Clipmarks | wildcat's space, astronomy, collection

Transistors in Space

Mon, 04 Aug 2008 10:17:53 GMT

clipped by: wildcat
clipper's remarks: NASA tests new radiation-proof chips

Space Test: New radiation-resistant transistors, attached to the International Space Station for evaluation, orbit Earth.

Mission planners for future flights to the moon, Mars, and beyond rightly worry about how to keep astronauts safe from the hazards of high-energy protons, neutrons, and ions streaming through space. These particles can cause cancer and brain damage, but they can be just as damaging to a spacecraft's electronics.

NASA is now testing how well a new type of transistor, shown to be radiation-resistant on Earth, will hold up in space. The transistors went up on the space shuttle Endeavor, and astronauts placed them in a test setup on the outside of the International Space Station on 22 March. After a year, researchers will check how radiation affects the transistors' operating voltages and currents.

A typical transistor is made up of a gate separated from the channel between the source and the drain by an insulating dielectric, usually silicon dioxide

Tags: nasa, radiation-proof, chips, space

Solar Sailing in Space

Fri, 25 Jul 2008 12:40:09 GMT

clipped by: wildcat
clipper's remarks: The concept of solar sailing was invented in the 1920s by two Russian scientists, and it has been the subject of a few projects over the years, says Louis Friedman, the executive director of the Planetary Society, a public space organization based in Pasadena, CA

Clip Source: www.technologyreview.com

NASA prepares to test a satellite that can be propelled by light particles from the sun.

For the first time, NASA is preparing to send into orbit a small satellite that can be propelled by solar sails. When light particles from the sun strike the surface of the sail, the energy is transferred to it, providing a propulsive force that moves the satellite through space.

NASA's goal is to test the complex deployment mechanism of the 10-square-meter sails, says Dean Alhorn, an engineer at NASA's Marshall Space Flight Center, in Huntsville, AL, and the lead engineer on the project. "A successful flight will not only make for a unique historical event, but will show that we have a reliable mechanism to deploy a solar sail in space for future missions," says Alhorn.

The satellite, called NanoSail-D, is scheduled to launch from Omelek Island, in the Pacific Ocean, on July 29 onboard the Falcon 1 rocket

Tags: nasa, sattelite, light particles, solar sails

A New Take on Warping Spacetime

Fri, 25 Jul 2008 11:18:39 GMT

clipped by: wildcat
clipper's remarks: "I wouldn’t expect a warp drive breakthrough any time soon, but laying a theoretical basis for a technology has to be step one."

Clip Source: www.centauri-dreams.org

Miguel Alcubierre’s 1994 paper, which demonstrated that it would be possible — within the context of General Relativity — to envision a space drive that could get you to your destination in a time shorter than it would take light itself to get there. Contracting space in front of the craft while inflating it behind, the drive is permissible because the starship itself would not be going faster than light. Rather, the space around it would be moving in such a way as to make the trip possible.

And that’s the key — the speed of light stricture does not apply to spacetime itself. Can we learn how to generate a region of expanding spacetime and one of contracting spacetime?

The authors then turn to supersymmetry — the theory that all particles have an associated superparticle with a differing spin — to explore the question

they consider the cosmological constant in terms of higher dimensions, relating these first to the work of Theodore Kaluza, who suggested a fifth dimension in 1919

Tags: warp, space, time, general relativity, supersymmetry

Are We Living in a Giant Void?

Mon, 21 Jul 2008 12:54:55 GMT

clipped by: wildcat
clipper's remarks: Their theory posits that if in fact Earth and our surrounding neighbors are in fact in an unusual or special region of space, ie, a void, then our perspective on the universe would be severely challenged

Clip Source: www.dailygalaxy.com

As a science fiction fan, I have come across something that annoys me. There seem to be a limited number of things that can happen in a series, and episodes start repeating themselves from series to series. One such occurrence is the idea of a ship being trapped in a void of stars; being literally nowhere near another star, and thus, all in black.

This void, as most episodes are entitled, is similar to the descriptions that filter out of Antarctica. When explorers are traversing miles and miles of white, they begin to lose the ability to determine where they are, and if they are moving.

The idea of an astronomical void is not just science fiction fodder however, and rather, according to Timothy Clifton and colleagues Pedro G. Ferreira and Kate Land at the University of Oxford, a possible explanation for why it looks as if our universe is expanding at an accelerated pace.

It is no surprise that Clifton’s theories are speculative, but the best science always starts out that way

Tags: life, giant void, astronomy

NASA engineers work on alternative moon rocket

Tue, 15 Jul 2008 02:33:37 GMT

clipped by: wildcat

Clip Source: www.physorg.com

By day, the engineers work on NASA's new Ares moon rockets. By night, some go undercover to work on a competing design. These dissenting scientists and their backers insist they have created an alternative rocket that would be safer, cheaper and easier to build than the two Ares spacecraft that will replace the space shuttle.

