Science Reporter, JULY 2016 10

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A team of astrophysicists from Belgium, led

by Michael Gillon of University of Liege, has

discovered three earth-like planets very close

to our solar system. In a report presented and

published in the journal Nature, he says, “This

is the fi rst opportunity to fi nd chemical traces

of life outside our solar system.” He adds, “All

three planets had the winning combina on of

being similar in size to earth and also poten ally

habitable.”The three planets are found to be orbi ng a

dwarf star, which is just 39 light years away from us.

While prac cally it may take us millions of years to

travel this distance currently, astronomically it is

considered very close and viable for observa ons.

Another encouraging piece of informa on is

that these planets are close enough to our solar system so that the atmospheres can be analysed and recorded with the

present available technology. In addi on, this also opens up the scope to delve into this star system for other habitable planets.

Gallon and his team used a specially calibrated 60-cm telescope, called the TRAPPIST (Transi ng Planets and Plane smal

Small Telescope), and located in ESO’s La Silla observatory in Chile, to make their observa ons. During their probes, they

tracked several dozen dwarf stars that were neither too big nor too hot for op cal telescopes.

Amongst them, they found a star about one-tenth the size of the Sun, and which was many mes cooler. The promising

star was called TRAPPIST-1. During the observa ons spanning over 60 days, they recorded the infrared radia ons from the star

and found that it was fading at some points in regular intervals – a situa on similar to an eclipse. This led to the path-breaking

conclusion of the presence of an orbi ng object – an exoplanet (similar to a planet but exis ng outside our solar system).

The studies also reveal that two of the planets were orbi ng around the dwarf star in a ght and close orbit, called the

dal lock posi on. The third was found to orbit in a broader orbit with longer dura on. Very li le is currently known about

the third planet. The inner two planets, in comparison, received nearly two to four mes the heat-radia on received by the

earth and had shorter orbi ng days. Due to the dal locking, only one hemisphere is exposed to the star, giving rise to clear

dark and light regions.

Though the nature of the star is many mes cooler than the Sun, the amount of radia on received is more for the planets

due to their proximity; this encourages the temperature condi ons for the possibility of fi nding liquid water and life in several

regions across the planets.

Gillon also elucidated that the topography, amount of water, presence of rocky ma er, atmosphere etc., may be diff erent

from the earth’s composi on. The mass of the planets could be one half to a maximum of double that of the earth’s.

Under such diff erences, the possibility of life can exists only if the planet comes under the “Goldilocks zone” as referred

to by astronomers. This is an ideal zone where the temperatures of the planet in rela on to its star are op mum- not too hot

such that water evaporates or too cold to freeze it. Water has to be in liquid state for ideal condi ons.

The closeness of the dwarf star to earth opens up op ons to study their surface closely and in detail. Earlier inves ga ons

overlooked the possibility around these dwarf stars, as they did not fi t into the classical range of a star. Dr Julien de Wit from

the Department of Earth, Atmospheric and Planetary Sciences adds that these ny dwarf stars are common in the Milky Way

and cons tute nearly 25% to 50% of the stellar objects in the Galaxy.

These dwarfs are cooler than the sun by almost half the intensity with a mass of only a tenth of the Sun. This discovery

also leads to the conclusion that several cooler dwarfs hold the poten al to habitable planets orbi ng in their gravita onal

belt.The discovery of these exoplanets around a small dwarf star has opened up a plethora of possibili es with a large number

of planets yet to be discovered around such stars. The future holds exci ng probabili es of discovering new life in the skies;

hitherto this has only been reserved for imagina on or created in science fi c on.

Contributed by Ms Susheela Srinivas, #189, I F cross, 3rd Stage, 4th Block, Basaveshwaranagar, Bengaluru-560079; Email: sushsri@gmail.com

THREE NEW PLANETS

DISCOVERED

Representative image

Though the nature of the star is many times cooler than the

Sun, the amount of radiation received is more for the planets

due to their proximity; this encourages the temperature

conditions for the possibility of fi nding liquid water and life in

several regions across the planets.

