Project Lucifer: Will Cassini Turn Saturn into a Second Sun? (Part 2)

Project Lucifer. Could the plutonium fuel onboard the Cassini mission cause a nuclear chain reaction on Saturn? Credit: NASA

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The story: The Lucifer Project is allegedly the biggest conspiracy theory NASA could possibly be involved in. First, back in 2003, the space agency (in co-operation with secret and powerful organizations) dropped the Galileo probe deep into Jupiter’s atmosphere. On board, was a significant quantity of plutonium. As the probe fell though the atmosphere, NASA hoped atmospheric pressures would create an implosion, generating a nuclear explosion thereby kick-starting a chain reaction, turning the gas giant into a second Sun. They failed. So, in a second attempt, they will drop the Cassini probe (again, laden with plutonium) deep into Saturn’s atmosphere in two years time, so this smaller gas giant can succeed where Jupiter failed…

The reality: As investigated briefly in Project Lucifer: Will Cassini Turn Saturn into a Second Sun? (Part 1), we looked at some of the technical problems behind Galileo and Cassini being used as makeshift nuclear weapons. They cannot generate an explosion for many reasons, but the main points are: 1) Tiny pellets of plutonium used to heat and power the probes are in separate, damage-proof cylinders. 2) The plutonium is not weapon grade, meaning the 238Pu makes a very inefficient fissionable fuel. 3) The probes will burn up and break apart, therefore disallowing any chance of lumps of plutonium forming “critical mass” (besides, there is no chance the plutonium could possibly form a configuration to create an implosion-triggered device).

OK, so Galileo and Cassini cannot be used as crude nuclear weapons. But say if there was a nuclear explosion inside Saturn? Could it cause a chain reaction in the core, creating a second Sun?


Thermonuclear bombs

The Soviet 50-megaton Tsar Bomba, the largest weapon ever detonated (1961)
The Soviet 50-megaton Tsar Bomba, the largest weapon ever detonated (1961)

Unless nuclear fusion can be maintained within a stellar body, the reaction will very quickly fizz out. So the Lucifer Project proposes Cassini will plunge many hundreds of miles into the atmosphere of Saturn and explode as a crude plutonium-fuelled fission explosion. This explosion will cause a chain reaction, creating enough energy to trigger nuclear fusion inside the gas giant.

I can see where this idea has come from, even though it is inaccurate. The fusion bomb (or “thermonuclear weapon”) uses a fission trigger to kick-start an uncontrolled fusion reaction. The fission trigger is constructed to explode like a normal fission bomb much like the implosion device described in Part 1 of this series. When detonated, huge quantities of energetic X-rays are produced, heating the material surrounding the fusion fuel (such as lithium deuteride), causing the phase transition to a plasma. As very hot plasma is surrounding the lithium deuteride (in a very confined and pressured environment) the fuel will produce tritium, a heavy hydrogen isotope. Tritium then undergoes nuclear fusion, liberating huge quantities of energy as the tritium nuclei are forced together, overcoming the electrostatic forces between nuclei and fusing. Fusion releases large quantities of binding energy, more-so than fission.

How does a star work?

A comparison of the size of Jupiter, a brown dwarf, a small star and the Sun (Gemini Observatory/Artwork by Jon Lomberg)
A comparison of the size of Jupiter, a brown dwarf, a small star and the Sun (Gemini Observatory/Artwork by Jon Lomberg)

The point that needs to be emphasised here is that in a thermonuclear device, fusion can only be attained when immense temperatures are reached within a very confined and pressurized environment. What’s more, in the case of a fusion bomb, this reaction is uncontrolled.

So, how are nuclear fusion reactions sustained in a star (like our Sun)? In the thermonuclear bomb example above, tritium fusion is achieved through inertial confinement (i.e. rapid, hot and energetic pressure on the fuel to cause fusion), but in the case of a star, a sustained mode of confinement is required. Gravitational confinement is needed for nuclear fusion reactions to occur in the core. For significant gravitational confinement, the star requires a minimum mass.

In the core of our Sun (and most other stars smaller than our Sun), nuclear fusion is achieved through the proton-proton chain (pictured below). This is a hydrogen burning mechanism where helium is generated. Two protons (hydrogen nuclei) combine after overcoming the highly repulsive electrostatic force. This can only be achieved if the stellar body has a large enough mass, increasing gravitational containment in the core. Once the protons combine, they form deuterium (2D), producing a positron (quickly annihilating with an electron) and a neutrino. The deuterium nucleus can then combine with another proton, thus creating a light helium isotope (3He). The outcome of this reaction generates gamma-rays that maintain the stability and high temperature of the star’s core (in the case of the Sun, the core reaches a temperature of 15 million Kelvin).

Ian O'Neill
The proton-proton chain that fuels nuclear fusion inside the core of our Sun. Credit: Ian O'Neill

As discussed in a previous Universe Today article, there are a range of planetary bodies below the threshold of becoming a “star” (and not able to sustain proton-proton fusion). The bridge between the largest planets (i.e. gas giants, like Jupiter and Saturn) and the smallest stars are known as brown dwarfs. Brown dwarfs are less than 0.08 solar masses and nuclear fusion reactions have never taken hold (although larger brown dwarfs may have had a short period of hydrogen fusion in their cores). Their cores have a pressure of 105 million atmospheres with temperatures below 3 million Kelvin. Keep in mind, even the smallest brown dwarfs are approximately 10 times more massive than Jupiter (the largest brown dwarfs are around 80 times the mass of Jupiter). So, for even a small chance of the proton-proton chain occurring, we’d need a large brown dwarf, at least 80 times bigger than Jupiter (over 240 Saturn masses) to even stand the hope of sustaining gravitational confinement.