They call their project Jupiter, and like Ares, it's a brainchild of workers at the Marshall Space Flight Center and other NASA facilities. The engineers involved are doing the work on their own time and mostly anonymously, with the help of retirees and other space enthusiasts.

A key Ares project manager dismisses their design as little more than a sketch on a napkin that won't work.

A spokesman for the competing effort, Ross Tierney, said concerned engineers at NASA and some contractors want a review of the Ares plans but can't speak out for fear of being demoted, transferred or fired.

Tags: nasa, alternative, moon rocket

Solar shades won't reverse global warming

Mon, 14 Jul 2008 10:54:12 GMT

clipped by: wildcat

Clip Source: www.abc.net.au

A proposal to place mirrors in the sky to reflect sunlight away from earth won't give back the climate we had before, says a new study.

Researchers at the University of Bristol in the United Kingdom applied global climate models to predict the effect of using reflective sunshades to reduce the amount of sunlight that enters the earth's atmosphere back.

They compared two future scenarios, both with CO2 levels four times the pre-industrial baseline. In one scenario nothing was done, and in the other, sunlight intensity was reduced to a level that would reduce the global average temperature to pre-industrial levels

The second scenario simulated the use of sunshades, which reduced sunlight by about 4.2%.

"Although we managed to cancel out warming on a global average, what you end up with is some areas that warm up and some that cool down," says Dr Dan Lunt, who led the study, published in Geophysical Research Letters .

Tags: solar shades, climate change, global warming

A Lake That Looks Like Mars

Mon, 14 Jul 2008 02:11:28 GMT

clipped by: wildcat

Clip Source: www.sciam.com

To see what extraterrestrial life might be like, scientists are busy studying freshwater coral reef–like structures in a Canadian lake

There's only so much you can do searching for extraterrestrial life when you're Earthbound. One approach is to locate and study the best terrestrial examples of what might resemble conditions that could support life on another planet.

View Slide Show Exploration of the Lake

That is exactly why astrobiologists are getting so excited about Pavilion Lake in British Columbia, Canada. Pavilion's lake floor is scattered with living coral reef–like structures called microbialites that result from microbes and minerals interacting over thousands of years. Although Pavilion's microbialites are believed to date back 11,000 years, they uncannily resemble structures that flourished on Earth some 540 million years ago.

Freshwater microbialites can be found in a handful of other places on Earth, but the diversity of structures at Pavilion is what sets it apart.

Tags: lake, extraterrestrial, life, canadian

The Anthropic Principle

Mon, 14 Jul 2008 01:48:32 GMT

clipped by: wildcat

Clip Source: www.physics.sfsu.edu

Has the universe developed for the express purpose of being observed and understood by intelligent beings, or is it just a lucky break for the intelligent beings that they exist at all?

The Anthropic Principle was proposed in Poland in 1973, during a special two-week series of synopsia commemorating Copernicus’s 500th birthday. It was proposed by Brandon Carter, who, on Copernicus’s birthday, had the audacity to proclaim that humanity did indeed hold a special place in the Universe, an assertion that is the exact opposite of Copernicus’s now universally accepted theory.

Carter was not, however, claiming that the Universe was our own personal playground, made specifically with humanity in mind. The version of the Anthropic Principle that he proposed that day, which is now referred to as the Weak Anthropic Principle (WAP) stated only that by our very existence as carbon-based intelligent creatures, we impose a sort of selection effect on the Universe

Tags: anthropic principle, human intelligence, universe

What Makes Earth Special Compared to Other Planets

Wed, 09 Jul 2008 11:10:09 GMT

clipped by: wildcat
clipper's remarks: "The most impressive attribute of the Earth is the existence and amount of liquid water on its surface,"

Clip Source: www.livescience.com

Earth is one special planet.

It has liquid water, plate tectonics, and an atmosphere that shelters it from the worst of the sun's rays. But many scientists agree our planet's most special feature might just be us.

"It's the only planet we know of that has life," said Alan Boss, a planet formation theorist at the Carnegie Institution of Washington in Washington, D.C.

Though other bodies in our solar system, such as Saturn's moon Titan, seem like they could have once been hospitable to some form of life, and scientists still have hope of eventually digging up microbes beneath the surface of Mars, Earth is still the only world known to support life.

"So far, we haven't found it anywhere else," said Alex Wolszczan of Pennsylvania State University, who co-discovered the first planets beyond our solar system. He agreed that life was Earth's single most impressive characteristic.

Tags: earth, us, water

Will the Future of Space Travel Be Driven by Entepreneurs or Nations?

