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, 12:55 AM GMT on January 25, 2009
Were you born during a period of solar minimum or solar maximum? Find out with this nifty tool from www.SpaceWeather.com.
You can also use it to correlate important Earth history events like stock market crashes, the Mets winning, and global warming/cooling with the 11-year solar cycle. Dates go back to the 1700s.
By: Susie77, 12:21 AM GMT on January 24, 2009
Space Weather News for Jan. 23, 2007
SOLAR ECLIPSE: On Monday, Jan. 26th, the Moon will pass in front of the sun producing an annular "ring of fire" eclipse. This is not a total eclipse; the Moon will cover only 93% of the sun's surface. Nevertheless, the Moon's dead-center transit across the solar disk will produce a sight of rare beauty for observers along the "path of annularity." Best views are to be had from islands in Indonesia where the ring of fire will appear to sink into the ocean at sunset. Meanwhile, in Australia, southeast Asia, southern parts of India and South Africa, observers will experience an off-center partial eclipse. Crescent-shaped sunbeams will dapple the ground while high overhead the Moon takes a curved bite out of the sun.
Please visit http://spaceweather.com for eclipse maps, timetables and photos.
BLUE-SKY FIREBALL: Last week a meteoroid of unknown size hit Earth's atmosphere over Denmark and exploded with a flash so bright it turned the nighttime sky daytime blue. A video of the remarkable fireball and eye-witness reports may be found at Spaceweather's fireball sighting page: http://spaceweather.com/glossary/fireballreports_17jan09.htm
By: Susie77, 12:51 AM GMT on January 16, 2009
This just in from NASA ( http://science.nasa.gov/headlines/y2009/15jan_marsmethane.htm?list870272 ):
The Red Planet is Not a Dead Planet
Jan. 15, 2009: Mars today is a world of cold and lonely deserts, apparently without life of any kind, at least on the surface. Indeed it looks like Mars has been cold and dry for billions of years, with an atmosphere so thin, any liquid water on the surface quickly boils away while the sun's ultraviolet radiation scorches the ground.
The situation sounds bleak, but research published today in Science Express reveals new hope for the Red Planet. The first definitive detection of methane in the atmosphere of Mars indicates that Mars is still alive, in either a biologic or geologic sense, according to a team of NASA and university scientists.
"Methane is quickly destroyed in the Martian atmosphere in a variety of ways, so our discovery of substantial plumes of methane in the northern hemisphere of Mars in 2003 indicates some ongoing process is releasing the gas," says lead author Michael Mumma of NASA's Goddard Space Flight Center. "At northern mid-summer, methane is released at a rate comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, Calif."
Methane -- four atoms of hydrogen bound to a carbon atom -- is the main component of natural gas on Earth. It is of interest to astrobiologists because much of Earth's methane come from living organisms digesting their nutrients. However, life is not required to produce the gas. Other purely geological processes, like oxidation of iron, also release methane. "Right now, we don't have enough information to tell if biology or geology -- or both -- is producing the methane on Mars," said Mumma. "But it does tell us that the planet is still alive, at least in a geologic sense. It's as if Mars is challenging us, saying, hey, find out what this means."
f microscopic Martian life is producing the methane, it likely resides far below the surface, where it's still warm enough for liquid water to exist. Liquid water, as well as energy sources and a supply of carbon, are necessary for all known forms of life.
"On Earth, microorganisms thrive 2 to 3 kilometers (about 1.2 to 1.9 miles) beneath the Witwatersrand basin of South Africa, where natural radioactivity splits water molecules into molecular hydrogen (H2) and oxygen (O). The organisms use the hydrogen for energy. It might be possible for similar organisms to survive for billions of years below the permafrost layer on Mars, where water is liquid, radiation supplies energy, and carbon dioxide provides carbon," says Mumma.
"Gases, like methane, accumulated in such underground zones might be released into the atmosphere if pores or fissures open during the warm seasons, connecting the deep zones to the atmosphere at crater walls or canyons," he says.
"Microbes that produced methane from hydrogen and carbon dioxide were one of the earliest forms of life on Earth," notes Carl Pilcher, Director of the NASA Astrobiology Institute which partially supported the research. "If life ever existed on Mars, it's reasonable to think that its metabolism might have involved making methane from Martian atmospheric carbon dioxide."
However, it is possible a geologic process produced the Martian methane, either now or eons ago. On Earth, the conversion of iron oxide (rust) into the serpentine group of minerals creates methane, and on Mars this process could proceed using water, carbon dioxide, and the planet's internal heat. Another possibility is vulcanism: Although there is no evidence of currently active Martian volcanoes, ancient methane trapped in ice "cages" called clathrates might now be released.