There’s no chance Saturn could sustain nuclear fusion?

NASA/JPL/SSI
Saturn, seen by Cassini. Image credit: NASA/JPL/SSI

Sorry, no. Saturn is simply too small.

Implying that a nuclear (fission) bomb detonating inside Saturn could create the conditions for a nuclear fusion chain reaction (like the proton-proton chain) is, again, in the realms of science fiction. Even the larger gas giant Jupiter is far too puny to sustain fusion.

I have also seen arguments claiming that Saturn consists of the same gases as our Sun (i.e. hydrogen and helium), so a runaway chain reaction is possible, all that is needed is a rapid injection of energy. However, the hydrogen that can be found in Saturn’s atmosphere is diatomic molecular hydrogen (H2), not the free hydrogen nuclei (high energy protons) as found in the Sun’s core. And yes, H2 is highly flammable (after all it was responsible for the infamous Hindenburg airship disaster in 1937), but only when mixed with a large quantity of oxygen, chlorine or fluorine. Alas Saturn does not contain significant quantities of any of those gases.

Conclusion
Although fun, “The Lucifer Project” is the product of someone’s lively imagination. Part 1 of “Project Lucifer: Will Cassini Turn Saturn into a Second Sun?” introduced the conspiracy and focused on some of the general aspects why the Galileo probe in 2003 simply burned up in Jupiter’s atmosphere, scattering the small pellets of plutonium-238 as it did so. The “black spot” as discovered the next month was simply one of the many dynamic and short-lived storms often seen to develop on the planet.

This article has gone one step further and ignored the fact that it was impossible for Cassini to become an interplanetary atomic weapon. What if there was a nuclear explosion inside Saturn’s atmosphere? Well, it looks like it would be a pretty boring affair. I dare say a few lively electrical storms might be generated, but we wouldn’t see much from Earth. As for anything more sinister happening, it is highly unlikely there would be any lasting damage to the planet. There would certainly be no fusion reaction as Saturn is too small and it contains all the wrong gases.

Oh well, Saturn will just have to stay the way it is, rings and all. When Cassini completes its mission in two years time, we can look forward to the science we will accumulate from such an incredible and historic endeavour rather than fearing the impossible…

Update (Aug. 7th): As pointed out by some readers below, molecular hydrogen wasn’t really the cause of the Hindenburg airship disaster, it was the aluminium-based paint that may have sparked the explosion, hydrogen and oxygen fuelled the fire.

US Signs International Deal to Collaborate on Lunar Missions

Astronaut Eugene Cernan from Apollo 17, the last mission to the Moon (NASA)

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NASA has signed a landmark agreement to collaborate with emerging space-faring nations for the exploration of the Moon. This collaboration will include Canada, Germany, India, Italy, Japan, South Korea, Britain and France in the aim to work with NASA developing new technologies and send a series of robotic exploratory missions to pave the way for a manned return mission. The director of NASA’s planetary science division points out that these eight member states are keen to send their first astronauts to the lunar surface. Whilst some may view this collaboration as an attempt by NASA to ‘spread the cost’ of space travel (especially in the current climate of budget cuts), the main point of this deal is to make manned missions to the Moon more of an international effort. This will give smaller space agencies more opportunities, boost the quality of the science that can be achieved and possibly lead us to some answers about how life formed on Earth 4 billion years ago…

The deal was brokered at NASA’s Ames Research Center, Moffett Field, California, last Thursday, and it is expected to be finalized tomorrow. The meeting took place during the largest Moon-specific conference since the US Apollo missions, highlighting the recent drive to get man back to the lunar surface. NASA had already allocated significant funding toward four manned landers, but scientists have asked for eight, so an international collaboration is required so adequate science can be carried out.

At the centre of this renewed vigour is the quest to understand how life was kick-started on Earth. From recent analysis of Apollo rocks brought back to Earth in the 1970’s, it is thought that the early Solar System was a violent place. Scientists believe this planetary chaos may be the root cause of life on Earth; analysing the lunar surface is critical so a better picture may be created of the Earth-Moon system billions of years ago.

What’s happening right now is that a revolution in planetary science is going on. We are taking these small pieces and we are starting to put together the puzzle, and we are surprised by what we find.” – James Green, Director of NASA’s Planetary Science Division.

Why is the Moon so special anyway? Surely most of the answers can be found down here on Earth? Well, that’s not entirely correct. The Moon is an open history book of the Solar System’s evolution. Its surface has not been altered by plate tectonics, volcanoes or atmospheric erosion processes (unlike the terrestrial surface); ancient events are etched in its rock, waiting to be read by future lunar explorers. This was the conclusion reached by National Research Council of the National Academy of Sciences last year. From the evidence stored in lunar rock, it is hoped that the “terminal cataclysm hypothesis” may be proven or disproved. This theory suggests that Uranus and Neptune once orbited within the orbit of Jupiter. The cataclysm occurred when the powerful Jovian gravitational field flung the smaller gas giants to the outer reaches of the Solar System.

But where is the Earth-Moon connection? This turmoil in the Solar System will have displaced huge numbers of asteroids and comets, scattering them toward the inner planets. This event may have been the trigger of the “late heavy bombardment” between 3.8 to 4 billion years ago which coincided with the formation of life on Earth. This period of time can be studied in great depth on the Moon.

