Sometimes I complain about the earthly weather, but mostly I like to post about astronomy and space events. Hope you enjoy the articles.
By: Susie77, 2:29 PM GMT on January 27, 2014
China’s polluted air is changing the weather, says study
Pollutant particles from China’s factories, industrial plants, and power plants affect cloud formations and weather systems worldwide, a new study shows.
Air pollution over Asia, most of which is coming from China, is affecting the world’s weather.
The findings, published in the journal Nature Communications, are based on analysis of climate models and data collected about aerosols and meteorology over the past 30 years.
“The models clearly show that pollution originating from Asia has an impact on the upper atmosphere and it appears to make such storms or cyclones even stronger,” says Renyi Zhang, a professor of atmospheric sciences at Texas A&M University and a co-author of the study.
“This pollution affects cloud formations, precipitation, storm intensity, and other factors and eventually impacts climate. Most likely, pollution from Asia can have important consequences on the weather pattern here over North America.”
Beijing and beyond
China’s booming economy during the last 30 years has led to the building of enormous manufacturing factories, industrial plants, power plants, and other facilities that produce huge amounts of air pollutants. Once emitted into the atmosphere, pollutant particles affect cloud formations and weather systems worldwide, the study shows.
Increases in coal burning and car emissions are major sources of pollution in China and other Asian countries.
Air pollution levels in some Chinese cities, such as Beijing, are often more than 100 times higher than acceptable limits set by the World Health Organization standards, Zhang says.
One study has shown that lung cancer rates have increased 400 percent in some areas due to the ever-growing pollution problem.
Six miles up
Conditions tend to worsen during winter months when a combination of stagnant weather patterns mixed with increased coal burning in many Asian cities can create pollution and smog that can last for weeks. The Chinese government has pledged to toughen pollution standards and to commit sufficient financial resources to attack the problem.
“The models we have used and our data are very consistent with the results we have reached,” says study co-author R. Saravanan, a professor of atmospheric sciences at Texas A&M University.
“Huge amounts of aerosols from Asia go as high as six miles up in the atmosphere and these have an unmistakable impact on cloud formations and weather.”
Zhang adds that “we need to do some future research on exactly how these aerosols are transported globally and impact climate. There are many other atmospheric observations and models we need to look at to see how this entire process works.”
Yuan Wang, who conducted the research with Zhang while at Texas A&M, currently works at NASA’s Jet Propulsion Laboratory as a Caltech Postdoctoral Scholar.
NASA, Texas A&M’s Supercomputing facilities, and the Ministry of Science and Technology of China funded the study.
By: Susie77, 1:37 AM GMT on January 24, 2014
[I did not include the images but if you click on the provided link, you can see them in full color. It's amazing to think that this event happened 12 million years ago -- before there were modern humans -- and the light of the dying star is just now reaching us.]
Courtesy of: EarthSky
Amateur astronomers are capturing the first images of the supernova, or exploding star, in the famous galaxy Messier 82 (M82), which appears along our line of sight to the famous Big Dipper asterism. The first to recognize the supernova, it seems, was a team of students at the University College London Observatory, inside the London city limits, on January 21, 2014 (view press release). It is bright enough to be visible in small telescopes, and it’s apparently still getting brighter. It’s well placed for viewing in the evening hours.
M82 is a near neighbor in our vast universe of galaxies. This is the closest supernova in years, at 11 or 12 million light-years away. Hopefully, it goes without saying that there is no danger. Members of the EarthSky community captured the images below. Enjoy thinking about this vast explosion in space, which actually happened millions of years ago. We are only now seeing its light.
Our friend Mike Hankey sent in this photo, which he took this morning (January 23, 2014). He said it was a relatively long exposure, of 3.5 hours. See images below this one to identify which star is the supernova. Thank you, Mike!
