New Horizons Explores The Frigid World of Pluto

NASA’s New Horizon spacecraft designed to flyby Pluto having travelled five billion kilometres  for the past nine and half years is going to have its closely approach with the dwarf planet by 7:50 am, Eastern Day Light Time on July 14^th 2015. Astronomers and science enthusiasts’ world over are passionately waiting for this epic moment that will last for few minutes. The probe will whiz past the planet’s surface at a velocity of 53,000 kmph during which it will capture thousands of images, collect scientific data of Pluto’s atmosphere, its surface and environment. Pluto has been the least explored planet in the solar system and no dedicated mission was ever commissioned for its study. New Horizons mission was instituted to study Pluto and explore the vast swarm of frosty bodies lying beyond Neptune and the bodies faintly moving in the frigid Kuiper belt region.

The probe has travelled so far that it will take 4.5 hrs for the radio signal sent from earth to reach the space craft. Hence it will remain radio silent for the entire period of its closet encounter with Pluto and Charon as the limited computing ability of the probe will be utilised in collecting the necessary data. Close-up image and scientific data will be sent to earth over a period of next 26 months and first high resolution pictures of Pluto are expected to be transmitted by July 15^th. The chances of this event becoming successfully are very high as the chances of collision of debris with probe is 1 in 10,000. This mission is of great relevance as it would shed light on less know details of the planet, its composition, moons and atmosphere but also it would help us in understanding the evolution of solar system including the Earth.

History of Pluto

The year 2015 marks the 85^th anniversary of discovery of the dwarf planet Pluto.

In 1930 a 24 year old farmer-turned-astronomer Clyde Tombaugh discovered the planet Pluto. The existence of a planet X in close proximity to Neptune was suspected by the founder of Lowell Observatory, Percival Lowell on the basis of perturbations experienced by the orbit of Neptune. The discovery of the planet was announced on March 13^th that coincided with the birthday of Percival Lowell and with the discovery of the planet Uranus a century and half earlier.  Soon suggestions were invited for naming of the new planet. The planet was christened as Pluto after the Roman God of underworld as per suggestions of 11 year old Venetia Burney of Oxford, UK.  As a mark of respect, the dust counter built by students aboard NASA’s New Horizons Space craft is named as Venetia.

In 1978 James Christy and Robert Harrington of the US Naval Observatory at Flagstaff discovered Charon, the largest moon of Pluto. Charon in Roman Mythology refers to the ferryman who brings souls of dead men to the lair of Pluto. The moon which was visible as a bulge regularly appeared and disappeared in the images as Pluto. Pluto and Charon seemed to orbit their mutual centre of gravity and also because of the bigger size of Charon, these two bodies were referred to as Binary Planets.

In 1988 astronomers aboard the Kuiper Airborne Observatory made crucial observations about the atmosphere of Pluto. They indicated that Pluto’s surface is covered by ice made of Methane, Nitrogen and Carbon monoxide. These ices sublimate to form the thin atmosphere of Pluto.

In 2005 Hal Weaver and his colleagues at John Hopkins Institute revealed the presence of two moons of Pluto, Nix and Hydra. Other moons Kereberos and Styx were discovered in 2010 and 2011. Styx is faintest of all moons.

On January 19^th 2006 the New Horizons space craft, the first probe to Pluto lifted off from the Cape Canaveral Air Force Base, Florida

In August 2006, International Astronomical Union (IAU) demoted Pluto to the status of dwarf planet as it failed to qualify the new definition of a planet. It dictates that a planet must orbit around the sun, it should be large enough for its gravity to shape it into a sphere and its must have cleared its orbit of other similar-sized bodies. Pluto was relatively small compared to the objects in its surrounding. It was just another object in Kuiper belt and hence now the solar system is reduced from the earlier number of nine to eight planets.

