Wednesday, November 30, 2011

How GRAVITY influence FIRE ....?

Color image of a burning dropletWe have seen fire in earth where gravity is dominant.

Can you guess how the same fire out of same fuel would behave in zero gravity
or say in space....?

Read this interesting article to know more...

In space, where there is no up or down, flames behave in unconventional ways.

When a flame burns on Earth, heated gases rise from the fire creating a buoyant flow that draws oxygen into the flame and combustion products away from it. In space, warm gases do not rise, and molecular diffusion drives flame behavior.

"In space molecular diffusion draws oxygen to the flame and combustion products away from the flame at a rate 100x slower than the buoyant flow on Earth," Dan Dietrich, project scientist, NASA's Glenn Research Center, said.

Flames in space burn with a lower temperature, at a lower rate, and with less oxygen than in normal gravity. This means that materials used to extinguish the fire must be present in higher concentrations. 

Lightning produces waves in Atmosphere leaking into Space

Waves created by lightning flashes – here shown in blue, green, and red – circle around Earth, creating something called Schumann resonance. These waves can be used to study the nature of the atmosphere they travel through. (Credit: NASA/Simoes)

 At any given moment about 2,000 thunderstorms roll over Earth, producing some 50 flashes of lightning every second. Each lightning burst creates electromagnetic waves that begin to circle around Earth captured between Earth's surface and a boundary about 60 miles up. Some of the waves -- if they have just the right wavelength -- combine, increasing in strength, to create a repeating atmospheric heartbeat known as Schumann resonance.
NASA's Vector Electric Field Instrument (VEFI) aboard the U.S. Air Force's Communications/Navigation Outage Forecast System (C/NOFS) satellite has detected Schumann resonance from space. This comes as a surprise.

Fernando Simões, Robert Pfaff, Henry Freudenreich.Satellite observations of Schumann resonances in the Earth's ionosphereGeophysical Research Letters, 2011; 38 (22) DOI: 10.1029/2011GL049668

Thursday, November 17, 2011

High Resolution Global Topographic Map of Moon

LRO Camera Team Releases High Resolution Global Topographic Map of Moon.

click on the image to go to the official website and high resolution image.

Source: NASA-LRO

topographical map of the moon

Wednesday, November 16, 2011

Why Greenland is melting faster today...?

It is the sea temperature, not  the air temperature that determine how fast Greenland’s ice cap melted at the end of the last ice age.

The study, published in the journal Paleoceanography, was conducted by an international team of researchers headed by senior researcher Paul Knutz of the Geological Survey of Denmark and Greenland (GEUS).

”Our study included analyses of the marine temperature in the upper water strata, and they indicate that the temperature during the period of deglaciation was relatively high,” says Knutz.

"We can see that the high temperatures start immediately before and continued during periods when a lot of icebergs broke off from glaciers and when a lot of melt water was produced,” he adds. “Therefore we interpret the temperature anomalies as something that resulted in increased melting and a retreat of the ice cap.”

Read in more detail.

Thursday, November 10, 2011

first images of the Asteroid which came close to earth

First images of the Asteroid which came close to earth has been released...

You can watch the video
Team of astronomers decided to animate an entire sequence of their high-resolution radar images of YU55 to make a short movie clip from the data from  Deep Space Network antenna in Goldstone, California.

you can watch it

Courtesy: Nasa

You can download the first images video

Wednesday, November 9, 2011

Material which absorbs 99% UV,VIS,IR

A super Black material has been invented which is able to absorb 99% UV, VIS, IR radiation.

New 'super-black' material absorbs light across multiple wavelength bands
This close-up view (only about 0.03 inches wide) shows the internal structure of a carbon-nanotube coating that absorbs about 99 percent of the ultraviolet, visible, infrared, and far-infrared light that strikes it. A section of the coating, which was grown on smooth silicon, was purposely removed to show the tubes' vertical alignment. (Credit: Stephanie Getty, NASA Goddard)

or check SPIE Optics and Photonics.

Sunday, November 6, 2011

Asteroid flies close on 8th Nov.....

An Asteroid named  2005 YU55 will have a flyby near earth and moon on 8-Nov-2011.
NASA scientists will track asteroid 2005 YU55 from the agency's Deep Space Network.
At the point of closest approach, it will be no closer than 324,600 kilometers or 0.85 the distance from the moon to Earth.

Look at this animation.

More details and videos:


Saturday, November 5, 2011

Haze over Himalaya....

It's early winter time.... and now look at Himalayan slopes.....
Haze along the Himalaya
click this link for detailed information....

Image courtesy: Nasa Earth Observatory

Wednesday, November 2, 2011

Greenhouse gases will overpower ozone hole....?

Check this latest paper discussing how the influence on Southern Hemisphere climate of the Antarctic ozone hole is slowly dissipating and will be progressively overtaken by human-induced emissions of carbon dioxide and other greenhouse gases...
Ozone depletion over the past three to four decades has had a marked impact on Antarctic and Southern Ocean climate.  However, this will shortly be overwhelmed by the influence of greenhouse gases.....
discusses this study......

Signatures of the Antarctic ozone hole in Southern Hemisphere surface climate change.
David W. J. Thompson, Susan Solomon, Paul J. Kushner, Matthew H. England, Kevin M. Grise & David J. Karoly
Nature Geoscience 4, 741–749 (2011) doi:10.1038/ngeo1296