The team found methane in the atmosphere of Mars by carefully observing the planet over several Mars years (and all Martian seasons) using spectrometers attached to telescopes at NASA's Infrared Telescope Facility, run by the University of Hawaii, and the W. M. Keck telescope, both at Mauna Kea, Hawaii.
"We observed and mapped multiple plumes of methane on Mars, one of which released about 19,000 metric tons of methane," says Geronimo Villanueva of the Catholic University of America in Washington, D.C. Villanueva is stationed at NASA Goddard and is co-author of the paper. "The plumes were emitted during the warmer seasons -- spring and summer -- perhaps because the permafrost blocking cracks and fissures vaporized, allowing methane to seep into the Martian air. Curiously, some plumes had water vapor while others did not," he says.
According to the team, the plumes were seen over areas that show evidence of ancient ground ice or flowing water. For example, plumes appeared over northern hemisphere regions such as east of Arabia Terra, the Nili Fossae region, and the south-east quadrant of Syrtis Major, an ancient volcano 1,200 kilometers (about 745 miles) across.
It will take future missions, like NASA's Mars Science Laboratory, to discover the origin of the Martian methane. One way to tell if life is the source of the gas is by measuring isotope ratios. Isotopes are heavier versions of an element; for example, deuterium is a heavier version of hydrogen. In molecules that contain hydrogen, like water and methane, the rare deuterium occasionally replaces a hydrogen atom. Since life prefers to use the lighter isotopes, if the methane has less deuterium than the water released with it on Mars, it's a sign that life is producing the methane.
Whatever future research reveals--biology or geology--one thing is already clear: Mars is not so dead, after all.
By: Susie77, 12:49 AM GMT on January 15, 2009
FANTASTIC ICE HALOS: Researchers in Finland have discovered a new way to create luminous ice halos in the night sky. Their tools are as simple as a bright lamp and icy, blowing air. Some of the arcs they routinely photograph were previously seen only in remote parts of Antarctica. Sample photos and must-see movies are featured in today's edition of http://spaceweather.com.
HOURS OF VENUS: Today and for the rest of the week, Venus is at maximum elongation (greatest apparent distance) from the sun. This means the silvery planet is "up" for more than three hours after sunset. Go outside after dark, face south, and take a long look. Venus is so bright it outshines city lights and even pierces thin clouds. The view through a backyard telescope may surprise you. Check http://spaceweather.com for images and more information.
By: Susie77, 2:54 PM GMT on January 10, 2009
Panoramic photo taken 31 December 2008, Fairbanks, Alaska.
Ice fog shrouds the city in mystery. High above, the starbursts of the UAF's fireworks display light the night sky.
Photographer: LeRoy Zimmerman, Ester Alaska
Scientific explanation of ice fog, courtesy of Dermot Cole, Daily News Miner:
Ice fog and the Fairbanks winter
By Dermot Cole
Published Sunday, January 4, 2009
It is 41 below as I arrive at the office late Saturday morning.
The fog that covers the land proves that the capacity of air to hold moisture drops to almost nothing at extreme temperatures.
It is that phenomenon — combined with a range of human activities that produce moisture — that creates our thick blanket of ice fog.
Fairbanks, with its stable air, is a natural laboratory for this form of Arctic air pollution.
Carl Benson of the Geophysical Institute at UAF has long been one of the leading figures in researching what happens in this fog. After more than four decades of study, he believes there is still much to learn about ice fog, including its chemistry and physics.
I talked to him Friday and reviewed some of his pioneering research on the topic, including a 1965 Geophysical Institute report, “Ice Fog: Low Temperature Air Pollution.”
The ability of air to hold water vapor is one of the key things to understand.
At room temperature, the air can hold about 180 times more water vapor than it does at 40 below.
That’s why opening a door creates a brief burst of cloud cover.
During these cold conditions, most of the water vapor in the air we exhale and in the exhaust we produce from automobiles and chimneys cannot be absorbed in the atmosphere.
Instead, the vapor instantly turns to ice crystals that float in the air. These are about 5 to 10 microns in size. A micron is one millionth of a meter, so these are microscopic crystals so light that they remain suspended for a day or two. The particles have a large surface area, compared to their weight, and they have a long “hang time,” to use football parlance.
The floating ice particles build up across time as the cold continues and they cloud our vision, if not our thinking.
The second necessary ingredient for ice fog is stagnant air.
With a little wind, the ice particles will be dispersed like dust in the wind — but our air is still because we have inversions and because Fairbanks has hills to the east, north and west that almost seal off the valley.
In most places, air temperature decreases as you gain altitude.
An inversion occurs when the natural order of things is reversed.
The inversions that occur in Fairbanks are caused by a net loss of heat from the Earth’s surface.
