From New Scientist, 11 September 1999
Creative burst
Robert
Adler
1)<!S1>THE FORMATION<!/S1> of the Solar System was hurried along by a nearby gamma-ray burst, two astrophysicists in Ireland suspect. Rather than aborting the birth of planets, the flood of energy may have melted primordial dust grains, seeded the formation of meteorites and helped form the rocky planets, including Earth.
2)For over a century, astronomers have tried to understand what made clumps of dust circling the young Sun melt into chondrules--rocky beads rich in iron and silicon minerals that make up the bulk of stony meteorites. Suggestions included shock waves and gigantic flashes of lightning<!MORE>.3)Now Brian McBreen and Lorraine Hanlon of University College Dublin suggest that all the chondrules in the Solar System formed in a matter of minutes 4.5 billion years ago when a gamma-ray burst--one of the most powerful explosions in the Universe--seared the dust and gas circling the Sun with intense X-rays and gamma rays. Astronomers aren't sure what causes gamma-ray bursts, but they may occur when supermassive stars explode at the end of their lives (New Scientist, 3 April, p 5).
4)In a paper that will appear in a future issue of Astronomy and Astrophysics, McBreen and Hanlon calculate that a gamma-ray burst within 300 light years would have flooded the dusty disc circling the young Sun with enough energy to fuse up to 100 Earth masses of material into droplets that cooled into chondrules. These, and the dust from which they formed, are rich in iron, which would have soaked up X-rays and gamma rays very efficiently. "It explains the key role played by iron, which dominates the X-ray and gamma-ray absorption," says McBreen.
5)If the theory is right, it makes the Solar System more unique than many scientists would like. McBreen and Hanlon believe that only one Sun-like star in a thousand would have been close enough to a gamma-ray burst to form chondrules. Because they also think that the dense chondrules settle quickly into the plane of a protoplanetary disc and speed the formation of planets, their theory implies that solar systems such as ours are rare.
6)"Forming chondrules really is a long-standing problem, so if this mechanism accounts for them, that would be pretty fantastic," says Alan Boss, an astrophysicist at the Carnegie Institution in Washington DC. Still, he is reluctant to rely on an unlikely event as a crucial factor in the formation of the Solar System, and wonders whether the idea can explain other features of chondrules, such as their size and abundance. "I don't think you'd want to invoke it unless it takes care of everything," he says.
7)Specialists in meteorites are intrigued by McBreen's idea. "Chondrule formation remains a thorny subject, so it's good to see a new idea in the area," says Ian Wright, a meteoriticist at the Open University in London. He notes that most of the researchers studying meteorites believe chondrules did not form all at once, although the case is not closed. "It will certainly cause debate, and it's an interesting idea that can be tested in our labs."
8)This appears to me to be just another 'unique' galactic accident, conjured up by scientists to explain the formation of the planets out of dust and gas in the orbits they now occupy. Genesis Continuous shows that the formation of star and planet systems is not some 'Bang' miracle of time, place, intensity and alchemy. Instead, it shows that the formation, (birth) of a star sets certain actions into play that naturally result in planet birth and evolution. There is only one place in the solar system capable of creating all the elements we know of and making them available for planetisimal building, and that is the sun itself.
9)Also, when we speak of terrestrial planets, isn't there just as much, if not more terrestrial substance at the centre of the gas giants? Just because it is not seen doesn't mean it isn't there.
10)The suggestion that chondrules of iron and silica divided up into all the 100 or so other elements is stretching the miraculous a bit too far. (I note that this aspect of Mr McBreen's theory has not been explained).
11)The sun is a radiant storehouse of probably all the elements known and as it burns it also erupts some of these elememts some thousands of miles into space. There is a ring of dust and rocks rich in iron already floating two to three solar widths above it right now.
12)It appears quite certain now that the sun is ever so much older than was believed until quite recently, and it is losing gravity. This means that stuff erupted billions of years ago will be either collected up by a planetisimal, planet or whatever, and some of it will be orbiting at various distances out from the sun. Chondrules should surely be associated with this material.
13)Since this announcement the findings of Dr Manuel have been published. He says that the sun is made of iron and is not a compressed ball of hydrogen with a small amount of iron at its centre.
14)It looks to me that the assumed mass of the sun was a calculation prior to examination. Is Dr Manuel right or is he wrong? One has to ask the question, 'How much of scientific cosmological calculation is based upon guesstimate'?
Oh well, back to the drawing board.
Genesis Continuous - Complete
