It is estimated that two-thirds of sulfur dioxide (SO2) air pollution in North America comes from coal power plants. In a recent scientific article published in Geophysical Research Letters, a team of scientists have confirmed that SO2 levels in the vicinity of U.S. coal power plants have fallen by nearly 50% since 2005. .
Courtesy NASAThis finding, using satellite observations, confirms ground-based measurements of declining SO2 levels. In many parts of the world, ground-based monitoring does not exist or is not extensive; therefore, the Ozone Monitoring Instrument (OMI) on the Aura satellite could potentially measure levels of harmful emissions in regions of the world where reliable ground monitoring is unavailable..
Previously, space-based SO2 monitoring was limited to plumes from volcanic eruptions and detecting anthropogenic emissions from large source regions as in China. A new spatial filtration technique allows the detection of individual pollution sources in Canada and the U.S.
"What we’re seeing in these satellite observations represents a major environmental accomplishment," said Bryan Bloomer, an Environmental Protection Agency scientist familiar with the new satellite observations. "This is a huge success story for the EPA and the Clean Air Interstate Rule," he said.
Since July 2011, heavy monsoon rains in southeast Asia have resulted in catastrophic flooding. In Thailand, about one third of all provinces are affected. On Oct. 23, 2011, when this image from ASTER, the Advanced Spaceborne Thermal Emission and Reflection Radiometer instrument on NASA's Terra spacecraft was acquired, flood waters were approaching the capital city of Bangkok as the Ayutthaya River overflowed its banks. In this image, vegetation is displayed in red, and flooded areas are black and dark blue. Brighter blue shows sediment-laden water, and gray areas are houses, buildings and roads. The image covers an area of 35.2 by 66.3 miles (56.7 by 106.9 kilometers) and is located at 14.5 degrees north latitude, 100.5 degrees east longitude.
With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on Terra. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping and monitoring of dynamic conditions and temporal change.
What do a banana and a chunk of coal have in common? Carbon!
Dr. Peter Griffith, Director of NASA's Carbon Cycle and Ecosystems office, spoke to twenty of us training to be Earth Ambassadors for NASA about why it's important to teach people about the way carbon moves around on our planet, in order to help them understand climate change.
He showed us this fantastic video that describes the Carbon Cycle on earth and describes how "young, fast carbon" like that in a banana differs from "old, slow" carbon, like that in coal and other fossil fuels.
Dr. Griffith also described how you can tell the difference between objects containing old carbon and young carbon by looking at the radioactive decay of carbon 14. Carbon in its normal state is called carbon 12, or C12. However, cosmic rays, like those from the sun, convert some atmospheric carbon into a slightly radioactive form called carbon 14, or C14. Over time, this carbon decays back into Carbon 12.
All living plants and animals contain some C14, since they constantly take in atmospheric carbon dioxide.
Fossil fuels like coal and oil, which have been underground for millions of years, contain only C12 (fully decayed Carbon,) while a banana still contains some C14 from atmospheric carbon dioxide the banana tree absorbed.
It is not surprising that the carbon downwind of power plants burning coal is mostly C12. Trees can also lock up carbon in their trunks and branches in for many years.
The carbon released by burning fossil fuels and setting tropical forests ablaze is carbon that would naturally have remained "locked" up. Human activities like these are creating an excess of long-lived carbon dioxide gas in the atmosphere and are causing our world's climate to warm.
NASA and other scientists are working hard to study the science of climate change. How our planet and its inhabitants will respond to the challenges resulting from this change remains to be seen.
Courtesy NASA/JPL-Caltech Below is a news release from NASA/JPL about a comet that is going through some difficult times. NASA is sort of harsh in this release, imho, and really does not take the comet's feelings into account. Take a gander to see what I mean. Even the title is a little severe.
