Saturday, 2 October 2010
Wednesday, 25 August 2010
Chandrayaan-1 (Sanskrit: चंद्रयान-१, lit: moon vehicle[3][4] pronunciation (help·info)) was India's first unmanned lunar probe. It was launched by the Indian Space Research Organisation in October 2008, and operated until August 2009. The mission included a lunar orbiter and an impactor. India launched the spacecraft by a modified version of the PSLV, PSLV C11[2][5] on 22 October 2008 from Satish Dhawan Space Centre, Sriharikota, Nellore District, Andhra Pradesh, about 80 km north of Chennai, at 06:22 IST (00:52 UTC).[6] The mission was a major boost to India's space program,[7] as India researched and developed its own technology in order to explore the Moon.[8] The vehicle was successfully inserted into lunar orbit on 8 November 2008.[9]
On 14 November 2008, the Moon Impact Probe separated from the Chandrayaan orbiter at 20:06 and struck the south pole in a controlled manner, making India the fourth country to place its flag on the Moon.[10] The probe impacted near Shackleton Crater at 20:31 ejecting underground soil that could be analysed for the presence of lunar water ice.[11]
The estimated cost for the project was 386 crore (US$ 80 million).[12]
The remote sensing lunar satellite had a mass of 1,380 kilograms (3,042 lb) at launch and 675 kilograms (1,488 lb) in lunar orbit.[13] It carried high resolution remote sensing equipment for visible, near infrared, and soft and hard X-ray frequencies. Over a two-year period, it was intended to survey the lunar surface to produce a complete map of its chemical characteristics and three-dimensional topography. The polar regions are of special interest as they might contain ice.[14] The lunar mission carries five ISRO payloads and six payloads from other space agencies including NASA, ESA, and the Bulgarian Aerospace Agency, which were carried free of cost.[15]
After suffering from several technical issues including failure of the star sensors and poor thermal shielding, Chandrayaan stopped sending radio signals at 1:30 AM IST on 29 August 2009 shortly after which, the ISRO officially declared the mission over. Chandrayaan operated for 312 days as opposed to the intended two years but the mission achieved 95 percent of its planned objectives.[1][16][17][18] Among its many achievements was the discovery of the widespread presence of water molecules in lunar soil.
On 14 November 2008, the Moon Impact Probe separated from the Chandrayaan orbiter at 20:06 and struck the south pole in a controlled manner, making India the fourth country to place its flag on the Moon.[10] The probe impacted near Shackleton Crater at 20:31 ejecting underground soil that could be analysed for the presence of lunar water ice.[11]
The estimated cost for the project was 386 crore (US$ 80 million).[12]
The remote sensing lunar satellite had a mass of 1,380 kilograms (3,042 lb) at launch and 675 kilograms (1,488 lb) in lunar orbit.[13] It carried high resolution remote sensing equipment for visible, near infrared, and soft and hard X-ray frequencies. Over a two-year period, it was intended to survey the lunar surface to produce a complete map of its chemical characteristics and three-dimensional topography. The polar regions are of special interest as they might contain ice.[14] The lunar mission carries five ISRO payloads and six payloads from other space agencies including NASA, ESA, and the Bulgarian Aerospace Agency, which were carried free of cost.[15]
After suffering from several technical issues including failure of the star sensors and poor thermal shielding, Chandrayaan stopped sending radio signals at 1:30 AM IST on 29 August 2009 shortly after which, the ISRO officially declared the mission over. Chandrayaan operated for 312 days as opposed to the intended two years but the mission achieved 95 percent of its planned objectives.[1][16][17][18] Among its many achievements was the discovery of the widespread presence of water molecules in lunar soil.
Solar Dynamics Observatory
NASA Launches New Spacecraft to Study the Sun
A new NASA spacecraft aimed at studying the inner workings of our sun blasted off Thursday to begin a five-year mission to better understand the mysteries of Earth's star.
The Solar Dynamics Observatory (SDO) lifted off atop an Atlas 5 rocket at 10:23 a.m. EST (1523 GMT) from Launch Complex 41 at Cape Canaveral Air Force Station in Florida. A first launch attempt on Wednesday was stymied by strong winds.
