SpaceJibe

April 21, 2016

The Curious Link Between the Fly-By Anomaly and the “Impossible” EmDrive Thruster

The same theory that explains the puzzling fly-by anomalies could also explain how the controversial EmDrive produces thrust.

About 10 years ago, a little-known aerospace engineer called Roger Shawyer made an extraordinary claim. Take a truncated cone, he said, bounce microwaves back and forth inside it and the result will be a thrust toward the narrow end of the cone. Voila … a revolutionary thruster capable of sending spacecraft to the planets and beyond. Shawyer called it the EmDrive.

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Shawyer’s announcement was hugely controversial. The system converts one type of energy into kinetic energy, and there are plenty of other systems that do something similar. In that respect it is unremarkable.

The conceptual problems arise with momentum. The system’s total momentum increases as it begins to move. But where does this momentum come from? Shawyer had no convincing explanation, and critics said this was an obvious violation of the law of conservation of momentum.

Shawyer countered with experimental results showing the device worked as he claimed. But his critics were unimpressed. The EmDrive, they said, was equivalent to generating a thrust by standing inside a box and pushing on the sides. In other words, it was snake oil.

Since then, something interesting has happened. Various teams around the world have begun to build their own versions of the EmDrive and put them through their paces. And to everyone’s surprise, they’ve begun to reproduce Shawyer’s results. The EmDrive, it seems, really does produce thrust.
In 2012, a Chinese team said it had measured a thrust produced by its own version of the EmDrive. In 2014, an American scientist built an EmDrive and persuaded NASA to test it with positive results.

And last year, NASA conducted its own tests in a vacuum to rule out movement of air as the origin of the force. NASA, too, confirmed that the EmDrive produces a thrust. In total, six independent experiments have backed Shawyer’s original claims.

That leaves an important puzzle—how to explain the seeming violation of conservation of momentum.

Today we get an answer of sorts thanks to the work of Mike McCulloch at Plymouth University in the U.K. McCulloch’s explanation is based on a new theory of inertia that makes startling predictions about the way objects move under very small accelerations.

First some background. Inertia is the resistance of all massive objects to changes in motion or accelerations. In modern physics, inertia is treated as a fundamental property of massive objects subjected to an acceleration. Indeed, mass can be thought of as a measure of inertia. But why inertia exists at all has puzzled scientists for centuries.

McCulloch’s idea is that inertia arises from an effect predicted by general relativity called Unruh radiation. This is the notion that an accelerating object experiences black body radiation. In other words, the universe warms up when you accelerate.

According to McCulloch, inertia is simply the pressure the Unruh radiation exerts on an accelerating body.

That’s hard to test at the accelerations we normally observe on Earth. But things get interesting when the accelerations involved are smaller and the wavelength of Unruh radiation gets larger.

At very small accelerations, the wavelengths become so large they can no longer fit in the observable universe. When this happens, inertia can take only certain whole-wavelength values and so jumps from one value to the next. In other words, inertia must quantized at small accelerations.

McCulloch says there is observational evidence for this in the form of the famous fly by anomalies. These are the strange jumps in momentum observed in some spacecraft as they fly past Earth toward other planets. That’s exactly what his theory predicts.

Testing this effect more carefully on Earth is hard because the accelerations involved are so small. But one way to make it easier would be to reduce the size of allowed wavelengths of Unruh radiation. “This is what the EmDrive may be doing,” says McCulloch.

The idea is that if photons have an inertial mass, they must experience inertia when they reflect. But the Unruh radiation in this case is tiny. So small in fact that it can interact with its immediate environment. In the case of the EmDrive, this is the truncated cone.

The cone allows Unruh radiation of a certain size at the large end but only a smaller wavelength at the other end. So the inertia of photons inside the cavity must change as they bounce back and forth. And to conserve momentum, this must generate a thrust.

McCulloch puts this theory to the test by using it to predict the forces it must generate. The precise calculations are complex because of the three-dimensional nature of the problem, but his approximate results match the order of magnitude of thrust in all the experiments done so far.

Crucially, McCulloch’s theory makes two testable predictions. The first is that placing a dielectric inside the cavity should enhance the effectiveness of the thruster.

The second is that changing the dimensions of the cavity can reverse the direction of the thrust. That would happen when the Unruh radiation better matches the size of the narrow end than the large end. Changing the frequency of the photons inside the cavity could achieve a similar effect.

McCulloch says there is some evidence that exactly this happens. “This thrust reversal may have been seen in recent NASA experiments,” he says.

That’s an interesting idea. Shawyer’s EmDrive has the potential to revolutionize spaceflight because it requires no propellant, the biggest limiting factor in today’s propulsion systems. But in the absence of any convincing explanation for how it works, scientists and engineers are understandably wary.

McCulloch’s theory could help to change that, although it is hardly a mainstream idea. It makes two challenging assumptions. The first is that photons have inertial mass. The second is that the speed of light must change within the cavity. That won’t be easy for many theorists to stomach.

But as more experimental confirmations of Shawyer’s EmDrive emerge, theorists are being forced into a difficult position. If not McCulloch’s explanation, then what?

Ref: arxiv.org/abs/1604.03449 : Testing Quantized Inertia on the EmDrive

February 26, 2016

Explaining EmDrive, the ‘physics-defying’ thruster even NASA is puzzled over

roger-shawyer-satellite-propulsion-research-ltd

Even if you don’t keep up with developments in space propulsion technology, you’ve still probably heard about the EmDrive. You’ve probably seen headlines declaring it the key to interstellar travel, and claims that it will drastically reduce travel time across our solar system, making our dreams of people walking on other planets even more of a reality. There have even been claims that this highly controversial technology is the key to creating warp drives.

