"Now there's a look in your eyes, like black holes in the sky.
Shine on you crazy diamond."
- Pink Floyd, September 15, 1975.
MUMBAI - A quieter sun is sporting fewer black eyes, and we could have reasons
to be concerned. The fewer sunspots, the hole-like dark blotches seen on the
solar face, means the sun has been its least active in the past 100 years,
Sunspots are considered the best available indicator of solar activity. A
prolonged phase of a more internally peaceful sun could cause significant
climate changes on Earth. Cooler weather
will affect crop patterns, or even cause a "Little Ice Age", scientists
In an increasingly inter-connected world, Asia, as the world's largest
populated continent, is unlikely to escape geographic or economic side effects.
Not surprisingly, prominent Asian solar scientists such as Arnab Rai Choudhury
of the premier Indian Institute of Science have invested over a quarter of a
century of time studying sunspots.
Sunspots are riddles giving new twists in a 4.6 billion-year-old story (the
estimated age of the sun). Question marks over sunspots reflect the continuing
mystery of this ordinary little yellow dwarf star, one of millions of similar
nondescript stars in the Milky Way galaxy. Yet the sun contains 98% of the
total mass of the solar system, and its interior is so vast it can hold over
1.3 million Earths.
Sunspots offer clues to internal solar mood swings. The number of sunspots
indicates the intensity of nuclear reactions deep within the solar core, at
mind-boggling temperatures of between 15 million to 20 million degrees Celsius.
These inner solar upheavals eject energy, heat and light that keep us alive.
But like many things in life that come as double-edge swords, the sun's inner
turmoil could also cause catastrophe on earth. More sunspots would mean more
violent solar storms that can destroy satellite-dependent communication systems
and electricity supplies for millions of people.
The laws of nature of course apply equally to all animate and inanimate matter.
Just as very disturbed people will inevitably disturb others, a very internally
disturbed sun suffering excessive inner turmoil will disturb the Earth.
While more tangibly felt disasters, like the swine flu, can hog obvious
headlines, any abnormal solar mood swings could be no less significant given
earth’s dependency on the sun. This is why sunspot-watching could gain more
importance than ever before.
Scientists have used sunspots to track the approximately 11-year cycles of
intense solar activity. In the ongoing sun cycle, year 2008 should have been
relatively inactive and 2009 was scheduled to have a cyclic upsurge in solar
activity, according to some scientific estimates.
But fewer sunspots have been seen this year than expected. In 2008 the Ulysses
space probe detected fewer sunspots, say scientists at the National Aeronautics
and Space Administration (NASA).
Seventy-eight of the first 90 days of 2009 have been without sunspots, pointing
to the dimmest solar activity in a hundred years. "Even the sun appears headed
for a recession," wryly observed the National Geographic journal on May 4.
The riddle is whether the current lesser number of sunspots is good or bad
news, or a mixture of both. "Fewer sunspots means lesser solar activity and
solar storms," said Professor Arnab Rai Choudhuri, a leading physicist in the
Bangalore-based Indian Institute of Science. "Solar storms can damage
human-made satellites and also trip power grids on earth, particularly in
geopolar countries like Canada."
Solar storms are bursts of charged particles churned out from the sun's inner
nuclear upheavals, hurtling earthwards carrying billions of watts of power at
speeds of millions of kilometers per second.
Excessive nuclear turmoil within the sun, as indicated by higher numbers of
sunspots, can unleash potentially destructive solar storms. The last major
solar storm 20 years ago blew out the power grid of Hydro-Quebec, one of North
America's largest electricity suppliers. At 2:44am on March 13, 1989, a
magnetic storm hit a single transformer grid and caused a catastrophic collapse
that brought down the entire grid in just 90 seconds. Nearly seven million
people suffered without electricity and the Canadian government was left with a
US$10 million repair bill.
But the downside of a quieter sun could be a colder climate. Scientists are
debating the possibility of a "Little Ice Age”, like the one between 1645 and
1715 in Europe that caused glaciers to swallow entire villages and water to
remain frozen for a year in Iceland in 1695. The National Geographic article of
May 4 discussed the chances of this.
"Overwhelming evidence is building up that the sunspot cycle and related
activity are correlated with global climate and temperature," said a research
paper  available at the Indian Institute of Astrophysics.
The authors said sunspots can affect the sea surface temperatures of the
Earth's three main oceans - the Atlantic, Pacific and Indian - as well as cloud
cover and Indian monsoon rainfall.
