Solar Sail Flotilla Could Divert Possibly Dangerous Asteroid

By Jeremy Hsu

SPACE.com Senior Writer

posted: 22 December 2010

06:51 am ET

A flotilla of solar sail spacecraft could change the course of the asteroid Apophis — which is headed a little too close to Earth for comfort — by shading the space rock from solar radiation, according to a French researcher.

Such a plan could help shift Apophis into a slightly safer orbit by the time it is expected to swing by Earth on April 13, 2036. But experts have warned previously that any efforts to divert the space rock could actually make matters worse.

The preliminary concept idea was proposed at a symposium on solar sails – which are spacecraft powered by sunlight pushing against a sail – a few months ago at the New York City College of Technology in Brooklyn.

"Apophis is a nice target for launching this kind of mission for 20 years from now; not too far, not too close," said Jean-Yves Prado, an engineer at the National Center for Space Study (CNES) in France.

How to move a space rock

A group of formation-flying solar sails could alter the asteroid's course by eliminating the so-called Yarkovsky effect, a phenomenon described by Russian engineer I.O. Yarkovsky a century ago.

That effect occurs when the sun warms an asteroid more on the sun-facing side than the far side. The rock then emits more thermal radiation on its near side, which creates a bit of thrust and changes its momentum slightly.

"It's really a very small effect and doesn't apply to very small asteroids because the temperature would be quite negligible, so thrust is negligible," Prado explained. "It also does not apply to very large asteroids because they are too heavy."

But for Apophis, which falls just in the middle of that mass range, the effect could make a difference.

The proposed mission would deploy four 441-pound (200 kg) solar sails from a transfer module that used solar electric propulsion to reach Apophis. Previous spacecraft that have used solar electric propulsion include NASA's Deep Space 1 and Dawn probes.

Once deployed, the solar sails would hover a few kilometers above the space rock and fly in formation according to master control by the transfer module, without a direct link between Earth and the individual sails.

The module could also position itself as a small gravity tractor to provide a small gravitational push on Apophis, Prado suggested.

Practical concerns arise

A previous NASA assessment of possible asteroid deflection methods had placed solar sails relatively high in terms of readily available and not-too-complex technology.

Launch windows would become available for such a mission to launch aboard a Russian Soyuz-Fregat rocket in 2016 and 2019, Prado said. He added that a second redundant mission could also launch to ensure success.

Several other solar sail researchers at the symposium raised questions about the mission design. One questioned the need for a chemical propulsion system on each solar sail that would balance out the solar pressure and keep the sails flying in their proper place.

Prado replied that his group had examined the possibility of using solar electric propulsion to also maintain low thrust and keep the solar sails in place, but had ruled it out based on cost.

Another researcher suggested that simply crashing four spacecraft with the mass of the solar sails into Apophis might be simpler.

The long view

An earlier, unrelated Russian proposal to nudge the space rock aside has been met with skepticism, in part because any solution might worsen Earth's chances, given the uncertainty regarding Apophis' exact trajectory.

NASA scientists previously pegged the possibility of an Apophis collision with Earth at a low 1-in-250,000 chance in 2036, when Apophis is expected to approach within 18,300 miles (29,450 km) of the planet in 2036.

The asteroid's second near pass by Earth comes in 2068, when it has a three-in-a-million chance (or about 1-in-333,000) of impacting on the planet.

Whether or not solar sails prove instrumental in protecting Earth from asteroids, proponents of the technology are excited about the progress they've made.

In July 2010, Japan's Ikaros spacecraft became the first vehicle to have deployed a solar sail and successfully rode the sunlight in deep space. Another effort by Britain called CubeSail, slated to launch next year, will use a solar sail as an atmospheric brake and will possibly be used to take down pieces of space junk

Carl Sagan (November 9, 1934-December 20, 1996)

He was a professor of Astronomy and Space Sciences at Cornell University. He was also the director of planetary science there. He had played a leading role in the American Space program since it was created. He advised and consulted with NASA since the 1950s. He received NASA medals for Exceptional Achievement twice as well as NASA Apollo achievement awards.

An asteroid is named after him. He also received “The John F. Kennedy Astronautics Award of the American Astronautical Society,” “The Explorers Club 75th Annual Award,” “Konstantin Tsiolkovsky Medal of the Soviet Cosmonauts Federation,” and “The Masursky Award of the American Astronomical Society.” He was trained both in astronomy and biology. He received the highest of the National Academy of Science, “The Public Welfare Medal.”

He has been was elected Chairman of the Division of Planetary Sciences of the American Astronomical Society, President of the Planetology Section of the American Geophysical Union, and Chairman of the Astronomy Section of the American Association for the Advancement of Science.