These are bold claims, and as the great cosmologist and astrophysicist Carl Sagan once said, “extraordinary claims require extraordinary evidence.” With that in mind, we thought it’d be helpful to break down what we know about the enigmatic EmDrive, and whether it is, in fact, the key to mankind exploring the stars.

So without further ado, here’s absolutely everything you need to know about the world’s most puzzling propulsion device.

 

What is the EmDrive?

See, the EmDrive is a conundrum. First designed in 2001 by aerospace engineer Roger Shawyer, the technology can be summed up as a propellantless propulsion system, meaning the engine doesn’t use fuel to cause a reaction. Removing the need for fuel makes a craft substantially lighter, and therefore easier to move (and cheaper to make, theoretically). In addition, the hypothetical drive is able to reach extremely high speeds — we’re talking potentially getting humans to the outer reaches of the solar system in a matter of months.

We’re talking potentially getting humans to the outer reaches of the solar system in a matter of months. The issue is, the entire concept of a reactionless drive is inconsistent with Newton’s conservation of momentum, which states that within a closed system, linear and angular momentum remain constant regardless of any changes that take place within said system. More plainly: Unless an outside force is applied, an object will not move.

 

Reactionless drives are named as such because they lack the “reaction” defined in Newton’s third law: “For every action there is an equal and opposite reaction.” But this goes against our current fundamental understanding of physics: An action (propulsion of a craft) taking place without a reaction (ignition of fuel and expulsion of mass) should be impossible. For such a thing to occur, it would mean an as-yet-undefined phenomenon is taking place — or our understanding of physics is completely wrong.

How does the EmDrive “work?”

Setting aside the potentially physics-breaking improbabilities of the technology, let’s break down in simple terms how the proposed drive operates. The EmDrive is what is called an RF resonant cavity thruster, and is one of several hypothetical machines that use this model. These designs work by having a magnetron push microwaves into a closed truncated cone, then push against the short end of the cone, and propel the craft forward.

This is in contrast to the form of propulsion current spacecraft use, which burn large quantities of fuel to expel a massive amount of energy and mass to rocket the craft into the air. An often-used metaphor for the inefficacy of this is to compare the particles pushing against the enclosure and producing thrust to the act of sitting in a car and pushing a steering wheel to move the car forward.

While tests have been done on experimental versions of the drive — with low energy inputs resulting in a few micronewtons of thrust (about as much force as the weight of a penny) — none of the findings have ever been published in a peer-reviewed journal. That means that any and all purportedly positive test results, and the claims of those who have a vested interest in the technology, should be taken with a very big grain of skepticism-flavored salt. It’s likely that the thrust recorded was due to interference or an unaccounted error with equipment.

Until the tests have been verified through the proper scientific and peer-reviewed processes, one can assume the drive does not yet work. Still, it’s interesting to note the number of people who have tested the drive and reported achieving thrust:

  • In 2001, Shawyer was given a £45,000 grant from the British government to test the EmDrive. His test reportedly achieved 0.016 Newtons of force and required 850 watts of power, but no peer review of the tests verified this. It’s worth noting, however, that this number was low enough that it was potentially an experimental error.
  • In 2008, Yang Juan and a team of Chinese researches at the Northwestern Polytechnical University allegedly verified the theory behind RF resonant cavity thrusters, and subsequently built their own version in 2010, testing the drive multiple times from 2012 to 2014. Tests results were purportedly positive, achieving up yo 750 mN (millinewtons) of thrust, and requiring 2,500 watts of power.
  • In 2014, NASA researchers, tested their own version of an EmDrive, including in a hard vacuum. Once again, the group reported thrust (about 1/1,000 of Shawyer’s claims), and once again, the data was never published through peer-reviewed sources. Other NASA groups are skeptical of researchers’ claims, but in their paper, it is clearly stated that these findings neither confirm nor refute the drive, instead calling for further tests.
  • In 2015, that same NASA group tested a version of chemical engineer Guido Fetta’s Cannae Drive (née Q Drive), and reported positive net thrust. Similarly, a research group at Dresden University of Technology also tested the drive, again reporting thrust, both predicted and unexpected.
  • Yet another test by a NASA research group, Eagleworks, in late 2015 seemingly confirmed the validity of the EmDrive. The test corrected errors that had occurred in the previous tests, and surprisingly, the drive achieved thrust. However, the group has not yet submitted their findings for peer review. It’s possible that other unforeseen errors in the experiment may have cause thrust (the most likely of which is that the vacuum was compromised, causing heat to expand air within it testing environment and move the drive). Whether the findings are ultimately published or not, more tests need to be done. That’s exactly what Glenn Research Center in Cleveland, Ohio, NASA’s Jet Propulsion Laboratory, and Johns Hopkins University Applied Physics Laboratory intend to do. For EmDrive believers, there seems to be some hope.

Implications of a working EmDrive

It’s easy to see how many in the scientific community are wary of EmDrive and RF resonant cavity thrusts altogether. But on the other hand, the wealth of studies raises a few questions: Why is there such a interest in the technology, and why do so many people wish to test it? What exactly are the claims being made about the drive that make it such an attractive idea? While everything from atmospheric temperature-controlling satellites, to safer and more efficient automobiles have been drummed up as potential applications for the drive, the real draw of the technology — and the impetus for its creation in the first place — is the implications for space travel.

