Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Protective Storm in Space - a new explanation for the death of the dinosaurs

04.06.2002


A shower of matter from space millions of years ago could have led to drastic changes in the Earth’s climate, followed by the extinction of life on a massive scale, which also killed off the dinosaurs. This at least is a theory put forward by scientists from the University of Bonn. Normally, the solar wind acts as a shield against showers of cosmic particles, which prevents too many energy-rich particles from raining down on our atmosphere. Since 1997 scientists from Bonn, funded by the German Research Council (Deutsche Forschungsgemeinschaft or DFG), have been examining how and why this gigantic shield works.

They were the undisputed masters of a whole geological era until they suddenly disappeared 65 million years ago. ‘Perhaps Earth just became too damp and too cold for dinosaurs at that time,’ Professor Hans Jörg Fahr from the Bonn Institute of Astrophysics and Extraterrestrial Research surmises. The reason for the sudden change in climate could have been excessive pressure on our cosmic umbrella.

The solar system does not stand still, in fact it orbits the centre of the Milky Way once every 250 million years. In the process it also passes through dense clouds of interstellar matter, which causes problems for the solar wind and thus for the Earth. Whereas the solar wind normally protects the Earth from a hail of interstellar particles like a huge bullet-proof vest, there are then suddenly up to a hundred times more particles raining down into the earth’s atmosphere at enormous speeds. On impact they smash the air molecules into electrically charged fragments. These function as condensation nuclei on which droplets of water form. “The result is dense cloud cover with greater precipitation and sinking temperatures,” says Professor Fahr, who bases his remarks on research worldwide.



Prof. Fahr and his colleagues Dr. Horst Fichtner and Dr. Klaus Scherer have shown that every 60 million years on average the solar system passes through dense clouds of matter, which could trigger off this sort of climate shock. Prof. Fahr adds: ‘At roughly these intervals many species suddenly became extinct.’ Research by other teams which have examined the link between cloud cover and solar activity has shown that cosmic factors could have had a dramatic impact on our climate on several occasions in the past. ‘The less solar activity there is and therefore the less protection there is from the solar wind, the more cosmic particles reach the earth, and the more clouds form on earth,’ is how Prof. Fahr sums up the process.

Experts call the electrically charged particles which our sun emits ‘solar wind’. They race through our solar system at a velocity of up to 800 kilometres per second, with a range extending a hundred times as far as the distance between the Earth and the sun.. ‘Every eleven years the sun’s activity and therefore the solar wind reaches a maximum. At these times, for example, there is an increase in the frequency of the colourful auroras, when particles of the solar wind are captured by the Earth’s magnetic field and are then catapulted into the upper atmosphere, where they make the oxygen glow,’ Dr. Michael Bird from the Institute of Radio Astronomy explains. During particularly active phases, e.g. during big solar eruptions, the shower of particles can even interfere with short-wave reception, disrupt orbiting satellites or even ‘switch off’ whole power stations.

‘In Bonn we are especially interested in how the solar wind reaches its high velocities,’ Dr. Bird explains. ‘These cannot be explained solely by the enormous heat in the sun‘s atmosphere.’ There seems, in other words, to be another source of energy which catapults the particles into space. The hot favourites for Bonn’s astrophysicists are exotic waves of magnetic fields in the corona, the ‘sun’s atmosphere’ which are amplified while they are expanding and then give the particles the necessary momentum. ‘We are tracking these waves by using radio astronomy,’ the US physicist adds.

Incidentally, cosmic weather might also be a decisive factor in the speed of evolution. The cosmic rays from which we are protected by the solar wind are so full of energy that they can change the DNA of living beings. If the solar wind’s shield effect is too weak, i.e. the Earth’s protective mantle is thin, within a short space of time this results in more mutations, which are the driving force of the evolution of life.

Professor Hans Jörg Fahr | alphagalileo

More articles from Earth Sciences:

nachricht New Technique for Finding Weakness in Earth’s Crust
30.09.2016 | University of Adelaide

nachricht Researcher creates a controlled rogue wave in realistic oceanic conditions
30.09.2016 | Aalto University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

Heavy construction machinery is the focus of Oak Ridge National Laboratory’s latest advance in additive manufacturing research. With industry partners and university students, ORNL researchers are designing and producing the world’s first 3D printed excavator, a prototype that will leverage large-scale AM technologies and explore the feasibility of printing with metal alloys.

Increasing the size and speed of metal-based 3D printing techniques, using low-cost alloys like steel and aluminum, could create new industrial applications...

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Paper – Panacea Green Infrastructure?

30.09.2016 | Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

 
Latest News

First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

30.09.2016 | Materials Sciences

New Technique for Finding Weakness in Earth’s Crust

30.09.2016 | Earth Sciences

Cells migrate collectively by intermittent bursts of activity

30.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>