The $850 million mission will take the most detailed, comprehensive measurements yet of our closest star — with 10 times better resolution than HD television — using three state-of-the-art instruments onboard.
"To the naked eye, the sun appears as a constant pale yellow ball," said SDO project scientist Madhulika Guhathakurta of NASA Headquarters in Washington, D.C., during a Tuesday briefing. But actually the sun is a volatile and unpredictable body, full of turmoil that scientists still don't understand, she said.
"SDO is designed to probe solar variability," Guhathakurta said. "It will revolutionize our view of the sun."
The discoveries made by the probe will help develop better ways of forecasting solar weather, inlcuding the violent flares of charged particles that sometimes erupt from the sun and can disrupt satellites and power grids on Earth.
"Our sun affects our lives more and more as we depend more and more on technology," said SDO project scientist Dean Pesnell at NASA's Goddard Space Flight Center in Greenbelt, Md. "We would like to predict this magnetic field, to predict what's going to happen in solar activity and to say a solar flare is coming."
One such flare, a March 1989 solar storm, knocked out the power supply in Quebec and disrupted power and communications across North America.
"The goal of an experiment like [this] is not just to take the data but to develop a real physical understanding of what goes on so we can make more sophisticated predictions," said Alan Title of the Lockheed Martin Solar and Astrophysics Laboratory, principal investigator of SDO's Atmospheric Imaging Assembly instrument.
The scientists are also intent on sharing SDO's wealth of data beyond the scientific world. They will pipe their data to a free downloadable iPhone application — 3D sun — that displays a constant stream of updated 3D views of the sun from SDO and other solar probes.
"This is way cool," Guhathakurta said, demonstrating the app.
The spacecraft will undergo about two months of calibration and testing before it begins taking real science observations.
"We can't wait to get this data started," said SDO project manager Elizabeth Citrin, also at NASA's Goddard Space Flight Center.
The liftoff was the second this week for NASA, which launched the space shuttle Endeavour on a 13-day trip to the International Space Station Monday.
Medical research and Space
Fundamental research, towards a better understanding of the human organism and its survival and wellbeing under the harsh conditions of space flight, contributes to the improvement of human health in space as well as on the ground. Fundamental research contributes also to the development of biomedical instrumentation and tools useful for the improvement of health both in extreme and normal conditions terrestrially.
Studying the adaptation of the human body to weightlessness provides a unique opportunity: being free from the gravity factor that is confounding and can mask discreet and/or too subtle effects: for example diffusion processes are of order of magnitudes smaller than convection effects; thus isolating diffusion from convection is always a challenging task on Earth while in microgravity convection no longer exist. The resulting better understanding allows improving our knowledge of human physiology. Therefore, improved models of human physiology and innovative methods for diagnosis, preventive measures, and treatment are developed and can often be adapted for terrestrial application, which in the end leads to improved health care on Earth.Many synergies are carried over by such research: tools required for the health monitoring in extreme terrestrial environments and accompanying living and working conditions in such environments presents similarities with the one required for space, but also ‘analogous’ conditions such as sedentary life or involuntary physical inactivity presents similarities with the consequences of spaceflight on human physiology.Human exploration of space contributes to human physiology and psychology research as well towards the development of miniaturised and smart tools, sensors, and (remote) monitoring systems and protocols. R&D in biomedical instrumentation, therefore, also represents a key area of work in innovative and breakthrough technology. A list of the research fields supported by ESA, whose projects are mainly related to health, is given below. Each of these addresses a question relevant to the consequences of a space mission (exposure to weightlessness, radiation, isolation,…) on the physiology of astronauts. The synergies and possible contributions to health on the ground are mentioned as well. Further details on these topics can be found hereafter.Research fields:
Physiology
Psychology
Clinical research
Fundamental research, towards a better understanding of the human organism and its survival and wellbeing under the harsh conditions of space flight, contributes to the improvement of human health in space as well as on the ground. Fundamental research contributes also to the development of biomedical instrumentation and tools useful for the improvement of health both in extreme and normal conditions terrestrially.
