For reminding us what technology can do. And what people can become. Image: Members of the Cassini mission team. Cassini has benefited from the work of some 260 scientists at NASA, ESA and Agenzia Spaziale Italiana (ASI), as well as several European academic and industrial contributors. Credit: JPL/Caltech.

Exomoons -- moons around planets in other star systems -- are an exhilarating and at the same time seemingly inevitable prospect. There is little reason to assume our Solar System is unique in its menagerie of moons, with the gas giants favoring us particularly with interesting mission targets, and then there's that fascinating double system at Pluto/Charon. If we visualize what we expect to find in any given stellar system, surely moons are part of the mix, and investigations like the Hunt for Exomoons with Kepler will doubtless find them. An actual exomoon detection would be a triumph for exoplanet science, especially given how recently it was that we nailed down the first confirmed exoplanet, 51 Pegasi b, in 1995 (or, if you prefer, the 1992 detection of terrestrial-mass planets orbiting the pulsar PSR B1257+12). We're new at this, and what huge strides we've made! Given the small size of the transit signal and its changing relation to the body it orbits, exomoons offer a...

It's wonderful to have my friend Al Jackson back at the top of the site with a look at the career and times of JPL's Frank Malina. Al's service in the Apollo program came as astronaut trainer on the Lunar Module Simulator; he then spent 40 more years at Johnson Space Center, mostly for Lockheed working the Shuttle and ISS programs. His doctorate was in 1975 from the University of Texas at Austin. The author of numerous scientific papers on interstellar concepts, Al is a fixture at deep space conferences and a continuing source of inspiration on matters scientific as well as science fictional. Today Al gives us an overview of a man who played a key role in the sounding rocket era following World War II, as the infant Jet Propulsion Laboratory began its rich history of exploration and technical development. by Al Jackson I travel from Houston to Austin by Highway 290 fairly often, and sometimes I stop at Brenham, Texas for lunch. I skip the fast food joints on 290 and go downtown. It...

Alex Tolley mentioned Ray Bradbury's story "The Golden Apples of the Sun" in connection with my first article on the Parker Solar Probe, and it's a short tale worth remembering in connection with a mission flying so remarkably close to our star. First published in 1953 in a Doubleday collection of the same name, the tale is a short, mythic take on dangerous questing, with its main character, the unnamed captain, a figure something like Melville's Captain Ahab. His goal is to fly to the Sun's surface and retrieve some of its fire: The captain stared from the huge dark-lensed port, and there indeed was the sun, and to go to that sun and touch it and steal part of it forever away was his quiet and single idea. In this ship were combined the coolly delicate and the coldly practical. Through corridors of ice and milk-frost, ammoniated winter and storming snowflakes blew. Any spark from that vast hearth burning out there beyond the callous hull of this ship, any small fire-breath that...

Is there something about human beings that ensures we will always explore? I think so, even while acknowledging that there are many who have chosen throughout history not to examine potential frontiers. The choices we make on Earth will be reflected in our future beyond the Solar System, assuming there is to be one. Nick Nielsen looks at these questions in a historical context today, seeing history as a fractal structure, but one whose future is not clear. A path that can lead to the stars as our destination is available in what he describes herein as a new stage of growth not limited by a single world and large enough to contain projects on a planetary scale. When he's not writing for Centauri Dreams, you can follow Nick's work on Twitter @geopolicraticus or on his blog Grand Strategy: The View from Oregon. by J. N. Nielsen The human condition: questions and answers What is perhaps Paul Gauguin's best known painting —D'où Venons Nous / Que Sommes Nous / Où Allons Nous [1]...

