SpaceJibe

September 29, 2009

Out There: Water, Water EVERYWHERE !

Water water EVERYWHERE !

Water water EVERYWHERE !

It’s now official that water has been found on the moon, and scientists have long seen it on Mars as well. In fact, water is all over the solar system and the rest of the galaxy – and since water is key to life as we know it, these discoveries raise the hope that we are not in fact alone.

The inner planets

Although the moon remains drier than any desert on Earth, new observations from three different spacecraft have uncovered what has been called “unambiguous evidence” of water across the surface of the moon.

On Mars, giant cracks were recently found etched across crater basins that hinted at ancient lakes, and liquid water is thought to have been common across a vast region of ancient Mars billions of years ago. Craters recently even revealed that more water ice is buried closer to the red planet’s equator than would be expected, “which implies there was more water in the atmosphere of Mars in the not too distant past,” explained Michael Meyer, lead scientist for NASA’s Mars Exploration Program.

But liquid and frozen water are not limited to Earth’s closest neighbors in space.

Even hellish Venus may once have been lush with oceans. Although space probes in the 1960s found the surface of Venus was now hot enough to melt lead, images collected from the European Space Agency’s Venus Express spacecraft suggest hints of past oceans. A runaway greenhouse effect – a far magnified version of the global warming seen occurring on Earth – apparently led its seas to evaporate away. “Its water, by absorbing heat, might have actually helped contribute to its greenhouse warming,” Meyer said.

The outer worlds and beyond

Most moons of the solar system’s gas giants are also rich in water.

  • On Saturn’s moon Titan, “cryovolcanoes” are thought to erupt with cold slurries of water ice and ammonia.
  • Another Saturnian moon, Enceladus, is thought to have an ocean beneath its icy shell that likely feeds jets of water ice seen spurting from that moon.
  • Jupiter’s moons Ganymede, Callisto and Europa, Neptune’s Triton and the Uranian moons Titania and Oberon are also thought to potentially harbor hidden seas.

The outer worlds themselves are rather icy. Neptune and Uranus are often dubbed “ice giants” because they are rich with water, ammonia, and methane. Pluto is thought to consist roughly of 30 percent water ice. Beyond them lie the Kuiper Belt, Oort Cloud and the scattered disk, home to untold numbers of comets and icy dwarf planets such as Eris.

In fact, water is often found as ice or gas around stars and in the clouds between them. Signs of water have even been seen on planets outside our solar system.

What does it mean?

The fact that water is so water is abundant should not be such a surprise. “Water is ridiculously common, one of the most common molecules in the universe,” said Nicolas Cowan, an astronomer and astrobiologist at the University of Washington in Seattle.

What seems rare is finding water in liquid form. In space, it either vaporizes if it is too hot or freezes if it is too cold .

“The only time you ever find it stable as a liquid is when you get enough atmosphere down to provide enough pressure to keep it liquid,” Cowan explained.

Scientists looking for aliens consider liquid water “the Holy Grail, the thing that people really want to find,” Cowan said. “Water is the main requirement we can see that life on Earth seems to have.” Although life also needs a source of energy of some kind, in many ways, “you don’t have to worry too much about that,” Meyer added, since Earth shows that life can live off many different kinds of energy, from the sun or heat or chemicals.

Other life forms

Of course, alien life might not require water at all. Although it makes sense for life to require carbon, “since carbon chemistry is amazingly complex, affording one the opportunity to become complex enough to start life,” Meyer explained, “you could have a liquid medium for carbon-based chemistry besides water – ammonia, for instance.”

The most exciting aspect of the water that researchers are uncovering in the solar system might be how it can support humanity, not aliens.

“If we find water in sufficient quantities that it makes sense for us to use it, we can go to there and make rocket fuel out of it by separating hydrogen from oxygen, make use of resources in situ rather than shipping everything from Earth,” Meyer said.

Still, don’t rule out extraterrestrial life in the solar system. All the water discovered on Mars is challenging what scientists know of the red planet – enough perhaps to “dream up scenarios where the surface of Mars was a more habitable place in the distant past, with critters retreating to the subsurface to still live,” Cowan noted.

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Magnetic Fields Guide Star Birth

Filed under: Cosmology — bferrari @ 9:39 am
Magnetic Fields effect starbirth

Magnetic Fields effect starbirth

The picture of star formation just got a little more complicated: Cosmic magnetic fields, which can channel condensing interstellar gas, play a more important role in the birth of stars that previously thought, a new study suggests.