Science Reporter, JULY 201611

SPECTRUM

ABNORMAL BODY MOVEMENTS IN

CHILDRENBACTERIAL meningi s is the result of a bacterial infec on of the blood that spreads to the cerebrospinal fl uid (CSF), which is the fl uid that fl ows around the meninges. Meninges are the three membranes viz. dura mater, arachnoid mater and the pia mater that envelop the brain and spinal cord and act as a protec ng covering for the two.

In meningi s, the meninges become infl amed. Infl amma on-related swelling of the membrane can cause serious problems that include sep cemia (blood poisoning), brain damage, coma, and even death.

The bacteria responsible for causing meningi s can spread from an ear infec on to the meninges or from the bloodstream of mother to infants. The most common source is the spread of bacteria into the bloodstream from an infec on in the heart.

Children are more prone to this infec on. Acute bacterial meningi s is a disease that frequently aff ects children below 10 years of age. It usually occurs when bacteria enter the bloodstream and migrate to the brain and spinal cord. The bacteria which commonly cause meningi s in children include Streptococcus pneumoniae, Haemophilus infl uenzae and Neisseria meningi dis.

The most common signs and symptoms of bacterial meningi s in children include abnormal body movements such as up-rolling of eye balls, s ff ness in fore- and hind-limbs, neck s ff ness, lethargy, convulsions/seizures, fever upto 105°C, headache, vomi ng, cough, fast breathing at rest, irritability, etc.

A project sponsored by the Indian Council of Medical Research (ICMR), en tled “Hospital based Sen nel Surveillance of Acute Bacterial Meningi s” is running in various centres in the country including Chris an Medical College (CMC), Vellore, Tamil Nadu; Chacha Nehru Bal Chikitsalya, CNBC, Delhi; Indira Gandhi Medical College (IGMC), Shimla, Himachal Pradesh, etc.

The project involves treatment of children (0-5 years) suspected to have meningi s and surveillance of the disease in respec ve areas. In our centre, the Department of Microbiology, IGMC, Shimla, around 15-20 suspected samples of acute bacterial meningi s are received for diagnosis each month. Out of the three species of bacteria, in Himachal Pradesh, Streptococcus pneumoniae is the most common cause of bacterial meningi s in children below fi ve years.

People need to be vigilant about abnormal body movements, and other symptoms, in children around them. Meningi s is completely curable if diagnosed at early stages. It may lead to serious long-term consequences such as deafness, epilepsy, hydrocephalus, cogni ve defi cits or even death, if not treated on me.

Contributed by Dr. Arushdeep Sidana, SRF in Department of Microbiology, Indira Gandhi Medical College, Shimla, H.P.; Email: arushdeep@ymail.com

DR. O. P. SHARMA CONFERRED WITH “ATMARAM PURASKAR”

SkullMENINGES Dura mater:

Periosteal layerMeningeal layer

Arachnoid villusArachnoid mater

Blood vessel

Pia mater

Brain:Grey matterWhite matter

The three meninges

THE President of India Shri Pranab Mukharjee recently gave away the pres gious “Atmaram Puraskar” to Dr. Oum Prakash Sharma for his outstanding contribu on towards promo ng Science and Technology through Hindi.

Dr. Oum Prakash Sharma, presently working as Deputy Director, Na onal Centre for Innova ons in Distance Educa on in Indira Gandhi Na onal Open University, is ac vely working towards populariza on of science and technology in the society since the last two decades. He is a popular science writer, innovator and IT expert.

While working at IGNOU, he has developed a number of innova ve &

technology enabled learning and support solu ons using newer technologies.

He has contributed more than hundred popular science ar cles and papers for various magazines, newspapers, websites, conferences, seminars and books. Since 2001, as Chief Editor, he is bringing out a popular science magazine ‘Vigyan Apke Liye’ in Hindi. For wider accessibility, he has digi zed the magazine and made it available on the Internet (h p://www.vigyanapkeliye.in).

