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ESA Launches GOCE To Map Earth's Gravity
DSG2 sends in an ESA press release which reads in part: "This afternoon, the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite developed by the European Space Agency was lofted into a near-Sun-synchronous, low Earth orbit by a Rockot launcher lifting off from the Plesetsk cosmodrome in northern Russia. GOCE is the first of a new family of ESA satellites designed to study our planet and its environment in order to enhance our knowledge and understanding of Earth-system processes and their evolution, to enable us to address the challenges of global climate change. In particular, GOCE will measure the minute differences in the Earth's gravity field around the globe." One consequence of mapping the planet's geoid in finer detail is that ocean currents can be limned more accurately. This BBC article from 2007 goes into some detail about this application.
There's that word again; "heavy." Why are things so heavy in the future? Is there a problem with the earth's gravitational pull?
There's no -1 for "I don't get it."
what really interests me is the fact that this satellite in such a low orbit that it actually has wings and an aerodynamic body to cope with the small amounts of air on that height. Those wings combined with the ion motor's onboard make it almost a plane/ satellite hybrid.
Article title: ESA Launches GOCE To Map Earth's Gravity ...to enable us to address the challenges of global climate change.
Article quote:
Great. Now we're going to have to start ejecting people into orbit because they stayed under their carbon credits quota, but they had too much gravitational pull and that's damaging the environment. I can just see the green movement in five years: "Stop warping spacetime! Excercise! And screw the whales."
#fuckbeta #iamslashdot #dicemustdie
GOCE is a gravity measuring satellite -- the spiritual successor to the amazing GRACE pair of satellites from a few years ago.
GRACE works by flying two satellites in the same orbit, one a few dozen miles ahead of the other. By monitoring the distance between the satellites with laser rangefinders, one can measure how strong gravity is -- the more gravity, the faster the satellite goes, so the distance between the satellites grows until the second one reaches the same area. This was the state-of-the-art, and GRACE made some amazing measurements. It was able, for instance, to measure the amount of extra groundwater during flooding along the Mississippi.
But GOCE does it all with one satellite. Where the baseline for GRACE was many miles, for GOCE it is just 50 cm.
Now, if you think about it, in any satellite, the amount of gravity you would feel is zero...or at least, very very close to zero, as you are orbiting inertially. But, really, gravity is only zero right at the center of mass of the satellite. You'd feel a tiny amount of acceleration the further you go. As you go toward the center of the earth, you would be in a lower orbit, and you would be pulled down with respect to the satellite.
GOCE measures this microgravity to rediculous precision. By measuring the difference in gravity affecting two test masses 50 cm apart, it can measure how strong gravity is at that point. It should have much better accuracy, and far better resolution, than GRACE.
GOCE is amazing in other ways, too. It flies very low, to get better resolution. So, it has fins! A satellite with fins, to keep it pointing along the direction of travel. Because there is some tiny amount of air drag at the altitude it is flying, GOCE has a tiny xenon ion engine pushing it along to keep it at the same altitude, and to keep the air drag on the satellite from overwhelming the gravity measurement.
Hats off to ESA, this is an amazing machine!
I love Mondays. On a Monday, anything is possible.
For 24 months, GOCE will collect three-dimensional gravity data all over the globe. The raw data will be processed on the ground to produce the most accurate map of the Earth's gravitational field to date and to refine the geoid: the actual reference shape of our planet. Precise knowledge of the geoid, which can be considered as the surface of an ideal global ocean at rest, will play a very important role in further study of our planet and, with any luck, by detecting subtle changes in gravitational potential, it will be able to provide mankind with its first indirect measurement of your girlfriend's mass.
Why not use a unfeasibly massive cloud of Internet grid connected next generation aspect oriented sensors instead? Spam everyone on the Internet, and ask them in which direction gravity is manifesting itself in their part of the world. I think most respondents will reply "down."
