NASA Send Robotic Plane to Study Mars

NASA wants to send a super-fast robotic plane to study Mars As a general rule, when NASA flies a scientific mission all the way to Mars, we expect that mission to last for a while. For instance, the Spirit and Opportunity rovers were slated to run for three months and are still operating 6 years later. But one NASA engineer wants to send a mission all the way to the Red Planet that would last just two hours once deployed: a rocket-powered, robotic airplane that screams over the Martian landscape at more than 450 miles per hour.

ARES (Aerial Regional-Scale Environmental Surveyor) has been on the back burner for a while now, and while it's not the first Mars plane dreamed up by NASA it is the first one that very well might see some flight time over the Martian frontier. Flying at about a mile above the surface, it would sample the environment over a large swath of area and collect measurements over rough, mountainous parts of the Martian landscape that are inaccessible by ground-based rovers and also hard to observe from orbiters.

The Mars plane would most likely make its flight over the southern hemisphere, where regions of high magnetism in the crust and mountainous terrain have presented scientists with a lot of mystery and not much data. Enveloped in an aeroshell similar to the ones that deployed the rovers, ARES would detach from a carrier craft about 12 hours from the Martian surface. At about 20 miles up, the aeroshell would open, ARES would extend its folded wings and tail, and the rockets would fire. It sounds somewhat complicated, but compared with actually landing package full of sensitive scientific instruments on the surface deploying ARES is relatively simple.

The flight would only last for two hours, but during that short time ARES would cover more than 932 miles of previously unexplored territory, taking atmospheric measurements, looking for signs of water, collecting chemical sensing data, and studying crustal magnetism. Understanding the magnetic field in this region will tell researchers whether the magnetic fields there might shield the region of high-energy solar winds, which in turn has huge implications for future manned missions there.

The NASA team already has a half-scale prototype of ARES that has successfully performed deployment drills and wind tunnel tests that prove it will fly through the Martian atmosphere. The team is now preparing the tech for the next NASA Mars mission solicitation and expects to see it tearing through Martian skies by the end of the decade.

popsci And dvice

Secrets of the Ocean

Weird and wonderful creatures of the deep: Decade-long 'sea census' uncovers 6,000 new species of marine creature Now more than 250,000 different sea creatures beneath the waves

A 'riot of species' has been uncovered in the world's oceans by the most comprehensive survey ever conducted of life in the seas, scientists announced today.

But the decade-long Census of Marine Life, the first global attempt to map the wildlife of the oceans, showed many species - from turtles to seabirds and sharks - were in decline in the face of human activity.

Blind Lobster

A blind lobster with bizarre claws belonging to the very rare genus Thaumastochelopsis, previously known only from four specimens of two species in Australia

Dr Ian Poiner, chairman of the project's scientific steering committee said that, from the Poles to tropical waters and the deep sea, there was an abundance of life.

Many discoveries had been made of new life, with around 6,000 potential new species found by the project and the overall estimate of known marine species increasing from 230,000 to nearly 250,000.

One shrimp-like creature, known as Ceratonotus steiningeri, has several spikes and claws and looks intimidating. It was first discovered five years ago three miles beneath the surface off the Atlantic coast of Africa.

It was one of 800 species found in that research trip, said discoverer Pedro Martinez Arbizu, a department head at the German Centre for Marine Biodiversity Research.

He was astonished to find that the tiny creature also was within the cataloguing he'd made earlier 8,000 miles away in the central Pacific.

'We were really very, very surprised about that,' Arbizu said. 'We think this species has a very broad distribution area.'

But after a decade of work researchers warn they could still not reliably estimate the number of species in the oceans, and it is thought there could be at least a million species in the Earth's seas in total.

Some of the 'most beautiful and wonderful' species found in the decade of discovery included a Jurassic shrimp thought to have become extinct 50 million years ago and a crab named the Yeti crab.

The census also included genetically sequencing tiny microbes to tell them apart, and Dr Poiner said there could be as many as one billion different types in the ocean.

The project, which involved more than 2,700 scientists spending a total of 9,000 days at sea on more than 540 expeditions, also used new technology such as tagging fish to see where they were swimming, fitting seals with monitors to record data as they dived and acoustic systems which measured fish populations as large as Manhattan Island.