Dr Sharma has authored seven popular science books and for his outstanding contribu ons been popularizing science & technology, he has earlier been honored with awards like Rajiv Gandhi Na onal

G y a n - V i g y a n Moulik Pustak Lekhan Puraskar (2015) for his book Vigyan ke Badhate Kadam; Sampurnanand Award (2015) for his book Vigyan ke Naye Ayam; Na onal Award for Science & Technology Communica on (2014) by Dept. of Science & Technology; Shri Turshan Pal Pathak Baal Vigyan Lekhan Puraskar (2013) by Vigyan Parishad, Allahabad, Sir C.V. Raman Vigyan Sancharak Samman (2015) by AISECT, Bhopal; and Saraswat Samman by Vigyan Parishad, Allahabad.

Science Reporter, JULY 2016 12

THE people of the city of Kolkata witnessed a never before seen op cal phenomenon on 30th April 2016. Around noon of this rather hot and humid day, people were surprised to see a mul -coloured ring resembling a rainbow, encircling the Sun. Word about this large ring around the Sun spread like wildfi re in the en re city promp ng everyone to gaze skywards. Pictures of this rare occurrence went viral on the social media.

So, what was this rare phenomenon that became the talk of the town? According to scien sts, this phenomenon is called a ‘solar halo’ or rather a ‘22 degree halo’. It forms around the Sun and occasionally around the moon, when it is known as a ‘lunar halo’, due to refrac on of sunlight, or moonlight, as it passes through hexagonal ice crystals present in the atmosphere.

According to Mrs. Minal Pandey, Science Teacher of La Mar niere for Girls School Kolkata, when temperature and humidity are high (which is the case in Kolkata which was reeling under an unprecedented con nuous heat wave spell during April) thin cirrus clouds are formed. When these clouds dri up to an al tude to say 20,000 feet above the earth’s surface, the water vapours present in the clouds freeze to form ny crystals of 20.5 micro meter diameter. When sunlight passes through these crystals, they act as

prisms and refract the light twice – once at the point of entry and again at the point of exit. The devia on is 22 degrees and hence the name. At mes the inner edge of the circle takes a reddish nge and the outer a bluish hue resembling a rainbow.

Although a solar halo may look like a rainbow, there are basic diff erences between the two. Rainbows are caused by water droplets suspended in the air usually a er a rain. Solar halo is caused by ice crystals. The rainbow appears to us on the opposite side of the sky from the Sun, this is due to the fact that sunlight gets refl ected within the rain water droplets before reaching us, so the Sun needs to be behind us when we see a rainbow. The solar halo occurs due to sunlight passing through ice crystals so the Sun needs to be high in the sky behind the cloud of ice crystals, which was the case in Kolkata. It was seen around noon when Sun was overhead.

Like a halo, a rainbow is also circular but because it happens when the sun is low in the sky and the rainbow is consequently close to the horizon we see it as semicircular. Further, a halo is more common than rainbows in cold places due to the fact that even at lower strata the air can be full of ice crystals.

However, a 22-degree halo is not followed by rain because cirrus clouds do not cause rains. It only indicates the presence of moisture high up in the air.

Contributed by Mr Shakunt Pandey. Address: ‘Lake Utsav’, P-331 Parnashree Pally, Flat No. 3A, 3rd Floor, Kolkata-700060; Email: shakuntpan33@gmail.com

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Solar Halo as observed in Kolkata by the author

KOLKATA WITNESSES RARE

RING AROUND THE SUNSUN

The solar halo occurs due to sunlight passing through ice crystals so the sun needs to be high in the sky behind the cloud of ice crystals, which was the case in Kolkata. It was seen around noon when sun was overhead.

The rainbow appears to us on the opposite side of the sky from the Sun, this is due to the fact that sunlight gets refl ected within the rain water droplets before reaching us, so the Sun needs to be behind us when we see a rainbow.

