Ed Minchau offers up the latest Carnival of Space at his Robot Guy site. Centauri Dreams readers will want to look at Amanda Bauer’s presentation of an image taken by the Pluto-bound New Horizons spacecraft. It’s actually a composite showing Jupiter and a startlingly nearby Io. We’ve all seen Jupiter images, of course (thank you Voyager, Galileo, et al.), but take a look at this one to note the plume of the erupting Tvashtar volcano, a stunning reminder of how active this tortured little world continues to be.

Space Files has a nice overview of solar sail technologies beginning with Lou Friedman’s plans to develop Cosmos-2, a replacement for the lamented sail that perished in its launch attempt back in 2005. We still need to shake out this intriguing concept in space, and with NASA funding for sails in limbo, the private sector is the place to turn. Space Files gets into Japan’s recent experiments (useful as we learn how to deploy various sail configurations) and ESA’s GeoSail study. Getting this technology operational may become more of a priority for NASA, ESA and other agencies if Cosmos-2 can prove what sails can do.

Ed also links to Brian Wang’s survey of advanced propulsion systems. How does Brian keep up the pace at his advanced nanotechnology site? Not only is he a prolific writer but the wealth of images and links he produces can snare and hold my attention when I’m really supposed to be getting on with other work. I also want to point out his interesting piece on Franklin Chang-Diaz’ VASIMR (Variable Specific Impulse Magnetoplasma Rocket) engine concept, where he kicks around the idea of pairing the VASIMR drive with a proposed but evidently feasible portable nuclear reactor. No shortage of speculative fireworks here:

The total critical mass is from 600-1200 kg. The total mass for the nuclear reactor is probably under 100 tons and possibly in the 10-20 ton range. A nuclear powered Vasimr rocket would enable one way trips to Mars in 39 days and delivering 22 tons of payload. Vasimr engines can get up to 50,000 ISP which is 1100 times more fuel efficient than the Space Shuttle. The nuclear space vehicle would weigh about 600-1500 tons fully fulled. So it would take several launches using chemical rockets to put the pieces in orbit for assembly. A slightly scaled back system with one or two nuclear reactors would still enable trip to Mars for 70-100 day trips to Mars.

Finally, though not in this week’s Carnival, I want to note Universe Today‘s intriguing speculations on detecting plant life on distant exoplanets:

The question remains as to whether plants on distant worlds will use chlorophyll as their means of photosynthesizing light. Will the light they absorb be red, or a different color? Will the light they reflect be green or something completely bizarre, like magenta or bright blue? If they do use chlorophyll, their spectrum will be similar to that of our own planet. If not, their spectral signature may be rather different than that of Earth’s vegetation.

The discussion is keyed to work by Luc Arnold (CNRS Observatoire de Haute-Provence), who has been investigating whether the spectral analysis of light reflected off a planetary surface could tell us about the presence of vegetation there. How to take out the various noise factors — the composition of the atmosphere, the density of clouds, and so on — is all part of the puzzle. It will take a generation of space telescopes beyond even ESA’s Darwin (or whatever terrestrial planet finder technology NASA ultimately chooses to fund) to handle this job, but what a field day for exobiologists (and controversy) when it happens.