All About the Planet Venus

By Patrick Omari

Named after the Roman Goddess of love, the planet Venus is the second furthest from the Sun. It has been referred to as Earth’s twin planet due to its remarkably similar size. Venus is also a rocky planet with a gaseous atmosphere, however it differs from Earth in a number of crucial ways.

Venus is the closest planet to Earth and the brightest object in the night sky, with the exception of the moon, and has been referred to as both the Morning and Evening Star due to its luminosity. Venus is most striking for its thick atmosphere which covers the entire planet and obscures the view of the surface from space and Earth. The hidden surface of the planet was the subject of much curiosity and speculation before the myths were dispelled by probes and exploratory spacecraft. Science fiction writers in particular pondered what what be on the surface of Venus, speculating about possible life on the surface.

However, numerous probes sent to the planet would remove any lingering doubt over the possibility of life on Venus. The surface temperature averages at around 460 degrees C with the atmospheric pressure 92 times that of Earth’s, the same as that found 1km under the oceans. The extremely high temperature is caused by a runaway greenhouse effect. Venus’ atmosphere is predominantly composed of carbon dioxide with clouds of sulphur dioxide. Heat from the Sun becomes trapped and the planet gets warmer and warmer, to the point it is at today.

At its closest Venus passes 41.8km away from Earth, takes 225 Earth days to orbit the Sun and 243 days to complete one rotation. Venus’ orbit is the closest of any planet to being circular, with an eccentricity of less that 0.01. The extremely slow rotation of Venus makes it stand out from the other planets, taking much longer to complete. Venus also spins in the opposite direction to Earth. Venus has no moons.

Venus has been the subject of a lot of the initial ideas of colonisation by Man of the Solar System. The discovery of the conditions on the surface seemed to all but rule out any human settlement on the surface, the extreme temperature and pressure would make life impossible. There has been some talk, however, of possible colonisation of Venus’ atmosphere. 50km above the surface the conditions are much more favourable and Earth-like. Floating cities filled with human-breathable air would float in the dense atmosphere, at that height the atmospheric pressure is the same as that of Earth and temperatures range from 0-50 degrees. A different approach could be to artificially cool Venus using giant mirrors or manipulating dust clouds. In just a few decades the planet would cool significantly enough to give conditions similar to Earth on the surface.

Venus is an interesting planet given its similar properties to Earth. It is also a living example of what a runaway greenhouse effect can do to a planet. The excessive CO2 content in the atmosphere has massively heated the planet beyond what it would be otherwise, a stark reminder of what could eventually happen to Earth.

Patrick is an expert Research and Travel consultant. His current interest is in Luton airport parking, Stansted parking and Gatwick hotels.
Article Source: http://www.science.freearticledirectories.com

All About the Planet Earth

By Patrick Omari

Earth is unique among all known planets, ones native to our Solar System or otherwise. It is the only planet that has liquid water on the surface and is also the only world containing life. Earth is the third planet out from the Sun and is the densest and largest of the four rocky terrestrial planets.

Formed at the same time as the rest of the Solar System the Earth would accrue enough mass to maintain an atmosphere, composed chiefly of nitrogen and carbon dioxide. It is believed that the Earth collided with another planetesimal early in its history, the remains of this collision would form the Moon. Earth’s moon is its only natural satellite with its gravitational effects having great effects on the planet. The Earth was also just the right distance from the Sun for liquid water to form on the surface, filling the oceans and eventually covering 71% of the planet’s surface.

Half a billion years after the formation of the planet the first self-replicating molecules were formed, and by a process of natural selection would go on to evolve into all life as we know it. The impact of life has been significant on the Earth, the oxygen in the atmosphere and the ozone layer are attributed to early plant life. The ozone layer protects the surface from many harmful rays from the Sun and has allowed colonisation of the land by multicellular organisms. Life would go on to evolve intelligence and humans. We are still the only known life in the universe, and most likely the only intelligent forms of life within millions of light years.

The Earth is almost a perfect sphere, with a slight bulge at the equator due to its rotation. The planet is mostly composed of iron, oxygen, silicon, magnesium, sulfur, nickel, calcium and aluminum. The planet is formed from a mostly iron core, a molten mantle and a thin rocky crust, much like the other rocky planets. The surface of Earth is split into several continental plates which all move around on the surface. This geological activity gives rise to earthquakes, mountains, tsunamis and volcanoes.