The simplified story of stellar birth involves giant clouds of gas and dust collapsing inward due to gravity, growing denser and hotter until nuclear fusion ignites a newborn star.

But in reality, there’s much more to the story: When a molecular cloud collapses, only a small fraction of the cloud’s material forms stars, and scientists haven’t been sure why that is.

Since gravity favors star formation because it draws material together, some other force must be hindering the process, scientists reason. The two leading candidates are turbulence and magnetic fields.

Magnetic fields (produced by moving electrical charges and present around stars and most planets, including Earth) channel flowing gas, making it hard to draw the gas in from all directions. Turbulence stirs the gas and induces and outward pressure that counteracts gravity.

“The relative importance of magnetic fields versus turbulence is a matter of much debate,” said astronomer Hua-bai Li of the Harvard-Smithsonian Center for Astrophysics. “Our findings serve as the first observational constraint on this issue.”

Li and his team studied 25 dense patches, or cloud cores, each one about a light-year in size. The cores, which act as seeds from which stars form, were located within molecular clouds as much as 6,500 light-years from Earth. (A light-year is the distance light travels in a year, or 6 trillion miles.)

The researchers studied polarized light, which has electric and magnetic components that are aligned in specific directions. From the polarization, they measured the magnetic fields within each cloud core and compared them to the fields in the surrounding, tenuous nebula.

The magnetic fields tended to line up in the same direction, even though the relative size scales (1 light-year cores versus 1,000 light-year nebulas) and densities were different by orders of magnitude. Since turbulence would tend to churn the nebula and mix up magnetic field directions, their findings show that magnetic fields dominate turbulence in influencing star birth.

“Our result shows that molecular cloud cores located near each other are connected not only by gravity but also by magnetic fields,” Li said. “This shows that computer simulations modeling star formation must take strong magnetic fields into account.”

The study will be detailed in an upcoming issue of the Astrophysical Journal.

Source

September 23, 2009

India’s Lunar Mission Finds Evidence of Water on the Moon

Filed under: Extraterrestrial Life, Inner Solar System, Moons — bferrari @ 5:54 pm
Indian probe discovers water on the moon!

Indian probe discovers water on the moon!

Dreams of establishing a manned Moon base could become reality within two decades after India’s first lunar mission found evidence of large quantities of water on its surface.

Data from Chandrayaan-1 also suggests that water is still being formed on the Moon. Scientists said the breakthrough — to be announced by Nasa at a press conference today — would change the face of lunar exploration.

The discovery is a significant boost for India in its space race against China. Dr Mylswamy Annadurai, the mission’s project director at the Indian Space Research Organisation in Bangalore, said: “It’s very satisfying.”

The search for water was one of the mission’s main objectives, but it was a surprise nonetheless, scientists said.The unmanned craft was equipped with Nasa’s Moon Mineralogy Mapper, designed specifically to search for water by picking up the electromagnetic radiation emitted by minerals. The M3 also made the unexpected discovery that water may still be forming on the surface of the Moon, according to scientists familiar with the mission.

“It’s very satisfying,” said Dr Mylswamy Annadurai, the project director of Chandrayaan-1 at the Indian Space Research Organisation (ISRO) in Bangalore. “This was one of the main objectives of Chandrayaan-1, to find evidence of water on the Moon,” he told The Times.

Dr Annadurai would not provide any further details before a news conference at Nasa today from Dr Carle Pieters, a planetary geologist of Brown University who oversaw the M3.

Dr Pieters has not spoken about her results so far and was not available for comment last night, according to colleagues at Brown University. But her results are expected to cause a sensation, and to set the agenda for lunar exploration in the next decade.

They will also provide a significant boost for India as it tries to catch up with China in what many see as a 21st-century space race. “This will create a considerable stir. It was wholly unexpected,” said one scientist also involved in Chandrayaan-1. “People thought that Chandrayaan was just lagging behind the rest but the science that’s coming out, it’s going to be agenda-setting.”

Scientists have long hoped that astronauts could be based on the Moon and use water found there to drink, extract oxygen to breathe and use hydrogen as fuel.

Several studies havesuggested that there could be ice in the craters around the Moon’s poles, but scientists have been unable to confirm the suspicions.

The M3, an imaging spectrometer, was designed to search for water by detecting the electromagnetic radiation given off by different minerals on and just below the surface of the Moon. Unlike previous lunar spectrometers, it was sensitive enough to detect the presence of small amounts of water.