He was the editor-in-chief of Icarus, the leading professional journal devoted to planetary research for twelve years. A Pulitzer Prize winner for many books, like Contact, he is one of the most legendary

Alternate Realities or Parallel Universes

These are self-contained, co-existing with one’s own. Multiverses are groups of universes. This is only fantasy now, but what if there was a parallel universe born with every choice we make, and ever have made. In fact right now as I write this and as you read this it is ultimately possible that you are creating endless amounts of parallel universes within a multiverse of possibilities.

This idea is found throughout mythology as well as books, sci-fi as well as others. In dark fantasy or horror it is often the place for hiding things. In Narnia, this is the place where a whole other life is lived.

Mars Moon Phobos Likely Forged by Catastrophic Blast

One of the two moons of Mars most likely formed from rubble catapulted into space after a comet or meteorite slammed into the Red Planet, a new study finds.


The moon, Phobos, looks a lot like an asteroid: It's lumpy, potato-shaped and very small. It has an average radius of just 11 kilometers (6.8 miles).

Scientists have long wondered about the origin of Phobos — is it merely a captured asteroid, the leftovers from Mars' formation or evidence of a cosmic Martian hit-and-run with another object?

The new study found that the moon's composition and density strongly indicate that, like the leading theory for Earth's own moon, Phobos is the result of a catastrophic impact with its parent planet.

Phobos is one of two moons of Mars. The other, Deimos, is smaller than its partner.

What makes a Phobos?

Researchers used data from the European Space Agency's Mars Express spacecraft to study Phobos' composition.

By analyzing the probe's infrared observations, astronomers found that Phobos and asteroids don't seem to be made of the same stuff. Instead, the moon has many minerals also seen on Mars, suggesting a common origin for the two bodies.

The team also found so-called phyllosilicates — minerals that can form in the presence of water — on Phobos. Phyllosilicates have been detected on Mars, too.
"This is very intriguing as it implies the interaction of silicate materials with liquid water on the parent body prior to incorporation into Phobos," said study co-author Marco Giuranna of the Istituto Nazionale di Astrofisica in Rome, Italy. "Alternatively, phyllosilicates may have formed in situ, but this would mean that Phobos required sufficient internal heating to enable liquid water to remain stable."

Independent observations from NASA's Mars Global Surveyor spacecraft support the composition data from Mars Express, the researchers said.

The research was presented Sept. 20 at the European Planetary Science Congress in Rome, Italy, and has been submitted to the journal Planetary and Space Science.

Too spongy for an asteroid

During the study, evidence piled up to rule out the captured-asteroid scenario for Phobos, researchers said.

The first sign came while they were studying the Martian moon's density to see how it matched with that of asteroids. They determined the density of Phobos to be about 1.86 grams per cubic centimeter.

"This number is significantly lower than the density of meteoritic material associated with asteroids," said Pascal Rosenblatt of the Royal Observatory of Belgium. "It implies a sponge-like structure with voids making up 25 to 45 percent of Phobos' interior."

Other evidence points toward a relatively spongy Phobos, too.

If it were denser, the moon probably wouldn't have survived the massive impact that created its Stickney Crater, Giuranna said. Stickney is about 10 km (6 miles) across — nearly half as wide as all of Phobos.

In addition, the researchers said, a highly porous asteroid — if that's what Phobos once was — probably would not have survived being captured by Mars' gravity.

Yet sponginess is consistent with the impact-formation hypothesis for Phobos, they added. Chunks of rock and rubble blown off Mars' surface would accrete somewhat haphazardly in its orbit, leaving interior pockets and voids.

Finally, the motion of both Phobos and its sister moon Deimos — which is also small, rocky and lumpy—argue against the asteroid-capture scenario, according to the researchers. Their orbits are too neat — too circular and too close to the Martian equator — for a couple of snagged space rocks, researchers said.

More missions, more data

Despite the evidence from Mars Express, more observations are still needed before scientists can conclusively determine the origin of Phobos, the researchers said.

The Russian Phobos-Grunt mission, set to launch in 2011, could help settle the question. Phobos-Grunt aims to land on Phobos, grab soil samples ("Grunt" being the Russian word for "soil") and return with them to Earth. Such samples could be compared to Martian meteorites that have landed on Earth.

Similar studies of lunar soil samples have shown that Earth and our moon are likely made of the same stuff. This determination helped scientists come up with the leading theory of our moon's formation: A long-ago catastrophic impact.