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Spacecraft equipped with a reactionless drive could potentially make it to the moon in just a few hours, Mars in two to three months, and Pluto within two years. These are extremely bold claims, but if the EmDrive does turn out to be a legitimate technology, they may not be all that outlandish. And with no need to pack several tons-worth of fuel, spacecraft become cheaper and easier to produce, and far lighter.
For NASA and other such organizations, including the numerous private space corporations like SpaceX, lightweight, affordable spacecraft that can travel to remote parts of space fast are something of a unicorn. Still, for that to become a reality, the science has to add up.

Shawyer is adamant that there is no need for pseudoscience or quantum theories to explain how EmDrive works. Instead, he believes that current models of Newtonian physics offer an explanation, and has written papers on the subject, one of which is currently being peer reviewed. He expects the paper to be published sometime this year. While in the past Shawyer has been criticized by other scientists for incorrect and inconsistent science, if the paper does indeed get published, it may begin to legitimize the EmDrive and spur more testing and research.

Spacecraft equipped with a reactionless drive could potentially make it to the Moon in just a few hours.

Despite his insistence that the drive behaves within the laws of physics, it hasn’t prevented him from making bold assertions regarding EmDrive. Shawyer has gone on record saying that this new drive produced warp bubbles which allow the drive to move, claiming that this is how NASA’s test results were likely achieved. Assertions such as these have garnered much interest online, but have no clear supporting data and will (at the very least) require extensive testing and debate in order to be taken seriously by the scientific community — the majority of which remain skeptical of Shawyer’s claims.

Colin Johnston of the Armagh Planetarium wrote an extensive critique of the EmDrive and the inconclusive findings of numerous tests. Similarly, Corey S. Powell of Discovery wrote his own indictment of both Shawyer’s EmDrive and Fetta’s Cannae Drive, as well as the recent fervor over NASA’s findings. Both point out the need for greater discretion when reporting on such instances. Professor and mathematical physicist, John C. Baez expressed his exhaustion at the conceptual technology’s persistence in debates and discussions, calling the entire notion of a reactionless drive “baloney.” His impassioned dismissal echoes the sentiments of many others.

Shawyer’s EmDrive has been met with enthusiasm elsewhere, including the website NASASpaceFlight.com — where information about the most recent Eagleworks’ tests was first posted — and the popular journal New Scientist, which published a favorable and optimistic paper on EmDrive. (The editors later issued a statement that, despite enduring excitement over the idea, they should have shown more tact when writing on the controversial subject.)

Clearly, the EmDrive and RF resonant cavity thruster technology have a lot to prove. There’s no denying that the technology is exciting, and that the number of “successful” tests are interesting, but one must keep in mind the physics preventing the EmDrive from gaining any traction, and the rather curious lack of peer-reviewed studies done on the subject. If the EmDrive is so groundbreaking (and works), surely people like Shawyer would be clamoring for peer-reviewed verification.

A demonstrably working EmDrive could open up exciting possibilities for both space and terrestrial travel — not to mention call into question our entire understanding of physics. However, until that comes to pass, it will remain nothing more than science fiction.

Read more: http://www.digitaltrends.com/cool-tech/emdrive-news-rumors/#ixzz41JSPv7jZ
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January 21, 2016

There’s a ninth planet out there – now we just need to find it

Filed under: Exoplanets, Kuiper Belt, Outer Solar System — bferrari @ 6:31 pm

Mathematics suggests hidden gas giant in solar system

The truth is out there; way, way out there (source: CalTech/R.Hurt)

The truth is out there; way, way out there (source: CalTech/R.Hurt)

Pic Scientists at CalTech claim to have found proof that there is a ninth planet in the solar system, using computer modeling and historical astronomy data.

The new planet has a mass about 10 times that of Earth and has a very eccentric path around our Sun, making one complete orbit every 10,000 or 20,000 years and travelling 200 times further from the Sun than our orbit. The planet hasn’t been seen, but can be determined to exist based on its effect on objects in the Kuiper Belt that encircles our solar system.

“This would be a real ninth planet,” said Mike Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy at the California Institute of Technology. “There have only been two true planets discovered since ancient times, and this would be a third. It’s a pretty substantial chunk of our solar system that’s still out there to be found, which is pretty exciting.”

That’s true, thanks to our modern definition of what a planet is. We’ve known about all the planets as far out as Saturn since before telescopes, and the advent of optics led to the discovery of Uranus back in 1781.

The existence of Neptune, like the new ninth planet, was proved mathematically before it was identified in 1846 based on the erratic movement of Uranus. Pluto was also proved mathematically to exist but it was nearly 100 years later before it was confirmed, and then demoted to dwarf planet status in an infamous 2006 astronomers’ vote.

There’s no fear of that in the case of the new ninth planet – it’s massive enough to cause objects in the Kuiper Belt to move in such a predictable fashion that Brown and his associate Konstantin Batygin estimate there’s only a 0.07 per cent possibility that they are mistaken about its existence.

In a paper published in the latest issue of The Astronomical Journal, the duo detail how they came to find the planet when a student of Brown’s noticed that 13 large objects in the Kuiper Belt were behaving oddly, as though they were being influenced by a much larger body.

Brown and Batygin spent the next 18 months building up complex mathematical simulations of what could be causing the movement and running them through a computer model. Brown supplied the astronomical data and Batygin applied physics to see what could be going on.

“I would bring in some of these observational aspects; he would come back with arguments from theory, and we would push each other. I don’t think the discovery would have happened without that back and forth,” said Brown. “It was perhaps the most fun year of working on a problem in the solar system that I’ve ever had.”

