Group items tagged

Earth's irregular natural satellites (NES) that are temporarily captured from the near-Earth-object (NEO) population. --> Possibly interesting for NEO exploration? http://arxiv.org/abs/1112.3781

How early could we detect these coming?

A wide scale 8 year experiment in China on combating desertification seems to have been successful. Instead of using cyanobacteria blooms in the sea, the tested method proposes to spray them on the boundaries of desert/farmland every few days, so that the carbon they capture stays on the ground. It is useful in fixing the organic material against wind erosion only complementary to planting hardy grasses. Very fast result, nevertheless. Could be classified as a geoengineering activity.

130 km2 as next step will be quite an area

Here you go. You can now scrap Lisa altogether. Who's going to tell Pacome?

Awesome and exciting stuff indeed! The data pinpoint the time when inflation occurred - about 10E-37 seconds into the Universe's life - and its temperature at the time, corresponding to energies of about 10E16 gigaelectronvolts, says cosmologist Michael Turner of the University of Chicago. That is the same energy at which three of the four fundamental forces of nature - the weak, strong and electromagnetic force - are expected to become indistinguishable from one another in a model known as the grand unified theory. I expect more fundamental physics insights to come out of this in the future. A full-sky survey from space may still be an interesting addition to the measurement capabilities, so I would not rule out LISA all together I guess...

from wired.com

why am I not surprised .....

http://www.academia.edu/4210419/Can_climate_models_explain_the_recent_stagnation_in_global_warming A view of well-respected scientists on how to proceed from here, that was rejected from Nature. In any case, a long way to go...

unfortunately it's too early to cheer and burn more coal ... there is also a nice podcast associated to this paper from nature Recent global-warming hiatus tied to equatorial Pacific surface cooling Yu Kosaka & Shang-Ping Xie Nature 501, 403-407 (19 September 2013) doi:10.1038/nature12534 Received 18 June 2013 Accepted 08 August 2013 Published online 28 August 2013 Despite the continued increase in atmospheric greenhouse gas concentrations, the annual-mean global temperature has not risen in the twenty-first century1, 2, challenging the prevailing view that anthropogenic forcing causes climate warming. Various mechanisms have been proposed for this hiatus in global warming3, 4, 5, 6, but their relative importance has not been quantified, hampering observational estimates of climate sensitivity. Here we show that accounting for recent cooling in the eastern equatorial Pacific reconciles climate simulations and observations. We present a novel method of uncovering mechanisms for global temperature change by prescribing, in addition to radiative forcing, the observed history of sea surface temperature over the central to eastern tropical Pacific in a climate model. Although the surface temperature prescription is limited to only 8.2% of the global surface, our model reproduces the annual-mean global temperature remarkably well with correlation coefficient r = 0.97 for 1970-2012 (which includes the current hiatus and a period of accelerated global warming). Moreover, our simulation captures major seasonal and regional characteristics of the hiatus, including the intensified Walker circulation, the winter cooling in northwestern North America and the prolonged drought in the southern USA. Our results show that the current hiatus is part of natural climate variability, tied specifically to a La-Niña-like decadal cooling. Although similar decadal hiatus events may occur in the future, the multi-decadal warming trend is very likely to continue with greenhouse gas

skype alternative - open source, no central server, encryption built in ....

its open source - go check it :-)

my ID: 7C53B574D888EE0E2A97FCD62B144DD14730E45C1B7158D4ED3EBCCB920CB93A68C62E6C9385

coooool !

It was also presented during SpaceTech.

sorry reposted that again, since I work thru my emails backwards ;)

The usefulness of having a robust trajectory :) ... They have to wait 6 more years for another date with Venus ...

"optimised trajectory" of course not, robust definitely! It was the subject of my paper presented at the AAS (the one in San Diego) "Designing robust interplanetary trajectories subject to one temporary engine failure". The problem here is that they do not have enough fuel for a correction maneuver that would allow to come back to Venus earlier, and break for a VOI. A robust scenario could have alloted the best amount of fuel and time to be able to recover from almost all possible unplanned events. In the paper, I introduce some confidence regions such that I get the robust control for p% chance of mission success in case m% chance of problem with the propulsion system.

You should run your method on this scenario and see if you could get a trajectory with a shorter come back time using the same spacecraft.... would be a big selling point for a new trajectory design approach

I like this work... it mixes physics, networks and biology ! Anyone heard about her ? Here's an interesting paper found on this website: http://nuweb.neu.edu/gbianconi/condensation.pdf

We worked on this with Luzi a few years back ... while the analogy is original and interesting it fails to capture the dynamics of a network, e.g. if a network has hubs that grow and shrink .... Luzi worked on an extended model to solve this issue, but, if I remember correctly, he got stuck in a computationally very hard problem .... We intended to develop and use the extended model to define relevant characteristic of the ESA network formed by mail exchanges.....

...but then the CMS YGT didn't really like the project

what a shame! ambition and innovation have not been fairly rewarded ...

I didn't have time yet. But formulating the failure with a MTBF or a FIT, you can easily imagine a more robust solution. Instead of one single burn, you would make several smaller burns - It will take more time and require more fuel though. Another "robust" approach is to consider weak stability boundary capture. Again it takes time, but chances of failure are lessen.

would be a pity indeed!

There is certainly more to come ...

...This slippery surface was bio-inspired by the carnivorous plant I showed you sometimes ago! I was sure it was a good idea! next time I will be quicker!!

And a good lesson that it is important to proceed quickly when you have an idea and don't wait ...

Yes, I will see what we could do, but they really did a good job, from the biomimetic of the surface, up to the realization of the material, and the tests...

I sit really possible/desirable?

It is possible, and NEOs may offer interesting ressources, but there is nothing in that paper. Why do they use the Sun-Earth system and not the Earth-Moon? The condition C>C1 is very weak and would have been much better had it been applied to the Earth-Moon system.

here now the paper

an astronaut? Too bad for him...

Nice...

opening of another commerical space activitiy area? ... probably not ...

Awesome, they managed. (this is a different deal as the micro ones )

this looks like a very nice project back in 2005 ...

Does it also attack people to capture their fish & chips like those beasts we have here in St. Ives?