M3 was one of two Nasa instruments among 11 pieces of equipment from around the world on Chandrayaan-1, which was launched into orbit around the Moon in October last year. ISRO lost control of Chandrayaan-1 last month, and aborted the mission ahead of schedule, but not before M3 and the other instruments had beamed data back to Earth.

Another lunar scientist familiar with the findings said: “This is the most exciting breakthrough in at least a decade. And it will probably change the face of lunar exploration for the next decade.”

Scientists are eagerly awaiting the results of two American unmanned lunar missions, which were both launched in June, that could also prove the existence of water on the Moon.

Early results from Nasa’s Lunar Reconnaissance Orbiter (LRO) recorded temperatures as low as -238C (minus 396.4F) in polar craters on the Moon, according to the journal Nature. That makes them the coldest recorded spots in the solar system, even colder than the surface of Pluto, and could mean that ice has been trapped for billions of years, the journal said. The LRO has also detected an abundance of hydrogen, thought to be a key indicator of ice, at the poles.

The other Nasa mission, the Lunar Crater Observation and Sensing Satellite (LCROSS), is due to crash a probe into a polar crater on October 9 in the hope of sending up a plume of ice that can be examined by telescope.

“We are on the verge of a renaissance in our thinking about the poles of the Moon, including how water ice gets there,” Anthony Colaprete, principal investigator for LCROSS, said in Nature.

Big bang

• The Moon is 4.6 billion years old, about the same age as the Earth

• It is thought to have formed from a giant dust cloud caused when a rogue planet collided with the Earth

• It is 238,000 miles from the Earth

• Gravity on the Moon is a sixth of that on Earth

Source

September 15, 2009

Biggest Black Hole Ever Found in Nearby Galaxy

Filed under: Black Holes, Outer Solar System, Supernova — bferrari @ 11:30 am
Most massive blackhole ever!

Most massive blackhole ever!

PASADENA, Calif. —  The most massive black hole yet weighed lurks at the heart of the relatively nearby giant galaxy M87.

The supermassive black hole is two to three times heftier than previously thought, a new model showed, weighing in at a whopping 6.4 billion times the mass of the sun.

The new measure suggests that other black holes in nearby large galaxies could also be much heftier than current measurements suggest, and it could help astronomers solve a longstanding puzzle about galaxy development.

“We did not expect it at all,” said team member Karl Gebhardt of the University of Texas at Austin.

The discovery was announced Monday at the 214th meeting of the American Astronomical Society.

Game changer

The finding “is important for how black holes relate to galaxies,” said team member Jens Thomas of the Max Planck Institute for Extraterrestrial Physics in Germany. “If you change the mass of the black hole, you change how the black hole relates to the galaxy.”

Because of this relationship, the revised mass could impact astronomers’ theories of how galaxies grow and form.

Higher black hole masses could also solve a paradox of the masses of faraway, developing galaxies called quasars.

These mysterious denizens of the early universe are very bright, developing galaxies with black holes surrounded by gas and dust, all rife with star formation.

Quasars are colossal, around 10 billion solar masses, “but in local galaxies, we never saw black holes that massive, not nearly,” Gebhardt said.

“The suspicion was before that the quasar masses were wrong,” he said. But “if we increase the mass of M87 two or three times, the problem almost goes away.”

Why M87 matters

M87 is 50 million light-years away. Nearly three decades ago, it was one of the first galaxies suggested to harbor a central black hole.

Now astronomers think that most large galaxies, including our own Milky Way, have supermassive black holes at their centers.

M87 also has an active jet shooting light out of the galaxy’s core, created where matter swirls closer to the black hole and approaches the speed of light, then combines with tremendous magnetic fields.

The spat-out material helps astronomers understand how black holes attract and gobble up matter, a sloppy process in which all is not consumed.

These factors make M87 “the anchor for supermassive black hole studies,” Gebhardt said.

While the new mass of M87 is based on a model, recent observations from the Gemini North Telescope in Hawaii and the European Southern Observatory’s Very Large Telescope in Chile support the model findings.

The study of M87’s mass will also be detailed later this summer in the journal Astrophysical Journal.

Source

Nearby Star May Be Getting Ready to Explode

Filed under: Black Holes, Gamma Ray Bursts, Outer Solar System, Supernova — bferrari @ 11:26 am
Ready to go Nova !?

Ready to go Nova !?

Bye-bye, Betelgeuse?

The nearby, well-known and very bright star may soon explode in a supernova, according to data released by U.C. Berkeley researchers Tuesday.

The red giant Betelgeuse, once so large it would reach out to Jupiter’s orbit if placed in our own solar system, has shrunk by 15 percent over the past decade in a half, although it’s just as bright as it’s ever been.