Studying the adaptation of the human body to weightlessness provides a unique opportunity: being free from the gravity factor that is confounding and can mask discreet and/or too subtle effects: for example diffusion processes are of order of magnitudes smaller than convection effects; thus isolating diffusion from convection is always a challenging task on Earth while in microgravity convection no longer exist. The resulting better understanding allows improving our knowledge of human physiology. Therefore, improved models of human physiology and innovative methods for diagnosis, preventive measures, and treatment are developed and can often be adapted for terrestrial application, which in the end leads to improved health care on Earth.Many synergies are carried over by such research: tools required for the health monitoring in extreme terrestrial environments and accompanying living and working conditions in such environments presents similarities with the one required for space, but also ‘analogous’ conditions such as sedentary life or involuntary physical inactivity presents similarities with the consequences of spaceflight on human physiology.Human exploration of space contributes to human physiology and psychology research as well towards the development of miniaturised and smart tools, sensors, and (remote) monitoring systems and protocols. R&D in biomedical instrumentation, therefore, also represents a key area of work in innovative and breakthrough technology. A list of the research fields supported by ESA, whose projects are mainly related to health, is given below. Each of these addresses a question relevant to the consequences of a space mission (exposure to weightlessness, radiation, isolation,…) on the physiology of astronauts. The synergies and possible contributions to health on the ground are mentioned as well. Further details on these topics can be found hereafter.Research fields:
Physiology
Psychology
Clinical research
Saturday, 21 August 2010
The Moon is shrinking!..
The Moon is shrinking!
Well, a little: new results from the Lunar Reconnaissance Orbiter indicate that over recent geological time, the Moon has shrunk by approximately 100 meters in diameter!
Here’s the evidence, or at least one piece of it:
[Click to unshrinkenate.]
That image shows the Gregory scarp, a cliff across the surface of the Moon. Scarps like these have been known for centuries — I’ve observed many myself using a backyard telescope — but it was always thought they were big and restricted to just some areas on the Moon. LRO, though has found many smaller scarps, and also importantly that these scarps are distributed globally, all across the surface of our nearest neighbor in space.
What does this have to do with shrinkage?This diagram shows how scarps are formed: thrust faults. If the Moon shrinks, even a little, the surface shrinks too, and gets compressed. This causes stress under the surface, building pressure. Eventually that pressure exceeds the strength of the rock above it, and you get a fault. One side of the fault slams upward, forming the scarp.
We see these sorts of features on many bodies in the solar system, including the Earth, where their origin is from tectonic plate motion. As the continental plates move past each other, friction allows the pressure to build up. There’s no such drift on the Moon — the surface is essentially one big piece — so something else must be causing it.
Shrinkage makes the most sense. The interior of the Moon is still warm from the leftover heat from its formation billions of years ago. Hundreds of kilometers of rock makes a pretty good insulator, so the Moon has cooled very slowly. As the interior cools, it shrinks, and the surface collapses down as well. Pressure builds, then snap! While a lot of these scarps are very long and dozens of meters in height, LRO’s sharp vision (it can see objects less than a meter in size!) can spot scarps that are only a kilometer or two in length and a few meters high. That sort of feature is not possible to see from Earth. They’re too small.
So this scarp formation has been going on essentially since the Moon formed, but the question is: does this process still continue today?
Maybe. The scarps seen are relatively young, something like 800 million to a billion years old. Dating them is difficult, but again LRO’s keen eye helps us out:
In this image, the scarp seen cuts right across some small craters. Geologists can use the number of craters to get an age for the landscape, which is how they have been able to get a rough estimate of how old the scarp is. Also, despite the lack of air and standing water, the Moon undergoes erosion. Solar wind, micrometeorites, and even the thermal expansion and compression caused by the Moon’s day/night cycle all work to grind up surface rock into dust. The scarps look quite fresh, limiting their age.
Another interesting bit of evidence is that the Apollo missions put seismographs on the Moon, which recorded quite a few moonquakes. Several dozen of these quakes were shallow, which may be related to scarp formation (since the thrust faults are near the surface).
So, does this mean the process is still going on? It’s not really possible to say as yet. A billion years is a long time, and it’s difficult to know if any small scarps are younger than that. As LRO scans more and more of the lunar surface, more of these types of landscape features will be seen.