Similar to Mars, the Earth has polar caps with ice at the Northern and Southern tips. The Earth has a strong magnetic field, which deflects much of the solar wind and protects the Earth from the harmful radiation. The Earth is tilted on its axis, meaning that some areas are closer to the Sun that others during orbit. This tilt gives rise the seasons.

The human population of Earth is expanding at an ever increasing rate and many concerns are being raised about the treatment of the planet and how long it will be until the finite resources are consumed. A lot of human activity is now going into finding alternative power sources and environmentally friendly methods of industry. The evolution of humans has been the first time in over four billion years that one species has had such a negative impact on the well-being of the rest of the planet.

Patrick is an expert Research and Travel consultant. His current interest is in Luton airport parking, Birmingham airport parking and Gatwick hotels.
Article Source: http://www.science.freearticledirectories.com

All About the Planet Mars

By Patrick Omari

Mars is the fourth planet from the Sun and is named after the Roman God of war. The planet is a distinctive shade of red and is the last of the rocky terrestrial planets. Mars is substantially smaller than Earth and Venus but larger than Mercury. The planet has been the subject of intense speculation about the existence of extra terrestrial life with evidence of water on the surface at the polar ice caps. While recent robotic explorations have shown that the presence of life is unlikely it has still not been conclusively ruled out.

Mars has a thin atmosphere, much thinner than Earth’s. It is kept this way by the solar winds stripping atoms from the top layer, Mars’s atmosphere lacks a magnetosphere to protect it. The surface pressure of the Martian atmosphere is less than one percent of that found on Earth. Despite the sparseness of the atmosphere however, it extends 5km higher than Earth’s due to lower gravity. Mars has a relatively low mass and the surface gravity is just 38 percent of Earth’s.

Mars is home to the largest mountain in the Solar System, Olympus Mons. It is three times higher than Mount Everest and the result of substantial volcanic activity with shallow slopes covering a massive area. Mars is also home to many other interesting geographical features such as canyons and valleys. Many of these features are attributed to running water, although it has been proved to no longer exist it is thought that at one time Mars may have had rivers on its surface. The Phoenix lander has found ice under the surface of the planet and Mars is the most water-rich location outside Earth that we have found so far.

Mars has two small moons, Phobos and Demios, both with irregular shapes. They are thought to be captured asteroids and the orbit extremely close to the planet. It is not fully understood how the moons have come to orbit Mars, however it is believed that Phobos is a relatively recent capture as it follows an unstable orbit and will collide with the Red Planet in around 50 million years.

Mars has been extensively explored by robotic spacecraft and probes by the USA, Russia, Europe and Japan. Probes began exploring Mars even before Man had landed on the Moon with the first flyby occurring in 1964. The Soviets were the first to successfully land objects on the planet, but they lost contact soon after arrival. In 1976 the NASA probes Viking 1 and 2 made it to the surface of Mars, spending several years there. They provided many images and helped to map the surface. The most recent probe to land on Mars is the Phoenix Lander. It arrived in May 2008 and began investigating the Martian soil, finding conclusive evidence of water ice. Phoenix landed much closer to the pole than any other spacecraft.

There are many future missions planned to Mars and in 2004 President George W. Bush announced that NASA’s vision for space exploration would be to launch a manned mission to the planet. NASA administrators believe that they will have successfully landed a man on Mars by 2037. Mars has been the subject of serious talk of eventual colonisation, as it is seen as the most suitable for life and the most habitable environment in the Solar System outside Earth. Mars has many of the elements needed for life present in its soil and with a carbon dioxide-rich atmosphere it is thought that with some terraforming that algae may be able to survive at the poles. Terraforming Mars is an area that is being looked into as a future destination for civilisation once the increasing heat of the Sun makes Earth uninhabitable.

Mars is a charismatic planet, inspiring countless works of fiction and a massive amount of speculation about the secrets it may hold. It has been a characteristic of our space exploration that many of the early romantic ideas of conditions on the surface have been dispelled and the planet has been found to be lifeless and largely barren. Martian thinking is now turning towards finding out its past and planning for its future.

