Cassini finds interstellar dust during its Solstice flyby of Enceladus

Wednesday, 20 April 2016

Saturn’s moon Enceladus is a frozen world, but it isn’t frozen solid. Colossal cryovolcanoes near the ice-locked moon’s south pole send plumes from its briny global ocean so far into space that they manage to feed bits of water ice into Saturn’s outermost rings. As part of the extended Solstice mission, NASA and the ESA sent Cassini diving through the plumes of these cryovolcanoes on a recent flyby of Enceladus. The intent was to scoop up particulate directly from the eruptions and find out what’s really going on below the moon’s icy surface. Far from just boring old water, Cassini found complex organic molecules, CO2, and even bits of Enceladus’ seafloor in the vaporous plumes.

But among the millions of pieces of ambient space dust and cryovolcano ejecta the orbiter found floating around Saturn, there were a very special few: thirty-six special particles that didn’t come from Enceladus, or even from Saturn. Cassini found grains of stardust condensed from the interstellar medium inside Saturn’s orbit.

Stardust inside the heliosphere isn’t totally unexpected. Back in the 90s, the Huygens probe found particles that the Galileo spacecraft later confirmed had come from the local interstellar cloud. But Cassini has a lot more instrumentation than Huygens. Cassini was designed to analyze “waves, particles, and fields” on the spot. That’s how the Cassini team decided these particles came from beyond our solar system: they were going too fast, and in the wrong direction, to have come from Saturn or even belong in an orbit around our Sun. When we pointed Cassini’s mass spec at those 36 dust particles, it reported that they were made not of ice, but of elements like calcium, magnesium, silicon and iron. These are rock-forming elements, and they’re produced by the death of huge stars.

Grains of stardust can be found preserved inside micrometeorites, and in that state they stay unchanged for billions of years. But the pieces of stardust that Cassini found are curiously homogenized in composition. “Surprisingly, the grains we’ve detected aren’t old, pristine and compositionally diverse like the stardust grains we find in ancient meteorites,” added Mario Trieloff, a co-author also at the University of Heidelberg. “They have apparently been made rather uniform through some repetitive processing in the interstellar medium.”

The authors speculate in their report on how this processing of dust might happen. Grains of dust and debris floating in a stellar nursery could be vaporized and recondense over and over, as shock waves from dying stars passed through. This could result in homogenized grains like the ones Cassini found zipping through the heliosphere out near Saturn. Whatever their extraction, lead author Nicolas Altobelli remarked that “[the] long duration of the Cassini mission has enabled us to use it like a micrometeorite observatory, providing us privileged access to the contribution of dust from outside our solar system that could not have been obtained in any other way.”

Continue Reading | comments

Volkswagen may settle with TDI diesel owners for $5,000; Audi developed emissions cheating software in 1999

As the Volkswagen dieselgate scandal has progressed, one enduring question has been how much the corporate executives knew, who authorized the adoption of the cheating technology, and when and how it was developed. We already know VW began using software “defeat devices” before the 2009 model year launched in the United States, but new information suggests the roots of the problem go even farther back — all the way to Audi and 1999.

The German publication Handelsblatt reports that it was Audi, not VW, that began working on a defeat device that would allow the company’s vehicles to turn parts of the engine off under certain conditions, but that the technology was never actually used by the luxury auto manufacturer. According to Reuters, it was this technology that VW relied on when it realized it couldn’t bring auto emissions under control through other means. This kind of internal development makes sense, since other manufacturers weren’t keen to work on the technology (Bosch sent VW a letter at one point warning it against deploying its products to circumvent air quality controls).

VW has already said it will significantly increase the amount of money it has set aside to deal with damages and claims associated with the EPA / CARB investigation. Currently the firm has allocated $7.6 billion dollars; analysts have suggested the total cost could be as high as €30 billion ($34 billion USD).

A slow investigation

The investigation into the scope of VW’s cheating has been slowed by the various ways that VW’s engineers actively obfuscated their conversation topic. Sources familiar with the ongoing probe have stated that the company used dozens of code words, including “acoustic software” to refer to the emission control defeat device, and that outdated and insufficient data retention practices have made it difficult to identify which individuals should be held accountable. Analyst Stuart Pearson with Exane BNP Paribas has stated he believes investors would tolerate €20-25 billion in costs if it simply means putting the issue behind VW.