At first the two considered that maybe other Kuiper Belt objects were causing the orbital anomalies, but the sums didn’t add up – the Belt would have had to have 100 times the mass we understand it has. So that left the influence of a planet, and one that was orbiting the Sun at right angles to the orbits of other planets.

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“Your natural response is ‘This orbital geometry can’t be right. This can’t be stable over the long term because, after all, this would cause the planet and these objects to meet and eventually collide,'” said Batygin. “Still, I was very skeptical. I had never seen anything like this in celestial mechanics.”

In order for the theory to be accurate, there would have to be other Kuiper Belt objects on a similar 90-degree trajectory. After three years of looking, the two found four largish objects that did just that.

“We plotted up the positions of those objects and their orbits, and they matched the simulations exactly,” says Brown. “When we found that, my jaw sort of hit the floor.”

Planets are supposed to form from the disk of matter that surrounds a young star, but the unusual orbit suggests that while the ninth planet might have started that way, it got knocked out of alignment, possibly by a major object like Jupiter, and sent on a new orbital trajectory.

Despite orbiting so far away from the Sun, planet nine should still be visible using our most powerful telescopes, and may have been picked up on star surveys and not recognized for what it is. The hunt is now on to be the first to get a clear sighting.

“I would love to find it,” says Brown. “But I’d also be perfectly happy if someone else found it. That is why we’re publishing this paper. We hope that other people are going to get inspired and start searching.”

Source

September 20, 2015

Stunning 7-mile scale model of the solar system created in Nevada

Filed under: Cool, Earth, inn, Inner Solar System, Outer Solar System — bferrari @ 9:06 am

A group of friends has created a stunning 7-mile scale model of the solar system on a dry lakebed in Nevada.

“The only way to see a scale model of the solar system was to build one,” explained science film-maker, noting the vast distances between planets. The visually striking project is documented in “To Scale: The Solar System” a 7-minute short film by Overstreet and Alex Gorosh.

Related: NASA releases dramatic new Pluto images

In the scale model Mercury, Venus and Earth are, respectively, 224 feet, 447 feet and 579 feet away from the Sun. Jupiter, Saturn and Uranus are, respectively, 0.57 miles, 1.1 miles and 2.1 miles from the fiery orb with Neptune 3.5 miles away, right on the edge of the solar system.

In reality, Neptune is around 2.8 billion miles from the Sun.

The group used cars to trace the planets’ orbits. Time lapse shots were taken from the top of a nearby mountain, creating a striking representation of the vast solar system.

To Scale: The Solar System from Wylie Overstreet on Vimeo.

January 28, 2015

‘Super Saturn’ with rings 200 times as large

Filed under: Cool, Outer Solar System — bferrari @ 12:49 pm
Illustration by artist Ron Miller of the gigantic ring system around J1407b.

Illustration by artist Ron Miller of the gigantic ring system around J1407b.

In 1610, after he built his telescope, Galileo Galilei first spotted enormous Saturn’s gigantic rings. More than 400 years later, astronomers have in a sense dwarfed that discovery with a similar first.

Using powerful optics, they have found a much larger planet-like body, J1407b, with rings 200 times the size of Saturn’s, U.S. and Dutch astronomers said.

It lies some 400 light-years away from Earth.

For decades, scientists have believed that many moons around large planets formed out of such ring systems. But this is the first one astronomers have observed aside from Saturn’s, they said.

It was discovered in 2012, but a detailed analysis of its data was recently completed and published.

Dominating the sky

How this new Super Saturn would look in our own sky.

How this new Super Saturn would look in our own sky.

If J1407b were in our solar system, it would dominate Earth’s nightly sky.

“If we could replace Saturn’s rings with the rings around J1407b, they would be easily visible at night and be many times larger than the full moon,” said Matthew Kenworthy from the Netherlands’ Leiden Observatory.

Unlike Galileo peering a relatively short distance through his simple telescope, today’s astronomers can’t eyeball the rings hundreds of light-years away.

But using two very powerful optical devices with eight cameras each, they can observe the effect the rings have as they pass across nearby star J1407 — written without a ‘b’ at the end.

It is similar to our sun. The rings of planet J1407b eclipse its light.

56-day eclipse

With the enormous size of the rings, the eclipse the astronomers observed lasted 56 days.

But the star did not go completely dark for nearly two months. Some of J1407b’s 30 rings are denser, blocking more light, and some of them are less dense, letting more light through.

And there are gaps between the rings, leading the scientists to theorize that “exomoons” have formed and cut clean orbits through the debris, like the moons around Saturn.

Our own solar system’s ringed giant has at least 60 moons, according to NASA.

Bigger than a planet

Like its system of rings, planet J1407b is also much larger than Saturn, said astrophysicist Eric Mamajek, whose team at the University of Rochester discovered the object. “You could think of it as kind of a super Saturn.”

It is called a brown dwarf, a size classification somewhere between a planet and a star, according to the California Institute of Technology.

Brown dwarfs are hot but don’t burst into nuclear fusion the way stars do, so they don’t give off light.

The scientists are calling on amateur astronomers to keep an eye on star J1407 in hopes they may observe the rings eclipsing it again and report the results to the American Association of Variable Star Observers, which collects astronomical data on “stars that change in brightness.”

And astronomers will also search for more such ringed systems.

November 12, 2014

TOUCHDOWN ! Rosetta’s Philae Probe Touches Down on a Comet !

