Here’s the latest in the weekly collection of space writing known as the Carnival of Space, in which people with their eyes on the stars go to work to explain the latest findings. Let’s start with the Sun, for even as we push our investigations of distant exoplanets, we have much to learn about the nearest star, as our recent discussion of the Solar Probe Plus reminds us. Launching this week’s Carnival, Vega 0.0 explains the plasma beta parameter, the ratio of gas pressure to magnetic pressure on the Sun, in an environment where plasma behaves like a fluid.

In his Astroblog, the ever reliable Ian Musgrave offers up a review of Stellarium Stellarium, for those not already acquainted with it, is a great, free photo-realistic planetarium program that amateurs should find helpful. Does Ian like it? Evidently so, given his description of the piece as an ‘enthusiastic Fan Boi review.’ And having worked with Stellarium myself, I can see why he’s enchanted with its possibilities. As Ian notes: “I’ve used the free planetarium program Stellarium since version 0.9, and it is no secret that it is my favourite planetarium program for unaided eye observation, and for illustrating aspects of the sky to school groups and the general public. With version 10.6.1 the Stellarium development team have produced a program that I truly love.”

An overview of risk at NASA, highlighting some of the riskier decisions in the past as well as some safe decisions made more recently, is the focus of a recent post by Amy Shira Teitel at Vintage Space. Risk is one thing when under tight time constraints and backed with a budget equaling 4 percent of GDP in the mid-1960s. But even that couldn’t prevent the disaster of the Apollo 1 fire. Read Amy’s thoughts on how NASA has managed the risk game in the years since. Some of these risks don’t involve lives but hardware, as the tricky operation of our Mars rovers demonstrates.

A long Chandra observation of Tycho has revealed a pattern of X-ray ‘stripes’ never before seen in a supernova remnant. As the Chandra Blog points out, “These stripes may provide the first direct evidence that supernova remnants can accelerate particles to energies a hundred times higher than achieved by the most powerful particle accelerator on Earth, the Large Hadron Collider.” These results may give us new insight into the origin of cosmic rays.

Starry Crittters also takes a look at Tycho’s supernova remnant, exploring a striking image showing what John Williams describes as ‘cotton-like clouds of dust and gas seen in the expanding bubble from the blast.’ The stripes that show up particularly well in the X-ray imagery help to support theories about magnetic fields amplified by supernova blast waves. The two posts show us how much the 450-year old supernova remnant has to teach us today.

Image: This image comes from a very deep Chandra observation of the Tycho supernova remnant, produced by the explosion of a white dwarf star in our Galaxy. Low-energy X-rays (red) in the image show expanding debris from the supernova explosion and high energy X-rays (blue) show the blast wave, a shell of extremely energetic electrons . These high-energy X-rays show a pattern of X-ray “stripes” never previously seen in a supernova remnant. Credit: X-ray: NASA/CXC/Rutgers/K.Eriksen et al.; Optical: DSS.

Carolyn Collins Petersen, AKA The Spacewriter, gives us her wide-ranging thoughts on skygazing, life on Mars and Hugo Chavez. That life on Earth might have its roots on Mars is fascinating in itself, but this was also the week when the strongman of Venezuela opined that ancient life on Mars was probably destroyed by the depredations of capitalism. “…there you go,” writes Carolyn. “Astronomy and planetary science lead one down some interesting paths, and not always scientific ones.” True, and the beauty of blogging is the freedom it gives us to range widely through topics looking for the threads that connect them together, as The Spacewriter does so well here.

WeirdWarp looks at how a planet or a moon acquires an atmosphere and then loses it. Chris Dann is interested not only in incoming materials from comets and asteroids but the escape of atmospheric gases into space. The question has interesting exoplanet implications, as witness the case of HD 209458b, about as close to a star as a planetary atmosphere can survive. Earth’s future? The Sun’s slow brightening (10 percent every billion years) has consequences that Chris explores.

Music of the Spheres reports on a visit to Space Expo, a space museum in Noordwijk, Netherlands that is also the visitor center for the European Space Agency’s technical development center (ESTEC). Lucky guy, to be traveling in Europe on business anyway, and to discover that one of your stops is the European Space Research and Technology Centre! I would have enjoyed the walk-through of the ISS modules described here.

The Navy’s anti-missile Aegis systems are being upgraded with anti-ballistic missile capabilities starting in 2012, and more upgrades will follow. NextBigFuture tells us that tests have shown 84 percent success rate with intercepts. That surpasses the performance of other systems in the planned missile defense network. The Aegis Combat System is an integrated naval weapons system now produced by Lockheed Martin.

Several brown dwarf stars have been found by European and NASA telescopes. One might be a Y-class brown dwarf. The Y-class family would include brown dwarfs that are cool enough to have water vapor in their atmosphere capable of condensing to form clouds and water. This would be quite a find, as another story in NextBigFuture notes: “Observations with ESO’s Very Large Telescope and two other telescopes have shown that this pair is the coolest pair of brown dwarfs found so far. The colder of the two components… is a candidate for the brown dwarf with the lowest temperature ever found — the surface temperature is similar to that of a cup of freshly made tea.” That one caught my interest as well in this Centauri Dreams post.

Closing out a trio of entries, NextBigFuture then discusses the Air Force and DARPA, which are days away from another X-51 hypersonic rocket test. Four of the ‘Waveriders’ were built for the Air Force by teams at Boeing and Pratt & Whitney Rocketdyne. You may remember an X-51A test last year that took the craft to Mach 5 under scramjet power.

Jupiter’s faded southern belt is turning red again! And about time — the belt had faded to white in early 2010, and based on past such occurrences, we knew it took about a year for the belt to come back to normal visibility. Emily Lakdawalla has photos in the Planetary Society Blog showing the belt’s return.

New Studies indicate that there are likely billions of other worlds in our galaxy alone. The latest work on Kepler data comes up with 1.4 to 2.7 percent of Sun-like stars as the figure expected to have planets the size of the Earth orbiting within the habitable zone. The numbers work out to something like 2 billion in our galaxy, as Paul Scott Anderson explains in the Meridiani Journal.

Nancy Atkinson at Universe Today clues in on Mauna Kea, on the Big Island of Hawaii, which is one of the best places in the world for ground-based astronomy. Nancy’s trip to the summit to see the multitude of giant telescopes there (13!) was scrubbed by weather, but she did get a behind the scenes tour of the W. M. Keck Observatory headquarters in Waimea. It turns out there is an operations room for each of the twin 10-meter Keck telescopes — the astronomers tend to work out of these rather than at the actual telescope site on the summit. Nancy’s photos will have you wanting to book that Hawaiian trip sooner rather than later.

Finally, Stuart Atkinson’s The Road to Endeavour follows the fortunes of the doughty Opportunity rover, now putting Santa Maria behind it and heading for Endeavour crater. I like the spirit of this post, which reminds us of the journey the rovers have taken us on, so far beyond what we had expected: “The road ahead is long, and there’s not going to be a lot on it to see, or make pretty colour views of, but every sol from now on will take us a little closer to Endeavour… every sol from now on we’ll see those faraway hills grow a little larger, a little sharper… every sol from now on we’ll be one sol closer to conducting fascinating science on the rim of an enormous, ancient martian crater that could re-write the science books for generations to come…”

Image: Opportunity’s tracks leading away from the Santa Maria Crater. Credit: JPL.