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Tuesday, November 13, 2012

From Earth To The Solar System


A Complete Journey Of The Solar System


The Earth

The Earth is certainly the most familiar planet, though it has only been a few hundred years since we fully realized it was a planet. We begin our study of objects in the Solar System with the Earth because it is interesting in its own right, and it provides a test of many observing techniques that we wish to use for other objects in the Solar System.

The Earth is, at least by human standards, a beautiful planet, as the following images indicate.


Wednesday, November 07, 2012

Image Planet Venus


  Image Planet Venus









 
Can refer to this website for more image ~ https://www.google.com/search?q=planet+venus&hl=en&tbo=u&tbm=isch&source=univ&sa=X&ei=BjOaUNbFKM2xrAeLuICwBA&sqi=2&ved=0CDkQsAQ&biw=1366&bih=629

Planet Venus



Venus is the second planet from the Sun, orbiting it every 224.7 Earth days.


Venus in approximately true-color, a nearly uniform pale cream, although the image has been processed to bring out details.[1] The planet's disk is about three-quarters illuminated. Almost no variation or detail can be seen in the clouds.
Venus in true - color. The surface is obscured by a thick blanket of clouds.




The surface of Venus

The Planet - Venus


Saturday, November 03, 2012

Sistem Suria


The Planet : Mercury


Mercury Pictures Gallery

http://space.about.com/od/mercury/ig/Mercury-Pictures-Gallery/
 

Sound Of Mercury


10 Things You Should Know About Mercury

Messenger Spacecraft Images of Mercury - An Overview of Mercury as Messenger Approached

1. Mercury is the closest planet to the Sun


Mercury speeds around the Sun in a wildly elliptical (non-circular) orbit that takes it as close as 47 million km and as far as 70 million km from the Sun. The planet completes a trip around the Sun every 88 days, speeding through space at nearly 50 km per second, faster than any other planet.
Mercury Globe - 10 Things You Should Know About Mercury

 

 

2. Mercury's existence has been known of since before the third century BC

 
The Greeks gave it two names, Apollo for when it appeared as a morning star and Hermes when it came as an evening star.

 

 Messenger Spacecraft Images of Mercury - MESSENGER Views an Intriguing Crater

 3. Mercury's surface very much resembles Earth's        Moon


Mercury is scarred by thousands of impact craters resulting from collisions with meteors. While there are areas of smooth terrain, there are also cliffs, some soaring up to a mile high, formed by ancient impacts.


Mercury Image - 10 Things You Should Know About Mercury

4. Mercury has a large iron core which is most likely at least partially molten


Mercury's interior is made of a large iron core with a radius of 1,800 to 1,900 km, nearly 75 percent of the planet's diameter and nearly the size of Earth's Moon. Mercury's outer shell, comparable to Earth's outer shell (called the mantle) is only 500 to 600 km thick.

 

 

5. Mercury actually has a very thin atmosphere

Messenger Spacecraft Images of Mercury - A Closer Look at the Previously Unseen Side Merucry's atmosphere is made up of atoms blasted off its surface.    Due to the heat of the planet, these atoms quickly escape into space. Thus unlike the Earth and Venus which have stable atmospheres, Mercury's atmosphere is constantly being replenished.

 

 

 

 

 Messenger Spacecraft Images of Mercury - Counting Mercury's Craters 6. Mercury is a planet of extremes

Temperature variations swing from 90 K to 700 K. It's hotter on Venus, but with less fluctuations. Mercuryalso has a very eccentric orbit; at perihelion it is only 46 million km from the Sun but at aphelion it is 70 million.

7. Mercury has no known moons or satellites

While Mercury may resemble our own moon in many ways, it has no moon of its own.

8. Until 1965, scientists thought that the same side always faced the Sun

In 1965, astronomers discovered that Mercury completes three rotations for every two orbits around the Sun. If you wanted to stay up for a Mercury day, you'd have to stay up for 176 Earth days.

9. The Caloris Basin is about 1,300 km in diameter

One of the largest features on Mercury, it was the result of an asteroid impact on the planet's surface early in the solar system's history. Over the next 1/2-billion years, Mercury actually shrank in radius from 2 to 4 km as the planet cooled from its formation. The outer crust, called the lithosphere, was compressed and grew strong enough to prevent the planet's magma from reaching the surface, effectively ending the planet's period of geologic activity.