Discoveries included the revelation that North Atlantic tuna on the eastern US seaboard were the same fish as those off the coast of Spain or in the Mediterranean as they migrated across the ocean.

The census also showed life was found in the most inhospitable places, and was much more connected than previously thought, through genetic relationships between creatures, the movement of species around the oceans and the 'snow' of food falling from the upper layers of the sea into the deep.

Dr Poiner said: 'It's the first time we truly have a global census of marine life, and have a global baseline which we can use to monitor change in the future - be the changes fishing activity, development of emerging energy, extraction of oil and gas, impacts of climate change, warming oceans or oceans becoming much more acidic.'

The census also looked back in time, using historical records of fish catches, sightings and even restaurant menus and photographs of family fishing trips to see what had happened to our seas.

Dr Poiner said that while 'wherever we went, there was a riot of species', many creatures had suffered significant declines.

In some cases, populations had plummeted by 90% from historical baselines, and fish such as swordfish which were being caught now were also much smaller than in the past.

And creatures at the bottom of the food chain known as phytoplankton, near the surface had declined globally, analysis of observations from ocean-going vessels since 1899 showed.

Dr Poiner said: 'Sadly the seas have been changed much more than we expected, these changes occurred much earlier than we expected and occurred quite quickly.'

And he warned that while recoveries were possible, and had occurred in some cases, to restore the population of species such as whales or degraded habitat took much longer than it took to do the damage.

According to the research, numbers of some species have declined within a human generation.

It also revealed that people began catching marine creatures a long time ago and on a much broader scale than previously thought.

The census will not only provide a baseline for measuring change but is already producing data which can be used by policy makers around the globe to introduce conservation efforts and to govern the high seas.

Victor Gallardo from Chile, vice chairman of the scientific steering committee, said: 'A human census is used for many practical purposes, like government allocations of seats in a legislature, or funds for education or healthcare.

'Likewise, this ocean life inventory constitutes a true census which can guide conservation.'

The project has also generated a website, iobis.org, on which anyone can see the distribution of a species in the ocean from a giant database of names and 'addresses' of marine creatures.

And it reveals just how little we still know about the seas, as the Census database has no records at all for around a fifth of the oceans' volume, while vast areas have very few records.

A yeti crab

A hairy-clawed 'yeti crab' is seen in this picture taken in 2006

hydrothermal vent snail

A hydrothermal vent snail found in Suiyo Seamount at the Tokyo Hydrothermal Vent

leafy Seadragon

A leafy Seadragon, Phycodurus eques, which is camouflaged to resemble a piece of drifting seaweed

Polychaete Worm

A polychaete worm found at a whale fall at Sagami Bay, Japan at a depth of 925 metres

Tiny Copepod

A tiny copepod collected from the Atlantic abyss during the DIVA 2 cruise in February/March 2005

Squid Worm

A recently discovered species called a squidworm found in the Celebes sea in Southeast Asia

Ceratonotus steiningeri

The Ceratonotus steiningeri, that was first discovered 5,400 metres deep in the Angola Basin in 2006. Within a year it was also collected in the southeastern Atlantic, as well as as in the central Pacific Ocean

Census Map Show Seafloor Biomass

Census scientists used nearly 200 studies to estimate the biomass on the seafloor globally from bacteria through fish and other large animals. The yellow-to-red zones in the map show seafloor biomass reaching 3 to 10 grams of carbon per square metre

Dr Niel Bruce Studying Specimens

Dr Niel Bruce of the Museum of Tropical Queensland studying specimens in lighted aquarium on Lizard Island Reef in Australia as part of the census

Hair Washing And Massaging Robot

A HAIR washing robot that uses 3D imaging to map and "remember" a person's head for the perfect rinse has been unveiled.

The hi-tech device - designed to cater for Japan's growing elderly population - was built by electronics giant Panasonic.

The machine - which resembles a dentist's chair with a wash basin - performs a 3D scan, measuring and recording the exact shape of the head, in order to apply the ideal amount of pressure when it uses its 16 rubber fingers to wash the hair.

The prototype was shown off at the 37th International Home Care and Rehabilitation exhibition in Tokyo yesterday.