Patrick is an expert Research and Travel consultant. His current interest is in Luton airport parking, Birmingham airport parking and Gatwick hotels.
Article Source: http://www.science.freearticledirectories.com

All About the Planet Jupiter

By Patrick Omari

Jupiter is the largest planet in the Solar System and is the innermost of the gas giants. Named after the Roman King of the Gods the planet is located beyond the asteroid belt. Jupiter orbits between 740 million and 778 million km from the Sun and is primarily composed of hydrogen and helium. It is the fourth brightest object in the sky behind the Moon, Sun and Venus and has an extremely fast rotation period, completing one every ten hours. The planet takes eleven years to complete an orbit of the Sun.

Jupiter is quite unlike Earth and its neighbours as it is mostly composed of gases rather than heavier elements. Jupiter is two and a half times more massive than all the other planets put together and is about as large as a planet of its type can grow. If it were to take on more mass the diameter would actually decrease from the increased gravity. If it were 75 times larger then it would be able to fuse hydrogen and become a star, this has lead some astronomers to label the planet as a failed star. However despite its humble status as a planet Jupiter does create a substantial amount of its own heat, generating more than it receives from the Sun.

The atmosphere of Jupiter is made of many distinctive bands of gas and light elements. Different areas of the planet have been shown to rotate at different speeds, and there are many storms present. The most notable storm on Jupiter is the Great Red Spot. This giant anomaly on the surface of the planet is larger than Earth and is a storm that has been raging ever since we first discovered the planet. Jupiter is peppered with similar storms and recently three large grey ones merged into one storm, similar to the red spot.

Jupiter has only been explored by automatic deep-space probes, there is no surface to land on and there have been no landings on any of its moons yet. The first probe to fly-by Jupiter was the Pioneer 10 in 1973. Pioneers 10 and 11 would gather a multitude of images and date about the planet, detecting the magnetic field and radiation belts. In 1979 Voyagers 1 and 2 passed Jupiter followed by Ulysses in 1992. The only probe to orbit Jupiter is the Galileo spacecraft, which reached the gas giant in 1995. The craft stayed in orbit for seven years, releasing an atmospheric probe in July 1995. The probe descended into Jupiter and sent back data for 57 minutes before it was crushed by the pressure. Eventually Galileo was sent into the planet in order to prevent it crashing into and contaminating any of Jupiter’s moons.

Jupiter has 63 moons, some of which are among the largest objects in the Solar System. The four largest are Io, Callisto, Ganymede and Europa, known as the Galilean moons after their discoverer Galileo. The moons of Jupiter are among the most interesting bodies in the Solar System with some striking geological activity and possible sites for life. The moon Europa may be the site of a liquid ocean underneath its icy crust and is a place that scientists are extremely interested in exploring. The moons of Jupiter are not as cold and lifeless as they may be otherwise due to tidal flexing providing friction on the inside of the planet and keeping them active. Io is the most geologically active body in the Solar System with over 400 volcanoes, Ganymede is the largest non-planet and Callisto is considered a possible site for extra-terrestrial microbial life.

Jupiter is not as openly considered for colonisation as our nearby planets Mars and Venus. The giant planet does however offer an inviting location for a stepping stone into the outer Solar System. Its many moons could make good places for colonies and may even provide economic benefits through mining. The future will see further missions to the moons to look for signs of life and liquid oceans.

Patrick is an expert Research and Travel consultant. His current interest is in Luton airport parking, Birmingham airport parking and Gatwick hotels.
Article Source: http://www.science.freearticledirectories.com

All About the Planet Saturn

By Patrick Omari

Saturn is the most visually striking planet in the Solar System. It is the second largest gas giant behind Jupiter and is surrounded by a spectacular series of rings. Saturn is the sixth furthest planet from the Sun at 1,400 million km away and is named after the Roman God Saturnus. The rings are made from icy particles and dust, Saturn has around 60 moons as well as the only moon with a stable atmosphere, Titan.

Saturn has a small core made from ice and rock with the rest of the planet being chiefly hydrogen and helium. There are thought to be liquid metallic hydrogen and liquid hydrogen and helium layers surrounding the core before the gaseous outer layers.