This increased interest in lunar science and the emergence of Japan, China and India create an opportunity NASA will not want to miss. This new international collaboration may be exactly what NASA needs to invigorate funding and help us understand how life was sparked on our blue planet.

Source: Mercury News

Friday’s Total Solar Eclipse can be Watched on the Internet

A solar eclipse at totality (NASA/F. Espenak)

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If you’ve ever wanted to see a solar eclipse, this might be the time to do it. It is a very rare chance to see an eclipse at totality because the Moon’s shadow is so small and, more often than not, it falls on sparsely populated regions of the planet. Often eclipse hunters are resigned to planning expensive trips to these locations, sometimes only to be disappointed by poor weather. But there’s an answer. This Friday’s eclipse will swing over Canada, the tip of Greenland, parts of Russia, China and Mongolia, including the Gobi desert, although nothing can replace actually travelling to one of these locations to witness this celestial event, NASA will transmit the eclipse live over the Internet. Excellent, now we can do some eclipse-chasing without leaving our armchairs…

Back in 1999, the south of the UK was fortunate to witness a total solar eclipse. I remember the excitement this caused on August 11th during that short British summer. Totality could be experienced in the southern-most county of Cornwall, but my hometown, Bristol, would see more than 90% totality. Although it wasn’t perfect, I decided to stay at home as the weather forecast for Cornwall wasn’t good, Bristol was better. Ultimately I wanted to see the “diamond ring” of the edge of the Sun peaking over the limb of the Moon. So, I kitted myself out. I constructed a rudimentary eclipse projector with a pair of binoculars and purchased a new tripod for my camera so I could photograph the projected image via the binocular set-up. I was good to go. But as with all British summers, I couldn’t rely on the weather. It turned out the weather front that was forecast for Cornwall had blown north ahead of schedule, blanketing my city and most of Cornwall. Alas, the eclipse was wasted on most of mainland Britain…

Path of totality on Friday (NASA)
Path of totality on Friday (NASA)

That’s the problem with trying to view the eclipse, often it will be in the wrong location at the right time, or the right location at the wrong time. Of course many eclipse hunters have luck on their side and are able to enjoy totality with clear skies, but for most of us have to make do with photos and videos taken by other people after the event. Not quite the same.

This Friday’s eclipse will be like most others, but this time it will start in Canada, pass over Greenland, Russia, China and Mongolia. If you are based in the USA, you might catch a glimpse of the event at sunrise in northeastern Maine. However, dedicated eclipse chasers like NASA astrophysicist Fred Espenak will be travelling to northern China to witness the event. But it hasn’t been easy. As the Olympics are starting next week in Beijing, travel expenses have sky-rocketed, plus fuel prices can only make things worse. Many Chinese eclipse tours can cost $3,000-$6,000 and if you fancied a trip to the High Arctic on a Russian icebreaker, expect to pay $23,000.

So we don’t miss out, NASA will be transmitting the live eclipse (presumably via their homepage www.nasa.gov) starting well before its peak at 7:09 am EDT. Also, museums like the Exploratorium in San Francisco have special eclipse events scheduled so we can all have the chance of seeing the event as it happens. Again, it’s not the same as experiencing it yourself, but at least you can guarantee clear skies via the Internet…

Source: AP

Virgin Galactic’s WhiteKnightTwo Sees Sunlight for the First Time (Gallery)

Sir Richard Branson and designer Burt Rutan walk aside the Virgin Mothership "Eve" (VMS EVE) in Mojave, CA. on the eve of its official rollout on July 28, 2008 (Virgin Galactic)

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Early this morning in the Californian Mojave Desert, Richard Branson and Burt Rutan unveiled the completed Virgin Galactic Mothership “Eve,” the first time this highly secretive project has seen the light of day. This is a significant moment for both Virgin Galactic and Scaled Composites, the company that built Eve, as it shows space tourism is only a heartbeat away. Now we await the completion of SpaceShipTwo that is expected to begin test flights with Eve by 2009.

The rollout represents another major milestone in Virgin Galactic’s quest to launch the world’s first private, environmentally benign, space access system for people, payload and science. – Virgin Galactic rollout press release (July 28th).


Eve is towed onto the airstrip at Mojave Air and Space Port (Virgin Galactic)
Eve is towed onto the airstrip at Mojave Air and Space Port (Virgin Galactic)

Eve is a large aircraft, with a wing span of 140 feet (42.7 meters), constructed from the world’s longest single carbon composite aviation component ever manufactured. Eve is basically a flying wing with two fuselages plus four efficient Pratt and Whitney PW308A engines attached. During operational flight sometime late 2009 or early 2010, it is hoped the mother ship will fly four times a day, carrying SpaceShipTwo up to 50,000 ft (9.5 miles) high. Once the aircraft reaches 50,000 ft, the spaceship will detach and ignite its rocket engines, blasting six fee-paying space tourists and two pilots to an altitude of around 360,000 feet (68 miles). This is considered to be the edge of space, allowing the SpaceShipTwo occupants five minutes of weightlessness before starting their journey back to Earth.

The cockpit of Eve (Virgin Galactic)
The cockpit of Eve (Virgin Galactic)

Today’s rollout onto the airstrip of Mojave Air and Space Port was witnessed by government officials, business partners and the future Virgin Galactic space tourists. Eve, named in honour of Branson’s mother, is the first WhiteKnightTwo aircraft of two that are on order with Scaled Composites. A total of five SpaceShipTwo’s are expected to complete the fleet.