Panasonic said they created the robot to meet the needs of under-pressure workers at hospitals and healthcare facilities as Japan's "silver generation" continues to grow.

The firm added: "With 16 fingers, the robot washes hair and rinses the shampoo bubbles with the dexterity of human fingers.

"The robot's two arms scan the head three dimensionally as they move and measure and remember the head shape to apply just the right amount of pressure to each person when shampooing and massaging."

Source : The Sun

Human Powered Aircraft

Todd Reichert has achieved what's believed to be an aviation first. The University of Toronto PhD candidate built a human-powered aircraft with flapping wings which he hopes has set a world record.

Leonardo da Vinci, of Florence, dreamt of doing it. Todd Reichert, of the University of Toronto, actually did.

On Wednesday, Reichert, a PhD student at the U of T Institute for Aerospace Studies, announced he had completed the first continuous flight of a human-powered aircraft with birdlike flapping wings, a device known as an ornithopter.

The creation of a craft that would allow humans to fly like birds has captured the imagination of inventors for centuries, but few working models have been built. Da Vinci drew up sketches for a flying machine in 1485, but never made one.

“Some people just dream about flying, at night in their dreams. I do,” said David Greatrix, a professor of aerospace engineering at Ryerson University. “Even though we have flying airplanes, it’s not the same.”

Reichert’s ornithopter flight, which lasted 19.3 seconds and covered 145 metres, is the first entirely powered by a human being. “This is the last first in aviation, and in many ways the most significant one,” said James DeLaurier, who oversaw the project.

“It was unreal,” Reichert, 28, said in an interview.

The flying craft, named the Snowbird, weighs just under 43 kilograms and has a wing span of 32 metres, comparable to a Boeing 737, though its weight amounts to approximately that of the pillows onboard a commercial jet. The Snowbird is made of carbon fibre, foam and balsa wood.

It took Reichert and another graduate student, Cameron Robertson, over four years to make the craft, and cost $200,000.

DeLaurier, a retired Institute for Aerospace Studies professor who is one of the world’s leading experts on ornithopters, devoted his career to birdlike flight. In 2006, he built and flew a motorized ornithopter called the Flapper, another aviation first. But a purely human-powered craft was his life’s ambition.

“(Reichert’s) ornithopter has since landed, but I’m still hovering a couple feet off the ground. It was a moment that’s difficult to describe,” DeLaurier said.

Over the summer, Reichert lost eight kilograms, went on a special diet and trained daily, especially his leg muscles.

He took 65 test runs before the Aug. 2 flight date in Tottenham, Ont. “I didn’t sleep the night before the flight,” Reichert said. “My mind was just racing.”

A representative from the Fédération Aéronautique Internationale, the world body governing aeronautical records, was present to witness the event.

A tow line tugged the craft into the air and then released it, and the Snowbird was off to its history-making flight. “It was such a neat feeling . . . you kept pushing and it kept maintaining altitude,” Reichert said. “All of a sudden, it clicked and we were able to stay up there.”

The Snowbird works by pumping a set of pedals attached to pulleys and lines that bring down the wings in an elegant flapping motion, a feat that requires both engineering and physical prowess.

“He combined brilliance with athleticism,” DeLaurier said. Part of the team’s goal was to promote sustainable and efficient transportation.

Greatrix said he was impressed with the team. “I’ll give them full marks for persistence. It’s all very promising from an aerospace engineering viewpoint,” he said.

Reichert’s mother, Majel Vye, was thrilled. “This is awesome, he worked so so hard for this,” she said.

The team is in talks with the Canada Aviation and Space Museum in Ottawa to donate the Snowbird for display.







Source : Arbroath Via The Star

Spacecraft to Fly Into The Sun

Flying into the sun's corona is suicidal to be sure, but scientists want to find out how the sun's atmosphere is heated.

Why the sun's atmosphere is nearly 200 times hotter than its visible surface is a long-standing mystery. A new spacecraft, called Solar Probe Plus, aims to find some answers.

Flying directly into the sun's corona is a suicidal mission to be sure, but scientists and engineers at the Johns Hopkins University Applied Physics Lab in Baltimore, which is developing Solar Probe Plus for NASA, plan to keep the spacecraft alive as long as possible.