VW is expected to argue that it should not be taken to trial if it can produce a solution for the emissions problems, but the company is due in court Thursday to state the terms of its agreement with regulators or face a courtroom. That deadline was pushed back from last month when the judge ruled that the two sides had made significant progress, there’s no word yet on whether or not VW will announce a solution tomorrow or ask for additional time. New rumors suggest that the EPA has reached an agreement and that VW owners will receive a check for $5,000, “with other conditions likely applied.”

The cozy regulator – auto industry relationship

There’s a larger problem here that we’ve alluded to in past stories, but that bears repeating in this context. Volkswagen cheated in a particularly egregious way and got caught doing it, but the hard truth is this: Long before VW acknowledged that it had cheated on US road tests, European publications were documented rampant deceit in both fuel economy and auto emissions.

This chart shows the difference between diesel emissions on paper and actual vehicle emissions.

This chart shows the gap between CO2 emissions. These results are the reason why European vehicles are often rated as being more efficient than their US counterparts, even when the exact same vehicle is sold on both sides of the Atlantic. European laws give manufacturers enormous amounts of leeway, allowing them to test vehicles at high-altitude sites with road surfaces so smooth, they alone impart a 3% fuel efficiency advantage. Companies are allowed to yank out sound systems, side mirrors, and all non-essential components; they can tape over panels and grills to improve wind resistance; they use low-resistance tires inflated with alternate gas blends; and they use different engine lubricants to improve efficiency.

The problem has only gotten worse in recent years. In 2001, vehicle scores were inflated by roughly 10%. They’re currently on track to hit 50%, which would make the EU’s official ratings about as useful for determining actual performance as a five year-old’s estimate of how many cookies he ate. The US doesn’t show the same gap between claimed and actual results, but the gap that exists has still been increasing in recent years.

If regulators on both sides of the pond are serious about stopping this kind of cheating, the solution can’t stop with penalizing VW. Clean air regulations that don’t actually get enforced are worse than no regulation at all. The presence of regulation means people will assume those regulations are actually being met when in reality, they aren’t.

Continue Reading | comments

Hawking, Zuckerberg unveil $10B plan to reach Alpha Centauri in 20 years

Thursday, 14 April 2016

A group called Breakthrough Initiatives, headed by Stephen Hawking, Russian philanthropist Yuri Milner, and Facebook’s Mark Zuckerberg, has maybe the most ambitious plan in human history: send a man-made mission to another star. This billionaire-funded project will involve a mothership, solar sails, super-lasers, and a swarm of near-light-speed probes no bigger than the common smartphone — if it ever gets off the ground, that is.

Dubbed Starshot, the idea itself is surprisingly novel given the amount of momentum it seems to have already. According to the plan, an Earth-based launch will put a “mothership” into space, loaded with about a thousand — yes, a thousand — interstellar probes described as roughly the size of an iPhone. These iProbes will disengage from the mothership, and each one will spread super-thin solar sails. Back on Earth, we’d then aim a yet-to-exist super-laser at these sails and blast them out in the direction of Alpha Centauri, our closest stellar neighbor.

.

According to their calculations, these tiny stellar sailors should travel about 600,000 kilometers in just two minutes, and at the end of this accelerating period will be traveling at up to a fifth of the speed of light. The beam loses coherence past this distance, so that’s what we’ll have to take. Alpha Centauri is just over four light-years away, so at 0.2c the team estimate their sail probes could reach Alpha Centauri in just over 20 years. Once there, they’ll user some sort of super-low-power propulsion system to reorient themselves, take readings, then beam those readings back to Earth. This would presumably be a part of Breakthrough Initiatives’ overall goal of finding alien life in the universe, but it could end up returning results that revolutionize just about any field within astronomy.

According to Milner, the big advances that make this possible have been in lasers, and the miniaturization of advanced computing and mechanical hardware. It’s only recently we could build the innards of these tiny starships, which will have to hold up to acceleration more than 60,000 times stronger than the force of gravity on Earth. Breakthrough has dubbed the eventual gram-scale starship brain they create the StarChip. Nice.

There are some very big and foreseeable obstacles to pulling all this off, however. First off, the sails in question would have to be extremely reflective to avoid being obliterated by their own super-laser — according to the New York Times, absorption of as little as a thousandth of a percent of the incoming energy would vaporize the sails entirely. They must also be incredibly thin and light, or ruin the whole concept of super small sat-lets, and rob the iProbes of their most meaningful advantage

Continue Reading | comments