What kind of civilization might eventually emerge on Mars? Colonies of various kinds have been examined in science fiction for decades, but as we close in on the possibility of actual human arrival on the planet, perhaps in the 2030s, we can wonder how living on a different world will change the people who eventually choose to call it home. The prolific Nick Nielsen likes to take the long view, arguing in the essay below that while there are contrasting definitions of civilization itself, we may yet learn through experiment and experience how a 'central project' emerging from local conditions may define the future of colonies on other worlds. Human history offers guidance, but it may be that a successful Martian colony will see its position as a gateway to the exploration of the Solar System. You can follow Nick on his Grand Strategy: The View from Oregon site, as well as his Grand Strategy Annex. by J. N. Nielsen Settling Mars Suppose that one or several planned large-scale missions...

John Glenn was 95 when he died, but I have to admit I didn't think he'd make it to 41. The first American to orbit the Earth was 40 years old when he rode an Atlas rocket into the sky on February 20, 1962. I was a gawky kid, space-crazed, who had read absolutely everything I could find about the space program, and I knew just enough to understand that the Atlas, for all its muscular beauty, wasn't necessarily the safest thing you'd want to fly. Our school had set up a black and white television on the stage in the auditorium so we could all see the liftoff, which took place at 8:47 A.M. in St. Louis. In this era of enormous home viewing screens it's hard to imagine what a single small television could show to an auditorium filled with students, but at the time it was a window into history and we watched avidly as the rocket cut into the sky, and got later updates from teachers as Glenn orbited. We all assumed the hard part was over after the launch, and I know I was certainly...

An antimatter sail, as described yesterday in the work of Gerald Jackson and Steve Howe, is an exciting idea particularly because it relies on only small amounts of antimatter, tapping its energies to create fission in a uranium-enriched sail. Thus the uranium is the fuel and the antimatter, as Jackson says, is the 'spark plug.' We reduce the needed amount of antimatter and define what the new Kickstarter campaign calls "...the first proposed antimatter-based propulsion system that is within the near-term ability of the human race to produce." The antimatter sail produces fission by allowing antimatter, stored probably as antihydrogen, to drift across to the sail, and as we saw yesterday, the potential for velocities up to 5 percent of lightspeed mean that such a sail could be deployed on interstellar missions. Proxima Centauri naturally emerges as a target, but Jackson and Howe's work is not a result of recent interest in that star and its one known planet. The 2002 study in which...

Have a look at the spiral of pinwheeling dust that can be seen around the young star Elias 2-27. We're looking at gravitational perturbations in a protoplanetary disk that, as this National Radio Astronomy Observatory news release says, mimic the vast arms we expect in a spiral galaxy. But here we're looking at a process with implications for planet formation, one that draws on data from the Atacama Large Millimeter/submillimeter Array (ALMA). This is the first time a spiral density wave has been detected in a protoplanetary disk's planet formation areas. Image: ALMA peered into the Ophiuchus star-forming region to study the protoplanetary disk around the young star Elias 2-27. Astronomers discovered a striking spiral pattern in the disk. This feature is the product of density waves - gravitational perturbations in the disk. Credit: L. Pérez (MPIfR), B. Saxton (NRAO/AUI/NSF), ALMA (ESO/NAOJ/NRAO), NASA/JPL Caltech/WISE Team. Some 450 light years from Earth in the Ophiuchus...

With manned missions to Mars in our thinking, both in government space agencies and the commercial sector, the challenge of providing adequate life support emerges as a key factor. We're talking about a mission lasting about two years, as opposed to the relatively swift Apollo missions to the Moon (about two weeks). Discussing the matter in a new essay, Brian McConnell extends that to 800 days -- after all, we need a margin in reserve. Figure 5 kilograms per day per person for water, oxygen and food, assuming a crew of six. What you wind up with is 24,000 kilograms just for consumables. In terms of mass, we're in the range of the International Space Station because of our need to keep these astronauts alive. McConnell, a software/electrical engineer based in San Francisco, has been working with Alex Tolley on the question of how we could turn most of these consumables into propellant. The idea is to deploy electric engines that use reclaimed water and waste gases to do the job. With...