NASA Says Comet Elenin Gone and Should Be Forgotten
Latest indications are this relatively small comet has broken into even smaller, even less significant, chunks of dust and ice. This trail of piffling particles will remain on the same path as the original comet, completing its unexceptional swing through the inner solar system this fall.
"Elenin did as new comets passing close by the sun do about two percent of the time: It broke apart," said Don Yeomans of NASA's Near-Earth Object Program Office in Pasadena, Calif. "Elenin's remnants will also act as other broken-up comets act. They will trail along in a debris cloud that will follow a well-understood path out of the inner solar system. After that, we won't see the scraps of comet Elenin around these parts for almost 12 millennia."
Twelve millennia may be a long time to Earthlings, but for those frozen inhabitants of the outer solar system who make this commute, a dozen millennia give or take is a walk in the celestial park. Comet Elenin came as close as 45 million miles (72 million kilometers) to the sun, but it arrived from the outer solar system's Oort Cloud, which is so far away its outer edge is about a third of the way to the nearest star other than our sun.
For those broken up over the breakup of what was formerly about 1.2 miles (two kilometers) of uninspiring dust and ice, remember what Yeomans said about comets coming close to the sun – they fall apart about two percent of the time.
"Comets are made up of ice, rock, dust and organic compounds and can be several miles in diameter, but they are fragile and loosely held together like dust balls," said Yeomans. "So it doesn't take much to get a comet to disintegrate, and with comets, once they break up, there is no hope of reconciliation."
Comet Elenin first came to light last December, when sunlight reflecting off the small comet was detected by Russian astronomer Leonid Elenin of Lyubertsy, Russia. Also known by its astronomical name, C/2010 X1, Elenin somehow quickly became something of a "cause célèbre" for a few Internet bloggers, who proclaimed this minor comet could/would/should be responsible for causing any number of disasters to befall our planet.
Internet posts began appearing, many with nebulous, hearsay observations and speculations about earthquakes and other disasters being due to Elenin’s gravitational effects upon Earth. NASA’s response to such wild speculations was then in turn speculated to be an attempt to hide the truth.
"I cannot begin to guess why this little comet became such a big Internet sensation," said Yeomans. "The scientific reality is this modest-sized icy dirtball's influence upon our planet is so incredibly miniscule that my subcompact automobile exerts a greater gravitational influence on Earth than the comet ever would. That includes the date it came closest to Earth (Oct. 16), when the comet’s remnants got no closer than about 22 million miles (35.4 million kilometers)."
Yeomans knows that while Elenin may be gone, there will always be Internet rumors that will attempt to conjure up some form of interplanetary bogeyman out of Elenin, or some equally obscure and scientifically uninteresting near-Earth object. Thinking of ways to make himself any more clear about the insignificance of this matter is somewhat challenging for a scientist who has dedicated his life to observing asteroids and comets and discovering their true nature and effects on our solar system.
"Perhaps a little homage to a classic Monty Python dead parrot sketch is in order," said Yeomans. "Comet Elenin has rung down the curtain and joined the choir invisible. This is an ex-comet."
NASA detects, tracks and characterizes asteroids and comets passing relatively close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes the physical nature of a subset of them, and predicts their paths to determine if any could be potentially hazardous to our planet. There are no known credible threats to date.
Its like the person writing this had a personal vendetta against this poor comet. Though the Monty Python reference at the end helps lighten the mood, the overall dismissive tone of this news release is a bit sad.
Poor Elenin and its remaining "piffling particles".
Courtesy NASAFrom NASA’s Image of the Day this past Tuesday:
On Oct. 4, 1957, Sputnik 1 successfully launched and entered Earth's orbit. Thus, began the space age. The successful launch shocked the world, giving the former Soviet Union the distinction of putting the first human-made object into space. The word 'Sputnik' originally meant 'fellow traveler,' but has become synonymous with 'satellite' in modern Russian.
This past September 30, almost exactly 54 years later, China launched their first inhabitable space laboratory module, Tiangong-1. The module, a part of a large and ambitious national space program, is the first step in placing a larger modular space station in orbit by 2020.
Combine this effort with Chinese plans to visit the moon and a manned Mars mission, could this be the beginning of a new space race? Personally, I hope so. NASA needs a kick in the pants, and a little “friendly” competition with China could push NASA and its partners in a good way.
During the last two decades, the Upper Atmosphere Research Satellite was revolving about Earth. The satellite arrived at what National Aeronautics and Space Administration called "the end of a productive scientific life" a full six years ago. The atmosphere of Earth will burn up most of UARS when it passes down to the planet. Several huge pieces, however, are expected to strike land. Source of article: UARS satellite pieces have 1 in 3,200 chance of hitting Earth
A lengthy lived life
In 1991, the Upper Atmosphere Research Satellite was put into orbit. The satellite was meant to study the Earth's atmosphere, specifically the ozone layer. The UARS was not supposed to last long. It was only supposed to be around three years at first. UARS had 60 percent of instruments still working after 14 years, but NASA decided shutting it down was the best option. There was gold foil-like material covering most of UARS which is the size of a bus.
Concern with re-entry
NASA explained that the satellite is a “heavily decaying orbit.” Between September 22 and 24, the UARS is expected to get back to the Earth’s atmosphere. There will be up to 100 pieces of the satellite that won't melt away, although the atmosphere is expected to burn up most of it. The portions might be very heavy. They might weigh as much as 300 pounds. National Aeronautics and Space Administration believes that UARS most likely won’t hit ground. There's a 1 in 3,200 chance any piece will hit the ground. The only continent that is not within the fall zone is Antarctica. There is a 1 in 20 trillion chance that each piece will hit a person.
Two hours to get away
National Aeronautics and Space Administration is providing hourly updates on the status of the UARS satellite. Even with that, the best estimate is that NASA will be able to provide two hours' warning on the UARS re-entry. UARS is falling fast. This is because of the solar activity going on. The increased solar activity is also blamed for troubles with communications satellites. Though UARS is falling from the sky easily, it is just one of the estimated 22,000 portions of "space junk" revolving about the earth.
NASA.gov: (PDF) http://www.nasa.gov/pdf/585584main_UARS_Status.pdf
There’s been some buzz about the relationship between clouds and climate recently, prompting Andrew Revkin of the New York Times’ Dot Earth blog to get his panties in a twist about the “…over-interpretation of a couple of [scientific] papers…”
What gives? I wanted to know too, so I’ve done a bit – ok, a lot – of research and this is what I can tell you: The heart of the discussion is not whether there is a cloud-climate connection (that’s clear), but rather over what that relationship behaves like. There are at least three possible theories, but before we get to those, let’s review some important background concepts.
Gimme the Basics First
First, scientists think of air as units of volume called air masses. Each air mass is identified by its temperature and moisture content. Clouds are basically wet air masses that form when rising air masses expand and cool, causing the moisture in the air to condense. You can see the process in action yourself just by exhaling outside on a cool morning. The Center for Multiscale Modeling of Atmospheric Processes has a webpage to answer your other questions about clouds.
Earth’s Energy Budget
Energy from the Sun is essential for life on Earth. Let’s pretend the Earth has an “energy budget” where solar energy is like money, absorption is like a deposit, reflection is like a transfer, and radiation is like a withdrawal. It’s not a perfect analogy, but it’ll work for starters: Most of the incoming solar energy (money) is absorbed by (deposited into) the ocean and earth surface, but some is absorbed or reflected (transferred) by the atmosphere and clouds. Most of the outgoing energy is radiated (withdrawn) to space from the atmosphere and clouds. The figure to the right illustrates this process.