But not all scientists are convinced sunspots can influence climatic patterns,
and therefore dependent essentials such as food crops. "How much sunspots
affect climate is still a subject of debate," Professor Choudhari told Asia
Choudhari, a leading Indian astrophysicist, developed his academically
well-known “solar dynamo theory” to explain the inner workings of the sun. "I
and my students have developed a code named Surya [a Sanskrit word
meaning the sun] for solving the basic equations of solar dynamo theory," he
Interestingly, Choudhary's celebrated research paper "Sunspots and their
cycles" had already predicted that the current sunspot cycle would be the
weakest ever. This 2007 research paper, with his two PhD students Piyali
Chatterjee and Jie Jiang from China , received the rare honor as "Editors'
suggestion" in the Physical Review Letters (PRL) of the American Physical
Society. The PRL, considered the world's foremost physics journal, ranks among
leading scientific journals in any discipline.
More crucially, Choudhuri predicted that the next sunspot cycle will reach its
peak in the years 2011-2012. If accurate, earthlings can expect increased solar
"Not all sunspot cycles are of equal strength. Some are weak and some are
strong," said Choudhari, "A stronger cycle is more likely to cause these
disturbances. Hence it is important to understand why different cycles are of
unequal strength, [in order to] predict the strength of a sunspot cycle in
advance." An early warning can limit damage, such as reducing power loads on
electric grids in solar storm prone regions.
Choudhari has been studying the sun for the past 25 years. "I was inspired
after doing my PhD in physics from the University of Chicago under the
supervision of Eugene Parker," he said. Legendary physicist Eugene Parker is
credited with path-breaking theories such as the existence of a solar wind -
the stream of charged electronic particles, or plasma, ejected from the upper
atmosphere of the Sun.
"More than 99% of the material in the universe exists in the plasma state -
often called the fourth state of matter,” said Choudhari. "The sun, our nearest
star, is an enormous plasma laboratory in which we observe many puzzling
In 1844, German astronomer Samuel Heinrich Schwabe discovered one such puzzle.
He noticed that sunspots appear on the sun's surface in a cyclic phase - in a
period of 11 years in which they wax and wane by appearing in a higher number
and a lower number.
The sunspot cycle nearing its peak unleashes violent solar phenomena such as
gigantic explosions, called solar flares, or Coronal Mass Ejections, in which
billions of tons of charged particles are hurled out of the solar surface at
speeds of millions of kilometers per hour.
Sunspots are considered the oldest pointers to such spectacular solar activity.
Scientists like Galileo have been monitoring sunspots since the 17th century.
The earliest recorded sunspot dates back to 28 BC, in the 100-volume
encyclopedic work, Book of Han, in China.
Leading sunspot trackers of today include the Solar Influences Data Analysis
Center (SIDC) - the solar physics research department of the Royal Observatory
of Belgium. The SIDC releases the International Sunspot Index, with daily
sunspot data stretching back from today to 1812.
Sunspots are evolving chapters in the enigmatic story of the sun, a revered
object of worship in ancient India, Egypt and Inca civilizations. Surya Namaskar,
or a ritualistic salute to the sun, continues to be part of a daily morning
routine for millions of Indians.
A relationship becomes less disturbing with acceptance of the unavoidable
reality that everything changes and evolves. This includes the billion-year
Earth-sun relationship. Having lived 4.6 billion years, the sun has enough
inner fuel to burn for approximately another five billion years. On its
deathbed, the sun will start fusing heavier elements such as helium and begin
to bloat in size across the solar system. Ultimately, the expanding, dying sun
will swallow the Earth and other planets in the solar system.
Then, after another billion years of life as a dull red giant, the sun is
expected to suddenly collapse into a white dwarf, the final corpse for a star
its humble size. Scientists estimate it would take a trillion years to fully
cool off from its internal inferno. The sunspots reflect the trillion-year
death throes in the making, with humankind as a little footnote.
Real-time live updates of sunspot images, now available online through
observatories such as the Solar Influences Data Analysis Center, tell this
daily story of how the sun, the giver of life, will one day take away life on
Earth. Nothing lasts forever, including the sun.
A nearer hour of reckoning possibly beckons. The year 2011-2012 for maximum
solar activity would mark the first time ever that detailed predictions were
made in advance for a sunspot cycle, according to Choudhari. "We now have to
wait for a few years for the sun-god himself to give a verdict on our debate,"
he said. Hopefully the verdict will not be another catastrophic solar storm
from this enigmatic diamond shining in the sky.
1. Paper titled "Magnetic Flux in the Solar Convective Envelope", by Hiremath,
K M and Lovely, M R; Indian Institute of Astrophysics, II Block, Koramangala,
Bangalore 560 034, India.
2. The paper "Predicting Solar Cycle 24 with a Solar Dynamo Model", Physics
Review Letters, March 30, 2007, by Arnab Rai Choudhuri, Piyali Chatterji -
Department of Physics, Indian Institute of Science, Bangalore 560012, India;
Jie Jiang -National Astronomical Observatories, Chinese Academy of Sciences,
Beijing 100012, China.