Eve in the hangar (Virgin Galactic)
Eve in the hangar (Virgin Galactic)

Today’s press release also states: “Driven by a demanding performance specification set by Virgin Galactic, WhiteKnightTwo has a unique heavy lift, high altitude capability and an open architecture driven design which provides for maximum versatility in the weight, mass and volume of its payload potential. It has the power, strength and maneuverability to provide for pre space-flight, positive G force and zero G astronaut training as well as a lift capability which is over 30% greater than that represented by a fully crewed SpaceShipTwo.”

Artist impression of Eve dropping SpaceShipTwo at an altitude of 50,000 ft (Virgin Galactic)
Artist impression of Eve dropping SpaceShipTwo at an altitude of 50,000 ft (Virgin Galactic)

Fights with Virgin Galactic currently cost a hefty $200,000, but this ticket price is likely to fall in time. Over 200 tickets have already been sold. Initially, the company is offering sub-orbital space flights, but eventually Branson wants to push one stage further and begin offering tourists orbital space flight. The entrepreneur has even more optimistic ideas for his future space tourist empire including sending people into space during an aurora, space hotels and trips to the Moon. To be honest, I’d be excited to try out that rocket ride into space after the leisurely flight attached to WhiteKnightTwo

Sources: Virgin Galactic, ITWire

By 2020, Droids Could Explore Space For Us

Rendering of the Phoenix Mars Lander with robotic arm working on the Mars surface (NASA)

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All the best sci-fi films have them, and they may become our future automated space explorers. Currently, one of the biggest drawbacks for using robots in space is that they depend on human input (i.e. commands need to be sent for every robotic arm motion and every rover wheel rotation). This means that, especially with missions operating far from Earth (such as the Phoenix Mars Lander and Mars Expedition Rovers), very simple and mundane tasks can take hours or even days to complete. One of the main reasons supporting manned exploration of space is that very complex science can be carried out very rapidly (after all, astronauts are human and many robotic operations that take weeks can be completed in seconds). But say if our robotic explorers had a high degree of automation? Say if they could sever the requirement for human input and carry out tasks with intelligent reasoning? As robotic and computer technology increases in sophistication, one Caltech scientist believes space exploration by artificial intelligence is closer than we think…

I remember watching the start of Star Wars: The Empire Strikes Back thinking it was so unfair that Darth Vader and his ilk had access to intelligent space exploration droids that could fly around the galaxy, land on alien worlds and automatically seek out the rebels on Hoth (directing the battle fleet to the icy moon, creating one of the most famous and atmospheric sci-fi battle sequences in movie history. In my opinion at least). But say if we were able to build such “droids” (in fact, droid is a good description of these space explorers, defined as ‘self-aware robots’) that could be sent out into space to explore and report back to mission control without depending on instruction from Earth?

Wolfgang Fink, physicist and researcher at Caltech, believes robotic exploration of space will always take the lead, and even reverse the need for manned missions. “Robotic exploration probably will always be the trail blazer for human exploration of far space,” he says in an interview with Sharon Gaudin. “We haven’t yet landed a human being on Mars but we have a robot there now. In that sense, it’s much easier to send a robotic explorer. When you can take the human out of the loop, that is becoming very exciting.”

While Fink is encouraged by the progress made by missions such as Phoenix and its robotic arm, he is keen to emphasize that the link between human and robot needs to be removed, thus allowing robots to make their own decisions on what science needs to be carried out. In reference to Phoenix’s robotic arm he said, “The arms are the tools, but it’s about the intent to move the arms. That’s what we’re after. To [have the robot] know that something there is interesting and that’s where it needs to go and then to go get a sample from it. That’s what we’ve after. You want to get rid of the joystick, in other words. You want the system to take control of itself and then basically use its own tools to explore.”

Empire Strikes Back (Lucasfilm)
An Imperial probe droid from the film Star Wars: Empire Strikes Back (Lucasfilm)

The key attribute robots need to possess is the ability to recognize something of interest, such as a rock or crater, something that a human mind would see as a scientific opportunity. At Caltech, Fink and others are working on programs that use images for robots to distinguish colours, textures, shapes and obstacles. Once artificial intelligence has the ability to do this, if the programming is complex enough, the robot can notice something that is out of place, or a region worth investigating (such as a strangely coloured patch of Mars regolith that a Mars robot will decide to dig into).

As you’d expect, software is being tested and Caltech scientists are beginning to try it out on a rover’s navigation functions. However, the robotic decision-making is very basic presently, but NASA has taken a keen interest in Fink’s work. For example, in 2017 NASA intends to send a robotic mission to Titan, one of Saturn’s moons. In all likelihood the moon will be explored by a balloon-type vehicle. However, it would be impractical for such a vehicle to depend on commands being sent from Earth (as it would take more than an hour for communications to transmit over that distance), so there would need to be a certain degree of automation built into the craft so fast decisions can be made in a dynamic environment such as Titan’s atmosphere.