It's not going to be easy. For starters, the probe will need to withstand temperatures up to about 2,600 degrees Fahrenheit. Plus, its heat shield can't ablate, or boil away like the shields on capsules returning through Earth's atmosphere are designed to do. That would pollute the particles and measurements Solar Probe Plus is being dispatched to gather.

"The whole point of the mission is to do particle detection and in situ measurements. If you're measuring part of your shield that's not going to work," Andy Dantzler, Solar Probe Plus project manager at Johns Hopkins University, told Discovery News.

The spacecraft also needs to be extremely lightweight so that it can fly.

"You need a lot of speed to go against the direction of the Earth," said Dantzler.

Eight weeks after launch, Solar Probe Plus will arrive at the sun to begin the first of 24 orbits using flybys of Venus to gradually shrink its distance to the sun. Eventually, it will come as close as about 4 million miles, which is inside the orbit of Mercury and about eight times closer than any previous spacecraft.

NASA is in the process of reviewing proposals for instruments to be included on the probe, but the overall mission goals are to figure out the sun's heating mechanism and determine how it whips up the solar wind -- the continuous blast of charged particles that permeate the solar system and define its boundaries.

"We want to know what it is that accelerates the plasma," Dantzler said. "We know it has to do with magnetic fields, but we don't really know how that comes about."

Various incarnations of Solar Probe Plus have been at the top of solar physicists' wish lists for more than 50 years, but until recently the technical problems exceeded the available budget to solve them.

"Solar Probe will be an extraordinary and historic mission, exploring what is arguably the last region of the solar system to be visited by a spacecraft," a NASA science oversight team headed by David McComas with the Southwest Research Institute in Texas, wrote in a report recommending the mission.

In addition to answering some basic science questions, information gathered by Solar Probe Plus could have some practical impacts by helping to improve space weather forecasts. Solar storms and magnetic disturbances from the sun can disrupt satellites and radio transmission, as well as take out power grids on Earth.

"Right now, predicting space weather is kind of like trying to predict hurricanes without knowing the acceleration effects of the oceans. Without that, you really can't understand them at all," Dantzler said.

Solar Probe Plus, which will cost more than $1 billion, initially was to launch in 2015, but has been bumped to 2018 to spread out the cost. NASA is expected to select the probe's science instruments this month.

Source : Discovery News

Azurite

Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits. It is also known as Chessylite after the type locality at Northern Territory, Australia.. The mineral has been known since ancient times, and was mentioned in Pliny the Elder's Natural History under the Greek name kuanos and the Latin name caeruleum. The blue of azurite is exceptionally deep and clear, and for that reason the mineral has tended to be associated since antiquity with the deep blue color of low-humidity desert and winter skies. The modern English name of the mineral reflects this association, since both azurite and azure are derived via Arabic from the Persian lazhward (لاژورد), an area known for its deposits of another deep blue stone, lapis lazuli ("stone of azure").

A gorgeous Nummular-shaped specimen embedded in a matrix of kaolinized siltstone. From the Malbunka Copper Mine, Areyonga, Alice Springs, Gardiner Range.







Source :- tywkiwdbi

Massive Solar Storm Causes Aurora Lights

Aurora Borealis in Wisconsin

Massive Solar Storm Causes Aurora Lights in United States and Canada As scientists have already warned us, huge solar storm hit Earth’s atmosphere today. A few of extraordinary massive eruptions of the plasma on Sun’s surface have reached Earth today and thanks to that increased solar activity, residents in some areas of North America were able to see aurora lights in the sky.

NASA has announced that there were four strong eruptions on Sun which were directed straight to Earth. Luckily, our atmosphere as well as magnetic field has played well its role and absorbed the radiation.

Scientists have been predicting for a while that solar storms like this one could cause significant damage to satellites. Scientists are predicting that increased solar activity in next few years will be followed with a number of similar solar storms.

