Stories tagged satellite

Apr
28
2011

A number of severe thunderstorms have swept through the SE US recently. Some storms generated tornadoes that were truly devastating. The news channels have many photos of the ground destruction. We can see the path of the storms in satellite images. Here is a link to one of those images.

A comparison of 250-meter resolution image from a NASA MODIS instrument at 0.65 µm and 0.87 µm visible channel images centered on Tuscaloosa, Alabama on 28 April 2011 showed signatures of a few of the larger and longer tornado damage paths from the historic tornado outbreak (SPC storm reports) that occurred on 27 April 2011. The yellow arrows point to some of the paths.

Here is a link to an animation between the two channelsMODIS Image of Tornado Paths on 28 April 2011: NASA Satellite image see tornado path
MODIS Image of Tornado Paths on 28 April 2011: NASA Satellite image see tornado pathCourtesy CIMSS UW-Madison

http://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2011/04/110428_m...

Aug
20
2010

We have heard about the many fires in Russia. NASA satellites have detected over 600 600 hotspots from wildfires within Russian territory in one day!

Fires produce a heat signature that is detectable by satellites even when the fires represent a small fraction of the pixel. Fires produce a stronger signal in the mid-wave IR bands (around 4 microns) than they do in the long wave IR bands (such as 11 microns). That differential response forms the basis for most algorithms that detect the presences of a fire, the size of the fire, the instantaneous fire temperature.

The unusually hot and dry mid-August conditions beneath a strong ridge of high pressure across British Columbia led to a major outbreak of wildfires across that western Canadian province. The satellite image shows the location of those fires as red squares. The smoke plumes are also seen on the satellite imagery.

Here's an image from a NASA instrument: The red squares are fire locations and the smoke from the fires is evident.
http://rapidfire.sci.gsfc.nasa.gov/gallery/?2010228-0816/BritishColumbia...

The aerosols released by fires and the degraded air quality caused by them represent tremendous costs to society, so reliable information on fire locations and characteristics is important to a wide variety of users. For this reason, NOAA tracks these plumes and makes them publically available from NOAA at:
http://www.osdpd.noaa.gov/ml/land/hms.html

Dec
26
2009

GOCE Satellite: The Gravity field and steady-state Ocean Circulation Explorer
GOCE Satellite: The Gravity field and steady-state Ocean Circulation ExplorerCourtesy ESA
Can it be true? Yes, for a mere $5,544 dollars round-trip airfare to Greenland! In March 2009, the European Space Agency launched the Gravity field and steady-state Ocean Circulation Explorer (GOCE) into orbit around our planet, which is now transmitting detailed data about the Earth’s gravity. The GOCE satellite uses a gradiometer to map tiny variations in the Earth’s gravity caused by the planet’s rotation, mountains, ocean trenches, and interior density. New maps illustrating gravity gradients on the Earth are being produced from the information beamed back from GOCE. Preliminary data suggests that there is a negative shift in gravity in the northeastern region of Greenland where the Earth’s tug is a little less, which means you might weigh a fraction of a pound lighter there (a very small fraction, so it may not be worth the plane fare)!

In America, NASA and Stanford University are also working on the gravity issue. Gravity Probe B (GP-B) is a satellite orbiting 642 km (400 miles) above the Earth and uses four gyroscopes and a telescope to measure two physical effects of Einstein’s Theory of General Relativity on the Earth: the Geodetic Effect, which is the amount the earth warps its spacetime, and the Frame-Dragging Effect, the amount of spacetime the earth drags with it as it rotates. (Spacetime is the combination of the three dimensions of space with the one dimension of time into a mathematical model.)

Quick overview time. The Theory of General Relativity is simply defined as: matter telling spacetime how to curve, and curved spacetime telling matter how to move. Imagine that the Earth (matter) is a bowling ball and spacetime is a trampoline. If you place the bowling ball in the center of the trampoline it stretches the trampoline down. Matter (the bowling ball) curves or distorts the spacetime (trampoline). Now toss a smaller ball, like a marble, onto the trampoline. Naturally, it will roll towards the bowling ball, but the bowling ball isn’t ‘attracting’ the marble, the path or movement of the marble towards the center is affected by the deformed shape of the trampoline. The spacetime (trampoline) is telling the matter (marble) how to move. This is different than Newton’s theory of gravity, which implies that the earth is attracting or pulling objects towards it in a straight line. Of course, this is just a simplified explanation; the real physics can be more complicated because of other factors like acceleration.

Albert Einstein
Albert EinsteinCourtesy none
So what is the point of all this high-tech gravity testing? First of all, our current understanding of the structure of the universe and the motion of matter is based on Albert Einstein’s Theory of General Relativity; elaborate concepts and mathematical equations conceived by a genius long before we had the technology to directly test them for accuracy. The Theory of General Relativity is the cornerstone of modern physics, used to describe the universe and everything in it, and yet it is the least tested of Einstein’s amazing theories. Testing the Frame-Dragging Effect is particularly exciting for physicists because they can use the data about the Earth’s influence on spacetime to measure the properties of black holes and quasars.