And finally, what does this mean for the ultimate size of the Moon? Well, you have to put this into perspective: the Moon’s diameter is about 3475 kilometers. This shrinkage is only about 0.003% of that. In other words, you’d never, ever be able to see that by comparing the Moon’s diameter now as it was, say, a billion years ago. So we’re not in any danger of the Moon collapsing down into a tiny little ball!
What it does mean is that despite it being perhaps the most well-studied object in the sky, our Moon is still capable of surprising us. Not only that, but some of its secrets are actually rather big, but so well-hidden we need to study the Moon pretty carefully to uncover them. Happily, we’re doing just that. There’s not a scientist on the planet who doesn’t like surprises, especially when they’ve been sitting right there in the sky for us to find.
The Moon is shrinking!
Well, a little: new results from the Lunar Reconnaissance Orbiter indicate that over recent geological time, the Moon has shrunk by approximately 100 meters in diameter!
Here’s the evidence, or at least one piece of it:
[Click to unshrinkenate.]
That image shows the Gregory scarp, a cliff across the surface of the Moon. Scarps like these have been known for centuries — I’ve observed many myself using a backyard telescope — but it was always thought they were big and restricted to just some areas on the Moon. LRO, though has found many smaller scarps, and also importantly that these scarps are distributed globally, all across the surface of our nearest neighbor in space.
What does this have to do with shrinkage?This diagram shows how scarps are formed: thrust faults. If the Moon shrinks, even a little, the surface shrinks too, and gets compressed. This causes stress under the surface, building pressure. Eventually that pressure exceeds the strength of the rock above it, and you get a fault. One side of the fault slams upward, forming the scarp.
We see these sorts of features on many bodies in the solar system, including the Earth, where their origin is from tectonic plate motion. As the continental plates move past each other, friction allows the pressure to build up. There’s no such drift on the Moon — the surface is essentially one big piece — so something else must be causing it.
Shrinkage makes the most sense. The interior of the Moon is still warm from the leftover heat from its formation billions of years ago. Hundreds of kilometers of rock makes a pretty good insulator, so the Moon has cooled very slowly. As the interior cools, it shrinks, and the surface collapses down as well. Pressure builds, then snap! While a lot of these scarps are very long and dozens of meters in height, LRO’s sharp vision (it can see objects less than a meter in size!) can spot scarps that are only a kilometer or two in length and a few meters high. That sort of feature is not possible to see from Earth. They’re too small.
So this scarp formation has been going on essentially since the Moon formed, but the question is: does this process still continue today?
Maybe. The scarps seen are relatively young, something like 800 million to a billion years old. Dating them is difficult, but again LRO’s keen eye helps us out:
In this image, the scarp seen cuts right across some small craters. Geologists can use the number of craters to get an age for the landscape, which is how they have been able to get a rough estimate of how old the scarp is. Also, despite the lack of air and standing water, the Moon undergoes erosion. Solar wind, micrometeorites, and even the thermal expansion and compression caused by the Moon’s day/night cycle all work to grind up surface rock into dust. The scarps look quite fresh, limiting their age.
Another interesting bit of evidence is that the Apollo missions put seismographs on the Moon, which recorded quite a few moonquakes. Several dozen of these quakes were shallow, which may be related to scarp formation (since the thrust faults are near the surface).
So, does this mean the process is still going on? It’s not really possible to say as yet. A billion years is a long time, and it’s difficult to know if any small scarps are younger than that. As LRO scans more and more of the lunar surface, more of these types of landscape features will be seen.
And finally, what does this mean for the ultimate size of the Moon? Well, you have to put this into perspective: the Moon’s diameter is about 3475 kilometers. This shrinkage is only about 0.003% of that. In other words, you’d never, ever be able to see that by comparing the Moon’s diameter now as it was, say, a billion years ago. So we’re not in any danger of the Moon collapsing down into a tiny little ball!
What it does mean is that despite it being perhaps the most well-studied object in the sky, our Moon is still capable of surprising us. Not only that, but some of its secrets are actually rather big, but so well-hidden we need to study the Moon pretty carefully to uncover them. Happily, we’re doing just that. There’s not a scientist on the planet who doesn’t like surprises, especially when they’ve been sitting right there in the sky for us to find.