Filed under: Comets, Gadgets, Kuiper Belt, Oort Cloud — bferrari @ 2:25 pm
Farewell Philae - narrow-angle view

Farewell Philae – narrow-angle view

ESA’s Rosetta mission has soft-landed its Philae probe on a comet, the first time in history that such an extraordinary feat has been achieved.

After a tense wait during the seven-hour descent to the surface of Comet 67P/Churyumov–Gerasimenko, the signal confirming the successful touchdown arrived on Earth at 16:03 GMT (17:03 CET).

The confirmation was relayed via the Rosetta orbiter to Earth and picked up simultaneously by ESA’s ground station in Malargüe, Argentina and NASA’s station in Madrid, Spain. The signal was immediately confirmed at ESA’s Space Operations Centre, ESOC, in Darmstadt, and DLR’s Lander Control Centre in Cologne, both in Germany.

The first data from the lander’s instruments were transmitted to the Philae Science, Operations and Navigation Centre at France’s CNES space agency in Toulouse.

“Our ambitious Rosetta mission has secured a place in the history books: not only is it the first to rendezvous with and orbit a comet, but it is now also the first to deliver a lander to a comet’s surface,” noted Jean-Jacques Dordain, ESA’s Director General.

“With Rosetta we are opening a door to the origin of planet Earth and fostering a better understanding of our future. ESA and its Rosetta mission partners have achieved something extraordinary today.”

“After more than 10 years travelling through space, we’re now making the best ever scientific analysis of one of the oldest remnants of our Solar System,” said Alvaro Giménez, ESA’s Director of Science and Robotic Exploration.

“Decades of preparation have paved the way for today’s success, ensuring that Rosetta continues to be a game-changer in cometary science and space exploration.”

“We are extremely relieved to be safely on the surface of the comet, especially given the extra challenges that we faced with the health of the lander,” said Stephan Ulamec, Philae Lander Manager at the DLR German Aerospace Center.

“In the next hours we’ll learn exactly where and how we’ve landed, and we’ll start getting as much science as we can from the surface of this fascinating world.”

Rosetta was launched on 2 March 2004 and travelled 6.4 billion kilometres through the Solar System before arriving at the comet on 6 August 2014.

Philae touchdown

Philae touchdown

“Rosetta’s journey has been a continuous operational challenge, requiring an innovative approach, precision and long experience,” said Thomas Reiter, ESA Director of Human Spaceflight and Operations.

“This success is testimony to the outstanding teamwork and the unique know how in operating spacecraft acquired at the European Space Agency over the decades.”

The landing site, named Agilkia and located on the head of the bizarre double-lobed object, was chosen just six weeks after arrival based on images and data collected at distances of 30–100 km from the comet. Those first images soon revealed the comet as a world littered with boulders, towering cliffs and daunting precipices and pits, with jets of gas and dust streaming from the surface.

Following a period spent at 10 km to allow further close-up study of the chosen landing site, Rosetta moved onto a more distant trajectory to prepare for Philae’s deployment.

Five critical go/no-go decisions were made last night and early this morning, confirming different stages of readiness ahead of separation, along with a final preseparation manoeuvre by the orbiter.

Deployment was confirmed at 09:03 GMT (10:03 CET) at a distance of 22.5km from the centre of the comet. During the seven-hour descent, which was made without propulsion or guidance, Philae took images and recorded information about the comet’s environment.

“One of the greatest uncertainties associated with the delivery of the lander was the position of Rosetta at the time of deployment, which was influenced by the activity of the comet at that specific moment, and which in turn could also have affected the lander’s descent trajectory,” said Sylvain Lodiot, ESA Rosetta Spacecraft Operations Manager.

“Furthermore, we’re performing these operations in an environment that we’ve only just started learning about, 510 million kilometres from Earth.”

Touchdown was planned to take place at a speed of around 1 m/s, with the three-legged landing gear absorbing the impact to prevent rebound, and an ice screw in each foot driving into the surface.

But during the final health checks of the lander before separation, a problem was detected with the small thruster on top that was designed to counteract the recoil of the harpoons to push the lander down onto the surface. The conditions of landing – including whether or not the thruster performed – along with the exact location of Philae on the comet are being analysed.

The first images from the surface are being downlinked to Earth and should be available within a few hours of touchdown.

Over the next 2.5 days, the lander will conduct its primary science mission, assuming that its main battery remains in good health. An extended science phase using the rechargeable secondary battery may be possible, assuming Sun illumination conditions allow and dust settling on the solar panels does not prevent it. This extended phase could last until March 2015, after which conditions inside the lander are expected to be too hot for it to continue operating.

Science highlights from the primary phase will include a full panoramic view of the landing site, including a section in 3D, high-resolution images of the surface immediately underneath the lander, on-the-spot analysis of the composition of the comet’s surface materials, and a drill that will take samples from a depth of 23 cm and feed them to an onboard laboratory for analysis.

The lander will also measure the electrical and mechanical characteristics of the surface. In addition, low-frequency radio signals will be beamed between Philae and the orbiter through the nucleus to probe the internal structure.

The detailed surface measurements that Philae makes at its landing site will complement and calibrate the extensive remote observations made by the orbiter covering the whole comet.

“Rosetta is trying to answer the very big questions about the history of our Solar System. What were the conditions like at its infancy and how did it evolve? What role did comets play in this evolution? How do comets work?” said Matt Taylor, ESA Rosetta project scientist.

“Today’s successful landing is undoubtedly the cherry on the icing of a 4 km-wide cake, but we’re also looking further ahead and onto the next stage of this ground-breaking mission, as we continue to follow the comet around the Sun for 13 months, watching as its activity changes and its surface evolves.”