Hellish Venus

It may seem downright bizarre, but a new model of Venus' super-hot atmosphere suggests its greenhouse gases may actually be cooling the planet's interior.

These gases initially cause Venus' temperature to rise, but at a certain threshold, they can trigger dynamic processes – which researchers call "mobilization" – in the planet's crust that cool the mantle and overall surface temperature, researchers found.

Venus surface temperature, on average, is a scorching 860 degrees Fahrenheit (460 degrees Celsius).

"For some decades we've known that the large amount of greenhouse gases in the atmosphere of Venus cause the extreme heat we observe presently," said study leader Lena Noack of the German Aerospace Center in Berlin.

Carbon dioxide and other greenhouses gases that led to Venus' hellish temperature were belched into the planet's atmosphere over time through erupting volcanoes.

Noack and her colleagues examined the interaction of carbon dioxide and other greenhouse gases in Venus' atmosphere and conclude that the planet may have been even hotter than it is today, Noack said.

"But at a certain point this process turned on its head – the high temperatures caused a partial mobilization of the Venusian crust, leading to an efficient cooling of the mantle, and the volcanism strongly decreased," Noack said. "This resulted in lower surface temperatures, rather comparable to today's temperature on Venus, and the mobilization of the surface stopped."

Noack and co-author Doris Breuer built a one-of-a-kind Venus computer model in which the planet's hot atmosphere was paired with a 3-D model of the interior.

Unlike on Earth, Venus' high temperatures have a much bigger effect on the rocky surface, which ultimately loses its insulating qualities, the researchers said.

"It's a little bit like lifting the lid on the mantle: The interior of Venus suddenly cools very efficiently and the rate of volcanism ceases," Noack said. "Our model shows that after that 'hot' era of volcanism, the slow-down of volcanism leads to a strong decrease of the temperatures in the atmosphere."

Their models also suggested differences in the time and place in which the volcanoes resurfaced Venus over time.

So even as Venus' atmosphere cooled, there would remain a few active volcanoes which resurface some spots with lava flows, researchers said. In fact, some of these volcanoes might be active even today, according to recent results from the European Space Agency's Venus Express mission.

Venus Express launched in 2005 and arrived at the cloud-covered planet a year later. The spacecraft recently detected 'hot spots' on Venus, or areas of unusually high surface temperatures, at volcanoes that were previously thought to be extinct.

Becoming Alien: Q&A With Conceptual Space Artist Jonathon Keats

By Mike Wall

SAN FRANCISCO — Setting foot on Mars isn't in the cards for most of us, but starting this week you can soak up the Red Planet's essence for just $45.

The Local Air & Space Administration, a shoestring operation run by conceptual artist Jonathon Keats, is selling mineral water infused with bits of Martian meteorite. LASA also hawks bottled moon essence for $30, and you can get some stellar water — made with carbonaceous chondrites containing bits of nanodiamond likely forged in the cores of faraway stars — for $60. [Photo of Martian mineral water.]

LASA began selling this stuff — which Keats bottled after smashing up some space rocks with a hammer — Thursday (Oct. 21), at the opening of its "Exotourism Bureau" here at San Francisco's Modernism art gallery.

For the past several weeks, LASA has also been growing cacti in asteroid soil and potatoes in the various mineral waters, thus spawning beings that are part Earthling, part alien.

LASA isn't Keats' first foray into space-science art. He has also created paintings based on signals picked up by the Arecibo Observatory radio telescope in Puerto Rico. And in a project called Speculations, he bought and sold property in the extra dimensions of space posited by string-theory physics.

SPACE.com caught up with Keats — who is a columnist at Wired Magazine and an art critic at San Francisco Magazine, as well as a novelist — to chat about space exploration, science and what it means to be alien:

To make LASA's mineral water, you actually got your hands on some space rocks. It's not a gag — you went out and bought some of these things off the Internet, right?

Yes. And that is essential in all of the work that I do. What I do is completely absurd, perhaps, looked at from the outside. Yet for that absurdity to have any depth to it, I feel that I need to take it absolutely seriously.

So when I was dealing in real estate, I had contracts that were perfectly valid in a court of law, provided that the court of law was willing to admit to the existence of extra dimensions of space. In this case I went on the Internet, and I've been purchasing from many of the same dealers who supply the world's laboratories.

Your real estate project — people actually bought some of those extra-dimensional lots?

Yes. I did better, I think, than Coldwell or any of the big firms if you look at volume. If you look at numbers, I didn't do so well. My most expensive lot was around $15 or so. But I was offering some real estate as low as 9 cents for a unit. I sold around 65 or 70 units in the first evening of sales, and there have been more sales since then, though my pressure tactics only lasted through that initial evening.