Following the reclassification of Pluto a section of scientific community terribly opposed the new definition of the planet. Later in 2008, all the trans-Neptunian dwarf bodies were classified under the category of Plutoids. Also a new system of classification came into existence under the category of dwarf planets which includes five planets in solar system: Pluto, Ceres, Haumea, Makemake and Eris (Pluto destroyer).

Solar System is demarcated into three categories of planets- the inner rocky planets (Mercury, Venus, Earth and Mars) the outer gas giants (Jupiter, Saturn, Uranus and Neptune) and the ice dwarfs located on outer fringes of the Solar system or the Kuiper belt region. These include Pluto and Charon.

US Missions to Planets

The US has sent a space probe to each and every planet so far and with this New Horizon mission its aims to complete the initial reconnaissance of the solar system. In 1960 NASA has envisioned a plan of sending probes to all the five planets. Missions were designed to take the advantage of the celestial phenomenon of rare alignment of Jupiter, Saturn, Uranus and Neptune (occurs once in every 175 years) and assisted flybys. However due to highly constrained budget of NASA, the grand mission has been reduced to missions Voyager 1 and Voyager 2. These missions have successfully completed the flybys of the four gas giants. By 1989, Pluto was the only bonafide planet left unexplored. However when Pluto was derecognised as a planet in 2006, it meant that all planets were explored.

New Horizons Mission

Several programs like the Pluto fast flyby, Pluto Kuiper Express were designed to study and understand the key characteristics of Pluto’s atmosphere. But these were abandoned due to budgetary constraints. By 2001 New Horizons Mission was selected by the NASA’s New Frontier Program. Over the next five years South West Research Institute (SRI) and John Hopkins Applied Physics Laboratory built the spacecraft. Unlike the spacecrafts designed for the inner solar system, this space craft had limited electronic activity. Since it is destined to travel to the outer boundaries of the space the interior paint and exterior blanket were designed to maximise heat retention in the outer space. As it moved into realms farther from the Sun, the probe wasn’t equipped with solar arrays. Instead it had built in Radio Isotope Thermoelectric Generator (RTG) to provide power that can last through the launch and Pluto-Charon encounter. Spacecraft carried the Plutonium-238 Oxide pellets as fuel enclosed in the Iridium and Graphite shell. Hence the US Department of Energy carried out several pre-launch tests to make sure that the launch wouldn’t cause accidental contamination of the Earth’s atmosphere. Altogether there are seven scientific instruments on board

Launch and Flybys

The New Horizons was scheduled for a launch on January 11^th 2006 to allow for the gravity of Jupiter to assist a flyby.  It soon missed the target and was the launch was postponed to January 17^th but was stalled due to high winds. Second attempt on the next day was halted due to low clouds. Finally the probe, hoisted by the Atlas V 551 variant lifted off majestically from the Cape Canaveral Air Force Station, Florida on January 19^th.  During its course of flight it had an incidental encounter with the asteroid 132524 APL in June 2006 from a distance of 63, 297 miles followed by a Jovian (Jupiter and its moons) encounter in 2007 and finally with Pluto in 2015.

Accomplishments

These encounters acted as trial runs for the scientists at ground station to use some instruments on board for making crucial observations and test space craft’s ability to perform automated manoeuvres during planetary flyby operations. Spacecraft was fitted with state-of-art instruments that delivered good quality of data about the atmospheric conditions, structures and composition of Jupiter clouds. It discovered debris from recent collisions within Jupiter rings and searched for new rings and moons of Jupiter as well.

The probe was so meticulously designed that the gravity assisted sling shot manoeuvre during the Jupiter flyby has accelerated probe velocity to 53,000kmph relative to Sun. This shortened the probe’s journey to Pluto by three years. Following close encounter with Jupiter the mission command has decided to send the probe into a phase of hibernation which lasted from February 2007 to December 2014. The probe was intermittently awakened by the flight control team to keep systems operational. It crossed the Orbital Boundary of Saturn in March 2008 and Uranus in March 2011.