Second, the data from the GOCE satellite will help accurately measure the real acceleration due to gravity on the earth, which can vary from 9.78 to 9.83 meters per second squared around the planet. This will help scientists analyze ocean circulation and sea level changes, which are influenced by our climate and climate change. The information that the GOCE beams back will also assist researchers studying geological processes such as earthquakes and volcanoes.

So, as I gobble down another mouthful of leftover turkey and mashed potatoes, I can feel confident that my holiday weight gain and the structure of the universe are of grave importance to the physicists of the world!

Well, Japan probably doesn't say "Go" exactly, because I don't think it means the same thing in Japanese. But the country is prepared to shell out $21 billion for a space-based, energy-beaming solar power plant.

The same sort of thing was talked about in this post, but that project was being lead by an upstart company, which kinda makes me think that their satellite power plant is a long way off. Japan wants the technology ready inside of four years. (They don't expect the plant to be operating until about twenty or thirty years from now, though.)

The plan is for the satellite to produce about 1 gigawatt. From my super-lazy internet searches, it looks like that's about the same output as a nuclear power plant. Nuclear power plants are cheaper to build (this site says the cost can be around $10 or $15 billion per station), and you don't have to go into space to fix them. But then there's also the cost of obtaining and processing nuclear fuel, and then dealing with it afterwards. Apples and oranges, maybe.

But it's kind of an interesting project, I think.

Apr
18
2009

Almost everything we'll need, right here: Almost.
Almost everything we'll need, right here: Almost.Courtesy Stefan Thlesen
BTW, Buzzketeers, if I ever catch you using the term “the john” when talking about a toilet, I will erase you from the story of my life. Sure, I just used it, but think I have the right to take possession of that word to divest it of its hurtfulness. Sort of like how ugly people are allowed to call stuff “fugly.”

Anyway, let’s consider the future of energy. We all know that we have to start conserving fossil fuels, so that we can use them with abandon in a dune buggy-filled Mad Max style future. (I like to think of this as “saving it for the party.”) In the mean time, we have to get clever. This week I noticed a couple of stories about people thinking outside the box with regards to energy. In one case, they’re thinking above the box, in the other they’re thinking below the box. (Or maybe they’re thinking in the box. It depends on what you use your boxes for.)

Check it out: a company called Solaren Corp has convinced the largest energy utility in California to purchase 200 megawatts of solar power from them by around 2016. The way they propose getting that power is the interesting thing—they plan on getting it from space.

Wait… that was poorly phrased. All solar power comes from space. What Solaren intends to do is launch a massive array of mirrors (as large as several miles across) into orbit to collect and reflect sunlight onto photoelectric cells. The cells will convert the sunlight into electric power, which will then be converted into radio waves and blasted down to a receiver on Earth. The radio energy will then be turned back into electricity. Solaren claims that the system could eventually generate 1.2 to 4.8 gigawatts of power at a price comparable to that of other alternative energy sources, enough to power 250,000 homes in California. And unlike land-based solar panels, the flow of energy wouldn’t depend on weather, and the orbit would be high enough that the system could provide energy 24 ours a day. They intend to launch it up to about 22,000 miles above the surface of the planet, meaning that it would be just inside of a high Earth orbit, and therefore geosynchronous. (I think.) Pretty neat, huh?

However, getting a couple miles of mirrors up to 22,000 miles above Earth is a little tricky. A little tricky, and super expensive. Building the receiving systems isn’t going to be cheap either. Some folks think that the project is altogether… unlikely. But the California power utility isn’t actually making an investment (i.e., taking a risk) they just promised to buy the power when it’s there (or if). But that commitment is probably comforting for investors.

Solaren says that the radio waves being sent back to Earth will be one sixth the intensity of sunlight. But what kind of radio waves are we talking about here? Visible light is composed of radio waves. So are radio, um, radio waves. Nope, we’re talking about microwaves. Microwaves have the advantage of being pretty high-energy. They have the disadvantage of being a little scary to me. And to other people. But it seems like it’s not all that dangerous; the center of the microwave beam would have an intensity of about 23 milliwatts per square centimeter. The limit for workplace exposure to microwaves in the US is 10 mw/cm2, so obviously 23 mw/cm2 is beyond what the government considers safe, but the area of maximum intensity is relatively small. Near the outside of the receiving array, the intensity would be closer to 1 mw/cm2. Birds flying through the center of the beam could have some trouble, and small aircraft and hot air balloons would do well to avoid it, but the metal shell of conventional planes should protect passengers entirely (the same way that your metal microwave protects you from the forces cooking your food). I suppose a super-villain could always hack into the satellite controls, and re-aim the system at a neighborhood. But that’s assuming that it ever gets built.