Tue, 08 Jul 2008 13:04:41 GMT

clipped by: wildcat

Clip Source: www.dailygalaxy.com

Costa Rican-American physicist/rocket scientist Franklin Chang-Diaz is typical of the new breed of entrepreneurs driving the future of space travel. The future astronaut has some interesting insights on the kind of power and propulsion will need in order to truly colonize space. By his calculations, a trip to Mars could take as little as 39 days, and, with the development of nuclear powered travel, people could visit anywhere in the solar system within a few weeks. Chang-Diaz believes that these kinds of developments aren’t too far away.

I think lots of people are going to be moving into space. I think we will be populating the moon, building enclaves of research and even money-making ventures there. Just last month, Ad Astra signed an agreement with Excalibur Exploration Ltd., a British company, to mine asteroids [when the time is right]

I believe there will be a huge demand for resources, particularly water, from asteroids and comets

Tags: space travel, entrepreneurs, future

For Better or Worse, Sex in Space Is Inevitable

Tue, 08 Jul 2008 02:43:08 GMT

clipped by: wildcat

Clip Source: www.livescience.com

Weddings in space could be right around the corner, and experts figure the inevitable cosmic consummation will be just around the next corner.

The Japanese firm First Advantage and the U.S.-based private spaceflight firm Rocketplane Global, Inc., announced last week they will host weddings in space for about $2.3 million (240 million yen) apiece.

For all we know, sex in space has already taken place. But NASA officials aren't talking about that much.

Beyond space tourism as a platform for steamy shenanigans, space missions are the perfect petri dishes for close encounters, and this year NASA certainly has a busy flight schedule, with five missions planned. And more countries than ever are now venturing into space, with Japanese astronaut Koichi Wakata slated to become Japan's first long-duration space flyer this year and China gearing up for its first spacewalk scheduled for October.

Things will get even more interesting with future long-duration missions envisioned for the moon, Mars

Tags: space travel, sex, nasa

Life on Mars: What's The Truth?

Sun, 29 Jun 2008 10:48:31 GMT

clipped by: wildcat

Clip Source: www.efluxmedia.com

A Tufts University chemist who heads the team interpreting data gathered by the Phoenix lander's wet-chemistry lab alleges that the Martian soil in the area where NASA's contraption landed "seems very friendly" to simple forms of life.

Scientists are almost sure there is ice underneath the Red Planet's surface, and they say they found a lot of minerals which are the building blocks of organic life. However, the high concentration of minerals is not good news.

Back in February, NASA announced that it is very less likely that life on the fourth planet of the Sun was ever possible. Scientists said at the time that the high concentration of minerals constitutes a harsh environment even for the toughest microbes. The conclusion regarding the possibility of life on Mars in an extremely salty environment came after scientists conducted a series of experiments by simulating the Martian conditions.

Tags: mars, life, colony

Moonstream- for future missions

Thu, 26 Jun 2008 11:47:45 GMT

clipped by: wildcat

Clip Source: anthonysims.com

Tags: moonstream, nasa, design, trasnportation

Mars' two-faced riddle 'solved'

Thu, 26 Jun 2008 10:54:02 GMT

clipped by: wildcat

Clip Source: news.bbc.co.uk

The puzzle of why the northern and southern hemispheres of Mars look so different may now have been solved.

Mars' crust is thicker in the southern hemisphere, and magnetic anomalies are found in the south but not the north.

New studies in Nature magazine suggest that a massive space rock smashing into the planet could have created an abrupt disparity between the two halves.

This asteroid would have been close to the size of Earth's moon and hit Mars' northern regions, scientists say.

According to one group of researchers, the rock struck with an energy equivalent to one million billion atomic bombs like the one dropped on Nagasaki in 1945.

Mars' northern hemisphere is an enormous lowland basin which might once have held a mighty ocean.

The new research suggests Mars bears the largest impact scar known anywhere in the Solar System.

Tags: mars

The Odyssey astronomically accurate?

Tue, 24 Jun 2008 01:14:05 GMT

clipped by: wildcat

Clip Source: www.world-science.net

Scholars have long debated whether there are bits of truth to The Odyssey—the ancient Greek epic of a king’s long seafaring struggle to get home as he battles or outwits monsters.

Now, scientists say some of the celestial events mentioned in the tale might be accurate, raising the possibility that the story has more truth than suspected.

The researchers studied possible references to astronomical events in the poem, and matched them with calculations showing the order in which these must really have occurred. The match was excellent, the investigators say.

The catch: some of the poem’s purported astronomical references are symbolic only.

Among countless disputed details about the story, not the least whether it is all attributable to the poet Homer, is whether King Odysseus returns home to a total solar eclipse. The poet tells of a terrifying “night” in which the sun is “blotted out of the sky” on this day.

Tags: the odyssey, epic, astronomy