In July 2014 during its non-hibernation phase the probe successfully imaged Pluto and Charon separated by a distance of 2.4 AU (average orbital distance of Earth from Sun) as two distinct bodies. In December 2014, the probe was finally awakened by the NASA team and official operations began in January 2015. By February 2015, it captured the first images of Hydra and Nix and by end of April the probe could capture images of Kerberos and Styx. In mid May the probe delivered high resolution images of entire Plutonian system and started making observations of Kuiper belt objects too. The probe encountered a minor technical glitch on July 4^th following which it entered into safe mode. Soon it was rectified and it officially entered flyby mode by July 8^th.  The close approach flyby mode is destined for July 14^th when the New Horizons will pass by Pluto from a distance of 12,500 kilometers  and 28,800 kilometers from Charon. Since probes close approach to Charon is more than twice the distance of Pluto the images of Charon will be twice as coarser than those of Pluto.

Post Pluto Flyby

After the completion of the Pluto’s flyby operation, the probe instead of entering into the orbit of dwarf planet will enter into the deeper recesses of space into the Kuiper belt objects. It was planned that the probe will identify the Kuiper Belt Objects (KBO). In this process if the probe travels beyond orbital boundary of 55AU, communication system will become weak, power supply too will run out and chances of assisted flybys would become bleak. Scientists have identified three KBO in range of 43 and 44 AU for plausible flybys but the final decision will be taken in August 2015.

Post flybys of KBO the probe is expected to join Voyager probes on the outer realms of Solar System. Based on the Plutonium decay, the probe is expected to be active till 2026. If it is healthy and robust like the Voyagers by the time it reached Heliosphere, it can meet Heliopause in 2047 and join Voyagers 1 and 2 floating in the interstellar space.

The mission is a glorious tribute to the scientific temper and inquisitiveness of the human mind. It reflects the deep seated urge of the humankind to explore, understand and study the intricacies of the celestial World and the invincible space.
 

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Changing Dietary Habits: Inclement Effects on Global Climate

Changing global climate has been posing severe challenges for healthy living. An international research report published in the Lancet journal recently warns about the looming “threat of the changing climate that can wipe out the health progress over the past 50 years”.
 

The report broaches on the direct and indirect effects of climate changes on the health. Direct effects refers to increase in the frequency and intensity of extreme weather events like heat waves, floods, drought and storms whose impact is enormous on health. The worst ever death toll recorded in India and Pakistan due to the severe heat wave this year fall under this category. Indirect impacts of climate changes include the changes in the infection patterns, effects of emissions, uncertainty regarding availability of food leading to malnutrition. Health effects also include those related to involuntary migration of people forcing them to leave the affected regions in search of better living conditions. This reduces social stability would indirectly affect the health.
 

The compendium, a collaborative effort of number of European and Chinese Climate Scientists, Environmental Scientists, Social Scientists, Medical and Health scholars, Energy policy experts, engineers and others have cautioned that major gains accrued in human health might be frittered away by the changes in climate. It elucidates the role of emissions in stunting positive health benefits and advised countries to cut down fossil fuel consumption to lower the incidence of respiratory diseases. This is congruent to the alarming levels of pollution in the capital city of Delhi where children are becoming more susceptible to life-threatening respiratory diseases. It also advised nations to reduce the consumption of red meat which is not environmentally friendly and strictly recommended a change in dietary habits. Another major threat to global health in recent years has been the increased incidence of conflict.
 

It also proposed to initiate a new independent global action plan “Countdown to 2030: Climate Change and Health Action.” The objectives of the plan will be carried out by an organisation that monitors the link between health status and affect of climate change and to UN every two years. Lancet Commission report further emphasises the need for strong international consensus to create a global economy wherein carbon emissions are reduced. This in turn would improve the health status. The report has a great bearing on the talks in climate change on global health with regard to UN Climate Change Conference, COP 21 to be held in Paris from 30^th November to 11^th December 2015.