Although this is all interesting and necessary, there will still be a basic human desire to explore space via manned missions, although a certain degree of self-awareness may be required of our robotic explorers as they carry out reconnaissance trips before we make the trip…

Source: PC World

Bad Idea: Blowing Up Asteroids with Nuclear Missiles

On 4 July 2005, NASA collided a projectile with comet Tempel 1. Should a nuclear warhead be used in the future to deflect asteroids? (NASA)

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The first thing that comes to mind when someone asks: “How do we deflect a near Earth asteroid?” is “Fire some nuclear missiles at it.” However, this might not be the best course of action. Akin to opening a walnut with a sledgehammer, there might be a better, less messy option. This is what Apollo astronaut Rusty Schweickart thinks at least. Last year, NASA issued a report suggesting they were seriously considering a nuclear option should an asteroid threaten Earth. However, the ex-lunar module pilot believes this decision was manipulated by political pressure, possibly indicating the asteroid threat was being used to speed up nuclear proliferation in space…

When ex-Apollo astronauts express an opinion, people tend to sit up and listen. After all, the astronauts throughout the space race years in the latter half of the 20th Century (from the USA and Russia) were the ultimate explorers, going above and beyond the call of duty, putting their lives on the line for their countries. Several of the retired Apollo astronauts have come forward over the years with their opinions on modern NASA, concerns for the future of the US position in space exploration and their belief in extraterrestrial cover-ups (!). And last Wednesday, during a public lecture in San Francisco, legendary astronaut Rusty Schweickart voiced his opinion about NASA’s decision to use nuclear technology when faced with an asteroid threat.

Schweickart has expressed concern with the possibility of using nuclear weapons to destroy, or deflect Earth-bound asteroids, pointing out there are many other less harmful ways of dealing with the asteroid threat. At the moment he points out that we are completely unprepared to deal with asteroids, but by 2015, we should have developed a gentler means of deflection. Simply blowing asteroids up have many knock-on implications. First and foremost, Schweickart believes that NASA may be open to manipulation to put forward the proliferation of space-based nuclear weapons under the guise of international “safety.” Another problem I can see is blowing up a large piece of rock only to create many smaller (but just as deadly) pieces of rock, doesn’t really extinguish the destructive power of an asteroid on collision course, in fact, it might increase it.

Schweickart’s organization, the B612 Foundation examines other, more subtle ways of deflecting dangerous asteroids are examined (nuclear warheads not included). Decisions such as when to take action, how to better track asteroids and how to deflect them should be an international effort and not one nation’s decision to detonate a nuclear bomb in space.

Source: Wired

IBEX Mission Will View the Final Frontier of the Solar System

The heliopause is the frontier between the Solar System and the interstellar medium. Credit: NASA/JPL

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Space is far from empty. The Solar System can be viewed as a “bubble” of solar matter – filled with particles emitted by the Sun as the solar wind – extending well beyond the orbit of Pluto. The solar wind velocity is supersonic for most of this distance (exceeding a million miles per hour), but the point at which it begins to interact with the interstellar medium (ISM), the solar wind drops to subsonic velocities, creating a region of compression known as the termination shock. After 26 years of flight, the Voyager 1 deep space probe entered this bizarre, turbulent region of space, where solar particles build up and magnetic fields become twisted. Now a new mission has been designed to watch this region of space from afar to begin to understand the boundary of our solar system, where violent turbulence rules and high-energy atoms are generated…

In 2004, Voyager 1 hit it and in 2006, Voyager 2 hit it. The first probe flew through the termination shock at around 94 AU (8 billion miles away); the second measured it at only 76 AU (7 billion miles). This result alone suggests that the termination shock may be irregularly shaped and/or variable depending on solar activity. Before the Voyager missions, the termination shock was theorized, but there was little observational evidence until the two veteran probes traversed the region. The termination shock is of paramount importance to understanding the nature of the outer reaches of the solar system as, counter-intuitively, the Sun’s activity increases, the region beyond the termination shock (the heliosheath) becomes more efficient at blocking deadly cosmic rays. During solar minimum, it becomes less efficient at blocking cosmic rays.

Artist impression of Voyager 1, the first probe to traverse the heliosheath (NASA)
Artist impression of Voyager 1, the first probe to traverse the heliosheath (NASA)

In an effort to map the location and characteristics of the termination shock and heliosheath beyond, NASA scientists are preparing the Interstellar Boundary Explorer (IBEX) for launch in October. IBEX is part of NASA’s Small Explorer program (SMEX), where inexpensive, small probes are used to efficiently observe particular cosmic phenomena. IBEX will be orbiting beyond the influence of the Earth’s magnetic field (the magnetosphere) at a 200,000 mile distance from the Earth. This is because the phenomenon IBEX will be observing can be generated by our own magnetic field. So what will IBEX be measuring? To understand the interaction between solar wind ions and the interstellar medium, IBEX will use two sensors to detect energetic neutral atoms (ENAs) being blasted from the outermost reaches of the solar system.

How are ENAs generated and how are they a measurement of the interaction between the heliosphere and the ISM? Out there in the ISM exists neutral atoms and ions. As the solar system passes through interstellar space, the strong magnetic field generated around the heliosphere deflects the charged ions, pushing them out of the way. However, slow-moving neutral atoms are not affected by the magnetic field and penetrate deep into the heliosheath. When this happens, these neutral atoms from the ISM interact with energetic protons (which do have charge) rapidly spiralling along the magnetic field embedded in the solar wind. When this interaction occurs (known as charge exchange), an electron is stripped from the ISM atom and attracted to the energetic solar wind proton, thus making it neutral. When this exchange occurs, an energetic hydrogen atom (electron and proton) is ejected. An ENA is born.

