Good news: How the Earth will survive when the Sun becomes a supergiant
The astronomy textbooks will have to be rewritten, say astrophysicists at the University of Sussex who have re-examined standard calculations about solar evolution and the distant future of the Earth.
The textbooks tell us that one day the Sun will burn up its nuclear fuel and expand to an enormous size, finally engulfing its inner planets including Earth. However, using the latest data based on real stars, the University of Sussex researchers suggest a (slightly) less catastrophic future for our planet.
As their hydrogen fuel runs out at the end of their ‘lives’, stars like the Sun expand to become a red supergiant of several hundred times their initial diameter. Most astronomers expect the solar red supergiant to swallow Mercury, Venus and then Earth in about 7.5 billion years’ time, when it has expanded beyond the orbit of our planet.
But Earth may survive after all, say the Sussex astronomers, if an important extra detail is considered: the ongoing loss of mass and weakening gravity while a star is a red supergiant.
Dr Robert Smith, Reader in Astronomy, explains the significance of this effect: “Taking this into account, the orbit of the Earth would increase beyond the Sun’s outer atmosphere by a small but crucial margin at all phases of the Sun’s evolution – allowing our planet to continue.”
The new calculations are published in the current issue of Astronomy & Geophysics. They were made by Dr Smith together with Dr Klaus-Peter Schröder from the University’s Astronomy Centre and Kevin Apps, the famous student stargazer who co-discovered 10 planets while still an undergraduate at Sussex.
Although the Earth may survive, long before then its surface will have become too hot to sustain human life. But the good news from the team of researchers is that it will be 5.7 billion years before our planet becomes a no-go zone for life – about 200 million years later than previously thought.
So, ask the Sussex astronomers, is there anywhere in the solar system that would be safe, or does our survival depend on finding another star system? Is it possible to hop outwards from one planet or satellite to the next, always keeping ahead of the Sun? There are periods, they calculate, when we could in principle survive on one of the outer planets such as Mars, but there will be long gaps when none of them is habitable.
Dr Smith concludes: “We had better get used to the idea that we shall need to build our own survival capsules - the planets are simply too far apart for planet-hopping to be a viable solution. Perhaps this is the ultimate justification for developing an International Space Station.”
Peter Simmons | alphagalileo
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...