Just another WordPress.com site

Posts tagged “as a result

Life in venus? – Kavignar Thanigai.

Scientists long have theorised that Venus formed out of ingredients similar to Earth’s, but followed a different evolutionary path.

Venus, NASA, NASA Venus, life on Venus, NASA Venus discovery, world news, science news, latest news, world news, international news

 

Today’s Venus is a hellish world with temperatures reaching 462 degrees Celsius at its surface and almost not water vapour, but for up to two billion years of its early history, the planet could have hosted life, a NASA study says. In those days, Venus may have had a shallow liquid-water ocean and habitable surface temperatures, according to computer modeling of the planet’s ancient climate by scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York.

The findings, published in the journal Geophysical Research Letters, were obtained with a model similar to the type used to predict future climate change on Earth.

“Many of the same tools we use to model climate change on Earth can be adapted to study climates on other planets, both past and present,” said the paper’s lead author Michael Way, a researcher at GISS.

 

“These results show ancient Venus may have been a very different place than it is today,” Way noted.

Today’s Venus has a crushing carbon dioxide atmosphere 90 times as thick as Earth’s. Scientists long have theorised that Venus formed out of ingredients similar to Earth’s, but followed a different evolutionary path. Measurements by NASA’s Pioneer mission to Venus in the 1980s first suggested Venus originally may have had an ocean. Previous studies have shown that how fast a planet spins on its axis affects whether it has a habitable climate. A day on Venus is 117 Earth days.

But recent research showed that Venus could have had an atmosphere similar to the Earth’s today. Another factor that impacts a planet’s climate is topography.The team postulated ancient Venus had more dry land overall than Earth, especially in the tropics.

That limits the amount of water evaporated from the oceans and, as a result, the greenhouse effect by water vapour. This type of surface appears ideal for making a planet habitable, according to the scientists. There seems to have been enough water to support abundant life, with sufficient land to reduce the planet’s sensitivity to changes from incoming sunlight.

The researchers simulated conditions of a hypothetical early Venus with an atmosphere similar to Earth’s, a day as long as Venus’ current day, and a shallow ocean consistent with early data from the Pioneer spacecraft. The researchers added information about Venus’ topography from radar measurements taken by NASA’s Magellan mission in the 1990s, and filled the lowlands with water, leaving the highlands exposed as Venusian continents.

The study also factored in an ancient sun that was up to 30 percent dimmer. Even so, ancient Venus still received about 40 per cent more sunlight than Earth does today.

“In the GISS model’s simulation, Venus’ slow spin exposes its dayside to the sun for almost two months at a time,” co-author and fellow GISS scientist Anthony Del Genio said.

“This warms the surface and produces rain that creates a thick layer of clouds, which acts like an umbrella to shield the surface from much of the solar heating. The result is mean climate temperatures that are actually a few degrees cooler than Earth’s today,” Genio said.

 

thanks : The Indian Express

dedicated by: kavignar Thanigai.

Advertisements

SAFEST COUNTRIES IN OUR WORLD LIST OUT BY INSTITUTE FOR ECONOMICS AND PEACE.

thanks: the week,the Economic Times

Dedicated by: KAVIGNAR THANIGAI.

Iceland is the safest country in the world, while Syria is the most dangerous, the latest report from the Institute for Economics and Peace has found.

The rankings were based on 23 different metrics, taking into account statistical factors such as murder rates and military expenditure, but also including perceptions of criminality within states and terrorism levels. The metrics are combined into a single number, called the Global Peace Index (GPI). The lower the number, the safer a country is regarded.

The report, released annually, ranked Syria as the 88th most peaceful country in 2008, out of 162 total nations. However, the outbreak of civil war and the rise of Islamic State (IS) have caused its peace ranking to shoot through the floor, according to The Independent. Syria earned a GPI of 3.645.

The ten least peaceful countries in the world
  • Syria
  • Iraq
  • Afghanistan
  • South Sudan
  • Central African Republic
  • Somalia
  • Sudan
  • Democratic Republic of Congo
  • Pakistan
  • North Korea

Iceland, by contrast, earned its rank from a low level of militarisation and conflict both domestically and internationally. Iceland is one of few countries in the world – and only Nato member – without a standing army. The closest agency it can deploy is the coastguard. Factors such as these earned Iceland the lowest GPI, at 1.148.

Nordic countries and Alpine states including Austria and Switzerland rank highly on the list of most peaceful countries – Denmark sits in second place, and Finland in sixth. Sweden and Norway are 13th and 17th, respectively, due to their higher crime levels and weapons exports; Sweden prefers to stay neutral in conflicts, yet is the 12th largest exporter of weapons in the world.

The ten most peaceful countries in the world
  • Iceland
  • Denmark
  • Austria
  • New Zealand
  • Finland
  • Switzerland
  • Canada
  • Japan
  • Australia
  • Czech Republic

The UK came in 39th place, due primarily to higher perceptions of criminality and a greater threat of terrorist attacks, according to the Independent. Being a nuclear state is also a detriment to its rank.

The ten least safe countries in the world are comprised primarily of states in the Middle East and north and central Africa. These states suffer from frequent bouts of civil war and the effects of the “War on Terror”. North Korea also made the bottom ten.

This is the ninth edition of the GPI report. Over the past eight years, the average country score has fallen by 2.4 per cent, indicating that, by and large, the world is becoming less peaceful.

India ranks 143rd on global peace index; Iceland tops list

MELBOURNE: India ranks a lowly 143rd on a global peace index, lagging way behind the likes of Bhutan, Nepal, Sri Lanka and Bangladesh with Iceland emerging as the most peaceful nation in the world.

According to the nonprofit Institute for Economics and Peace, Iceland, the thinly populated island in the midst of the North Atlantic has retained its place as the most peaceful country in the world.

The institute released its Global Peace Index for 2015 recently, which ranks 162 nations around the globe based on factors like the level of violent crime, involvement in conflicts and the degree of militarisation. The nations are given a score on that basis. The more the score, the less peaceful the country is.

India is ranked at 143 on the index with a score of 2.504.

“The number of casualties from internal conflict also rose in India where a Maoist insurgency stills runs rife. The downgrade in India’s score is tempered, however, by an improvement in political stability. The world’s second most populous country witnessed an historic election in 2014 as the Bharatiya Janata Party secured India’s first one-party majority since the mid-1980s,” the report said.

Six out of the top 10 most peaceful countries were European, with Denmark and Austria holding the second and third spots.

“Europe maintained its position as the most peaceful region in the world, supported by a lack of domestic and external conflicts,” the report said.

Pakistan fares badly ranked at 154 with its score deteriorating on the back of a worsening of its perceptions of criminality, as a result, the country remains second from the bottom in South Asia.

“The country’s dire domestic security situation continues to be hampered by the presence of Islamist militant groups. Even though the number of deaths from internal conflict did not worsen significantly over the past twelve months, Pakistan suffered a handful of high-profile incidents — most notably the separate attacks on Jinnah International Airport and an army-run school in Peshawar,” the report said.

Afghanistan remains the most lowly ranked in South Asia at 160.

Bhutan (18), Nepal (62), Bangladesh (84) and Sri Lanka (114) are all ranked above India, Pakistan and Afghanistan.

US is also ranked at a lowly 94 scoring badly in terms of militarisation, homicides and fear of violence. China is ranked 124.

Syria and Iraq where the Islamic State terror group has taken over large swathes of land are at the bottom of the table as the least peaceful countries.