Science Reporter, JULY 201613

LARGE animals play a key role in mi ga ng climate

change in tropical forests across the world by

spreading the seeds of large trees that have a high

capacity to store carbon, new research co-led by the

University of Leeds has said.

The research, published in the journal Nature

Communica ons, sheds important new light on the

role seed dispersal by animals plays in mi ga ng

climate change, and how this role can vary in tropical

forests across the world.

In tropical forests of the Americas, Africa and

South Asia, a large majority of tree species depend on animals for seed dispersal. Tree species with large seeds a ain greater

adult sizes than those having smaller seeds. Using simula ons, the researchers showed that declines of large animals will result

in forests having fewer large trees – and hence carbon losses from these forests over me – as they play an important role in

seed dispersal.In contrast, a rela vely large propor on of large-statured tree species in tropical forests of South East Asia depend on wind

and gravity rather than animals for seed dispersal. In these forests, the loss of animal dispersers will not have as pronounced an

eff ect on carbon storage.

Experts from 15 ins tu ons, including the Faculty of Biological Sciences at the University of Leeds, together with colleagues

from the Na onal Centre for Biological Sciences in Bangalore, India, examined how tree species dispersed by large animals

diff ered from tree species dispersed by smaller animals and by other methods, for example wind and gravity, in their ability to

store carbon.Dr Mahesh Sankaran, of the School of Biology at Leeds, was part of the team that led the study. He said: “There is growing

recogni on that the loss of animals from ecological communi es, known as defauna on, poses a threat to carbon storage in

tropical forests, but much of this understanding is derived from pa erns seen in South American forests alone. Our work shows

that carbon storage responses to defauna on will vary across the tropics, largely as a result of diff erences in the evolu onary

histories of forests on diff erent con nents.”

Dr Anand Osuri, post-doctoral researcher at the Na onal Centre for Biological Sciences and lead author, said: “Our study

shows that, on the pan-tropical scale, consistent rela onships between species’ seed dispersal strategies and adult size are likely

to be one of the main factors driving shi s in carbon storage poten al in response to defauna on.”

ABEL PRIZE — 2016

SPECTRUMSPECTRUM

ANIMALS IN MITIGATING

CLIMATE CHANGE

WIDELY acclaimed as the ‘Nobel Prize in Mathema cs’, the Abel Prize for the current year (2016) has been awarded to Sir Andrew John Wiles, Professor in Mathema cs, Oxford University “for his stunning proof of the Fermat’s Last Theorem by way of the modality conjecture for semi-stable ellip cal

curves, opening a new era in number theory” and thereby solving the more than three-century-old mystery.

Prof. Wiles got his early educa on at King’s College School and Lay’s School, Cambridge before obtaining a degree in Mathema cs (1974) from Merton College, Oxford and Ph.D. (1980) from Clare College, Cambridge.

In a book he came across Fermat’s Last Theorem for the fi rst me, when he was only a 10-year-old boy and as nobody had proven it, his child-like enthusiasm impelled him to take up the challenge. However, soon he could realize his limita ons and gave up the idea, but only un l he reached the age of 33, when he again became interested in it a er Ken Ribeh proved the epsilon conjecture (1986.

Then he had to struggle for almost a decade for developing a general proof of it with occasional help from his student Richard Taylor, which won the Breakthrough Prize in Mathema cs in 2014. Wiles published his work in the form of two papers in the Annals of Mathema cs in 1995. His work made it easy to study ellip c curves and modular forms.

Prof. Wiles now aims to work on the Birch and Swinnerton-Dyer conjecture. Contributed by Dr. Sunita Chand, Professor, Department of Mathematics, Institute of Technical Education and Research (ITER), Siksha ‘O’ Anusandhan University, Jagamara, Bhubaneswar, (Odisha); Email: mami_chand@yahoo.co.inDr. Ramesh Chandra Parida, Retd. Professor, Orissa University of Agriculture and Technology (OUAT)

Sir Andrew John Wiles