Thursday, December 24, 2009



                 On Friday, 2010 January 15, an annular eclipse of the Sun is visible from within a 300-km-wide track that traverses half of Earth. The path of the Moon's antumbral shadow begins in Africa and passes through Chad, Central African Republic, Democratic Republic of the Congo, Uganda, Kenya, and Somalia. After leaving Africa, the path crosses the Indian Ocean where the maximum duration of annularity reaches 11 min 08s.

                    The central path then continues into Asia through Bangladesh, India, Burma (Myanmar), and China. A partial eclipse is seen within the much broader path of the Moon's penumbral shadow, which includes eastern Europe, most of Africa, Asia, and Indonesia.

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Thursday, November 12, 2009


             NASA has launched a rare campaign to dispel widespread rumours fuelled by a new Hollywood movie that the world is coming to an end in 2012.

             The latest big screen offering from Sony Picture, "2012," arrives in theaters on Friday, with a 200-million-dollar production about the end of the world supposedly based on myths backed by the Mayan calendar.
               The doomsday scenario revolves around claims that the end of time will come as an obscure Planet X -- or Nibiru -- heads toward or collides with Earth.
The mysterious planet was supposedly discovered by the Sumerians, according to claims by pseudo-scientists, paranormal activity enthusiasts and Internet theorists.
Some websites accuse NASA of concealing the truth on the wayward planet's existence, but the US space agency denounced such stories as an "Internet hoax."
"There is no factual basis for these claims," NASA said in a question-and-answer posting on its website.
If such a collision were real "astronomers would have been tracking it for at least the past decade, and it would be visible by now to the naked eye," it added. "Obviously, it does not exist."
"Credible scientists worldwide know of no threat associated with 2012," it insisted.
After all, "our planet has been getting along just fine for more than four billion years," added NASA.
There is another planet, Eris, floating in space. But the dwarf planet similar to Pluto will remain safely lodged in the outer solar system and it can come no closer than four billion miles (6.4 billion kilometers) to Earth, according to NASA.
Scores of Internet postings and books delve into the supposed disaster, including "Apocalypse 2012" and "How to Survive 2012."
Initial theories set the disaster for May 2003, but when nothing happened the date was moved forward to the winter solstice in 2012 to coincide with the end of a cycle of the ancient Mayan calendar.
NASA insisted the Mayan calendar in fact does not end on December 21, 2012, as another period begins immediately afterward. And it said there are no planetary alignments on the horizon for the next few decades.
And even if the planets were to line up as some have forecast, the effect on our planet would be "negligible," NASA said.
Among the other theories NASA has set out to debunk are that geomagnetic storms, a pole reversal or unsteadiness in the Earth's crustal plates might befall the planet.
For example, some myths claim the Earth's rotation and magnetic polarity are related, with a magnetic reversal taking place about every 400,000 years.
"As far as we know, such a magnetic reversal doesn't cause any harm to life on Earth," and a reversal in Earth's rotation is "impossible," NASA reassured, adding that a magnetic reversal is "very unlikely" to occur in the next few millenia.
And while comets and asteroids have always hit the Earth, "big hits are very rare," NASA noted. The last major impact was believed to be 65 million years ago, spurring the end of dinosaurs.
"We have already determined that there are no threatening asteroids as large as the one that killed the dinosaurs," the space agency said.

Tuesday, October 6, 2009

Indian Scientists Leads Global Team In Astronomy

                        After Chandrayaan-1's discovery of water molecules on the Moon comes another astronomy breakthrough for India. An international grouplead by Sudip Bhattacharyya, a 36-year-old space scientist at Mumbai's Tata Institute of Fundamental research, has discovered a way to measure the size of neutron stars.

                        Before we go any further, what is a neutron star? Speaking to TOI on Monday, Bhattacharyya explained: "To put it simply, it is the final stage of a very massive star. When the massive star burns up its fuel, it collapses to become a neutron star," he said, adding that there are between 100 million and 1,000 million neutron stars in the galaxy.

  On average, a neutron star is very small — approximately 10km in diameter — and 10,000 light years from Earth, thus making it extremely difficult to study and measure. Bhattacharyya and his team's research revealed the unsuspected property of X-ray bursts given off by the stars, which led to the discovery that the pattern of X-rays generated might reveal their true size.

                    "Since these X-rays cannot reach the Earth because of a blanket created by the atmosphere, data was collected of more than 900 bursts from 43 neutron stars through a Nasa satellite and transmitted to us," Bhattacharyya said.

                     The scientist and his colleagues — Coleman Miller of the University of Maryland and Galloway Monash of the University of Australia — modelled how the temperature of the bursts changed as they faded and found it varied in relation to the radius of the star. The team's research has been accepted for publication in the journal Monthly Notices of the Royal Astronomical Society.

Wednesday, September 23, 2009

Space-based Solar Power

Space-based solar power (SBSP) (or historically space solar power (SSP)) is a system for the collection of solar power in space, for use on Earth. SBSP differs from the usual method of solar power collection in that the solar panels used to collect the energy would reside on a satellite in orbit, often referred to as a solar power satellite (SPS), rather than on Earth's surface. In space, collection of the Sun's energy is unaffected by the day/night cycle, weather, seasons, or the filtering effect of Earth's atmospheric gases.

Average solar power per unit area outside Earth's atmosphere during any given time period is about 136%[citation needed] that available on Earth's surface during direct sunlight (1336 W/m2). A major interest in SBSP stems from the length of time the solar collection panels can be exposed to a consistently high amount of solar radiation. For most of the year, a satellite-based solar panel can collect power 24 hours per day, whereas a land-based station can collect for only 12 hours per day, yielding lower power collection rates around the sunrise and sunset hours.

The collection of solar energy in space for use on Earth introduces the new problem of transmitting energy from the collection point, in space, to the place where the energy would be used, on Earth's surface. Since wires extending from Earth's surface to an orbiting satellite would be impractical, many SBSP designs have proposed the use of microwave beams for wireless power transmission. The collecting satellite would convert solar energy into electrical energy, which would then be used to power a microwave emitter directed at a collector on the Earth's surface. Dynamic solar thermal power systems are also being investigated.