The interstellar community is a small one, and reporting the loss of one of our number is not easy. SETI researcher Stéphane Dumas, who had been working with Claudio Maccone on the application of the Karhunen-Loève transform (KLT) for SETI observations, has died unexpectedly at his home in Quebec. I remember a wonderful conversation with Stéphane at one of the 100 Year Starship meetings in Houston, where we got into a spirited exchange about interstellar propulsion. It was, alas, the only time I spent with the man, but he was also active on the advisory board for Jon Lomberg's One Earth Message project, and so we interacted electronically. Below is a video of Stéphane and Claudio Maccone presenting the latest work in mathematical SETI. You'll find Stéphane's talk at about 34:56 on the counter. [youtube djzCAc0pXx8 500 416]

The unusual star designated KIC 8462852, and now widely known as 'Tabby's Star,' continues to be an enigma. As discussed in numerous articles in these pages, KIC 8462852 shows anomalous lightcurves that remain a mystery. Recently Michael Hippke explored a related question: Was the star dimming over time, as postulated by Louisiana State's Bradley Schaefer? The two sharply disagreed (references below), leading Hippke and co-author Daniel Angerhausen to re-examine their conclusions. Now, with further collaboration from Keivan Stassun and Michael Lund (both at Vanderbilt University) and LeHigh University's Joshua Pepper, Hippke and Angerhausen have a new paper out, peer-reviewed and accepted for publication by The Astrophysical Journal. What follows are Michael Hippke's thoughts over the controversy as it stands today, with the dimming of KIC 8462852 again in doubt. by Michael Hippke Tabetha Boyajian et al. released a paper on the preprint platform astro-ph in September 2015, which...

If you've been following the Breakthrough Starshot concept in these pages and elsewhere, you'll know that it's small at one end and big on the other. A beamed sail mission, it would use sails four meters to the side -- quite small by reference to earlier beamed sail designs -- driven by a massive phased laser array on the Earth. The array is projected to be a kilometer to the side, incorporating laser emitters working in perfect synchronization to produce what Pete Worden, formerly of NASA Ames, described in Palo Alto as "a laser wind of 50 gigawatts." Worden is now executive director of Breakthrough Starshot. As with the sail, so with the payload. We have no macro-scale spacecraft here but a 'Starchip' about the size of a postage stamp, making it a kind of futuristic smartphone containing not just cameras, communication equipment and navigation instruments but tiny thrusters. If you want to imagine something like this, you take trends in digital technology like Moore's Law and...

When you don't have the technology to get to an interesting place like the Oort Cloud, it's more than a little helpful when nature brings an Oort Cloud object to you. At least we think that the object known as C/2014 S3 (Pan-STARRS) has moved into the warmer regions of the Solar System from the Oort. A gravitational nudge in that distant region would be all it took to send the object, with an orbital period now estimated to be 860 years, closer to the Sun. And here things get interesting, because C/2014 S3 is the first object discovered on a long-period cometary orbit that shows all the spectral characteristics of an inner system asteroid. The level of activity on the object, apparently the result of sublimation of water ice, is five to six orders of magnitude lower than what we would expect from an active long-period comet at a similar distance from the Sun. Karen Meech (University of Hawaii) and colleagues believe that the object formed in the inner system at about the same time as...

Some of you may recall an episode of Star Trek: The Next Generation in which the inhabitants of a planet called Aldea use a planetary defense system that includes a cloaking device. The episode, “When the Bough Breaks,” at one point shows the view from the Enterprise’s screens as the entire planet swims into view. My vague recollection of that show was triggered by the paper we looked at yesterday, in which David Kipping and Alex Teachey discuss transit light curves and the ability of a civilization to alter them. After all, if an extraterrestrial culture would prefer not to be seen, a natural thought would be to conceal its transits from worlds that should be able to detect them along the plane of the ecliptic. Light curves could be manipulated by lasers, and as we saw yesterday, the method could serve either to enhance a transit, thus creating a form of METI signaling, or to conceal one. In the latter case, the civilization would want to create a change in brightness that would...