On the serious side, serious scientists have proposed using laptop accelerometers to detect earthquakes: http://www.wired.com/science/planetearth/news/2008/03/quake_network
Maybe something free on the iPhone App Store could help the gravity folks out? You get a pop-up: "Please drop your iPhone from exactly one meter to the ground. We will now measure the impact time. Thank you."
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
...knowledge and understanding of Earth-system processes and their evolution,...
We all know that Evolution and Gravity are just theories and there's no concrete evidence that they exist. Okay? We also need to teach "Intelligent Downward Pull". There may be some intelligent force that really loves us and doesn't want us flying off into space - upon which we'd hit the Sun because it revolves around the Earth.
When did "Global Warming" become politically incorrect and "Climate Change" became politically correct?
When they realized they might be wrong.
#fuckbeta #iamslashdot #dicemustdie
You can have both global warming and local cooling.
For instance, one possible effect is that while the average temperature over the whole planet does rise (global warming), the melting of the ice will shutdown the gulf stream and make some countries like Britain colder.
It's down.
Unexpect the expected!
http://en.wikipedia.org/wiki/Rockot
It's a rather small Russian rocket.
The average global temperature has been going up, much more so in recent years. Thus the term "global warming." When some scientists predicted that if the earth gets hot enough there might be a catastrophic rebound and another ice age the term "climate change" began to be used. It's more accurate, since the warming may lead to extreme cooling.
Not a sentence!
Now if only we could launch a satellite to keep an eye on carbon...we did? What happened?
Would it be possible to pin-point the location of impact to the Earth that formed our Moon? I would think the impacted site would be more dense from compression.
Then again, I'm no geologist.
Life is not for the lazy.
As a climate scientist, I've seen that shift in wording too. I think it was largely a PR move, designed to combat fundamental misconceptions that laymen have regarding "Abrupt Climate Change" (the officially accepted title).
I'm embarrassed to admit it, but climate change has me pretty scared. I might live to see some of the effects (drought, famine, extreme weather) and I wonder if my life will be as comfortable as my parents was. I used to assume that advancing technology would make my life much better, and I'm just now coming to grips with the possibility that it won't.
But what really scares me is the ostrich-like manner with which people react to the problem. They seem to be in denial, which is understandable. Scientists aren't bringing good news, so it's natural to be resentful. But I figured that some deep survival mechanism would kick in eventually as people looked at the rigorous nature of the modeling, the diverse data sets all leading to the same conclusions, and the myriad positive feedback effects that makes climate change accelerate on its own.
Instead, people seem to react as though the existence of climate change is somehow a political question rather than a scientific question. They don't seem to be looking at that evidence. Instead, they seem to decide that their political party's position on climate change is "X", so they believe "X". (Note that I'm talking about the existence of anthropogenic abrupt climate change. I realize that our response to climate change is a legitimate political question.)
No. Currently ICBM's are accurate anywhere from 1 to 100 cm. It doesn't really matter if it's off even 5x that amount, the target will get hit or be incinerated.
Custom electronics and digital signage for your business: www.evcircuits.com
Speaking of earthquakes, we had a small tremor a week or so ago here in Melbourne, Australia. We just had another one a short while ago. I'm sure there are people on here who live where they get earth tremors all the time but it's unusual to have two in a short space of time down here.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Currently ICBM's are accurate anywhere from 1 to 100 cm.
American and Russian ones, because these nations have their own gravity mapping satellites. (and I believe the number was somewhere around 100m, i.e. the payload has a 50% chance of landing in a circle with 100m diameter of the target).
Can you say the same about French and British ICBMs? Do the US share all of the significant digits of their gravity maps? Do they keep them up to date, too?
Global warming is a consequence of climate change. Global cooling is a consequence of climate change.