Artist impression of IBEX (NASA)
Artist impression of IBEX (NASA)

Now, this is where the clever bit comes in. As mentioned before, neutral atoms do not “feel” magnetic fields, so when ENAs are created they are ejected in a straight line. Some of these atoms will be directed toward the Earth. IBEX will then measure these ENAs and work out where they came from. As they will have travelled directly to IBEX, the location of the termination shock may be deduced. Over a period of time, IBEX will be able to build up a picture of the locations of these atomic interactions and relate them the characteristics of the boundary of our Solar System.

But the best thing is, we won’t need to send a probe into deep space and wait for decades before it traverses the boundary layer, we will be able to make these measurements from Earth orbit. Such an exciting mission. Roll on the Pegasus rocket launch October 5th, 2008!

Source: Physorg.com

If Life Exists on Venus, Could it be Blown to Earth?

Venus Express observation of Venus, solar wind blowing atmospheric gases into space (ESA)

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We’ve heard about the possibility of extraterrestrial life arriving on Earth from another planet, asteroid or comet, but the mode of transport usually includes a chunk of rock falling through the atmosphere as a meteorite. But there could be another form of interplanetary transportation. What if there are microbial forms of alien life floating in the upper atmosphere of Venus (the planet’s clouds contain compounds that could indicate presence of micro organisms)? Could they make the trip to Earth? Apparently it is possible, if Earth and Venus are correctly aligned, the solar wind may carry microbes from the upstream Venus to downstream Earth in a matter of days…

Earth and Venus are often referred to as ‘sisters’ as their size and geology are very similar. Although the Venusian surface may appear unsuitable for life to thrive (the temperature and atmospheric pressures are very extreme), it may be possible that microbial life exists in the clouds. As Nancy pointed out in her recent article about colonizing Venus, the environment 50 km above the Venusian surface is the most terrestrial-like in the whole of the Solar System (except Earth of course).

So it should come as no surprise that some scientists believe this may be a good location to search for the most basic forms of life. Two such scientists are Prof Chandra Wickramasinghe and Dr Janaki Wickramasinghe from the Cardiff Centre for Astrobiology, UK, who believe the chemical composition of Venus clouds are consistent with the presence of micro-organisms. Their research uses data from Venus Express (launched by ESA in 2005) which is currently orbiting the planet, trying to understand why Venus is so different from the Earth after 4.6 billion years of planetary evolution.

So the Wickramasinghe’s think that Venus and Earth are not only geologically similar, they may be biologically similar too. “Venus and Earth have often been referred to as sisters because of their geological similarities. Our research proposes that the two sisters may be biologically interconnected as well,” Chandra says. But they don’t stop there. If life does exist in the Venusian cloud tops, perhaps these micro organisms can survive the trip through space, seeding the terrestrial atmosphere. Naturally, this can only occur if the planets are in alignment, so the solar wind can erode the Venus atmosphere, transporting microbes as it does so.

However, the life on Venus theory has its critics. “The idea of life on Venus, particularly the clouds where the temperature and pressure are similar to the Earth, has been floated around for a while but is not really very likely,” says Prof Fred Taylor, a planetary scientist at Oxford University.

This is however an interesting field of research that may go to some way in explaining the phrase and book title: “Men Are From Mars, Women Are From Venus.” So, looking for life on Mars and Venus doesn’t seem so outrageous after all…

(A thank you goes to my friend Ross Fenion who sent me the lead to this story and made the “…Women Are From Venus” link, it wasn’t me…)

Source: BBC

Astronomers Discover a Supernova/Gamma Ray Burst Hybrid

Spiral galaxy NGC 2770 with two supernovae SN 2007uy and SN 2008D. Credit: NASA

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Just when we thought we were beginning to understand what supernovae and gamma ray bursts were all about. Astronomers have just uncovered the true nature of what they thought was a regular supernova observed in January. At the time, it looked like a supernova emitting a 5-minute long burst of X-rays. But these X-rays were of a lower energy (known as “soft” X-rays) than expected leading some to believe this was a normal emission from a supernova explosion that was being observed during detonation (astronomers don’t usually get the chance to observe a star as it explodes and usually have to make do with analysing the supernova remnant). However, it is now believed this strange supernova event may have been emissions from a dying star at an intermediate mass, neither producing a supernova nor a gamma ray burst, but a combination of both…

Orbiting above Earth on January 9th 2008, the NASA/STFC/ASI Swift telescope caught a rare glimpse of what seemed to be a “normal” supernova at the precise moment of detonation. This observation was completely by luck, as Swift was already observing a supernova remnant (SN 2007uy) in spiral galaxy NGC 2770 that had exploded the previous year (90 million light-years away near the Lynx constellation). Then, as Swift was retrieving data from the SN 2007uy remnant, SN 2008D blasted a 5-minute long burst of X-rays in the same galaxy making this the first supernova to be directly observed.

However, looks can be deceiving. Researchers from a host of institutions including Italian National Institute for Astrophysics (INAF), the Max-Planck Institute for Astrophysics (MPA) and the European Southern Observatory (ESO) have analysed the supernova data thoroughly and at first agreed with the original assessment that it was indeed “normal.”

What made this event very interesting is that the X-ray signal was very weak and ‘soft’, very different from a gamma-ray burst and more in line with what is expected from a normal supernova.” – Paolo Mazzali, INAF’s Padova Observatory/MPA, research leader.

