- Spacecraft Finishes Mapping Cosmic Microwave Background
- Unicorn Nebula Sparkles in Infrared
- True Earth: The Real, Bluer Marble
- Video: Ghostly Steam Devils on Wisconsin Lake
- Hopping Mars Rover Could Be Superfast Explorer
- Exclusive: First Autistic Presidential Appointee Speaks Out
- 200 New Species of Frogs, Spiders, Mammals and More Discovered
- Nobel Worthy: Best Graphene Close-Ups
- Top 10 Deep-Space Photos From Infrared Telescope’s Final Days
- Retrograde Planets Could Survive Around Binary Stars
Posted: 06 Oct 2010 04:39 PM PDT
After nine years of plotting the oldest light in the universe, the Wilkinson Microwave Anisotropy Probe has shut down. The satellite, which single-handedly helped establish the standard model of cosmology, took its last look at the cosmos Aug. 20, and settled into a final parking orbit around the sun Sept. 8.
WMAP launched June 30, 2001, with the goal of sensing subtle temperature differences in the cosmic microwave background, the glow of the first atoms to release their radiation 380,000 years after the Big Bang. Since then, it has provided the most accurate measurement of the age of the universe, proved the existence of dark energy, showed that just 4 percent of the universe is made of ordinary matter and supported the idea that the universe inflated from sub-atomic scale to the size of a soccer ball in its first trillionth of a second.
"It's gone way beyond what I imagined, things I didn't even think about at the time," said cosmologist Charles Bennett of Johns Hopkins University, WMAP's principal investigator.
Before WMAP, much of the universe's history was a blank book. Astronomers had some idea that the universe started with a Big Bang sometime between 8 billion and 20 billion years ago, and rapidly expanded after that. But they had very little notion of exactly when, or exactly how.
"WMAP added an extraordinary amount in terms of nailing things down," Bennett said. Astronomers now know that the universe is 13.75 billion years old, give or take 0.11 billion years, a measurement that was recognized in the Guinness Book of World Records as the "most accurate measure of the age of the universe."
The components of the universe were largely mysterious, too. A study of supernovas suggested in 1998 that the expansion of the universe was accelerating. Some cosmologists blamed a mysterious substance dubbed dark energy for shoving the universe outward, but many were skeptical.
"When the WMAP results first came out in 2003, it really made believers of everybody," Bennett said. By comparing computer models of what hypothetical universes with different compositions should look like to WMAP's view of the actual universe, the team of cosmologists proved that 73 percent of the universe is made of dark energy, 22.4 percent is dark matter and just 4.6 percent is the regular, visible matter that makes up stars, planets and people.
"It was almost miraculous," Bennett said. "All of a sudden, in one fell swoop, we suddenly had all these numbers: the density of atoms, the density of dark energy, the age of the universe, when the first stars formed, the distance light has traveled to get to us…. It was just really stunning to suddenly have all this fall into place."
WMAP takes a direct image of the remnant glow of the early universe. This light has been losing energy and stretching out over the last 13.75 billion years, so by the time it reached the WMAP probe in its orbit between the Earth and the sun, the light was detectable as meters-long microwaves.
The tiny hot spots in this cosmic microwave background are primordial lumps of matter that ultimately grew into the stars and galaxies visible today.
The fact that this glow was visible to WMAP at all is remarkable, Bennett said. It could have easily been too dim, or the universe could have been too dusty. But everything worked out just right, he said.
"I just think it's amazing that it's humanly possible to say things like how old is the universe," he said. "We know it because of the light, and the patterns in the light. Nature has provided us this fossil, and we're really lucky that we can detect it and measure it."
When the satellite first launched as MAP (the W was added later in honor of Princeton University cosmologist David Wilkinson, who died in September 2002), it was designed to last only 2 years.
"We always planned to turn it off, and the question was what was the right time," said cosmologist and WMAP team member David Spergel of Princeton University. "We weren't sure it would last this long."
By the time the team decided to call it quits, the probe's batteries were failing, Spergel said. "I'm not sure it would have made it much longer anyway."
The probe spent its working life in spot of neutral gravity called a Lagrange point, where the pull of the Earth and the sun more or less cancel out. It was the first spacecraft ever to orbit at the point called L2, which is becoming a popular destination for future telescopes like the James Webb Space Telescope.
