting of atoms blasted off its surface by the solar wind. Because Mercury is so hot, these atoms speedily flee into space.