The inside of Saturn can reach extremely hot temperatures, with the interior temperature of 11,700 degrees C thought to be due to the Kelvin-Helmholtz mechanism of gravitational compression. The atmosphere of Saturn is not as strikingly active as the one on Jupiter, but it does display some of the same characteristics. The gases have a banded appearance and there is evidence of cloud layers and storms.

The rings of Saturn initially were a great source of confusion for early astronomers, lacking the high-powered telescopes to identify them. Galileo thought that Saturn was three bodies, but was lost for an explanation as to why the outer two would disappear only to reappear again later. It took until 1655 for Christiaan Huygens to correctly identify Saturn’s rings. The rings are mainly composed of water ice and they extend from 6,630km to 120,700km from the surface.

The origin of the rings is not known for certain, with theories that they are the remnants of a moon ripped apart by tidal forces or a leftover material from Saturn’s formation both being considered.

Saturn has been visited by probes during the 80s and more recently in 2004. In 1980 and 1981 the Voyager probes, 1 and 2, both performed fly-bys of the gas giant on their way out of the Solar System. They provided high quality images of the planet and its rings.

Voyager 1 flew close to Titan, obtaining more data about the atmosphere on the moon. The main probe to gather data about Saturn and its satellites was the Cassini-Huygens probe which reached the planet in July 2004. The probe gathered a lot of data on Titan including details of its lakes, coastlines and other geographical features.

The craft then released the Huygens lander which became the first craft to land on a moon other than our own. Cassini would also go on to discover liquid water erupting from geysers on the surface of Enceladus, another of Saturn’s moons.

Titan dominates Saturn’s moons, making up 96% of their mass. Titan is unique among the moons of the Solar System as it has an extremely thick atmosphere, not dissimilar to the one found on Venus. The atmosphere of Titan, however, has a reverse effect of Venus as it has an anti-greenhouse effect which cools the surface where Venus’s atmosphere has heated the surface to scorching effect.

The Cassini-Huygens probe discovered the liquid methane lakes on Titan, the first stable bodies of liquid found on any extra-terrestrial body. There are weather systems similar to Earth in effect on Titan with rain and high winds all present. The average surface temperature is between -179 and -290 degrees C, with atmospheric pressure higher than Earth and much lower gravity.

Despite its low temperatures Titan is compared to early Earth with its high amount of organic chemical activity. The moon is thought to be one of the most likely places in the Solar System to find alien life.

The nature of gas giants means that they don’t lend themselves well for direct colonisation or human visits. However in Saturn’s case it may prove that Titan is an excellent place for a future colony if the low temperature and high pressures can be overcome.

Any human landing on the planet-facing side of the moon would also be treated to some of the most spectacular views in the Solar System, with Saturn and its rings taking up a large portion of the sky.

Patrick is an expert Research and Travel consultant. His current interest is in Luton airport parking, Birmingham airport parking and Gatwick hotels.
Article Source: http://www.science.freearticledirectories.com

All About the Planets Uranus and Neptune

By Patrick Omari

Uranus and Neptune are known as the ice giants, huge blue planets located in the outer Solar System. They are similar to Jupiter and Saturn in that they are predominantly composed of gases and ice but differ in many key areas. While still dwarfing the inner planets the ice giants are smaller than the other gas giants. Due to their distance from Earth they were the last planets to be discovered, Uranus in 1781 and Neptune in 1846.

Uranus is the seventh planet from the Sun and orbits between 3,004,419,704 km and 2,700,938,461 km from the star. It has 27 known moons as well as a faint ring system. Uranus takes 17 hours to complete a rotation and 84 Earth years to complete one orbit of the Sun. The planet is named after the Greek God of the sky, the father of Saturn and grandfather of Jupiter.

What makes Uranus different from any other planet in the Solar System is that the axis is tilted onto its side. The tilt of Uranus is 97.7 degrees, meaning that the pole is facing the Sun, making its day/night cycles and seasons entirely different to any of the other planets. Each pole of Uranus gets 42 years of light followed by 42 years of darkness. What caused this extreme tilt is not known for sure but is thought to be due to a large planetary body striking the ice giant.