But the gravity balance is only quasi-stable. Any telescope perched there needs to adjust its position with booster rockets every so often just to sit still. To avoid the possibility that WMAP will hit Earth, scientists sent it into a parking orbit around the sun.
"It's basically as if it was another planet just going around the sun," Bennett said.
Spergel sees the end with "a combination of sadness and satisfaction…. It's definitely for me personally the end of a stage in my career. For all of us, it was something that was a major part of our lives for 15 years."
But Bennett sees it differently. "I don't feel like that at all. I think it's a huge victory," he said. "We didn't want it to fly forever, we wanted to get the answers. And we did that. I'm very happy about it."
He also points out that while the observation stage is over, the work is not. There's still the last two years of data to sift through.
"This is not the end of the mission, only the end of the satellite data-taking," he said. "We're still going to take a couple of years to finish analyzing all the data we took, apply new analysis techniques and get better data than ever."
Images: 1) WMAP's view of the universe from the first seven years of data. NASA/WMAP Science Team. 2) NASA/WMAP Science Team.
Posted: 06 Oct 2010 10:38 AM PDT
The nearby nebula Monoceros R2 explodes into color in this new infrared image from the VISTA telescope at the Paranal Observatory in Chile.
Located about 2,700 light-years away in the constellation Monoceros (the Unicorn), Monoceros R2 is an active stellar nursery in the Milky Way galaxy where young stars condense from a dark cloud of dust, gas and molecules. In previous visible-light images, the nebula glowed blue with scattered starlight. But most of the infant stars, and their spectacular effects on the matter between them, were hidden by a shroud of dark dust.
Infrared light, however, can pierce the dust cloud and allow young stars and their outflows to shine through. The new image reveals folds, loops and filaments sculpted by intense particle winds and radiation emitted by the hot young stars.
"When I first saw this image, I just said 'Wow!'" said VISTA consortium leader Jim Emerson of Queen Mary, University of London in a press release.
Images: Infrared: ESO/J. Emerson/VISTA. Visible: Digitized Sky Survey 2.
Posted: 06 Oct 2010 10:30 AM PDT
A new satellite photograph of Earth depicts our planet in all its aquatic splendor, revealing a truth somewhat obscured in the original Blue Marble image.
That photograph is among the defining images of the 20th century. It gave humankind a new perspective on our planet, seen all at once against the backdrop of space — immense, beautiful, precarious.
Much of Earth's surface was covered by clouds, however, and what's visible is dominated by Africa. A viewer's eye is naturally drawn to the landmass; the same holds for updated Blue Marble images produced by NASA in 2001 and 2002, which center on North America and the Asian subcontinent.
But with three-quarters of Earth's surface covered by water — arguably the most important ingredient for life, and certainly the host of most life on Earth — it's not land on which a planetary photographer should focus. It's water. And so it is with this new NASA image, in which land is just barely visible as a fringe of the Pacific Ocean.
In addition to restoring a certain geoscientific perspective, the photograph complements the original Blue Marble in another way. That image helped catalyzed an emerging environmental awareness, one conscious of both Earth's beauty and humanity's role as planetary steward. Nearly four decades later, our power to alter the environment is considered so profound as to define a new geological age, and even water is not exempt.
"One of the unknowns concerning future climate change is what changes will occur in the water cycle. There are disagreements over this, but one possibility that has been suggested is that the water cycle might speed up," said climatologist Claire Parkinson, lead scientist on NASA's Aqua Project.
It may be that as temperatures rise, more water will evaporate, hastening its turnover in the atmosphere. On average, it now takes about nine days for an evaporated water molecule to come come back down. "The issue is by no means settled," said Parkinson, and predictions are necessarily uncertain, but in the future it may take eight or even seven days. The water cycle could neatly fit a human week.
Posted: 06 Oct 2010 09:36 AM PDT
Early fall means steam devils. When waters are still warm, but morning air is growing frigid, little tornadoes of steam can form on lake surfaces. Storm chaser Andrew Pritchard of DeKalb, Illinois captured the ephemeral twisters on the surface of Deep Lake, Wisconsin on Oct. 2.