Research indicates that change in the dietary habits has a great impact on the climate change. Though the statement is little intriguing, scientific study and resource utilisation pattern clearly suggested that plant based diet is more healthy and environmental friendly than meat diet. Food and Agriculture Organisation (FAO) reports also expounded that changing dietary habits in the past few decades have contributed to current environmental degradation and resource stress.

In recent times due to rise in income levels people are increasingly turning towards high energy food sources like animal sources especially meat. While it took a century for Europe to reach a stage where every meal has meat a similar change could be witnessed in majority of Asian countries within a generation. People are now switching to meat based meal. Obtaining proteins from meat is far more resource intensive than from plants as they use more cropland, water and energy. Their transportation to slaughter houses and processing of the meat are high energy intensive processes. Hence consumption of meat depletes more natural resources and consequently puts great pressure on food production systems, damages ecosystem and triggers climate change. Meat production is 10 times more water intensive than plant- calories. It is estimated that 15,415 litres of water is need to produce a kilogram of beef. In other words nearly 30 plant calories are needed to produce one calorie of meat.

Due to sharp increase in the global population there is a growing demand for food grains. Currently 36% of the calories produced by World crops are utilised as animal feed and only 12% of calories contribute to human diet. The population of the livestock is 14 billion as compared to human population of 7.2 billion and their environmental foot print is much higher. Livestock accounts for 14.5% of the Green House Gas (GHG) Emissions. Live stock production consumes three times more water resources than agriculture accounting for 71% of World water consumption. Livestock production occupies about 30% of Earth’s land surface. Moreover, extensive rearing of livestock over a period of time resulted in the biodiversity loss and extinction of other wild animals.

Incidence of various diseases like diabetes, heart attacks, strokes etc increased with regular consumption of meat. Obesity has become a chronic problem in all meat eating nations. On an average while the consumption of meat in India is 3.2 kilograms it is 125.4 kilograms in US, the second largest meat consuming nation after Luxembourg. Worryingly the demand for meat is projected to increase by 50 % by 2025 with Asian countries accounting for a large part of it.

Higher demand for meat will be catastrophic for environment. To meet the increasing demand meat suppliers would resort to feeding the livestock with food grains rather than grass. This in turn would put great pressure on the food grains, natural resources and environment. Livestock are injected with hormones to trigger growth and as a prophylactic measure fed with antibiotics to curtail spread of diseases. In fact most of the deadly diseases of recent origin infecting humans are mostly Zoonotic (originated from animals). The disposal of livestock wastes largely results in contamination of water and oil with antibiotic residues and other high metal elements.

While the burden of changing to animal based diet on environment and health is extensively studied and documented, the message has failed to reach the intended subjects. With the World glaring at the imminent natural resources crunch, increasing global temperatures, burgeoning population and increasing demand for food grains and ever increasing health complications- it is high time that people change their dietary habits.

It is advisable to rely more on plant based diets for their calorific needs to reduce pressure on natural resources and environment. To this end, government and civil society should take the responsibility of spreading this message of promoting healthier plant based diet.

Interestingly, a recent research indicated that if crops are not diverted towards animal feeds and for bio fuel production an extra four billion people can be fed. Meat consumption actually releases more GHG’s than the cars annually. According to FAO report, beef production on average needs 28 times more land, 11 times more water than all other livestock categories and produces five times more GHG and six times more reactive nitrogen. While it is difficult for people to become vegetarian completely, they can choose other meat alternatives like chicken or sea food which is less resource- intensive.

 

Thus adopting a healthy plant based diet with minimal meat consumption would not only help in conservation of resources and minimising global warming but also helps in stemming the incidence of various life style diseases. If emission of green house gases can be minimised extreme climate changes can be averted and global health too can be conserved. Switch to a balanced diet to save our planet.

 

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