So from pie in the sky (a huge mirror pie), let’s turn our attention to fudge underground. It doesn’t have quite the sunshiny appeal of space mirrors, but it’s a little more feasible at the moment.

Remember how, in Mad Max 3: Beyond Thunderdome, Master Blaster was harvesting methane fuel from pig feces? Well, that works in the real world too, and not just with pig feces.

Consider the following: if you were to safe all of your… solid waste for one year, you could produce an amount of fuel equivalent to about 2.1 gallons of diesel fuel. I know—it doesn’t seem as much a it should, right? But if a city of 250,000 people was converting its waste into fuel, they’d have enough to drive 80 buses 62,000 miles each. If that figure sounds oddly specific, it’s only because that’s what Oslo, Norway intends to do. The city is all set to fuel its public transportation with brown gold. (Or with the biomethane produced by it.)

The cost of producing an amount of biomethane equivalent to a liter of diesel fuel comes to about 98 cents, while a liter of diesel costs about $1.30 at the pumps in Norway. And, unlike some other biofuels we won’t mention, it only gets into your food supply after you’ve eaten it.

Because the fuel comes from recently grown organic materials, it’s supposed to be carbon neutral, which is good. The article doesn’t say how energy intensive the process of making it is, though. Also, methane itself is a pretty bad greenhouse gas, but I suppose if it’s all burned efficiently that shouldn’t be a problem. (Burned methane makes CO2 and water.)

Energy may be plentiful in the future. We’ll just have to watch where we step.

The collision between two large satellites on February 10 has created a cloud of debris that likely will cause problems in Earth orbit for decades.
Source: Universe Today.

Not our moon, but Europa, a moon of Jupiter. Scientists are planning new missions to explore Europa, which they now believe contains a water-filled ocean, and possibly life.

Oct
02
2007

Sputnik 1 starts space race 50 years ago


Sputnik 1: Oct. 4, 1957
The "Sputnik crisis" was a turning point of the Cold War that began on October 4, 1957 when the Soviet Union launched the Sputnik 1 satellite. With its intercontinental ballistic missile, the R-7 Semyorka, Russia was first out of the starting blocks in the space race.

The "simplest satellite"

Called PS-1, for "Prosteishiy Sputnik" — the Simplest Satellite, Sputnik 1 weighing just 184 pounds, was built in less than three months. Soviet designers built a pressurized sphere of polished aluminum alloy with two radio transmitters and four antennas.

Sergey Korolyov

Sergey Korolyov, both visionary scientist and iron-willed manager, pressed the Kremlin to let him launch a satellite. The reaction of the world so impressed Khrushchev that he pressed Korolyov to do it again. Working round-the-clock, Korolyov and his team built another spacecraft in less than a month. On Nov. 3, they launched Sputnik 2, which weighed 1,118 pounds. It carried the world's first living payload, a mongrel dog named Laika, in its tiny pressurized cabin.

Sputnik creates initiatives in science and math

The Sputnik crisis spurred a whole chain of U.S. initiatives, including NASA, NSF, DARPA, and even the "New Math".

The finish line - stepping on the Moon

Russia continued its lead in the space race with a moon probe, a photo of the far side of the Moon, a human in orbit, a woman in orbit, extra-vehicular activity, landing a probe on another planet (Venus), and the first space station. The United States captured the biggest prize, though, putting a human on the Moon (July 20, 1969).

We've previously posted about Comet McNaught over Minneapolis. NASA's STEREO satellite, which is normally used to look at our sun, caught some awesome pics of this super close comet. Watch the movie of Comet McNaught.

Aug
19
2006

Satellite vulnerability: Photo from Wikipedia Commons
Satellite vulnerability: Photo from Wikipedia Commons

One possible solution

The high energy particles spewed out of sunspots can knock out satellites and electric power grids. To prevent this from happening the US Air Force and the US Defence Advanced Research Projects Agency (DARPA) have proposed using very low frequency radio waves to flush particles from radiation "belts" above Earth and dump them into the upper atmosphere over either one or several days.

What are the consequences?

This deluge of dumped charged particles would temporarily change the ionosphere from a "mirror" that bounced high frequency radio waves around the planet to a "sponge" that soaked them up, says Dr Craig Rodger of Otago University's physics department.
“Airplane pilots and ships would lose radio contact and some Pacific Island nations could be isolated for as long as six to seven days, depending on the system’s design and how it was operated,” he says.
GPS would likely also suffer large-scale disruptions, as signals between ground users and satellites were scrambled by the ionosphere, he added. Otego media release

Is it worth it?

Can people like Joe can go without geocaching for a week. Smart bombs also would need to take a breather because they use GPS to find their targets. We are seeing a minimum of sunspot activity right now. Sunspots peak every eleven years. The last memorable blast from the sun was July 14, 2000 so we need to make up our minds before 2011.