"With the first freeze of the season," Pritchard wrote on his blog, "I figured photogenic morning steam would be a sure thing. I ended up with that and more."
Steam devils form the same way dust devils, water spout tornadoes or land spout tornadoes do, but on a smaller scale. "Light winds blowing across the lake surface created little areas of vorticity, which were stretched by updrafts into tall and tight circulation patterns," Pritchard wrote. "Pretty mesmerizing stuff to watch as they really do resemble little water spouts."
Video credit: Andrew Pritchard, Prairiestorm Media
Posted: 06 Oct 2010 07:40 AM PDT
By Mark Brown, Wired UK
The creators of an ambitious new Mars vehicle claim that it could explore more of the planet in a few days, than Spirit and Opportunity managed in six years.
Since landing on Mars in January of 2004, NASA's traditional Red Planet rovers have driven just under 20 miles across the surface. MIT graduate students working with Draper Laboratory believe their invention could meet that milestone in a matter of hours.
The concept is a robot that hops instead of drives. The idea would allow it to overcome the planet's rocky surface in giant propelled leaps, which could fling the vehicle miles at a time.
It's further along than just a concept though. The laboratory is testing methods for lift, manoeuvre and landing, in a testbed that simulates the planet's gravity. The vehicle uses a cold-gas control system to fire itself in the air and steer its course. Work on creating an effective landing system is currently underway.
The biggest concern for its creators is fuel. While the rovers work on small, lightweight batteries charged via solar panels, the hopping design would require some more traditional fuel to power its giant leaps.
The same team also has its eye on the moon. Draper Laboratory has plans to enter the design into Google's Lunar X Prize, a $30 million (£18 million) prize challenge that has privately-funded teams attempting to launch vehicles and robots to the moon. To qualify for the hefty prize bucket, the creation must then travel across the satellite's surface, sending images and data back to Earth.
NASA's first rover, Spirit, is stuck in soft soil, but its twin brother Opportunity is still going (at a top speed of two inches per second), and is on its way to the Endeavour crater. Curiosity, the agency's third rover, is planned to deploy on the planet next year.
Image: Draper Laboratory
Posted: 06 Oct 2010 06:00 AM PDT
When Ari Ne'eman walked onstage at a college campus in Pennsylvania in June, he looked like a handsome young rabbi presiding over the bar mitzvah of a young Talmudic scholar.
In truth, Ne'eman was facilitating a different kind of coming-of-age ceremony. Beckoning a group of teenagers to walk through a gateway symbolizing their transition into adult life, he said, "I welcome you as members of the autistic community." The setting was an annual gathering called Autreat, organized by an autistic self-help group called Autism Network International.
Ne'eman's deliberate use of the phrase "the autistic community" was more subversive than it sounds. The notion that autistic people — often portrayed in the media as pitiable loners — would not only wear their diagnosis proudly, but want to make common cause with other autistic people, is still a radical one. Imagine a world in which most public discussion of homosexuality was devoted to finding a cure for it, rather than on the need to address the social injustices that prevent gay people from living happier lives. Though the metaphor is far from exact (for example, gay people obviously don't face the impairments that many autistic people do), that's the kind of world that autistic people live in.
Now, as the first openly autistic White House appointee in history — and one of the youngest at age 22 — Ne'eman is determined to change that.
In December, he was nominated by President Obama to the National Council on Disability (NCD), a panel that advises the President and Congress on ways of reforming health care, schools, support services and employment policy to make society more equitable for people with all forms of disability.
Ne'eman spoke to Wired.com in July in his first interview with the media since his appointment.
His nomination proved controversial, in part because some self-proclaimed allies of the autistic community think national dialogue on the subject should focus primarily on finding causes and cures so that autism can be prevented in future generations.
In March, the editor of an anti-vaccine website called The Age of Autism challenged Ne'eman's ability to serve the needs of more profoundly impaired autistic people. "Do the highest functioning with the community," wrote Kim Stagliano, "have a right to dictate the services and research that should be available for their less fortunate 'peers?' I don't think so."
