London, September 22 (ANI): With the help of a rocket, scientists have created an artificial cloud at the edge of space, to learn how high-flying dust reflects radio waves.
“Noctilucent”, or night-shining, clouds float dozens of kilometres higher than other clouds, at an altitude of about 80 kilometres.
Because of their height, they can be seen glowing before sunrise or after sunset as the sun illuminates them from below the horizon.
In recent years, they have spread to latitudes as low as 40degrees, while also growing in number and getting brighter – a change that some attribute to global warming.
The ice-covered particles in these clouds are commonly thought to get their start as tiny dust particles that had been sloughed off comets and meteoroids.
These particles build up a charge as they are bombarded by fast-moving electrons and ions.
Since charged particles reflect radio waves, they are good candidates for radar studies, which could help measure the dust at an early stage in the clouds’ formation.
But the radar data is hard to interpret.
To get a better sense of how high-flying dust reflects radio waves, researchers launched the Charged Aerosol Release Experiment (CARE) recently from NASA’s Wallops Flight Facility in Virginia, US.
The experiment, which blasted off on a Black Brant XII suborbital sounding rocket, spewed more than 100 kilograms of aluminium oxide into the atmosphere at an altitude of about 280 km.
A combination of ground- and space-based instruments will watch this cloud for days and perhaps months as its particles become charged, sink, and disperse.
Laser pulses will be used to measure the density of the particles in the cloud. These will be compared with radar measurements of the plume.
“Our primary science goal is to understand (how) radar (scatters) from a dusty plasma,” said CARE’s principal investigator, Paul Bernhardt of the Naval Research Laboratory in Washington, DC.
“We want to understand what kind of information you get back when you send out radar pulses,” he added.
Radar has been used to examine icy dust that hovers some 90 km above the Earth and can grow to become the ice particles inside noctilucent clouds, according to Scott Bailey of Virginia Tech in Blacksburg.
But at the moment, interpreting radar measurements of these proto-cloud particles is difficult.
Studying an artificial cloud created in a controlled manner could help resolve these uncertainties.
“If the radar could be used to say exactly what the population of particles is up there that the ice is forming around, that would be a major step forward,” Bailey told New Scientist. (ANI)
Related posts:
- Martian dust storms can generate lightning Washington, August 9 (ANI): Scientists, using a new detector, have for the first time observed evidence that Martian dust storms can generate lightning. Dust storms on Earth build up an electric field as dust particles collide, and then emit...
- Scientists discover “Super Planetary Nebulae” in deep space London, August 15 (ANI): A team of scientists in Australia and the United States has discovered a new class of object which they call “Super Planetary Nebulae.” Planetary nebulae are shells of gas and dust expelled by stars near...
- Largest cometary outburst sent “mini comets” flying at 451 kms an hour Washington, September 17 (ANI): In high-resolution images of comet Holmes, which erupted in 2007, astronomers have detected multiple “mini comets” bursting out at 451 kilometers an hour, which is the largest known cometary outburst in history. According to National...
- Scientists see storm brewing over Titan’s tropical desert Washington, August 13 (ANI): A new research has discovered significant cloud formation within the tropical zone near the equator of Saturn’s largest moon, Titan, which is evidence that the parched, dry desert of the natural satellite can support large-scale...
- Signs of ideal ’surfing’ conditions spotted in turbulent ocean of solar wind Washington, Sept 2 (ANI): Researchers at the University of Warwick, UK, have found what could be the signal of ideal wave “surfing” conditions for individual particles within the massive turbulent ocean of the solar wind. The discovery could give...
- Signs of water on moon more widespread than expected: Scientists Washington, Sep 18 (DPA) The element hydrogen – a key ingredient in water – is more widespread than expected at the moon’s south pole, scientists said Thursday. NASA scientists announced the first data sent back to Earth from the...
- India gets its highest hockey ground with artificial turf Shilaroo (HP), Aug 10 (ANI): After the highest cricket ground, India got its highest hockey ground with synthetic turf at an altitude of 2450 meters from sea level in Himachal Pradesh. The construction of the synthetic astro turf hockey...
aluminium oxide: Avoid breathing vapors, or dusts
http://www.inchem.org/documents/icsc/icsc/eics0351.htm