While Philae begins its close-up study of the comet, Rosetta must manoeuvre from its post-separation path back into an orbit around the comet, eventually returning to a 20 km orbit on 6 December.

Next year, as the comet grows more active, Rosetta will need to step further back and fly unbound ‘orbits’, but dipping in briefly with daring flybys, some of which will bring it within just 8 km of the comet centre.

The comet will reach its closest distance to the Sun on 13 August 2015 at about 185 million km, roughly between the orbits of Earth and Mars. Rosetta will follow it throughout the remainder of 2015, as they head away from the Sun and activity begins to subside.

“It’s been an extremely long and hard journey to reach today’s once-in-a-lifetime event, but it was absolutely worthwhile. We look forward to the continued success of the great scientific endeavour that is the Rosetta mission as it promises to revolutionise our understanding of comets,” said Fred Jansen, ESA Rosetta mission manager.

June 30, 2014

Ancient asteroid destroyer finally found, and it’s a new kind of meteorite

Filed under: Asteroids, Comets, Earth, Inner Solar System, Kuiper Belt, Oort Cloud — bferrari @ 8:56 am

Illustration of a meteor shower.argus/Shutterstock.com

For 50 years, scientists have wondered what annihilated the ancestor of L-chondrites, the roof-smashing, head-bonking meteorites that frequently pummel Earth.

Now, a new kind of meteorite discovered in a southern Sweden limestone quarry may finally solve the mystery, scientists report. The strange new rock may be the missing “other half” from one of the biggest interstellar collisions in a billion years.

“Something we didn’t really know about before was flying around and crashed into the L-chondrites,” said study co-author Gary Huss of the University of Hawaii at Manoa.

The space rock is a 470-million-year-old fossil meteorite first spotted three years ago by workers at Sweden’s Thorsberg quarry, where stonecutters have an expert eye for extraterrestrial objects. Quarriers have plucked 101 fossil meteorites from the pit’s ancient pink limestone in the last two decades. [Photos: New Kind of Meteorite Found in Sweden]

Researchers have nicknamed the new meteorite the “mysterious object” until its formal name is approved, said lead study author Birger Schmitz, of Lund University in Sweden and Chicago’s Field Museum. It will likely be named for a nearby church, the sterplana, he said.

Mysterious find

Geochemically, the meteorite falls into a class called the primitive achondrites, and most resembles a rare group of achondrites called the winonaites. But small differences in certain elements in its chromite grains set the mysterious object apart from the winonaites, and its texture and exposure age distinguish the new meteorite from the other 49,000 or so meteorites found so far on Earth.

“It’s a very, very strange and unusual find,” Schmitz told Live Science’s Our Amazing Planet.

The new meteorite was recently reported online in the journal Earth and Planetary Science Letters, and the study will appear in the journal’s Aug. 15 print edition.

Until now, all of the quarry’s fossil meteorites were L-chondrites. Schmitz, who has led the chondrite cataloging, admitted the rock hunt had become “quite boring.”

But the rare find has not only revitalized interest in the quarry, it has also brought together the world’s top meteorite experts for a global hunt through geologic time. Thanks to Schmitz’s careful detective work on meteorites, scientists now know that each kind of meteorite leaves behind a unique calling card: tough minerals called spinels. Even if meteorites weather away, their spinels linger for hundreds of million of years in Earth rocks. Schmitz and his cohorts think they can pin down how many meteorites rained down on Earth in the past 2.5 billion years, as well as what kind fell, by extracting extraterrestrial spinels from sedimentary rocks. Their work may confirm suspicions that recent meteorite falls represent a mere fraction of the rocks drifting in space.

“I think our new finding adds to the understanding that the meteorites that come down on Earth today may not be entirely representative of what is out there,” Schmitz said. “One thing our study shows is that we maybe don’t know as much as we think we know about the solar system.”

Ancient wreckage

The limestone quarry preserves the remnants of a cosmic cataclysm that took place 470 million years ago, during the Ordovician Period. Scientists think there was an enormous crash between two large bodies out in the asteroid belt. The crash blew apart two asteroids, or an asteroid and comet, slinging dust and debris toward Earth. One of the impactors was the source of all L-chondrite meteorites. But no one has ever found a piece of the rock that hit the L-chondrite parent, until now.

The Swedish meteorite’s exposure age the length of time it sailed through space is the key to placing the fossil space rock at the scene of the crash. The meteorite zipped from the asteroid belt to Earth in just 1 million years. That’s the same remarkably young exposure age as the L-chondrites recovered from the Thorsberg quarry, suggesting the rocks sprayed Earth in the same wave of space debris. [Infographic: Asteroid Belt Explained]

Meteorite expert Tim Swindle, who was not involved in the study, praised the team’s careful analysis and said it was unlikely that any other meteorite but an Ordovician fragment would have such a short exposure age. “Very, very few modern meteorites have exposure ages that low,” said Swindle, a professor at the University of Arizona in Tucson. “Typically, it takes things longer to get here from the asteroid belt,” he said. “It’s a telling argument.”

But because so little is left of the original meteorite almost all its minerals have been altered to clay Swindle thinks there’s wiggle room for linking it to known classes of meteorite, instead of calling it a new find.

“I think it’s entirely plausible [that it’s a new kind of meteorite], and it’s a great study, but that’s not a guarantee they’ve got it right,” Swindle said. “But if they didn’t, it’s because of new things we’ll find out in future work, not because of their analysis.”