Uranus is composed of three layers, a rocky core, an icy mantle and an outer layer of gaseous hydrogen and helium. Uranus is the coldest planet in the Solar System, despite being closer to the Sun than Neptune. The lowest temperature ever recorded on Uranus was -224 degrees C, just 49 Kelvin. Why Uranus doesn’t emit as much of its own internal heat as other planets is not known for sure, but it has been speculated that the internal structure of the planet blocks much of the heat from the core from reaching the surface.

Neptune is the second ice giant, the eighth planet from the Sun orbiting at a distance of around four billion km. Neptune takes 164 years to orbit the Sun and takes 16 hours to complete one rotation, giving the planet short days and extremely long years when compared to Earth. After Pluto’s demotion from planet status Neptune has become the furthest planet from the Sun.

The structure of Neptune is similar to Uranus with its atmosphere making up around 10 percent of its mass, slowly becoming more solid as you reach the core where temperatures sit at around 5000 Kelvin. The atmosphere is scattered with clouds that form in the upper layers, believed to made of ammonia, ammonium sulphide, hydrogen sulfide and water. Neptune has a ring system, but it is much less prominent than Saturn’s.

Neptune has a much more active weather system than Uranus with many clouds and storms. The planet exhibits many similar features to those found on Jupiter, including its own great dark spot. The winds are thought to even reach speeds of up to 600 m/s, near supersonic speeds. The great dark spot was discovered in 1989 by the Voyager 2 probe. There are many other similar but smaller storms present on Neptune.

The ice giant has many moons but only one is large enough to be spherical, Triton, which orbits in the opposite direction to Neptune’s orbit, a unique property among the moons of the Solar System. Because of this it is believed that Triton is a captured body from the Kupier belt, a huge asteroid belt surrounding the Solar System. Pluto is one of the largest objects in the belt, bodies present in the Kuiper belt are known as Plutinos.

The ice giants are the least explored planets in the Solar System, Voyager 2 visited in the late 80s gathering images and scientific data. Neither planet is considered a high priority for human visitation or colonisation due to their immense distances from Earth. Their moons do not lend themselves well to settlements and the Saturnian and Jovian moons have much more to offer.

Patrick is an expert Research and Travel consultant. His current interest is in Luton airport parking, Birmingham airport parking and Gatwick hotels.
Article Source: http://www.science.freearticledirectories.com

Why is Neptune Blue?

By Elena Athanasiou

Our First Close-Up View of Neptune

Though Neptune is so far away from the Earth that it only looks like a tiny faraway star when observed with binoculars, we have discovered that this planet is actually a startlingly brilliant blue celestial object upon closer inspection. When Voyager 2 flew by Neptune in 1989 (twelve whole years after it was originally launched from Earth in 1977), we got our first glimpse of the planet, revealing it to be a brilliant blue. So, what gives Neptune its blue color? We must first clarify what we are actually seeing and we also must know exactly what to analyze to discover the answer.

What We Are Actually Seeing

When we see the planets in the night sky, we are actually viewing the light from the sun that is reflecting off of them. Therefore, we can ascertain that we are seeing reflected sunlight off of Neptune. But, why does this reflected light appear blue and not yellow like the sun's light normally looks?

Where Do We Look?

The answer to why Neptune is blue lies within Neptune's atmosphere, which merges into its liquid mantle. More specifically, we must examine the components of its outer atmosphere to find out the solution to our question. What do the high cloud tops of Neptune's atmosphere reveal?

Unveiling Neptune's Atmosphere

There are three major gases that make up Neptune's atmosphere: hydrogen, helium, and methane (along with trace amounts of water and ice particles). While hydrogen and helium make up about 99% of its atmosphere, it is the remaining roughly 1% of methane that is important. The presence of methane is why Neptune appears blue.

What Does This Methane Do?

These icy methane particles in the clouds take the red and orange light waves and absorb them, leaving the blue light waves to escape and reflect outward to our eyes. This is how the sunlight is reflected off of Neptune's atmosphere and appears blue.

Conclusion

Why is Neptune blue? We've seen that after the sun's light reaches Neptune, the methane in the atmosphere of Neptune absorbs the red end of the spectrum's light waves, allowing only the blue light to be reflected back towards Earth.

Article Source: http://EzineArticles.com/?expert=Elena_Athanasiou
http://EzineArticles.com/?Why-is-Neptune-Blue?&id=2795309