Aurora lights over Michigan, USA

Aurora lights over Michigan, USA

Solar storm light show over Saskaton, Canada

Source :- Incredible World

Top 10 Biggest Star Ever

Below is a Top 10 list of the largest known stars by radius (half of the diameter). The unit of measurement used is the radius of the Sun (approximately 695,500 kilometers, or 432,450 miles). The exact order of this list is not complete yet, nor is it completely well defined: There are sometime high uncertainties in derived values and sizes.The distances to most of these stars are uncertain to differing degrees and this uncertainty affects the size measurements.Several large stars have extended atmospheres, are embedded in mostly opaque dust shells or disks, and pulsate, such that determining their radii is not well defined. Estimates for VV Cephei A are especially uncertain.

1 :- VY Canis Majoris

VY Canis Majoris (VY CMa) is a red hypergiant star located in the constellation Canis Major. At between 1800 and 2100 solar radii (approx 2.7 billion km across or 1.7 billion miles), it is the largest known star and also one of the most luminous known. It is located about 1.5 kiloparsecs (4.6×1016 km) or about 4,900 light years away from Earth. Unlike most hypergiant stars, which occur in either binary or multiple star systems, VY CMa is a single star. It is categorized as a semiregular variable and has an estimated period of 2000 days

2 :- VV Cephei A

VV Cephei, also known as HD 208816, is an eclipsing binary star system located in the constellation Cepheus, At between 1,600–1,900 solar radii approximately 2,400 light years from Earth.

A red hypergiant fills the system's Roche lobe when closest to its companion blue star, the latter appearing to be on the main sequence. Matter flows from the red hypergiant onto the blue companion.

3 :- Mu Cephei

Mu Cephei also known as Herschel 's Garnet Star, is a red super giant star in the constellation Cepheus. At 1,550 solar radii It is one of the largest and most luminous stars known in the Milky Way. It appears garnet red and is given the spectral class of M2Ia.

4 :- WOH G64

WOH G64 is a red hypergiant in the Large Magellanic Cloud. With 2000 times the radius of the Sun . The size of WOH G64 At 1,540 solar radii is estimated at 2,785,000,000 km.

5 :- V354 Cephei

V354 Cephei is a red hypergiant star (pulsating variable star) located within the Milky Way. It is located approximately 9,000 light-years away from our Sun and is currently considered the fifth largest known star, with a radius estimate of 1520 times that of the Sun, or 1,057,160,000 km. Assuming the size estimate is correct, if it were placed in the center of our Solar System, it would extend to 7 AU (between the orbits of Jupiter and Saturn).

6 :- RW Cephei

RW Cephei is an M-class red hypergiant star in the constellation Cepheus. Six of the largest stars known, RW Cephei is estimated at 1,260–1,610 solar radii. RW Cephei, while nearly as large as the orbit of Jupiter, is not as large as other stars in the constellation of Cephus, namely V354 Cephei and VV Cephei A.

7 :- KW Sagittarii

KW Sagittarii is a red hypergiant, It is located approximately between 9,000-13,000 light-years away from our Sun. It is 1460 solar diameters, in fact Seven of the largest known stars, its luminosity is 370,000 times the Sun's. It is located in the constellation Sagittarius.

8 :- KY Cygni

KY Cygni is a red Super Giant star (spectral class M3m) located in the constellation Cygnus. It is Eight of the largest stars known, at about 1,420 times the Sun's diameter, and is also one of the most luminous, with about 300,000 times the Sun's luminosity. It is approximately 5,200 light-years away.

9 :- Betelgeuse (Alpha Orionis)

Betelgeuse is a semiregular variable star whose apparent magnitude ranges between 0.2 and 1.2, the most for any first magnitude star. It is the ninth brightest star in the night sky located around 640 light-years from Earth. Although given the Bayer designation Alpha Orionis (α Orionis / α Ori), Betelgeuse is but the second brightest star in the constellation Orion, outshone by Rigel (Beta Orionis) almost all the time. The star marks the upper right vertex of the Winter Triangle and center of the Winter Hexagon.

Classified as a red Super Giant, Betelgeuse is one of the largest and most luminous stars known. For comparison, if the star were at the center of our solar system its surface would extend past the orbit of Jupiter, wholly engulfing Mercury, Venus, the Earth and Mars. The angular diameter of Betelgeuse was first measured in 1920–1921 by Albert Abraham Michelson and Francis G. Pease using the 100 in (2.5 m) John D. Hooker astronomical interferometer telescope atop Mount Wilson Observatory.

