Group items tagged

Seems looking into turbulence is a source of innovative concepts. After the black hole modelling here was found a mathematical expression which describes "how turbulence can alter the shape and course of a flock of birds, a swarm of insects or even an algal bloom (phytoplankton!) and could help us to better predict them". More relevant for motions in air and sea, rather than space, where the fluids are dense enough to exhibit turbulence ; but what about a swarm moving in and exploring an exoplanet's atmosphere?

"The old model is no longer valid for the ocean's overturning, not because it's a gross simplification, but because it ignores crucial elements such as eddies and the wind field. The concept of a conveyor belt for the overturning was developed decades ago, before oceanographers had measured the eddy field of the ocean and before they understood how energy from the wind impacts the overturning,"

Just in case you missed these one... should be of interest for ACT's climate modelling squad. "As well as telling us more about Venus, it could be sending a warning to those on Earth seeking to inject our atmosphere with sulphur droplets in an attempt to mitigate climate change."

Let's go to Titan !!!

I bet we'll find there a black monolith which will take us to the stars... No, wait, was it that moon?

title speaks for itself - so if it's not meteorites to blame, what is it?

link doesn't work for me

something for Pacôme?

the lucky guy is skiiing

hello, i'm back! Yeah i knew about this work, my friends from paris observatory... It's a kind of preparatory study for future missions like Sagas

make you wonder when the FLPP will actually lead to something flying !

I did not even know that the airforce continued the X37 project when it was cancelled at NASA ... interesting stuff indeed ...

Wonder what is the most creative: the system or the name! NAUTILUS-X = Non-Atmospheric Universal Transport Intended for Lengthy United States X-ploration http://spirit.as.utexas.edu/~fiso/telecon/Holderman-Henderson_1-26-11/Holderman_1-26-11.ppt

dreaming ...

some really nice pictures from Mercury's flyby mission

I love the comments: "damn i almost thought this was about Mercury messenger... an OSX messenger app..." "I'm just glad we have an atmosphere" "The US is in the biggest economic crisis since the Great Depression... and we're spending all this money... for this? What a waste. Get rid of NASA - it will save us trillions! " sic :-(

Cynthia, Marion - have a look at this: I assume that this also affects our model, correct?

And I suppose they will (or already have) modify their GCM to take this in account...

A new mechanism was discovered on how H2 and N2 participate in the radiation budget. This may help to resolve the "faint young sun paradox", a hypothesis according to which during the earlier age of the solar system when sun radiation had lower intensity than now, the earth was warmer. Extended, it could reassess the past habitability of Mars.

Jeremy England, a 31-year-old assistant professor at the Massachusetts Institute of Technology, has derived a mathematical formula that he believes explains this capacity. The formula, based on established physics, indicates that when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy. This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life. The simulation results made me think of Jojo's attempts to make a self-assembling space structure. Seems he may have been on the right track, just not thinking big enough

:-P Thanks Thijs... I do not agree with the premise of the article that a possible correlation of energy dissipation in living systems and their fitness means that one is the cause for the other - it may just be that both go hand-in-hand because of the nature of the world that we live in. Maybe there is such a drive for pre-biotic systems (like crystals and amino acids), but once life as we know it exists (i.e., heredity + mutation) it is hard to see the need for an amendment of Darwin's principles. The following just misses the essence of Darwin: "If England's approach stands up to more testing, it could further liberate biologists from seeking a Darwinian explanation for every adaptation and allow them to think more generally in terms of dissipation-driven organization. They might find, for example, that "the reason that an organism shows characteristic X rather than Y may not be because X is more fit than Y, but because physical constraints make it easier for X to evolve than for Y to evolve." Darwin's principle in its simplest expression just says that if a genome is more effective at reproducing it is more likely to dominate the next generation. The beauty of it is that there is NO need for a steering mechanism (like maximize energy dissipation) any random set of mutations will still lead to an increase of reproductive effectiveness. BTW: what does "better at dissipating energy" even mean? If I run around all the time I will have more babies? Most species that prove to be very successful end up being very good at conserving energy: trees, turtles, worms. Even complexity of an organism is not a recipe for evolutionary success: jellyfish have been successful for hundreds of millions of years while polar bears are seem to be on the way out.

Our friends from NASA have come out with a plan to the human exploration of Venus in the time that everyone is speaking about Mars.

Love the concept acronym, which pretty much says it all... Not sure which astronaut would fancy floating around in an atmosphere where clouds are made of sulphuric acid. Besides I don't see the point of a manned mission if one can't reach the surface.. tele-operation would be easy and so much cheaper.