Dr Robert Smith, Emeritus Reader in Astronomy, said his team previously calculated that the Earth would escape ultimate destruction, although be battered and burnt to a cinder. But this did not take into account the effect of the drag caused by the outer atmosphere of the dying Sun.
He says: "We showed previously that, as the Sun expanded, it would lose mass in the form of a strong wind, much more powerful than the current solar wind. This would reduce the gravitational pull of the Sun on the Earth, allowing the Earth's orbit to move outwards, ahead of the expanding Sun.
“If that were the only effect the Earth would indeed escape final destruction. However, the tenuous outer atmosphere of the Sun extends a long way beyond its visible surface, and it turns out the Earth would actually be orbiting within these very low density outer layers. The drag caused by this low-density gas is enough to cause the Earth to drift inwards, and finally to be captured and vaporised by the Sun.”
The new paper was written in collaboration with Dr Klaus-Peter Schroeder, previously at Sussex, who is now in the Astronomy Department of the University of Guanajuato in Mexico.
Life on Earth will have disappeared long before 7.6 billion years, however. Scientists have shown that the Sun's slow expansion will cause the temperature at the surface of the Earth to rise. Oceans will evaporate, and the atmosphere will become laden with water vapour, which (like carbon dioxide) is a very effective greenhouse gas. Eventually, the oceans will boil dry and the water vapour will escape into space. In a billion years from now the Earth will be a very hot, dry and uninhabitable ball.
Can anything be done to prevent this fate? Professor Smith points to a remarkable scheme proposed by a team at Santa Cruz University, who suggest harnessing the gravitational effects of a close passage by a large asteroid to "nudge" the Earth's orbit gradually outwards away from the encroaching Sun. A suitable passage every 6000 years or so would be enough to keep the Earth out of trouble and allow life to survive for at least 5 billion years, and possibly even to survive the Sun's red giant phase.
“This sounds like science fiction,” says Professor Smith. “But it seems that the energy requirements are just about possible and the technology could be developed over the next few centuries.” However, it is a high-risk strategy - a slight miscalculation, and the asteroid could actually hit the Earth, with catastrophic consequences. “A safer solution may be to build a fleet of interplanetary 'life rafts' that could manoeuvre themselves always out of reach of the Sun, but close enough to use its energy,” he adds.
Jacqui Bealing | alfa
First Juno science results supported by University of Leicester's Jupiter 'forecast'
26.05.2017 | University of Leicester
Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of Technology
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy