In today's world, one of the more useful gifts for a scientist to have is the ability to save money. Enter the Jet Propulsion Laboratory's Wesley Traub, who copes with problems like NASA's indefinite hold on Terrestrial Planet Finder with a low-cost alternative of his own. Last year, Traub and crew experimented with the Solar Bolometric Imager, an observatory lofted by a balloon to altitudes of 35 kilometers and more. Their study of air distortions at those altitudes convinced Traub that the balloon's movements through the stratosphere would not distort received images, and that led to speculation about doing exoplanet science close to home. A balloon-based TPF? Hardly, but Traub does talk about imaging perhaps twenty exoplanets, according to a recent story in New Scientist. The method: A coronagraph teamed with a one to two-meter mirror. The so-called Planetscope weighs in at $10 million, making it a bargain when compared to space-based observatories, and cheap enough to tempt...

What are the chances that we'll find habitable planets around Alpha Centauri A and B? Centauri Dreams has long kept an eye on the work of Greg Laughlin (UC-Santa Cruz) and colleagues, who have been working on the Alpha Centauri question with ever more interesting results. Following their work on Greg's systemic site has been fascinating, and for those who would like to be quickly brought up to speed, it's useful to know that Laughlin has made their recent paper summarizing these findings available online. Anyone serious about the study of these closest stars to Earth will want to download and read these promising results. Laughlin's group simulated the formation of planetary systems around Centauri B, beginning with a disk populated with 400 to 900 lunar-mass protoplanets, then following its development over 200 million years. To say the results are encouraging would be an understatement. All the simulations lead to multiple-planet systems, with at least one planet of Earth mass or...

Centauri Dreams has long championed Webster Cash's innovative New Worlds mission concepts, which would use a 'starshade' to block the light of distant stars to reveal their planetary systems. Cash envisions using multiple spacecraft for this assignment, one the starshade itself, the other a telescope that would make the needed observations. After a series of ups and downs, New Worlds now receives new life in the form of a $1 million award from NASA to study the starshade's possibilities. Remember that we're still at an early research level when it comes to funding of this kind -- the actual observatory, a design Cash calls New Worlds Observer -- would cost an estimated $3.3 billion to design and build. Other mission concepts are still in play (fully nineteen observatory concepts have been chosen for further study), so the road ahead is by no means clear as we look toward space missions that can identify Earth-like planets around other stars. But Cash's designs are well vetted, and...

What exactly is that dark material spread so widely over Saturn's various moons? From Hyperion to Iapetus, Dione and Phoebe, we find a black substance coating a wide range of objects, suggesting that whatever the stuff may be, there must be a common mechanism for moving it from one moon to another. A series of papers on Saturn's moons appears in the February issue of Icarus, where these interactions are now under study. Just what the material is remains a mystery. But Roger Clark (US Geological Survey) notes that as the Cassini data build, we're beginning to track down some of its components, including bound water and, possibly, ammonia. Studying Dione, Clark's team noted the fine-grained nature of the dark material there. Its distribution and composition indicate the dark material is not native to the moon, and indeed, the same signature appears not only among other moons but also in Saturn's F-ring. From the abstract to the study by Clarke and colleagues: Multiple lines of evidence...

About two weeks ago we looked at the work of Michael Meyer (University of Arizona), whose team examined over 300 Sun-like stars (spectral types F5-K3) at mid-range infrared wavelengths. A wavelength of 24 microns detects warm dust, material at temperatures likely to be found between 1 and 5 AU from the parent star. The headline that day was Meyer's contention that many if not most such stars produce terrestrial planets. Now Meyer is presenting these findings at the annual meeting of the American Association for the Advancement of Science, doubtless putting the exoplanet hunt back in the daily papers, at least for a day. Bear in mind that in using the term 'terrestrial' we're talking about small, rocky worlds like the inner planets of our Solar System. That could include worlds like our own, of course, but could also include hellish places like Mercury and Venus and their analogues around other stars. Nonetheless, it's exciting to think that the chances of rocky planet formation are...