10. Mercury is the least explored of our solar system's inner planets.

Only one spacecraft has ever visited Mercury: Mariner 10 in 1974-75. Mariner 10's discovery that Mercury has a very weak magnetic field, similar to but weaker than Earth's, was a major surprise. NASA is planning a new mission to Mercury called Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER), which will orbit Mercury toward the end of this decade. MESSENGER will investigate key science questions using a set of miniaturized instruments.

Information Mercury



Named after the Roman god of commerce, travel and thievery, Mercury is the closest planet to the Sun and the eighth largest. Mercury's existence has been known of since before the third century BC. The Greeks gave it two names, Apollo for when it appeared as a morning star and Hermes when it came as an evening star.

Mercury has a large iron core which is most likely at least partially molten. The silicate outer shell is only 500 to 600 km thick. It actually has a very thin atmosphere made up of atoms blasted off its surface by the solar wind. Due to the heat of the planet, these atoms quickly escape into space. Thus unlike the Earth and Venus which have stable atmospheres, Mercury's atmosphere is constantly being replenished. 

Mercury is a planet of extremes. Temperature variations swing from 90 K to 700 K. It's hotter on Venus, but with less fluctuations. Mercury also has a very eccentric orbit; at perihelion it is only 46 million km from the Sun but at aphelion it is 70 million.
Mercury has no known moons or satellites.
Mercury orbits closest to the Sun of all the planets, and is the smallest. Mercury's diameter is 4,879 km (3,032 mi), and its volume and mass are about one-eighteenth that of Earth. Discover more information about Mercury, including pictures.

Mercury is so close to the Sun, it is hard to directly observe from Earth, except during twilight. Mercury makes an appearance indirectly, however 13 times each century, Earth observers can watch Mercury pass across the face of the Sun, an event called a transit. These rare transits fall within several days of May 8 and November 10. The first two transits of Mercury in the 21st century oc…

Friday, November 02, 2012

The Solar System Song


Ten things you may not know about the solar system

Image via New Scientist



1 ) We live inside the sun
Normally we think of the sun as being that big, hot ball of light 93 million miles away. But actually, the sun’s outer atmosphere extends far beyond its visible surface. Our planet orbits within this tenuous atmosphere, and we see evidence of this when gusts of the solar wind generate the Northern and Southern Lights. In that sense, we definitely live “inside” the sun. But the solar atmosphere doesn’t end at Earth. Auroras have been observed on Jupiter, Saturn, Uranus, and even distant Neptune. In fact, the outer solar atmosphere, called the “heliosphere,” is thought to extend at least 100 A.U. That’s nearly 10 billion miles. In fact the atmosphere is likely teardrop shaped due to the sun’s motion in space, with the “tail” extending tens to hundreds of billions of miles downwind.

 2 ) Even really small bodies can have moons
It was once thought that only objects as large as planets could have natural satellites or moons. In fact the existence of moons, or the capability of a planet to gravitationally control a moon in orbit, was sometimes used as part of the definition of what a planet truly is. It just didn’t seem reasonable that smaller celestial bodies had enough gravity to hold a moon. After all, Mercury and Venus have none at all, and Mars has only tiny moons. But in 1993, the Galileo probe passed the 20-mile wide asteroid Ida and discovered its one-mile wide moon, Dactyl. Since then moons have been discovered orbiting nearly 200 other minor planets, further complicating the definition of a “true” planet.

 3 ) Jupiter has the biggest ocean of any planet
Orbiting in cold space five times farther from the sun than Earth, Jupiter retained much higher levels of hydrogen and helium when it formed than did our planet. In fact, Jupiter is mostly hydrogen and helium. Given the planet’s mass and chemical composition, physics demands that way down under the cold cloud tops, pressures rise to the point that the hydrogen must turn to liquid. In fact there should be a deep planetary ocean of liquid hydrogen. Computer models show that not only is this the largest ocean known in the solar system, but that it is about 40,000 km deep – roughly as deep as the Earth is around!
 
4 ) There are Mars rocks on Earth (and we didn’t bring here)
Chemical analysis of meteorites found in Antarctica, the Sahara Desert, and elsewhere have been shown by various means to have originated on Mars. For example, some contain pockets of gas that is chemically identical to the martian atmosphere. These meteorites may have been blasted away from Mars due to a larger meteoroid or asteroid impact on Mars, or by a huge volcanic eruption, and later collided with Earth.

5 ) Almost everything on Earth is a rare element
The elemental composition of planet Earth is mostly iron, oxygen, silicon, magnesium, sulfur, nickel, calcium, sodium, and aluminum. While such elements have been detected in locations throughout the universe, they are merely trace elements, vastly overshadowed by the much greater abundances of hydrogen and helium. Thus Earth, for the most part, is composed of rare elements. This does not signify any special place for Earth, however. The cloud from which the Earth formed had a much higher abundance of hydrogen and helium, but being light gases, they were driven away into space by the sun’s heat as the Earth formed.