Some of these online attacks escalated into threats. One anonymous emailer to a federal agency in Washington wrote that "assholes like Ari Ne'eman" should "have their tongues cut out" for suggesting that autistic people need respect, civil rights, and access to services more than they need pity and a cure. This conviction has made him a leader of the emerging neurodiversity movement, which Ne'eman sees as a natural outgrowth of the civil rights, women's rights, and disability rights movements of the late 20th century.
In the wake of the controversy, an anonymous Senate hold was put on Ne'eman's nomination. While this hold was in place, he was unavailable to talk to the press. But just before the coming-of-age ceremony at Autreat, the hold was dropped, and he was finally able to take his seat on the council. Now, Ne'eman says, he's eager to clear the air about what he really believes about autism, neurodiversity, the controversy over his nomination, and what autistic people really need.
Wired.com: Much of the national conversation about autism in recent years has centered around statements by celebrities like Jenny McCarthy and Jim Carrey who claim that autism is caused by vaccines and other environmental factors, and can be cured by things like special diets, behavioral interventions, and alternative medicine. Is that the most productive conversation we can be having about autism as a society?
Ari Ne'eman: No. There's a disturbing lack of attention to science in that conversation, but the problem goes deeper than that. What we have is a national dialogue on autism without the voices of the people who should be at the center: those who are on the [autism] spectrum ourselves. Instead of focusing on things like quality of life and civil rights, the autism community has been distracted by narrow questions of causation and cure.
Going back to the dark days of Bruno Bettelheim and "refrigerator mothers," the focus of the conversation has been on placing the blame for autism, and on trying to make autistic people something we are not and never can be: normal. This focus on a cure has prevented us from actually helping people. There's been a lot of progress in the disability rights movement over the past 20 years, but people on the spectrum haven't benefited from it because those representing us at the national level have been focused on causes and cures.
We need to stop making autism advocacy about trying to create a world where there aren't any autistic people, and start building one in which autistic people have the rights and support they deserve. That's the goal of groups like ASAN, Autism Network International, and of the neurodiversity movement as a whole.
Posted: 06 Oct 2010 04:00 AM PDT
Posted: 05 Oct 2010 03:55 PM PDT
Posted: 05 Oct 2010 02:08 PM PDT
Images: NASA/JPL-Caltech/WISE Team. Unless otherwise noted, blue and cyan represent light emitted at wavelengths of 3.4 and 4.6 microns, which is predominantly from stars. Green and red represent light from 12 and 22 microns, respectively, which is mostly emitted by dust.
Posted: 05 Oct 2010 12:03 PM PDT
By Alisdair Wilkins, io9
Astronomers believed that binary star systems were too volatile to support many planets, because the overlapping gravitational forces of the two stars would pull most planets apart. But one exoplanet 69 light-years away survives just fine… by orbiting the wrong way.
The Nu Octantis system is a binary star system that can be seen in the southern skies, particularly in the higher latitudes around Antarctica. Manfred Cuntz and Jason Eberle, both researchers at the University of Texas-Arlington, propose there's a planet orbiting the primary star in the Nu Octantis system based on slight wobbles in the star's movement, which are known to be caused by orbiting planets.
Planets around binary stars aren't impossible, but they were thought to exist only in very small zones right around one of the two stars, so that the planets were safely away from the destructive influence of the other star. If there is a planet in Nu Octantis, then it's got to be well outside this safe zone, which raises the very real question of how it is surviving the gravitational pummeling of the other star.
According to their simulations, Cuntz and Eberle have come up with an answer – the planet could indeed exist outside the safety zone, as long as it's in a retrograde orbit. This means that it's revolving around the main star in the opposite direction of the second star. So if, say, the second star orbited the primary star in a clockwise direction, then the planet would orbit the primary star counterclockwise. This increases the possible range of orbital stability, allowing the planet to escape gravitational destruction.
Retrograde orbits are rare, and we've never seen anything quite like this before in our exploration of extrasolar planets. Still, they're not unknown, at least in this solar system's moons – most famously, Neptune's major moon Triton is in a retrograde orbit, a likely artifact of its previous existence as a massive asteroid in the Kuiper Belt.
If the researchers are right, this greatly expands the amount of planets we could expect to find in binary systems, particularly within potentially habitable zones. That's particularly good news for our neck of the galactic woods, because most of the star systems in our immediate vicinity are binary stars.
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