At this time of year, when the daily dose of local sunshine is not enough to warm the Earth at all, the inversions become more pronounced, with greater heat loss from the surface.
Fairbanks has a “heat island,” which is the warmth created by the use of energy for heat, light and transportation, but that does not create enough heat to eliminate the net heat loss of the inversion.
In other words, thanks to the radiative properties of snow, the clear skies above the fog and the lack of sunshine, we are losing heat at the ground level.
The snow, like everything else, transfers energy by radiation. When there is a cloud cover, the clouds absorb some of that energy from the snow. Some of the energy returns to the surface, raising the temperature. Clouds usually mean warmer weather, while clear skies often signal a cooling trend.
“These radiation inversions become especially well developed at night over snow surfaces and are common both night and day in parts of the Arctic and Antarctic. They are also very common in Fairbanks,” Benson wrote in one of his essays on ice fog.
The Fairbanks inversions are steep, which means that the temperature increase with altitude is dramatic, often ranging from 15 to 30 degrees in a few hundred feet.
“During midwinter the sun is above the horizon for less than four hours per day at a maximum angle of less than 2 degrees. This nearly continuous nighttime environment is partly responsible for the strength and persistence of the surface inversion in the winter,” Benson wrote.
Some people believe, mistakenly, that cold air flows down from the hills and settles on the flats.
“This would be a happy circumstance, if it occurred, because such drainage would tend to flush the air pollutants out of the city,” Benson wrote. “However, the air in the flats is so much colder, and therefore denser, than that moving down from the hills, that it cannot penetrate.”
The air at the surface, where the ice fog collects, becomes “effectively decoupled from the air above.”
“As long as we burn fuel, we’re going to have exhaust and part of the exhaust is water vapor,” Benson told me.
At 40 below, the water vapor in exhaust condenses and freezes in an instant.
For every pound of gasoline we burn, there is about a pound of water as a byproduct, which becomes fog at these temperatures. We also get about three pounds of carbon dioxide from that pound of fuel.
The exhaust products weigh more because oxygen from the air combines with hydrogen and carbon in the fuel to produce water and carbon dioxide.
It is only at these low temperatures that we can see one of the components of exhaust, namely the water.
As I arrive at the office Saturday morning to wrap up this column, it’s not cold enough to see clouds of carbon dioxide. Yet.
By: Susie77, 10:58 PM GMT on January 09, 2009
Space Weather News for Jan. 9, 2009
APPROACHING COMET: Comet Lulin (C/2007 N3), discovered in 2007 by a collaborative team of Taiwanese and Chinese astronomers, is swinging around the sun and approaching Earth. The photogenic comet has a bright tail and an "anti-tail" visible in mid-sized backyard telescopes. At closest approach in February, Comet Lulin is expected to brighten to naked-eye visibility. Visit http://Spaceweather.com for sky maps, pictures and more information.
NEW SUNSPOTS: For the second time this week, a sunspot is coalescing on the surface of the sun. The spot's high latitude and magnetic polarity identify it as a member of new Solar Cycle 24; its appearance continues a recent trend of gradually intensifying new-cycle solar activity. The spot is growing rapidly and may soon provide a nice target for backyard solar telescopes.
FULL MOON ALERT! This weekend's full Moon is the biggest and brightest of 2009. It's a "perigee Moon" as much as 50,000 km closer to Earth than other full Moons we'll see later this year. Perigee moonlight shining through icy winter air can produce beautiful halos, coronas, moondogs and other atmospheric optics phenomena. Sample photos are featured on today's edition of Spaceweather.com.
By: Susie77, 1:45 PM GMT on January 02, 2009
Space Weather News for Jan. 2, 2009
FIRST METEORS OF 2009: The annual Quadrantid meteor shower peaks on Jan. 3rd when Earth enters a stream of debris from shattered comet 2003 EH1. The timing of the encounter favors observers in western North America and across the Pacific Ocean who could see dozens to hundreds of meteors during the dark hours before sunrise this Saturday morning. Visit http://spaceweather.com for a sky map and more information.
SOMETHING NEW: For the new year, Spaceweather.com is pleased to announce a new service: Space Weather Radio, broadcasting live "sounds from space" around the clock. Today you can listen to the Air Force Space Surveillance Radar in Texas. When a meteor passes over the facility--ping!--there is an audible echo. (Activity should be high during the Quadrantid meteor shower this weekend.) In the near future we'll be adding broadcasts of solar radio bursts and VLF signals from the ionosphere. The streams are punctuated by Daily Space Weather Updates from Dr. Tony Phillips. Click here to begin listening: http://SpaceweatherRadio.com
Light Thunderstorm Rain