 6 ) The “edge” of the Solar System is 1,000 times farther away than Pluto
Most people have been taught that the solar system just goes out to the orbit of Pluto. Today we don’t even consider Pluto a full-fledged planet, but the impression remains. Still, we have discovered numerous objects orbiting the sun that are considerably farther than Pluto. These are “Trans-Neptunian Objects” (TNOs), or “Kuiper Belt Objects” (KBOs). The Kuiper Belt, the first of the sun’s two reservoirs of cometary material, is thought to extend to 50 or 60 astronomical units (AU, or the average distance of the Earth from the sun). An even farther part of the solar system, the huge but tenuous Oort comet cloud, may extend to 50,000 AU from the sun, or about half a light year – more than a thousand times farther than Pluto.

7 ) You can make volcanoes using water as magma
Mention volcanoes and everyone immediately thinks of Mount St. Helens, Mount Vesuvius, or maybe the lava caldera of Mauna Loa in Hawaii. Volcanoes require molten rock called lava (or “magma” when still underground), right? Not really. A volcano forms when an underground reservoir of a hot, fluid mineral or gas erupts onto the surface of a planet or other non-stellar astronomical body. The exact composition of the mineral can vary greatly. On Earth, most volcanoes sport lava (or magma) that has silicon, iron, magnesium, sodium, and a host of complicated minerals. The volcanoes of Jupiter’s moon Io appear to be composed mostly of sulfur and sulfur dioxide. But it can be simpler than that. On Saturn’s moon Enceladus, Neptune’s moon Triton, and others, the driving force is ice, good old frozen H20! Water expands when it freezes and enormous pressures can build up, just as in a “normal” volcano on Earth. When the ice erupts, a “cryovolcano” is formed. So volcanoes can operate on water as well as molten rock. By the way, we have relatively small scale eruptions of water on Earth called geysers. They are associated with superheated water that has come into contact with a hot reservoir of magma.
 
8 ) George Lucas doesn’t know much about “Asteroid Fields”
In many science fiction movies, spacecraft are often endangered by pesky asteroid fields. In actuality, the only asteroid belt we are aware of exists between Mars and Jupiter, and although there are tens of thousands of asteroids in it (perhaps more), they are quite widely spaced and the likelihood of colliding with one is small. In fact, spacecraft must be deliberately and carefully guided to asteroids to have a chance of even photographing one. Given the presumed manner of creation, it is highly unlikely that spacefarers will ever encounter asteroid swarms or fields in deep space.

9 ) Pluto is smaller than the USA
The greatest distance across the contiguous United States is nearly 2,900 miles (from Northern California to Maine). By the best current estimates, Pluto is just over 1400 miles across, less than half the width of the U.S. Certainly in size it is much smaller than any major planet, perhaps making it a bit easier to understand why a few years ago it was “demoted” from full planet status. It is now known as a “dwarf planet.”

 10 ) The hottest planet isn’t closest to the sun
Many people know that Mercury is the closest planet to the sun, well less than half of the Earth’s distance. It is no mystery, therefore, why people would assume that Mercury is the hottest planet. We know that Venus, the second planet away from the sun, is on the average 30 million miles farther from the sun than Mercury. The natural assumption is that being farther away, it must be cooler. But assumptions can be dangerous. For practical consideration, Mercury has no atmosphere, no warming blanket to help it maintain the sun’s heat. Venus, on the other hand, is shrouded by an unexpectedly thick atmosphere, about 100 times thicker than our own on Earth. This in itself would normally serve to prevent some of the sun’s energy from escaping back into space and thus raise the overall temperature of the planet. But in addition to the atmosphere’s thickness, it is composed almost entirely of carbon dioxide, a potent greenhouse gas. The carbon dioxide freely lets solar energy in, but is far less transparent to the longer wavelength radiation emitted by the heated surface. Thus the temperature rises to a level far above what would be expected, making it the hottest planet. In fact the average temperature on Venus is about 875 degrees F, hot enough to melt tin and lead. The maximum temperature on Mercury, the planet closer to the sun, is about 800 degrees F. In addition, the lack of atmosphere causes Mercury’s surface temperature to vary by hundreds of degrees, whereas the thick mantle of carbon dioxide keeps the surface temperature of Venus steady, hardly varying at all, anywhere on the planet or any time of day or night!