Dana Berry/SkyWorks Digital
Artist impression of the twin jets from a GRB. Credit: Dana Berry/SkyWorks Digital

However, astronomers at the Asiago Observatory in Northern Italy had designated the event as a Type 1c supernova, more commonly associated with long-period gamma-ray bursts. Type 1c supernovae are generated by hydrogen-poor progenitor stars with helium-rich outer layers prior to exploding at the end of their lives. But SN 2008D generated soft X-rays more associated with smaller stellar explosions. Therefore SN 2008D was probably produced by a star that was massive at birth (approximately 30 solar masses), rapidly using up its hydrogen fuel in its short life until it was only 8-10 solar masses. At this point it exploded, probably creating a remnant black hole. This chain of thought has led Paolo Mazzali and his team to think SN 2008D was produced by an object of a mass at the boundary of a normal supernova and gamma-ray burst.

Since the masses and energies involved are smaller than in every known gamma-ray burst related supernova, we think that the collapse of the star gave rise to a weak jet, and that the presence of the Helium layer made it even more difficult for the jet to remain collimated, so that when it emerged from the stellar surface the [X-ray] signal was weak.” – Massimo Della Valle, co-investigator.

Researcher and co-author Stefano Valenti points out that this discovery indicates that all black hole-producing supernovae have the potential to be gamma-ray burst progenitors. “The scenario we propose implies that gamma-ray burst-like inner engine activity exists in all supernovae that form a black hole,” he added.

Source: ESO

Project Lucifer: Will Cassini Turn Saturn into a Second Sun? (Part 1)

Project Lucifer. Could the plutonium fuel onboard the Cassini mission cause a nuclear chain reaction on Saturn? Credit: NASA/US Department of Defense

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The story: On October 15th 1997, the Cassini-Huygens mission blasted off from Cape Canaveral Air Force Station to explore Saturn and its moons. It continues to study the ringed gas giant today and its mission has been extended till 2010. Cassini is is powered by 32.8 kg (72 lbs) of plutonium fuel. A radioactive power source is the only option for missions travelling beyond the orbit of Mars as sunlight is too weak for solar panels to be effective. However, NASA (in association with secret organizations, such as the Illuminati or the Freemasons) wants to use this plutonium for a “higher purpose”, dropping Cassini deep into Saturn at the end of its mission where atmospheric pressures will be so large that it will compress the probe, detonating like a nuclear bomb. What’s more, this will trigger a chain reaction, kick-starting nuclear fusion, turning Saturn into a fireball. This is what has become known as The Lucifer Project. This second sun will have dire consequences for us on Earth, killing millions from the huge influx of radiation by this newborn star. Earth’s loss becomes the Saturn moon Titan’s gain, suddenly it is habitable and the organizations playing “God” can start a new civilization in the Saturn system. What’s more, exactly the same thing was attempted when the Galileo probe was dropped into Jupiter’s atmosphere in 2003…

The reality: Now that the Cassini mission has been extended by two years, we can expect this conspiracy theory to become more and more vocal in the coming months. But like the Galileo/Jupiter/second sun theory, this one is just as inaccurate, once again using bad science to scare people (much like Planet X then)…


So what happened when Galileo dropped into Jupiter?

NASA
Galileo undergoing preparations before launch in 1989. Credit: NASA

Well… nothing really.

In 2003, NASA took the prudent decision to terminate the hugely successful Galileo mission by using its last drops of propellent to push it at high speed into the gas giant. By doing so, this ensured the probe would burn up during re-entry, dispersing and burning any contaminants (such as terrestrial bacteria and the radioactive plutonium-238 fuel on board). The primary concern about letting Galileo sit in a graveyard orbit was that if mission control lost contact (very likely as the radiation belts surrounding Jupiter were degrading the probe’s ageing electronics), there may have been the possibility that Galileo would crash into one of the Jovian moons, contaminating them and killing any possible extra-terrestrial microbial life. This was a serious concern, especially in the case of Europa which could be a prime location for life to thrive below its ice-encrusted surface.

Now this is where the intrigue begins. Long before Galileo plummeted into Jupiter’s atmosphere, conspiracy theorists cited that NASA wanted to create an explosion within the body of the gas giant, thus igniting a chain reaction, creating a second sun (Jupiter is often called a ‘failed star’, although it has always been way too small to support nuclear reactions in its core). This was proven wrong on many counts, but there were three main reasons why this could not happen:

  1. The design of the radioisotope thermoelectric generators (RTGs) supplying energy to the craft wouldn’t allow it.
  2. The physics behind a nuclear explosion (nuclear fission) wouldn’t allow it.
  3. The physics of how a star works (nuclear fusion) wouldn’t allow it.

Five years after the Galileo impact, Jupiter still looks to be in fine health (and it certainly isn’t close to being a star). Although history has already proven you can’t create a star from a gas giant using a space probe (i.e. Jupiter + ProbeStar), conspiracy theorists think that NASA’s evil plan failed and there is some evidence that something did happen after Galileo got swallowed by Jupiter (and that NASA is pinning their hopes on the Cassini/Saturn combo).