Astronomers believe Betelgeuse is only 10 million years old, but has evolved rapidly because of its high mass. Due to its age, Betelgeuse is expected to explode as a supernova, possibly within the next millennium.

10 :- Antares (Alpha Scorpii)

Antares is a red Super Giant star in the Milky Way galaxy and the sixteenth brightest star in the nighttime sky (sometimes listed as fifteenth brightest, if the two brighter components of the Capella quadruple star system are counted as one star). Along with Aldebaran, Spica, and Regulus it is one of the four brightest stars near the ecliptic. Antares is a slow variable star with an average magnitude of +1.09.

Telenoid R1 Robot

World's Creepiest Telenoid R1 Robot Japanese Inventor develops the bald, Legless

Its pale torso is about the size of a small child, it has no legs and just stumps for arms.

For a man who has made his life's work coming up with increasingly creepy robots, Hiroshi Ishiguro has really outdone himself this time.

The Japanese roboticist has just unveiled his latest creation - a strange robotic creature called the Telenoid R1.

Ishiguro has, in the past, tried to exactly replicate living humans and once developed an eerie robot replica of himself that he named Geminoid HI-1.

He also came up with a terrifyingly lifelike female robot called the Gemnoid F.

But the new Telenoid is something of a departure for the eccentric inventor.

Ishiguro designed the Telenoid R1 to be a robot that could appear like many different ages and that is easily transportable.

It is intended to be used as a communication device so that people can 'chat' from long distances: the robot is supposed to be able toe transmit the presence' of a person from a distant place.

To operate, the user must sit at a computer with a webcam that tracks the user's movements and captures their voice.

Actuator's in the robot's body help it to move in a realistic way.

These movements are then mimicked by the Telenoid which is sitting with the message's recipient.

The Telenoid R1 will be demonstrated at this year's Ars Electronica festival in Linz, Austria.

Ishiguro says: 'The unique appearance may be eerie when we first see it. However, once we communicate with others by using the telenoid, we can adapt to it.

'If a friend speaks from the telenoid, we can imagine the friend’s face on the telenoid’s face.

'If we embrace it, we have the feeling, that we embrace the friend.'

A commercial version of the Telenoid will go on sale later this year for about £5,000.

Crab Robot

The Crab Robot (Cybernetic Autonomous Remote Barricade) Droid, is a revolutionary robotic sentry system designed by Jamie Martin.
"Robot design, modelling and animation by Jamie Martin. Modelled and animated in Maxon Cinema 4D. Edited in Final Cut Pro."
"Policing has been revolutionised with the introduction of the C.R.A.B. robotic sentry system, due to soon be trialled live on the streets of London, England.
The advanced robotics technology behind the C.R.A.B.’s artificial intelligence have been secretly developed over the past 12 years as a joint venture between weapons manufacturer Dalton/Stanley and megacorporation Omni Consumer Products.
The results of their historical collaboration has been to produce the most advanced robotic defence system ever constructed, featuring next-generation weaponry and armour protection. The C.R.A.B. is set to pave the way for all future Police and Military automaton technology from here onwards, and will be found on patrol in the public domain very soon.







Source :- Jamie Martin Design

The biggest star ever discovered

A huge star in a neighboring galaxy could be the biggest and Largest star ever discovered.

Scientists say it is hundreds of times more massive than the sun and is twice as big as any other star previously discovered.

Astronomers discovered the star by using the European Space Observatory's Telescope, which is located in Chile's Atacama Desert.

The star has a mass of about 265 times that of the sun and is just over a million years old.

Scientists have predicted surface temperatures can surpass 40,000 degrees Celsius. That's seven times hotter and several million times brighter than the sun.

Dr. Richard Parker, Scientist Shefield University, said, "It's incredibly significant. Until recently people assumed that there was a fundamental upper limit to how massive a star could be and that upper limit was 150 times the mass of our own sun, which in itself is quite large."

The star is part of a cluster of massive stars in the Tarantula Nebula, which is a sprawling cloud of gas and dust in a galaxy, about 165,000 light-years away from the Milky Way.

stephen hawking aliens

British world-renowned theoretical physicist Stephen hawking alien life has Narratived that how alien creatures may look like in his mind for a new Discovery Channel video documentary series: "Into the Universe," according to reports of Courier Mail News.

