Neurology India
menu-bar5 Open access journal indexed with Index Medicus
  Users online: 8372  
 Home | Login 
About Editorial board Articlesmenu-bullet NSI Publicationsmenu-bullet Search Instructions Online Submission Subscribe Videos Etcetera Contact
  Navigate Here 
 Resource Links
  »  Similar in PUBMED
  »  Article in PDF (354 KB)
  »  Citation Manager
  »  Access Statistics
  »  Reader Comments
  »  Email Alert *
  »  Add to My List *
* Registration required (free)  

  In this Article

 Article Access Statistics
    PDF Downloaded26    
    Comments [Add]    

Recommend this journal


Table of Contents    
Year : 2019  |  Volume : 67  |  Issue : 8  |  Page : 204

Opportune circumstances for sustenance of life on a planet

Date of Web Publication24-May-2019

Correspondence Address:
Login to access the Email id

Source of Support: None, Conflict of Interest: None

Rights and PermissionsRights and Permissions

How to cite this article:
. Opportune circumstances for sustenance of life on a planet. Neurol India 2019;67, Suppl S2:204

How to cite this URL:
. Opportune circumstances for sustenance of life on a planet. Neurol India [serial online] 2019 [cited 2023 Mar 27];67, Suppl S2:204. Available from: https://www.neurologyindia.com/text.asp?2019/67/8/204/259136

This picture has been contributed by Dr. Manmohan Singh, Professor, Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi.

The sun provides us our life-sustaining energy. It is the centre of the solar system. Although it appears stationary, it moves along its orbit at an average velocity of 450,000 miles an hour. The sun was formed more than 4.5 billion years ago. To sustain life in the form that we recognise, a habitable planet has to have certain unique ‘earthlike’ features. It should orbit a star that has a stable energy output for billions of years, which in our case, is the sun. It should be in the “Goldilocks” zone so that it is at an optimum distance from the source of energy to maintain a suitable life-sustaining temperature. This will ensure that its surface water is liquid, not frozen. It should have plenty of water to sustain the chemical reactions necessary for life. The distance from the sun and the mass of a planet also determine whether or not it can retain “light gases (or any gases) in its atmosphere. The atmosphere of the earth, that predominantly contains oxygen and nitrogen, is ideal for sustenance of life and is dependent on this ‘ideal’ distance between the sun and the earth. The planet should have a circular orbit around its sun so that constant weather conditions prevail. There should not be a source of high radiation close to it. The presence of a large planet, such as Jupitar, that has an immense gravitational field, close to the planet sustaining life, like the earth, is also essential. The immense gravity of the large planet helps in deflecting most of the comets that enter the solar system away from the planet on which life is thriving. Without this large planet with an immense gravitational field, comets would collide with the planet that is sustaining life forms, much more frequently. In this photograph, taken in Jaisalmer, Rajasthan, the tourists sitting on the camel's back and their guide are completely unaware of how lucky they are to be present at this point in time in the history of the earth where every circumstance is opportune for sustenance of their life. This picture has been taken by a Canon EOS 5D Mark III, Lens 24-105mm, f/4.5-5.6


Print this article  Email this article
Online since 20th March '04
Published by Wolters Kluwer - Medknow