J. G. Ballard (1930-2009) emerged as one of the leading figures in 20th Century science fiction. His fascination with inner as opposed to 'outer' space infused his characters and landscapes with a touch of the surreal, taking the fiction of the space age into deeply psychological realms. Christopher Phoenix here looks at the question of centuries-long journeys to the stars, with reference to a Ballard story in which a crew copes with isolation on what appears to be an interstellar mission. What we learn about ship and crew informs the broader discussion: If it takes more than a single generation to make an interstellar crossing, what can we do to keep our crew functional? And is there such a thing as happiness under these constraints? By Christopher Phoenix A few months back, Centauri Dreams ran Gregory Benford's review of Kim Stanley Robinson's novel Aurora. After reading that review and the discussion that followed, I began thinking about fiction that explores how starflight might...

"No matter how these issues are ultimately resolved, Centauri Dreams opts for the notion that even the back of a cereal box may contain its share of mysteries." I wrote that line in 2005, and if it sounds cryptic, read on to discover its origins, ably described by Christopher Phoenix. I first encountered Christopher in an online discussion group made up of physicists and science fiction writers, where his knack for taking a topic apart always impressed me. A writer whose interest in interstellar flight is lifelong, he is currently turning his love of science fiction into a novel that, he tells me "incorporates some of the ideas we talk about on Centauri Dreams as a background setting." Today's essay examines the ideas of a physicist who dismissed the idea of interstellar flight entirely, while using a set of assumptions Christopher has come to challenge. by Christopher Phoenix "All this stuff about traveling around the universe in space suits -- except for local exploration which I...

I'm on the road and don't have a lot of time for writing, but I want to go ahead and get these new Pluto images up. They're now available on the NASA site, and were introduced at the news conference at JHU/APL that just concluded. I'll also quote just a bit of the news release for each photo. New close-up images of a region near Pluto's equator reveal a giant surprise: a range of youthful mountains rising as high as 11,000 feet (3,500 meters) above the surface of the icy body. The mountains likely formed no more than 100 million years ago -- mere youngsters relative to the 4.56-billion-year age of the solar system -- and may still be in the process of building, says Jeff Moore of New Horizons' Geology, Geophysics and Imaging Team (GGI). That suggests the close-up region, which covers less than one percent of Pluto's surface, may still be geologically active today. This one I mis-typed in my Twitter coverage for those who were following it, but the correct number is 100 million years....

While both Alan Stern and Glen Fountain admitted to having anxious moments over the weekend when New Horizons went silent, it became clear at yesterday's news conference that those moments were short and quickly subsumed with ongoing duties. Stern is principal investigator for New Horizons, and the man most closely identified with making the mission a reality, while Fountain is project manager for New Horizons at JHU/APL in Maryland. It was Stern who pointed out that the spacecraft has been in safe mode a number of times already. Nine times, as a matter of fact, since launch, although as of yesterday we are back in the realm of normal operations. So the circumstances were not unfamiliar even if this safe mode came so close to destination that it raised inevitable concern and a flutter of worry on Twitter. Stern said he was in the control center six or seven minutes after getting the call that something was wrong. It also turns out that this was the first safe mode occurrence in which...

Centauri Dreams regular James Jason Wentworth wrote recently with some musings about Bracewell probes, proposed by Ronald Bracewell in a 1960 paper. Bracewell conceived the idea of autonomous craft that could monitor developments in a distant solar system, perhaps communicating with any local species that developed technology. Pondering how such a craft might manage station-keeping over the aeons, Jason hit on the idea of using a natural effect that would draw little attention to itself, one he explains below. An amateur astronomer and interstellar travel enthusiast who worked at the Miami Space Transit Planetarium and volunteered at the Weintraub Observatory atop the adjacent Miami Museum of Science, Jason now makes his home in Fairbanks (AK). He was the historian for the Poker Flat Research Range sounding rocket launch facility near Fairbanks. His space history and advocacy articles have appeared in Quest: The History of Spaceflight magazine and Space News. by James Jason Wentworth...