Hawking, 68, pointed out that the universe has 100 billion galaxies, each with hundreds of millions of stars, and that in such a huge place Earth is unlikely to be the only planet where life has evolved.

"To my mathematical brain, the numbers alone make thinking about aliens perfectly rational," he said. "The real challenge is to work out what aliens might actually be like."

Stephen hawking suggested that extraterrestrials exist not just on planets but also in many other parts of the universe, perhaps in the center of stars or even floating in space.

"If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans," Hawking warned in the documentary.

Hawking also suggested that while most aliens are probably microorganisms or simple animals some could be intelligent and pose a threat to humanity.

His views are expressed in a new documentary made for the Discovery Channel. In it he points out that the universe has more than 100 billion galaxies, each containing hundreds of millions of stars. In such circumstances, Earth is unlikely to be the only planet where life has evolved, Hawking claims.

While many forms of life may be little more than microbes, Hawking says a few life forms could be intelligent and pose a threat to the human race. Aliens might simply raid Earth for its resources and then move on.

"We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet. I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and settle as a colony whatever planets they can reach," Hawking says.

"If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didn’t turn out very well for the Native Americans," the scientist says. While there may be benign aliens out there, Hawking says trying to make contact is "a little too risky".

It took three years to complete the documentary which was a major challenge as well as a triumph for 68 year old Hawking who is Paralysed by motor Neurone disease and has very limited powers of communication.

John Smithson, executive producer for Discovery, said, "He wanted to make a Program that was entertaining for a general audience as well as scientific and that’s a tough job, given the complexity of the ideas involved." 'Into The Universe with Stephen Hawking' started on the Discovery Channel yesterday [Sunday April 25]. The broadcaster has described the Program as a new kind of cosmology series.

"It takes the world's most famous scientific mind and sets it free, powered by the limitless possibilities of computer animation. Hawking gives us the ultimate guide to the universe, a ripping yarn based on real science, spanning the whole of space and time -- from the nature of the universe itself, to the chances of alien life, and the real possibility of time travel."

Galaxy Merger

Galaxy mergers can occur when two (or more) galaxies collide. They are the most violent type of galaxy interaction. Although galaxy mergers do not involve stars or star systems actually colliding, due to the vast distances between stars in most circumstances, the gravitational interactions between galaxies and the friction between the gas and dust have major effects on the galaxies involved. The exact effects of such mergers depend on a wide variety of parameters such as collision angles, speeds, and relative size/composition, and are currently an extremely active area of research. There are some generally accepted results, however:

* When one of the galaxies is significantly larger than the other, the larger will often "eat" the smaller, absorbing most of its gas and stars with little other major effect on the larger galaxy. Our home galaxy, the Milky Way, is thought to be currently absorbing smaller galaxies in this fashion, such as the Canis Major Dwarf Galaxy, and possibly the Magellanic Clouds. The Virgo Stellar Stream is thought to be the remains of a dwarf galaxy that has been mostly merged with the Milky Way.

* If two spiral galaxies that are approximately the same size collide at appropriate angles and speeds, they will likely merge in a fashion that drives away much of the dust and gas through a variety of feedback mechanisms that often include a stage in which there are active galactic nuclei. This is thought to be the driving force behind many quasars. The end result is an elliptical galaxy, and many astronomers hypothesize that this is the primary mechanism that creates ellipticals.

Note that the Milky Way and the Andromeda Galaxy will probably collide in about 4.5 billion years. If these galaxies merged, the result would quite possibly be an elliptical galaxy as described above.

One of the largest galaxy mergers ever observed consisted of four elliptical galaxies in the cluster CL0958+4702. It may form one of the largest galaxies in the Universe.

Galaxy mergers can be simulated in computers, to learn more about galaxy formation. Galaxy pairs initially of any morphological type can be followed, taking into account all gravitational forces, and also the hydrodynamics and dissipation of the interstellar gas, the star formation out of the gas, and the energy and mass released back in the interstellar medium by supernovae.






Video & Source on mvnm via Youtube