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The new hitchhiker's guide to the galaxy

Updated on: 06 March,2011 07:52 AM IST  | 
Sowmya Rajaram |

The Big Bang Theory may be in dispute, life may be possible on Jupiter's moons, and global warming may have more to do with sunspots than man-made CO2 emissions. A whole lot of exciting changes have unfolded since Physics textbooks had to be rewritten after Pluto was declassified as a planet in 2006

The new hitchhiker's guide to the galaxy

The Big Bang Theory may be in dispute, life may be possible on Jupiter's moons, and global warming may have more to do with sunspots than man-made CO2 emissions. A whole lot of exciting changes have unfolded since Physics textbooks had to be rewritten after Pluto was declassified as a planet in 2006

Generations of students in classrooms across the world have been reading about the nine planets in our solar system, and the creation of the universe following the Big Bangu00a0-- the theory that postulates that the universe, originally in an extremely hot and dense state 13.7 billion years ago, has since cooled by expanding to the present diluted state, and continues to expand today.

While the first finding had to be altered in 2006 after Pluto, the cold planet far far away from the sun, was declassified as a planet, the second is now disputed. And whether you are an astronomy enthusiast or not, that's big, banging news.

20 billion years old
Well known astrophysicist Jayant Narlikar has long been a proponent of the steady state theory of cosmology, (the theory that gained credence in the 1950s and 60s as an alternative to the Big Bang Theory). It suggests that there was no moment of creation, and that the universe has always existed for an infinite time in the past and will continue to exist for an infinite time in the future, looking like it does now.


Members of Khagol Mandal look up at Mumbai's night sky through
one of their many telescopes. An amateur astronomy club,
Khagol has members aged 10 to 85, and meets every
Wednesday for chats on the latest developments.
Pic/Prathik Panchamia


Along with Vijay Mohan of the Inter-University Centre for Astronomy and Astrophysics (IUCAA, Pune) and Ferdinando Patat and Ken Freeman, Narlikar has found a cluster of about 50 stars that are 20 billion years old; which is effectively proof that the universe existed before the Big Bang.

They have arrived at this conclusion by using the space telescope and archival data from the Hubble observatory, and another in Chile.

If proven, Narliker's findings have the potential to change everything we know about the birth of the universe. Naysayers have always been around, but most of them are conservatives who disown it as un-Godly, since God is believed to have created the universe.

Researchers, however, are being cautious before disowning the Big Bang Theory, which has the might of a whole lot of evidence backing it. "It (BBT) has a huge amount of evidence in its favour. A star's age is estimated on the basis of how much material has been burnt.

So, in this case, the age measurement of the star itself may be wrong. It's certainly an interesting claim, but it needs a lot of confirmation before being adopted as a bonafide theory," says Dr Mayank Vahia, Professor, Department of Astronomy, Tata Institute of Fundamental Research (TIFR).

Blame the sun for global warming
Al Gore will not like this. The Inconvenient Truth may actually be that sunspot activity, and the 11-year cycle of the sun that causes it to change its polarity may have as much or even more to do with climate change than mankind's CO2 emissions.

Stumped? Here's what scientists who subscribe to this theory, say. The sun goes through an 11-year cycle where its magnetic polarities are reversed, causing changes in the occurrence of sunspots upon its surface. When sunspot activity is high, solar flares release high-energy particles into space, which are then absorbed by the Earth's atmosphere. That causes the atmosphere to trap heat, leading to a rise in temperatures.

The theory is supported by the correlation between sunspot activity and major periods of climate change on Earthu00a0-- for example, sunspot activity was very low during 1645-1715, at the depth of the Little Ice Age. In contrast, it was high during the Medieval Warm Period. The year 2009-2010 was also an unusually low sunspot activity period, which caused much concern among the astronomical fraternity and caused the years to be labelled as 'cool' years (China experienced the coldest winter in 100 years, and northeast America was pounded by record snowfall, in addition to Britain's much-delayed summer).

Hold on to your horses thoughu00a0-- that doesn't mean you can leave the taps open and cut trees indiscriminatelyu00a0-- because for every person that subscribes to this school of thought, there are people who dismiss the theory entirely.

"At Khagol Mandal, we refrain from making subjective judgments, but my personal opinion is that while sunspot activity may have some impact on global temperatures, the greenhouse effect, caused by the burning of fossil fuels, is largely responsible for climate change," says Pradeep Nayak, head of Khagol Academy, an offshoot of Mumbai's largest amateur astronomers club.

The likes of Joanna Haigh, an atmospheric physicist at Imperial College London, who studied daily measurements of the spectral composition of sunlight made between 2004 and 2007 by NASA's Solar Radiation and Climate Experiment (SORCE) satellite, observed that the variations in the solar spectrum have caused roughly as much warming of the Earth's surface as have increases in carbon dioxide emissions in the three-year period.