Some are saying this is the nearest supernova since Supernova 1987A in the Large Magellanic Cloud. However, there was another supernova, Supernova 1993J, in M81 some 20 years ago. The supernova’s preliminary designation is PSN (Preliminary Supernova) J09554214+6940260. Expect a better name soon! Skyandtelescope.com reports:
A spectrum reported by Yi Cao and colleagues (Caltech) suggests that the supernova may still be two weeks away from reaching its peak brightness. The spectrum shows it to be a Type Ia supernova — an exploded white dwarf — with debris expanding at 20,000 kilometers per second. It is reddened, and hence must also be dimmed, by dust in M82 along our line of sight.
You need a telescope to see the supernova, so check with your local science or astronomy club. Some may be having impromptu star parties in its honor. M82 is well up in the northeastern sky by 7 or 8 p.m. (for observers at mid-northern latitudes). The waning gibbous moon doesn’t rise until much later.
Read more at skyandtelescope.com
By: Susie77, 5:02 PM GMT on January 17, 2014
Courtesy of EarthSky
As seen during Northern Hemisphere winter (or Southern Hemisphere summer), the stars seem brighter. Why? It’s partly because – on December, January and February evenings – the part of Earth you’re standing on is facing into the spiral arm of the galaxy to which our sun belongs.
Consider the sky at the opposite time of year. In June, July and August, the evening sky seen from the entire Earth is facing toward the center of the Milky Way galaxy. The galaxy is about 100,000 light-years across, and its center is some 25,000 to 28,000 light-years away. We don’t see into the exact center of the Milky Way, because it’s obscured by galactic dust. But during those Northern Hemisphere summer months (Southern Hemisphere winter months), as we peer edgewise into the galaxy’s disk, we’re gazing across some 75,000 light-years of star-packed space (the distance between us and the center, plus the distance beyond the center to the other side of the galaxy). Thus, at that time of year, we’re looking toward the combined light of billions upon billions of stars.
On June, July and August evenings, we look toward the galaxy’s center as indicated by the red arrows. On December, January and February evenings, we look away from the center, as indicated by the blue arrows. Other features, including our galaxy’s primary spiral arms and the sun’s location in the Orion Spur, are also shown. Artist’s illustration via NASA/JPL/Caltech/R.Hurt. View larger.
In northern winter, we’re looking the opposite way – into the suburbs of the galaxy and into the spiral arm of the galaxy in which our sun resides. There really are some gigantic stars located in this direction, and they are relatively close to us – in our own neighborhood, so to speak, our own spiral arm. So we’re seeing fewer stars on Northern Hemisphere winter evenings (or Southern Hemisphere summer evenings), as we look across only about 25,000 light-years of Milky Way, toward the deep space beyond our galaxy’s boundaries.
And that’s why, while the combined light of so many distant stars visible on June, July and August evenings gives the sky a hazy quality, the evening sky in December, January and February looks clearer and sharper.
Our spiral arm of the galaxy is called the Orion Arm, or sometimes the Orion Spur. It’s not one of the primary spiral arms of the Milky Way but only a “minor” spiral arm. Our local Orion Arm is some 3,500 light years across. It’s approximately 10,000 light years in length. Our sun, the Earth, and all the other planets in our solar system reside within this Orion Arm. We’re located close to the inner rim of of this spiral arm, about halfway along its length.
Perhaps you know the bright stars of the prominent constellation Orion the Hunter? This constellation is visible in the evening during Northern Hemisphere winter (Southern Hemisphere summer). The stars of mighty Orion also reside within the Orion Arm of the Milky Way. In fact, our arm of the galaxy is named for this constellation.
Bottom line: During the Northern Hemisphere winter months (Southern Hemisphere summer months), everyone on Earth is looking away from the star-rich center of the galaxy, toward the outskirts of our Milky Way galaxy, during the evening hours. We are looking into the spiral arm of the galaxy to which our sun belongs. That’s why we see so many bright stars; they are neighbors of sorts to our sun in our local spiral arm. And it’s one reason why this part of the sky has a sharp and clear quality; we are seeing fewer stars, surrounded by the inky depths of space beyond our galaxy’s boundaries.