“To see this change is very striking,” said retired Berkeley physics professor Charles Townes, who won the 1964 Nobel Prize for inventing the laser. “We will be watching it carefully over the next few years to see if it will keep contracting or will go back up in size.”

Betelgeuse, whose name derives from Arabic, is easily visible in the constellation Orion. It gave Michael Keaton’s character his name in the movie “Beetlejuice” and was the home system of Galactic President Zaphod Beeblebrox in “The Hitchhiker’s Guide to the Galaxy.”

Red giant stars are thought to have short, complicated and violent lifespans. Lasting at most a few million years, they quickly burn out their hydrogen fuel and then switch to helium, carbon and other elements in a series of partial collapses, refuelings and restarts.

Betelgeuse, which is thought to be reaching the end of its lifespan, may be experiencing one of those collapses as it switches from one element to another as nuclear-fusion fuel.

“We do not know why the star is shrinking,” said Townes’ Berkeley colleague Edward Wishnow. “Considering all that we know about galaxies and the distant universe, there are still lots of things we don’t know about stars, including what happens as red giants near the ends of their lives.”

Eventually, the huge star may become a nesting doll of elements, with a mixed iron-nickel core surrounded by onion-like layers of silicon, oxygen, neon, carbon, helium and hydrogen.

As the iron fuel runs out, it may explode into a supernova, blasting newly created elements out into the universe and leaving behind a small, incredibly dense neutron star.

All the heavier elements in the universe — including all the oxygen, carbon and iron in your own body — were created in such a way.

It’s possible we’re observing the beginning of Betelgeuse’s final collapse now.

If so, the star, which is 600 light-years away, will already have exploded — and we’ll soon be in for a spectacular, and perfectly safe, interstellar fireworks show.

• Click here for the U.C. Berkeley press release.

• Click here for an explanation of how that means Betelgeuse may be ready to blow.

Source

September 9, 2009

Star Trek and a New State of Matter: Transparent Aluminum

Filed under: Black Holes, Gadgets, Hollywood, Wierd — bferrari @ 1:45 pm

Hello Computer...

Hello Computer...

Scientists claim to have created a form of aluminum that’s nearly transparent to extreme ultraviolet radiation and which is a new state of matter.

It’s an idea straight out of science fiction, featured in the movie “Star Trek IV.”

The work is detailed in the journal Nature Physics.

The normal states of matter are solid, liquid and gas, and a fourth state, called plasma, is a superheated gas considered more exotic. Other experiments have created strange states of matter for brief periods. This one, too, existed only briefly.

To create the new, even more exotic stuff, a short pulse from a laser “knocked out” a core electron from every aluminum atom in a sample without disrupting the metal’s crystalline structure, the researchers explain.

”What we have created is a completely new state of matter nobody has seen before,” said professor Justin Wark of Oxford University’s Department of Physics.

“Transparent aluminum is just the start,” Wark said. “The physical properties of the matter we are creating are relevant to the conditions inside large planets, and we also hope that by studying it we can gain a greater understanding of what is going on during the creation of ‘miniature stars’ created by high-power laser implosions, which may one day allow the power of nuclear fusion to be harnessed here on Earth.”

Fusion is a dream of scientists who would create cheap and plentiful power by fusing atoms together, as opposed to nuclear fission that generates electricity today.

The discovery was made possible with a high-powered synchrotron radiation generator called the FLASH laser, based in Hamburg, Germany. It produces extremely brief pulses of soft X-ray light, each of which is more powerful than the output of a power plant that provides electricity to a whole city.

The Oxford team, along with their international colleagues, focused all this power down into a spot with a diameter less than a twentieth of the width of a human hair. At such high intensities the aluminum turned transparent.

While the invisible effect lasted for only an extremely brief period – an estimated 40 femtoseconds – it demonstrates that such an exotic state of matter can be created using very high power X-ray sources.

“What is particularly remarkable about our experiment is that we have turned ordinary aluminum into this exotic new material in a single step by using this very powerful laser,” Wark said. “For a brief period the sample looks and behaves in every way like a new form of matter. In certain respects, the way it reacts is as though we had changed every aluminum atom into silicon: it’s almost as surprising as finding that you can turn lead into gold with light.”

Source

From: Glynn, Melanie
Sent: Wednesday, September 09, 2009 12:43 PM
To: Ferrari, Robert; Lowe, Russ; Seigel, Harold
Cc: Steven Knauff
Subject: RE: Still

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