At the same time, Haigh says that because solar activity is cyclic, it should have no long-term impact on climate. "If the climate were affected in the long term, the sun should have produced a notable cooling in the first half of the twentieth century, which we know it didn't," she says, in an article published in Nature News last year.

MJ was right. We're not alone
NASA's Kepler mission has announced the discovery of 1,200 new potential planets, in the Milky Way alone. And it has also been found that 2/3rds of all stars have planets around them. "It's an exciting discovery," says Vahia. "It proves that there are multiple star systems in this galaxy. So, the next question obviously is, did life evolve on any of them?"

Dr Rathnasree, Director of Delhi's Nehru Planetarium, shares his excitement. "Initially, only very large Jupiter-like planets in very close orbits around their parent stars were discovered. As detection techniques improved, smaller planets and more Earth-like planets started being discovered.

For a given star, a range of orbits around it might be considered habitableu00a0-- where the conditions would be suitable for the presence of liquid water." She tells us that recently, a planet was found orbiting the star Gliese 581 plumb in the habitable zoneu00a0-- this was nicknamed the Goldilocks planet as it was found in a zone, which theoretically could be consideredu00a0-- not too hot and not too cold.

Then there is the big news of high resolution images that have confirmed the presence of water on Jupiter's moon Europa, making it "a very exciting find indeed," according to Hrishikesh Joglekar, a study group member of Khagol Mandal. "Ten years ago, a mission to Jupiter had come back with findings about water on Europa. Today, we have hard evidence in the form of high-resolution photographs that show us that's actually true, albeit in ice form."

So, how is that important? For one, it indicates that the circumstances for life on Earth are not as special as they were once considered to be. Theoretically, this means that the raw material for life is available elsewhere in the universe too. "All life is carbon-based and consists of carbon and water.

For life to exist in any form, it needs to be able to make a copy of itself," explains Dr Vahia. "It is also a sign that if we ever run of out water on Earth, it is available elsewhere in the universe too," Joglekar smiles.

Water, water, everywhere... on the moon too

"The moon was believed to be extremely dry and the complete absence of water on the moon was taken for granted following the Apollo missions. But recently, the Chandrayaan mission analysis revealed the most conclusive evidence so far of presence of polar ice content on the moon. Contrary to expectations that such a presence would be indicated only in the permanently shadowed regions of the lunar poles, these hydrate signals were found all over the surface of the moon, and that there is a continuous, ongoing process of creation and destruction of liquid water albeit in very minute quantities," says Dr Rathnasree.

Planet Tyche?

The number of planets in our solar system today? Eight. Oh, wait, it might be nine. If astrophysicists John Matese and Daniel Whitmire, professors at the University of Lousiana at Lafayette are to be believed, Tyche, a binary companion to the sun, larger than Jupiter, may exist in the alleged Oort cloudu00a0-- a repository of small icy bodies at the edge of our solar system.

Their paper published in scientific journal, Icarus in November 2010, argues that evidence for this planet would be recorded by the Wide-field Infrared Survey Explorer (WISE), a NASA mission, launched in December 2009 that scanned the celestial sky at four infrared wavelengths about 1.5 times.

In an email interview to Sunday Mid day, Matese says, "The evidence for such an object is an unusual pattern of the orbits of observed cometsu00a0 (in particular, their major axis orientations) coming from the outer Oort cloud. These comets typically have their orbits changed (made to come close to the Sun) by the gravity of distant matter in our galaxy. But this mechanism creates its own distinctive pattern of orbits.

In a 1999 paper, we asserted that there was an 'unusual' aspect to the observed pattern, affecting 20 per cent of the comets, that was consistent with a Jupiter mass solar companion orbiting in the comet cloud. This unusual aspect has since persisted, and the likelihood that it is a statistical fluke has lessened. Also, there has been no claim in the literature in the ensuing time that it is more likely due to an alternative physical explanation."

If such an object exists, it would be slightly larger than Jupiter, and the International Astronomical Union might choose not to use the term 'planet' for it.

The handbook

Your guide to solar terms


Sunspots: Dark spots on the surface of the sun. When the sun's magnetic field changes every 11 years, eruptions occur that throw out matter and cause temperature in that area to
drop slightly in comparison to the rest of the surface, causing the area to look darker. These are called sunspots.


Dark Matter: Matter in the universe that cannot be seen, but can be detected by its gravitational effects on other bodies.


Dwarf Planets: A celestial body orbiting the sun that is big enough to be rounded by its own gravity but has not cleared its neighbouring region of planetesimals and is not a satellite. Pluto is considered a dwarf planet.

Hypergalaxy: A system consisting of a spiral galaxy surrounded by several dwarf white galaxies, often ellipticals. Our galaxy and the Andromeda galaxy are examples of hypergalaxies.

Light Year: An astronomical unit of measure equal to the distance light travels in a year, approximately 5.8 trillion miles.

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