What do you hope people who buy LASA's mineral water get out of the experience?

I hope that they are able to explore these alien realms from within. I don't know what that will entail for any given person. [Moon's Water Comes in Three Flavors]

For me, what is most interesting is not so much what is out there but what the process of incorporating those alien minerals into my system means for me as a person. The fact that this does make me alien by degree — little by little, the more that I drink, the more alien I become.

For me, the optimal way in which to experience life is to have the advantage of being a little bit of an outsider, whatever it is I encounter, whatever it is that I do, because that gives me a sort of perspective on it.

The bodies in our solar system are exchanging material all the time — there are rocks from Mars on Earth, rocks from the moon on Earth. Is part of what you're trying to say that we're all interconnected in the solar system?

I like that idea you're bringing up. I think also that interconnectedness throughout time is very interesting. So for example, in the case of the stellar mineral water — I can't really offer you an excursion to our sun. It would be too hot. The water would boil off, and there would be other problems too, which you can imagine.

But I can offer you an excursion to other stars that once were. That nanodiamond which you are absorbing as you're drinking this water comes from stars that predate us and that are the materials from which we come. So there's almost a deja vu that takes place. It's almost an encounter with our ancestors.

You've actually tasted all three mineral waters. Knowing what's in them, do you manufacture a taste in your head, or do they just taste like water?

I think it's inevitable because of the nature of the material, that it does seem to have something strange about it. I can't place a flavor. It isn't like it tastes like chicken — well, I don't think so.

I guess that the carbonaceous chondrite, if you were to eat enough of it, might taste like burned chicken. I can't help but believe that each one of them has a distinct flavor to it. [Astronauts Drink Recycled Urine...and Celebrate]

But I suspect that that is as much an act of fraudulence on my own part toward myself as the sort of low-impact fraudulence undertaken every day by mineral water companies such as Evian and others toward their customer base might happen to be. I just don't know that Evian tastes any different than Calistoga, or that Calistoga is any different than Fuji. Fuji, or Fiji I think it is. I don't even know my competition, my terrestrial competition.

Have you gotten any interest from folks wanting to buy this stuff already?

I've gotten some curiosity. It's also been interesting to find how many people have asked whether I think anyone will actually drink this stuff, and when I say that I have, have looked at me as if I really am an alien, and I mean a Martian glowing green.

It seems fascinating to me that probably every single one of us as a child ate quite a lot of dirt. And probably most of us still do, at least a little bit. Yet dirt from Mars or from the moon is somehow seen to be toxic, dangerous, and I wonder why that is. I suspect that it is in some way related to the xenophobia that comes through in terms of our treatment of illegal aliens, in terms of the sort of war that you see between people of different religions in the Middle East, for example.

I hope that in some non-literal, non-polemical way, this project might also in a sense reflect on xenophobia of all different kinds, and by encouraging others to become alien in some respect that it might help to encourage a certain empathy for people who are alien in legal terms, or in terms of having different beliefs.

Did you ever think about offering customers a full alien meal, with the potatoes and the water?

That's a good idea. But maybe in that case it would make more sense to use the water as a base for wine or something like that.

I was going to ask you about that. Did you consider booze? You could call it "Moonshine." It would probably sell.

You know, I think that you should probably pursue that. You will put us out of business, and that will allow me to start working on some new projects.

It seems like you keep coming back to space science and astronomy. Is that because you want to divine our place in the universe, or are you just interested in this stuff?

The sciences continually recur in my work. Religion is another theme that comes up again and again. So too is commerce. Those are some of the fundamentals of our world. So I continually come back to science and continually poke and prod, because I am interested in what our assumptions are about the sciences.

Why space? Certainly, I am interested in it. That's just a matter of my personality. But the second reason, very briefly, is that space is out there. And because my art is almost always about getting us outside of ourselves, space is a very convenient place to go.

http://www.space.com/entertainment/keats-space-exploration-art-q-a-101022.html

Astronomers Worldwide Forge New Rules for ET Engagement

Lee Speigel Contributor

AOL News

(Oct. 8) -- Is alien disclosure just around the corner?
I can't say for sure, but lately there's been a lot of news that, if looked at collectively, could be interpreted as pointing in that direction.
It seems as if everyone from the Vatican to the military to scientists conducting the Search for Extraterrestrial Intelligence, or SETI, are getting on the ET bandwagon.