The geochemical tests were performed on sand-sized chromite spinels, which confirmed the rock’s extraterrestrial origin. The altered clay is also about 100,000 times richer in iridium than terrestrial rocks. Iridium is the element that marks the meteorite impact horizon when the dinosaurs went extinct.

Hunt for space history

Schmitz now plans to search for these strange achondrite spinels in the quarry sediments, as well as in other rocks of the same age around the world. Ordovician meteorite spinels from L-chondrites have been found in China, Russia and Sweden, and small micrometeorites have been discovered in Scotland and South America. Researchers think about 100 times as many meteorites fell on Earth during the Ordovician compared with today, but only about a dozen impact craters of the proper age have been identified. [Crash! 10 Biggest Impact Craters on Earth]

A bigger quest is also in the works. Schmitz and his colleagues plan to dissolve tons of rock in acid in a global search for meteoritic spinel grains. This detective work will help researchers pin down the history of the asteroid belt and solar system. Spinels can provide an estimate of how many meteorites fell in the past, and what kind hit Earth. These tiny pieces of vanished meteorites may fill in missing history, because meteorite impact craters often vanish due to geologic forces.

“This can give you a ground truth for models for how the solar system may have evolved over time,” said Gary Huss, a co-author on the Swedish meteorite study who will collaborate on the spinel search. “I think a lot of people have worried for some time that we don’t really know what’s going on in the asteroid belt.”

Source

June 16, 2014

NASA’s real life Enterprise may take us to other star systems one day

Dr. Harold “Sonny” White is still working on a warp drive at NASA’s Johnson Space Center. His work is still in the experimental stage but that doesn’t mean he can’t imagine what the real lifeEnterprise ship would look like according to his math.

You’re looking at it right now.

..

 

This is the starship that may take us where no human has gone before. And it has me screaming like a little Klingon girl.

 

 

Concept 3D artist Mark Rademaker told io9 that “he worked with White to create the updated model, which includes a sleek ship nestled at the center of two enormous rings, which create the warp bubble.”

The updated model is the one you can see above, a variation of the original concept which, according to Dr. White, was rendered by Rademaker based on an idea by Matthew Jeffries, the guy who came with “the familiar Star Trek look.” This is the original warp drive spaceship concept:

Dr. White—whose daily life is working in future propulsion solutions for interplanetary travel in the near future, like ion and plasma thrusters—developed new theoretical work that solved the problems of the Alcubierre Drive concept, a theory that allowed faster-than-light travel based on Einstein’s field equations in general relativity, developed by theoretical physicist Miguel Alcubierre.

A spaceship equipped with a warp drive would allow faster-than-light travel by bending the space around it, making distances shorter. At the local level, however, the spaceship wouldn’t be moving faster than light. Therefore, warp drive travel doesn’t violate the first Einstein commandment: Thou shall not travel faster than light.

Not a fantasy, but real science

But Interstellar is just science fiction. Dr. White’s work at the Advanced Propulsion Theme Lead for the NASA Engineering Directorate is science. And while his department only gets peanuts compared to NASA’s budget (not to talk about the Pentagon’s) I find his words comforting:

Perhaps a Star Trek experience within our lifetime is not such a remote possibility.

See, Dr. White and his colleagues aren’t making a movie or coming up with 3D renders for the sake of it. They just don’t just believe a real life warp drive is theoretically possible; they’ve already started the work to create one:

Working at NASA Eagleworks—a skunkworks operation deep at NASA’s Johnson Space Center—Dr. White’s team is trying to find proof of those loopholes. They have “initiated an interferometer test bed that will try to generate and detect a microscopic instance of a little warp bubble” using an instrument called the White-Juday Warp Field Interferometer.

It may sound like a small thing now, but the implications of the research huge. In his own words:

Although this is just a tiny instance of the phenomena, it will be existence proof for the idea of perturbing space time-a “Chicago pile” moment, as it were. Recall that December of 1942 saw the first demonstration of a controlled nuclear reaction that generated a whopping half watt. This existence proof was followed by the activation of a ~ four megawatt reactor in November of 1943. Existence proof for the practical application of a scientific idea can be a tipping point for technology development.

The roadmap to the warp drive

According to Dr. White, this is a roadmap that they need to follow to achieve that final objective of rapid interstellar travel.

Every time I read that paragraph I smile—and these renders just make my smile so wide it looks stupid.

OK, Dr. White, you got our attention. Make it so.

Source

May 28, 2014

21-year-old makes astronomy breakthrough

Filed under: Black Holes, Cool, Cosmology, Outer Solar System — bferrari @ 11:53 am
This stock photo shows a dense swarm of stars. (AP PHOTO/NASA-ESA)

This stock photo shows a dense swarm of stars. (AP PHOTO/NASA-ESA)

At just 21 years old, a California college student has made an incredible discovery: Michael Sandoval and his astrophysics professor at San Jose State have spotted what they believe is one galaxy that was swallowed up by another.

The result is a dense system of stars—apparently the densest ever found. They’re calling it a “hypercompact cluster,” since no word for the object currently exists, theSan Jose Mercury News reports.

The finding occurred as Sandoval took the first course he’d ever taken on the subject, NBC Bay Area reports. “Some people take years and never find” such space phenomena, says astrophysics professor Aaron Romanowsky.

Sandoval took about a week to find it, inspired by the work of a classmate who’d found what had previously appeared to be the densest known bunch of stars.

To make the story even more impressive, Sandoval’s find came as he grieved for his mother, who died in October. He’d been living at home in recent years to take care of her during an illness, sometimes having to take her to the ER before heading to class the next day.