The Greenhouse Effect
Thanks to the greenhouse effect, our planet is warm enough to live on. The greenhouse effect occurs within the earth’s energy budget when some of the heat radiating (withdrawing… remember our budget analogy from above?) from the ocean and earth surface is reflected (transferred) back to Earth by greenhouse gases in the atmosphere. Greenhouse gases include carbon dioxide, methane, and water vapor. This National Geographic interactive website entertains the concept.
Climate change is occurring largely because humans are adding more greenhouse gases to the atmosphere. More greenhouse gases in the atmosphere means more heat reflected back to earth and warmer temperatures. Warmer temperatures might sound pretty good to your right now (especially if you live in Minnesota and could see your breath this morning as you walked to school or work), but it’s not. Why? Check out NASA’s really great website on the effects of climate change.
Alright, already. What’s the climate-cloud relationship?
From what I can tell, there are three possible theories about the climate-cloud relationship:
So which is it? Probably NOT Theory #1. Maybe Theory #2… or maybe it’s Theory #3? Scientists aren’t quite sure yet, so neither am I, but the evidence is stacking against Theory #1 leaving two possible options. The next big question seems to be surrounding the size of the effects of Theory #2 and Theory #3.
Using what you just read about cloud formation, the earth’s energy budget, greenhouse gases, and climate change (Woah. You just learned a lot!), what do you think? What’s the climate-cloud relationship?
If you want, you can read more about what scientists are saying about the climate-cloud relationship here:
Courtesy NOAA/NASA GOES ProjectHead over to NASA's Global Climate Change website and see how you fare with their interactive climate quizzes. There are six quizzes you can do. I have to admit I was surprised at some of the answers. But even if you don't get every one of the right (I answered about 55% correctly), hopefully you'll learn something from your mistakes.
The Earth's moon has been an endless source of fascination for humanity for thousands of years. When at last Apollo 11 landed on the moon's surface in 1969, the crew found a desolate, lifeless orb, but one which still fascinates scientist and non-scientist alike.
This image of the moon's north polar region was taken by the Lunar Reconnaissance Orbiter Camera, or LROC. One of the primary scientific objectives of LROC is to identify regions of permanent shadow and near-permanent illumination. Since the start of the mission, LROC has acquired thousands of Wide Angle Camera images approaching the north pole. From these images, scientists produced this mosaic, which is composed of 983 images taken over a one month period during northern summer. This mosaic shows the pole when it is best illuminated, regions that are in shadow are candidates for permanent shadow.
Courtesy NASANASA has been filling my email inbox with some cool images of late. Here are some of my recent faves.
Courtesy NASA/JPL-Caltech/SwRI For starters, check out these two images of the Earth and the moon – similar subject and faming separated by 34 years. The first picture represents the first time the Earth and moon were ever captured together by a spacecraft -- was recorded Sept. 18, 1977, by NASA's Voyager 2 when it was 7.25 million miles from Earth. The second photo is from the Juno spacecraft just a couple of weeks ago (August 26, 2011) and also shows the moon (right) and Earth (left) this time from 6 million miles from Earth. I am not sure why the image from 1977 and further away is better than the image from 2011 and closer, though I suspect it has something to do with the fact that the onboard camera for the Juno spacecraft is named JunoCam...ugh. (As an aside, you can follow Voyager 2 on Twitter, where it tweets updates on its distance from Earth.)
Courtesy NASA/NOAA GOES Project
Courtesy NASAVarious images of recent and current hurricanes are awe-inspiring. A recent selection includes Hurricane Irene from the International Space Station as it was forming on August 22, another of Irene taken by the GOES-13 satellite 28 minutes before the storm made landfall in New York, and tropical storm Katia from August 31 as it was forming over the Atlantic Ocean.
Lastly, today NASA released images of the Apollo 12, 14 and 17 landing sites taken by the Lunar Reconnaissance Orbiter (LRO). I think they are super cool.
Courtesy NASA's Goddard Space Flight Center/ASU
We don’t have shuttles anymore, but NASA still is doing some amazing stuff.