I am not a denier, but I am not about to be told we must halt climate change. This is a phenomenon that is as old as the earth, and to think we can just stop it when we want to is ludicrous. If you want to limit our impact on that change, fair enough. But don't tell me it has to stop, because you make yourselves look like idiots. The climate has changed in cycles, and despite the CO2 lobbys best propoganda, the climate was already on an upward curve regarding CO2 before we even discovered fire. And if you take those same records which are used to promote the current scare tactics, you would see that after it (CO2) goes up, it goes down - way way down. It is cyclic.
So even if we completely stop producing CO2 now, the cycle will continue. So you are left with politics. The real question is one of adaptation, not prevention. It amuses me when people blame cows for farting too much, completely forgetting there are billions of humans farting too. And as our population continues to increase, we will rely more and more on vegetable matter to survive, and this makes us fart even more. It's us that causes the problem right down to our basic existence.
So go ahead and do your worst. The only way to stop climate change is to kill the planet. We are better off finding ways to live with it. We are responsible for the crops that will suffer in a warmer world. We helped their colonisation much better than they would have done on their own. We bred cattle. We use fresh water for more things than there is sufficient fresh water to accomplish, and waste it. We over fish the seas, poach wildlife, deforest whole areas and drive animals to extinction. We use chemicals to eradicate species we don't find a use for, even when we don't know what that means for other species in that chain. Then we let chemicals run into the seas killing and mutating who knows what in the process. Worrying about the climate is secondary to all those concerns IMHO.
But then I've always been a "happy camper". I try not to leave any evidence of my passing. Like grasshopper on the rice paper, you try to leave no mark. The current world seems to care only about what it wants, not what it should do, or how it should do it. Fuck the consequences. Well it seems like in Soviet Russia, the consequences fuck you !
To be honest, I'll be dead long before this starts to bite and I have no kids, so I'm finding it hard to care too much. On principal I care, but for practical purposes, it's already too late. I live in a one room flat. I use no gas for cooking, only electricity. I don't have central heating or air-con. I have a car (17 years old, 45 mpg, 0.16% volume CO2 [limit is 3.5%])that is used maybe once a week. I'm not obese, I recycle where possible and I resist convenience products. What else can I do anyway ? But senior climate scientists find it acceptable to fly around the world just to have meetings on the serious state of global warming.
??????
Half of the word in the name are ignored. They just picked a few letters that could make a sound.
It's a crapronym! (c) 2009 Apeiron
Crapronym - a kludge of an acronym that ignores the rules of abbreviation
Look, if you can't give a project a name like, Percy or "The Gravity Observation Thing", at least go with an honest unpronounceable abbreviation. You can leave out the articles and prepositions if helps. But this is just laziness.
Utilizing the synergization of benchmark e-solutions to pre-workaround action items!
IPCC is run by a political origination with an axe to grind. Al Gore, a Politician won a peace prize for little movie campaign. Can you blame people that they say its all politics these days.
Hell even ask about model details and your slammed with a global warming denier label. You don't get your question answered.
The science is now so obscured with media and other groups agenda bias that its pretty hard to claim its not all politics. Really what does your emotional state ("I'm pretty scared") have to do with the science?
I was in fact working with climate scientists for a while, and i was quite shocked that most think its appropriate to misrepresent the certainty of the models because they "know" best. Now tell me again why people shouldn't think that the science is just as politicized as the rest of the debate?
The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
I think the term global dimming more accurately describes a separate problem that is sometimes referred to as global cooling. Aerosols decrease the size of cloud droplets, thus increasing the albedo (whiteness) of the clouds. This reflects more sunlight back into space. Its effects have been seen in long-term sunlight brightness studies (in Israel) and in long term evaporation rate measurements (amazingly, evaporation depends on the number of photons hitting the surface rather than just the temperature, so it serves as an independent check of the phenomenon).
It's not such a big deal anymore because regulations were effective at curbing emissions of these aerosols. Unfortunately, it used to act to counter greenhouse gases like CO2...
I think we're talking about different things. You're talking about natural variability, and I'm talking about human-caused climate change. Scientists are aware that both phenomena exist, and based on the research I saw at the December 2008 American Geophysical Union conference, I'm fairly confident that we can tell how much climate variability is due to humans.