“I didn’t want to be sitting home, feeling sorry for myself,” Sandoval says. “That’s not what she would have wanted, anyway.” (Another recent space discovery involves an ancient space collision.)

Source

October 9, 2013

Meet the asteroid that might hit Earth in 2880

Radar image of 1950 DA acquired by the Arecibo Observatory on March 4, 2001. (NASA/JPL/S. OSTRO)

Radar image of 1950 DA acquired by the Arecibo Observatory on March 4, 2001. (NASA/JPL/S. OSTRO)

There are over 10,000 near-Earth objects (NEOs) that have been identified so far — asteroids and comets of varying sizes that approach the Earth’s orbital distance to within about 28 million miles. Of the 10,000 discoveries, roughly 10 percent are larger than six-tenths of a mile in size — large enough to have disastrous global consequences should one impact the Earth.

This is one of them.

First discovered in February 1950, 1950 DA is a 1.1-kilometer-wide asteroid that was observed for 17 days and then disappeared from view. Then it was spotted again on Dec. 31, 2000 — literally on the eve of the 21st century. Coupled with radar observations made a few weeks later in March 2001 it was found that, along with a rather high rotation rate (2.1 hours), asteroid 1950 DA has a trajectory that will bring it very close to Earth on March 16, 2880. How close? Close enough that, within a specific 20-minute window, a collision can not be entirely ruled out.

Top 10 Ways to Stop an Asteroid

The image above was made from radar observations by the Arecibo Observatory in Puerto Rico in March 2001, when 1950 DA passed within 4.8 million miles of Earth. Is this the mug shot of a future continent-killer?

Radar analysis and research of 1950 DA performed by NASA’s Jet Propulsion Laboratory scientists J.D. Giorgini, S. J. Ostro, Don Yeomans and several others from JPL and other institutions revealed that the impact probability from 1950 DA in March 2880 is, at most, 1 in 300 based on what is known about the asteroid so far.

1 in 300 may sound like a slim chance, but actually this represents a risk 50% greater than that of the average hazard due to all other asteroids from now to then.

However, that’s a maximum value. The study also noted the collision probability for 1950 DA as being in the range from 0 to 0.33%. That upper limit could increase or decrease as more is learned about the asteroid. (The next opportunity for studying 1950 DA via radar is in 2032.)

There are many factors that influence the path of an asteroid through space. Its spin rate, reflectivity (albedo), composition, mass, terrain variations… gravitational interactions with other bodies, some of which may not even have been discovered yet… all of these can affect the movement of an asteroid and, more specifically, its exact position at a future point in time. While many of these things still aren’t precisely known for 1950 DA, one in particular could end up being the saving grace for our descendants: the Yarkovsky effect.

PHOTOS: Russian Meteor Strike Aftermath

A small but important force acting upon asteroids, the Yarkovsky effect is a “nudge” created by thermal emission. As an asteroid gathers heat energy from the sun, it releases some of that energy back into space. Thanks to Newtonian mechanics the sheer act of doing so creates a physical push back on the asteroid itself, altering its course ever so slightly. Over a long span of time, this slight alteration could result in the relocation of 1950 DA away from the spot in space where Earth will be on March 16, 2880… at least enough so that a miss is certain.

In fact, recent research by JPL scientists D. Farnocchia and S.R. Chesley have taken into consideration the Yarkovsky effect on 1950 DA based on known values from previous observations, as well as new research suggesting that the asteroid has a retrograde rotation. While their latest assessment does put the risk of an impact in 2880 within the lower end of the probability spectrum (4×10^-4, or -0.58 on the Palermo Scale) it is still far from zero, and in fact remains higher than any other known potential impacts.

PHOTOS: NASA’s Asteroid Capture Mission

So what would happen if the half-mile-wide 1950 DA were to hit Earth? While that depends on a lot of things, such as its composition, speed, angle of impact, where it impacts, etc., needless to say it would cause a lot of damage across a large area. I’m talking an energy release upwards of half a million megatons, which, were it to strike say, New York City, everything within at least a 100-mile radius would be flattened by the force of the impact alone — that’s halfway to Boston and Washington, DC. And that’s not even taking into consideration the air blast, atmospheric dust cloud, secondary impacts from debris, or damage from any resulting tsunami (if the impact were in the ocean)… the destruction would easily extend out many more hundreds of miles, and the repercussions — physical, financial, economic, and emotional — would extend around the globe.

But again, precisely where 1950 DA will be in another 866 1/2 years (and whether or not it will occupy the same point in space as our planet) relies on many factors that aren’t well known — even though its orbit is pretty well understood. More in-depth observations will need to be made, and that is why asteroids like this must be carefully — and continually — watched.

Luckily, 35 generations offers plenty of time to improve our knowledge. According to JPL’s Near-Earth Object program, “If it is eventually decided 1950 DA needs to be diverted, the hundreds of years of warning could allow a method as simple as dusting the surface of the asteroid with chalk or charcoal, or perhaps white glass beads, or sending a solar sail spacecraft that ends by collapsing its reflective sail around the asteroid. These things would change the asteroids reflectivity and allow sunlight to do the work of pushing the asteroid out of the way.”

ANALYSIS: Meet Asteroid 2013 MZ5, 10,000th Near-Earth Object

Still, whether because of ongoing research, faith in future generations of scientists, or just sheer probability, JPL remains confident that 1950 DA should cause little concern. “The most likely result will be that St. Patrick’s Day parades in 2880 will be a little more festive than usual as 1950 DA recedes into the distance, having passed Earth by.”

Let’s just hope the luck of the Irish is with our planet big time that year…

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