Cue the Big Black Spot

The mystery black spot in 2003 (by Eric Ng) compared with one of the Shoemaker-Levy 9 fragment impact sites in 1994 (NASA)
The mystery black spot in 2003 (by Eric Ng) compared with one of the Shoemaker-Levy 9 fragments impact sites in 1994 (NASA)

Backing up the conspiracy theorists’ claims that there was an explosion inside the Jovian atmosphere after Galileo hit was the discovery of a dark blob near the equator of Jupiter a month after the event. This was widely reported across the web, but only a couple of observations were made before it disappeared. Some explanations pointed out that the blob could have been a short-lived dynamic atmospheric feature or it was a shadow from one of the Jovian moons. After this initial excitement, nothing else surfaced about the phenomenon. However, some were keen to point out that the dark patch on Jupiter’s surface may have been a manifestation of a nuclear detonation from Galileo deep within the planet which, after a month, eventually floated to the surface. Comparisons had even made with the 1994 features generated by the impact of the pieces of Comet Shoemaker-Levy 9 (pictured above).

What ever the cause of this dark feature, it didn’t come from Galileo as a nuclear detonation simply was not possible. What’s more, a nuclear detonation from the Cassini mission when it enters Saturn’s atmosphere in 2010 is also impossible, and here’s why…

The Radioisotope Thermoelectric Generators (RTGs)

NASA
The Cassini RTG, one of three on board. Credit: NASA

RTGs are a tried and tested technology in use since the 1960’s. Various RTG designs have been used on a huge number of missions including Pioneer 10, Pioneer 11, Voyager 1, Voyager 2, Galileo, Ulysses, Cassini and, most recently, New Horizons. RTGs are a very dependable source of power for space missions where solar panels have not been an option. For Cassini, if solar panels were used, they would need to have a huge area to collect the meagre sunlight at 10 AU, thus impractical to launch and operate.

The three RTGs on board Cassini are fuelled by small pellets of plutonium-238 (238Pu) encased separately in shock-proof containers known as general purpose heat source modules. There are 18 modules in each RTG. Through the use of thermocouples, the steady heat generated by the radioactive decay of the plutonium isotope is converted into electricity to supply Cassini. It is worth noting at this point that 238Pu is not weapon grade (i.e. it is very difficult to generate nuclear fission, 239Pu is more suited for this purpose). There are also dozens of Radioisotope Heater Units (RHUs) on board Cassini that provide a steady heat to critical subsystems, which contain single pellets of Pu-238. Again, these units are separated and shielded, each weighing 40 grams. For more details on this, check out the NASA Factsheet: Spacecraft Power for Cassini.

Inside an RHU and RTG (Roland Piquepaille)
Inside an RHU and RTG (Roland Piquepaille)

Shielding is critical for each plutonium pellet, primarily to prevent radioactive contamination during launch of space missions. Should there be an incident during launch, space agencies such as NASA must assure the containment of the radioactive material. Therefore all RTGs and RHUs are completely safe regardless of the stresses they are put under.

So, like Galileo, Cassini will hit Saturn’s atmosphere at a high velocity (Galileo hit the Jovian atmosphere at a speed of 50 km/s) and disintegrate very quickly before burning to a cinder. The point I want to highlight here is that Cassini will break apart like any fast-moving object during re-entry.

Still, conspiracy theorists are quick to point out that Cassini is carrying a huge amount of plutonium, totalling 32.8 kg (even though it is not the weapon-grade 239Pu and all the bits of 238Pu are tiny pellets, encased in damage-proof containers, being scattered through Saturn’s atmosphere). But ignoring all the logical arguments against, it will still generate a nuclear explosion, right?

Alas, no.

So how does a nuclear bomb work anyway?

David A Hardy
Artist impression of Galileo burning up when falling into the Jovian atmosphere. Credit: David A Hardy

For a general run-down of the basics behind a nuclear weapon, check out the very clear description at How Stuff Works: How Nuclear Bombs Work (scroll down to “Implosion-Triggered Fission Bomb,” as this is what the conspiracy theorists believe Cassini will emulate).

So there’s Cassini, plummeting through Saturn’s atmosphere in two years time. As it gets deeper, bits fall off and burnt by the friction caused by re-entry. When I say fall off, I mean they are no longer attached. For a nuclear detonation to occur we need a solid mass of weapon grade plutonium. By solid mass, I mean we need a minimum amount of the stuff for nuclear fission to occur (a.k.a. “critical mass”). The critical mass of 238Pu is approximately 10 kg (US DoE publication), so Cassini has enough 238Pu for three crude nuclear bombs (ignoring the fact that it is very difficult to build a 238Pu weapon in the first place). But how could all those tiny pellets of 238Pu be pulled together, in free-fall, casings removed, letting the pressure of Saturn’s atmosphere force it all together tipping it toward critical mass? Is that really possible? No.

An imploding nuclear weapon (answers.com)
An imploding nuclear weapon (answers.com)

Even if by some chance all the 238Pu in one RTG melded together, how would it detonate? For detonation of an implosion-triggered fission bomb to occur, sub-critical masses need to be forced together at the same instant. The only way this is possible is to surround the sub-critical masses with high-explosives so a shock wave rapidly collapses the sub-critical masses together. Only then may a chain reaction be sustained. Unless NASA has been really sneaky and hidden some explosives inside their RTGs, detonation is not possible. Using atmospheric pressure alone is not a viable explanation.

Now we can see that it is pretty much impossible for the plutonium on board Cassini to create a nuclear explosion. But if there was a nuclear detonation, could a chain reaction occur? Could Saturn become a star?

Find out in Part 2 of Project Lucifer: Will Cassini Turn Saturn into a Second Sun?

(A special thanks goes to Selene Spencer at Paranormal Radio for highlighting this topic on their website’s discussion forum.)