Robyn Beck, AFP / Getty Images

Dusk falls over the Very Large Array, one of the world's premier astronomical radio observatories, on the Plains of San Agustin, 50 miles west of Socorro, N.M.
Just last week, in Prague, the capital of the Czech Republic, the International Academy of Astronautics' SETI Permanent Study group created new guidelines for how earthlings should best handle official contact with extraterrestrials.
"The guidelines were and still are: Do good science and don't cry wolf. Make sure that what you're about to announce is, in fact, what you think it is," Jill Tarter, director of the SETI Institute's Center for SETI Research in California, told AOL News.
"In the case of the first protocol, it was: Don't respond until there's some consensus, a) that we should respond; and b) when we respond, who's going to speak for Earth and what are they going to say?
"We originally took that to the United Nations Committee on the Peaceful Uses of Outer Space, and it's duly filed away. When we presented that, we suggested that the U.N. might want to be proactive, and to think about the fact that this might happen."
For decades, SETI scientists, using radio and optical telescopes, have searched the heavens for proof that we're not alone in the universe. In the new SETI guidelines, the protocol for confirmation of an alien intelligence is clearly laid out:
"If the verification process confirms -- by the consensus of the other investigators involved and to a degree of certainty judged by the discoverers to be credible -- that a signal or other evidence is due to extraterrestrial intelligence, the discoverer shall report this conclusion in a full and complete, open manner to the public, the scientific community and the secretary-general of the United Nations."
Last November, Tarter was a participant at a Vatican-sponsored astrobiology conference -- a gathering of international scientists and religious leaders who considered the idea that life may exist elsewhere in the cosmos. In fact, a Jesuit astronomer, Jose Funes, director of the Vatican Observatory, had previously suggested that the idea of "brother extraterrestrials" would not conflict with Catholic doctrine.

Seth Shostak, SETI Institute
SETI astronomer Jill Tarter, who has devoted her career to hunting for signs of sentient beings in the cosmos.
"It was all about the question of life in the universe, and how we might find it, or life of a different kind -- weird life -- on this planet," said Tarter.
Tarter, whose work formed the basis of the character portrayed by Jodie Foster in the 1997 movie "Contact," suggests religious groups would be fine with the idea that Earth is not the only inhabited planet around.
"People say, 'Oh, my God, it's the end of religion if you detect a signal,' and I think organized religion is a lot more flexible than that," she said. "It's been around for millennia. Our view of the universe has changed hugely, so I don't think that this would be the death knell or the singularity in organized religion."

It's also hard to escape all the recent UFO items in the news.
Two months ago, the National Archives of England released UFO-related documents, including some that revealed how former Prime Minister Winston Churchill reportedly covered up wartime accounts of UFO sightings because he feared they might create a panic among the population.

Later this month, we'll find out how the European Union will finally respond to Italian Northern League leader Mario Borghezio's request, made in June, that EU member governments disclose their UFO files and establish a European UFO commission.

Ten days ago, at the National Press Club in Washington, several former Air Force officers came together, offering testimony of their experiences with UFOs at nuclear weapons sites, both in the U.S. and abroad, going back several decades.

An upsurge of UFO reports in China this year has prompted a planetary astronomer at the Purple Mountain Observatory of the Chinese Academy of Sciences to speculate that "contact between humans and extraterrestrial life will, hopefully, come this century."

Last week's announcement of the discovery of an Earth-like planet in our galactic neighborhood created a stir in the scientific community as well as the media.

While Tarter is engaged in the search for radio signals from possible distant civilizations, she acknowledges the significance of finding a planet that may harbor only primitive life forms.

"The universe is appearing to be more bio-friendly as we get closer to having a real Earth analog," she said. "It's really nice to see something that's about Earth-sized in an orbit that might, in fact, allow there to be a temperate and water-filled area on the planet."
And this week, British researchers hope to find alien life forms closer to home, in Earth's upper atmosphere, a prospect Tarter finds intriguing.
"There could be, in fact, another shadow biosphere on Earth where there's a different form of metabolism that might not use DNA, or might use different bio-solvents -- it's actually not completely out of the question."
Tarter suggests that life might even be found in non-Earthlike habitable zones, in places where "extremophile" organisms may thrive -- life forms that may actually require hazardous conditions.

Sponsored Links "As we've looked at extremophiles and looked at our own solar system better, we appreciate that," she said. "There might be life under the ice of [Jupiter's moon] Europa, and that could happen in other planetary systems. The nice thing is that we're getting close enough to it being science -- that we can actually go after the details and not just have to tell a story. It's really exciting."
So, does all of this -- SETI, Vatican, UFOs, high-atmosphere microbes -- or any of this signal a coming extraterrestrial disclosure?
Maybe I'm just tying a string of alien beads together that are leading nowhere, but I can't help wondering