Posts Tagged ‘panspermia’
[NEWS] Five Universe Today (@universetoday) links: colours, panspermia, Venus, superhabitable worlds
- Brian Koberlein at Universe Today considers the question of what was the first colour in the universe. (Is it orange?)
- Matt Williams at Universe Today considers how comets and other bodies could be exporting life from Earth to the wider galaxy.
- Matt Williams at Universe Today explores one study suggesting Venus could have remained broadly Earth-like for billions of years.
- Matt Williams at Universe Today also notes another story suggesting, based on the nature of the lava of the volcanic highlands of Venus, that world was never warm and wet.
- Fraser Cain at Universe Today took a look at the idea of superhabitable worlds, of worlds better suited to supporting life than Earth.
[URBAN NOTE] Five science links: coffee, CERN, Titan, HCN–0.009–0.044, panspermia
- Motherboard notes that climate change endangers a majority of the coffee species growing in the wild.
- Universe Today notes that CERN is planning to build a successor to the LHC, one a hundred kilometres in diameter.
- A review of data from Cassini, Universe Today reports, suggests the probe saw rain fall in the north polar region of Titan.
- A new analysis suggests that mysterious object in the heart of the galaxy, HCN–0.009–0.044, is actually a black hole massing 32 thousand suns. Universe Today has it.
- Universe Today shares an ambitious proposal for future humanity to use interstellar probes to seed life on potentially hospitable but lifeless worlds, a planned panspermia.
[NEWS] Five sci-tech links: Superstorms, solar power, superhumans, space colonies, panspermia
- Vice’s Motherboard reports on how we do not understand the storms of the Anthropocene era, fueled by climate change.
- Vice suggests that the very sharp and continuing fall in the price of solar power might well allow the Earth to escape ecological ruin, by providing energy alternatives.
- The Guardian reports on the prediction of Stephen Hawking that technological advances will lead to the emergence of a race of superhumans that might well destroy–at least, outcompete–traditional humanity.
- Over at Tor, James Nicoll recently contributed an essay arguing that technological challenges and the lack of incentive mean that the human colonization of space is not going to happen for a good while yet.
- Universe Today highlights a new paper suggesting that panspermia unaided by intelligence can work on a galactic scale, even across potentially intergalactic distances.
[NEWS] Four science links: neutrinos and Antarctica, ‘Oumuamua, Ceres and Pluto, panspermia
- This feature explaining how neutrino telescopes in Antarctica are being used to study the Earth’s core is fascinating. The Globe and Mail has it.
- Universe Today shares “Project Lyra”, a proposal for an unmanned probe to interstellar asteroid ‘Oumuamua.
- Dwarf planets Ceres and Pluto, Nora Redd suggests at Discover, may have much more in common than we might think. Is Ceres a KBO transported into the warm asteroid belt?
- Universe Today reports on one paper that takes a look at some mechanisms behind galactic panspermia.
[LINK] “Life-Bearing Rocks in Slow Motion”
Centauri Dreams’ Paul Gilster reports on the latest computer simulation suggesting that panspermia–the dispersal of life through space from one world to another–is a viable hypothesis.
I’ve been fascinated with Edward Belbruno’s work on ‘chaotic orbits’ ever since meeting him at an astrodynamics conference in Princeton some years back. The idea is to develop low-energy routes for spacecraft by analyzing so-called ‘weak stability boundaries,’ regions where motion is highly sensitive and small changes can create gradual orbital change. A low-energy route was what Belbruno used in 1991 to help the Japanese spacecraft Hiten reach the Moon using almost no fuel, a proof of concept about which the physicist said “It saved the spacecraft, and it saved my career.”
That comment came from a lecture to the Mathematical Association of America in 2009 that you can listen to here. It’s fascinating in its own right, but doubly so since Belbruno is back in the news with new findings on the idea of panspermia, and specifically that version of panspermia called lithopanspermia. In this hypothesis, elemental life forms are distributed between stars in planetary fragments created by asteroid impacts, volcanic eruptions and other disruptive events. Drifting through space, the fragments are eventually caught in another solar system’s gravity, some of them conceivably falling on worlds in the habitable zone of their star.
Could something like this have caused life to begin on Earth? Belbruno’s work, with Amaya Moro-Martín (Centro de Astrobiología and Princeton University) and Renu Malhotra (University of Arizona) simulates conditions when the Sun was young and still a part of the cluster that gave it birth. Using simulations performed by Princeton graduate student Dmitry Savransky, the researchers applied the theory behind chaotic orbits and in particular the idea of ‘weak transfer,’ which they believe offers rocky fragments moving at low velocities a high probability of moving between close stars. In fact, they believe our system could have exchanged materials with its nearest planetary system neighbor 100 trillion times before the Sun left its native cluster.
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Moro-Martin adds that the work does not prove lithopanspermia actually happened, but indicates it is an open possibility, with further study needed into the question of rocky materials landing on a terrestrial planet. Could life have arisen on Earth before the dispersal of the cluster? The authors believe that it could, assuming life arose shortly after there is evidence of liquid water on its crust. From the paper on this work:
Within this timeframe, there was a mechanism that allowed large quantities of rocks to be ejected from the Earth: the ejection of material resulting from the impacts at Earth during the heavy bombardment of the inner solar system. This bombardment period lasted from the end of the planet accretion phase until the end of the LHB 3.8 Ga, i.e. it finished when the solar system was approximately 770 Myr old (Tera et al. 1974; Mojzsis et al. 2001; Strom et al. 2005). It represents evidence that planetesimals were being cleared from the solar system several hundred million years after planet formation (Strom et al. 2005; Tsiganis et al. 2005; Chapman et al. 2007). This period of massive bombardment and planetesimal clearing encompassed completely the “window of opportunity” for the transfer of life-bearing rocks discussed above and therefore provides a viable ejection mechanism that may have led to weak transfer.
Links to the original papers are available at the original post.