Vostok ice core data confirms that for nearly half a million years, the climate has changed cyclically. But in all that time, the maximum CO2 concentration never went above 300 ppm. (It's hit higher levels millions of years ago, but that was a slow and gradual change. Plus the Earth was essentially a different planet back then, with a different solar luminousity and biosphere so comparisons across that much time are tricky.)
I presume you're referring to the Vostok ice core data I just linked. You're right to say that natural variations are cyclic- that graph displays variations that are governed by (among other effects) Milankovitch cycles which are caused by periodic variations in the earth's orbit.
But I'll reiterate the point I made in my original post: CO2 concentrations are at 380 ppm today. That's a level it hasn't hit in the last half million years. If we're seeing natural variability alone, it's quite a coincidence that it occurs right when we started excavating fossil fuels to fuel a billion cars.
Plus, the Vostok data is a little difficult to analyze in this manner, but it seems like at Vostok the CO2 always increased 600 years AFTER the temperature started to increase. At least, that's the way it used to work. Right now, the CO2 concentration is at an unprecedented level but the temperature is barely above normal. Again, that suggests that we're not facing natural climate change, we're dealing with anthropogenic abrupt climate change.
I've read through their reports and rebuttals, and I've not seen any difference between the science they're reviewing and my own work (or the work of my colleagues or my advisor). In fact, some of my personal research results support their conclusions. I guess that means that my dissertation research is just politically motivated claptrap?
Wow. If you politely asked a climate scientist for details of their model, and got that reaction then you were talking to a pretty bad scientist. Alas, PhDs cannot be revoked...
The science isn't obscured from where I'm sitting, and it isn't for anyone within driving distance of a university library. Those biases you're talking about don't make it into the peer reviewed journals like Geophysical Research Letters. I'd recommend those sources over the secondhand sources that you're reading. They sound like horrible sources of information.
Umm... I'm not writing a scientific journal article right now. It's just an online forum. I definitely wouldn't include statements like that in my article submissions.
What a coincidence! I, too, work with climate scientists. And my experience with scientists in general is that they're much less likely to overstate their case than other people. Scientists are more likely to add caveats to their statements, and less likely to make statements of certainty when all that the evidence supports is "strong probability". What you're describing is just the normal way scientists act.
Show me an experiment from a peer reviewed journal article that you think is politicized. I'll review it and get back to you. On the other hand, if you were talking about Rush Limbaugh's editorial about climate science, then I think we mean different things when we use the word "science".
Holy shit, I completely misread that! I thought you said they DIDN'T think it was appropriate. Please post their names and research affiliations so I know who to avoid at conferences!
(The reason I misread that comment was, I think, because my experience from 10 years in science has been completely opposite to yours. Of course, it's possible that your experience was more representative than mine...)
No when they realized that stupid people were getting confused when they got hit by a big winter storm. "Dang it's cold! Guess we don't have none of that librul warmin here." /Cletus the slack-jawed yokel. The idea that destabilizing an equilibrium leads to extremes in both directions is too big a concept for people who can't correctly say how long it takes the earth to go around the sun.
snig
My experience is "anecdotal" evidence. But it is however my experience. They won't put in a journal. But when a reporter is asking....
The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
Instead, people seem to react as though the existence of climate change is somehow a political question rather than a scientific question.
It became political the moment it became obvious that it would cost something to fix. The evidence may not be in doubt, but like all finite resources, the mindset today is "take what you can now" -- not plan for tomorrow. The collapse of the social security system, medicaid, the global recession, all point to a fundamental lack of interest in the future. Politics globally has aquired a hedonistic taint. The evidence could be indisputable and as solid and proven as gravity but it wouldn't change people's reactions.
#fuckbeta #iamslashdot #dicemustdie
Last time I had data on ICBMs (80s?) a miss of 50 or 100 miles by an ICBM was considered a "near miss". /shrug