Tuesday, 17 August 2010
Space missions....The Milky Way is a Spiral Galaxy and is the galaxy where our Solar System is located. No one knows exactly what the Milky Way Galaxy looks like from the outside. It is a spiral-shaped galaxy, with arms that resemble the shape of a spinning firework.
The most visible part of our own Milky Way Galaxy is part of the sky that looks like a misty cloud. It is really a band of millions of stars. The part that we can actually see is called the Milky Way. When we look at it, we are looking at the centre of our Galaxy where most stars are. We cannot actually see the centre because we are situated a long way from the centre of the Orion arm, an outer arm of the Galaxy. When we look at the region where the famous Orion constellation is situated, there seem to be fewer stars. This is because we are looking towards the edge of the Galaxy.
If we could look at it from the side, the Milky Way Galaxy would be rather thin disc with a dense, bulging centre surrounded by a halo. This halo is a mass of older stars surrounding the central mass, which contains the most stars. The thinner edges of the disc are the outer arms of the Galaxy.
In addition to the millions of stars in the Milky Way Galaxy, there are also many nebulae, which are regions where stars are being born.
About our Galaxy
The Milky Way Galaxy is about 2000 light years thick (tall) but 100,000 light years across. It contains an estimated 100,000 million stars. There is a bulge in the center of it. The Milky Way also has a halo that has a radius of 50,000 light years, which is above the nucleus. The halo is made up of very old stars called globular clusters.
Age
The Milky Way is believed to be more than 13 billion years old.
Location of our Sun
Our Sun, which is one of those stars in the Milky Way Galaxy and is about 30,000 light years from the centre. It orbits the centre of the Galaxy at a speed of 274 kilometres per second.
Did you know?
* The speed of light: Light from our Sun takes just 8 minutes.
* The Greek philosopher Democritus (450–370 BC) was the first known person to propose that the Milky Way might consist of distant stars.
* A galaxy is made up of billions or trillions of stars bound together by their own gravity and there are millions of galaxies in the universe. Our Solar System is in the Milky Way Galaxy and is more on the west side of the Milky Way.
* Harlow Shapley, an American astronomer (November 2, 1885- October 20, 1972 was the first person to estimate the size of the Milky Way Galaxy, as well as our position of the Earth in the galaxy.
Wednesday, 3 March 2010
WOW......
Water on MOON!!!!
Wed, Mar 3,2010 05:49 AM
New analysis of scientific data from a NASA instrument aboard the 2008 Indian moon mission Chandrayaan-1 has detected more than 40 ice-filled craters in the lunar north pole, reviving hopes for colonization of the moon by humans in future. "Using data from a NASA radar that flew aboard India's Chandrayaan-1 spacecraft, scientists have detected ice deposits near the moon's north pole. It's estimated there could be at least 600 million metric tons of water ice," NASA reported on Tuesday.
"The new discoveries by Chandrayaan-1 and other lunar missions show that the moon is an even more interesting and attractive scientific, exploration and operational destination than people had previously thought," Prof Paul Spudis, Principal Investigator of the Mini-SAR, was quoted as saying in an ISRO statement.Once you have such large quantities of water it will help in setting up colonies," said ISRO spokesperson S Satish on the publication of the Mini-SAR finding
New analysis of scientific data from a NASA instrument aboard the 2008 Indian moon mission Chandrayaan-1 has detected more than 40 ice-filled craters in the lunar north pole, reviving hopes for colonization of the moon by humans in future. "Using data from a NASA radar that flew aboard India's Chandrayaan-1 spacecraft, scientists have detected ice deposits near the moon's north pole. It's estimated there could be at least 600 million metric tons of water ice," NASA reported on Tuesday.
"The new discoveries by Chandrayaan-1 and other lunar missions show that the moon is an even more interesting and attractive scientific, exploration and operational destination than people had previously thought," Prof Paul Spudis, Principal Investigator of the Mini-SAR, was quoted as saying in an ISRO statement.Once you have such large quantities of water it will help in setting up colonies," said ISRO spokesperson S Satish on the publication of the Mini-SAR finding
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