Paul Scott Anderson is a freelance space writer with a life-long passion for space exploration and astronomy and has been a long-time member of The Planetary Society. He currently writes for Universe Today and Examiner.com. His own blog The Meridiani Journal is a chronicle of planetary exploration.
A planet about to be consumed by its expanding red giant star. Credit: Mark Garlik/HELAS
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Some interesting new additions to the exoplanet family were announced last week by astronomers from Penn State University. While finding exoplanets these days may be considered “just another day at the office,” astronomers discovered three unique planets and an additional “mystery” object. What’s unique about these planets is the fact that the stars they orbit are all old and dying – red giant stars which have swollen up as they near the end of their lives, which ordinarily would consume any unlucky planets which may be too close to escape…
The three stars are HD 240237, BD +48 738, and HD 96127; the second one also has the mystery object orbiting it, which may be another planet, a low-mass star or a brown dwarf — something whose mass is in between that of a smaller, cooler star and a giant planet.
“We will continue to watch this strange object and, in a few more years, we hope to be able to reveal its identity,” said team leader, Alex Wolszczan.
Wolszczan was the first astronomer to discover exoplanets, three small planets orbiting a pulsar (neutron star) in 1992.
It is expected that our own Sun will also become a red giant star in another five billion years or so. Not a good thing for us obviously, but still a long ways off thankfully, since at that time, all of the inner planets of the solar system will probably be consumed by the expanding Sun.
The subject of planets orbiting dying stars will also be the focus of an upcoming conference, Planets Around Stellar Remnants, in Puerto Rico next January. It is organized by Penn State’s Center for Exoplanets and Habitable Worlds, and will take place exactly 20 years since Wolszczan made his discovery.
Interesting, since by far most of the exoplanets found so far orbit “normal” stars, like our Sun, which are still in mid-life or younger. But now, they’ve been observed around stars at all different stages of evolution, from the youngest stars, even those still with protoplanetary disks, to the oldest, stars which have already died and burned out, like pulsars. What this seems to indicate is that planets are a normal part of star formation, from beginning to end. The numbers now being found by astronomers, in the thousands and likely millions or billions, also suggest this; a big change from just a few decades ago when it was unknown if there were any other solar systems out there at all. There are, a lot of them.
Head shot of NASA's Robonaut. Credit: NASA/JPL/Joe Bibby
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When you hear about robots and space exploration, the first thing many people may think of is R2-D2 and C-3PO from Star Wars. While we may not be quite there yet, robots have become a major, even necessary, part of space missions. The many probes, landers and rovers that have been sent throughout the solar system are essentially robots, which have become more advanced over time. Then there’s the new Robonaut, a humanoid robot designed to assist astronauts with a variety of tasks in space including on the International Space Station, for example. But what is next? That was the subject of a panel discussion last Tuesday at the Von Braun Memorial Symposium in Huntsville, Alabama. The future being planned by the robotics experts involved is one of both humans and robots working together in space. The future is now…
“Can we have both robotics and human exploration of space?” was the question of the day. While there have long been advocates of both, there has also been a prevailing debate over which is better; robotic missions are less expensive and don’t put people in danger, but there are some things that only humans could do efficiently and quickly. The rovers on Mars for example, have done an amazing job of exploring the Martian surface, although human astronauts could do a lot of the same tasks faster. Also of course, people can experience the wonder and excitement of exploration in a way that machines can’t.
Instead of choosing between the two scenarios, the best idea, which I personally agree with, is to do both in tandem. That was the focus and apparent consensus of the symposium, that the best way forward is for humans and robots to work together, complimenting each others’ strengths and weaknesses. Humans might be better suited for on-site detailed exploration such as sample-taking, while robots could better handle other, more dangerous jobs.
The use of robotics has become a “pervasive technology across both military and space” according to Dr. Suzy Young of UA-Tuscaloosa’s Research Office. She also cited sources which claim that robotic intelligence could start to approach that of humans by 2040. It may still sound like science fiction, but it is quickly becoming science fact. Maybe those lovable droids from Star Wars aren’t too far off now after all.
You’ve probably heard by now how NASA is going to focus more on deep space exploration, both manned and robotic, leaving the low-Earth orbit and suborbital realms to commercial companies, a major change. There is, however, an opportunity for public input for deep space exploration as well, thanks to a new initiative for competitive ideas from universities, students, companies and government agencies. This means that you may have a chance to forward your proposals to help solve the problems that will need to be resolved in the coming years.
NASA’s new technology offices are getting ready to spend millions of dollars, it was announced at a seminar held last Monday as part of the Von Braun Memorial Symposium in Huntsville, Alabama. NASA is hoping to get between $375 million and $560 million in the fiscal year 2012 budget, which would be enough for competition prizes of $1 million or more.
“We have a space technology program, and there’s some money behind it,” Marshall Chief Technologist Andrew Keys said at the seminar.
The new heavy-lift rocket being designed will initially cost $1 billion or more, and still use proven conventional technology for its first planned launch in 2017. But as those first rockets are then replaced by larger ones, technological challenges will have to be overcome for new, better boosters to be designed, for example, which will ne necessary to take human farther into deep space to places like Mars.
The solar sail is also a good example of new technology, which is much different from conventional rockets, using the pressure of photons emitted from the Sun for propulsion, a very novel idea which is now being proven to be both possible and useful.
As in other facets of business and technology, competition will be a good thing, helping to bring out the best ideas and concepts from a larger knowledge pool, allowing the space industry to move more quickly and efficiently into the solar system and beyond. We may not have Star Trek-style warp speed yet, but the future is looking bright for space exploration, a future that can be better shared by all of us.
View of Enceladus' surface, image taken October 19, 2011. NASA/JPL-Caltech/Space Science Institute
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Saturn’s tiny moon Enceladus was the centre of attention for the Cassini spacecraft again last week, with beautiful new photos being released of the moon and its water vapour geysers erupting from the south pole. Some views show surface detail on the moon, some are of the geysers themselves and there is a very nice shot of Enceladus silhouetted against Saturn and its rings in the background. There is even a dual ultraviolet stellar occultation in which two of the stars in the belt of the constellation Orion are seen shining through the plumes! Even though these are still raw, unprocessed images, they again capture the beauty of Enceladus and the Saturnian system.
These new images were taken October 19, 2011 during the E-15 flyby, in which Cassini flew about 1,230 kilometres (765 miles) above the surface of Enceladus. The geysers can be seen in the image below, albeit these are not the closest views that Cassini has obtained. Still, it can be clearly seen how far they extend out from the moon, for a few hundred kilometres.
Enceladus and its water vapour geysers, image taken October 19, 2011. Credit: NASA/JPL-Caltech/Space Science Institute
Some surface detail can be seen in the next image below, a hint of the geological complexity of this moon, most notably seen in the “tiger stripe” fissures at the south pole, where the geysers erupt from inside the moon, escaping to the vacuum of space outside, where the water vapour freezes and falls back to the surface of Enceladus as a form of snow. As some have suggested, Enceladus may be a good place for skiing (with the snow being a very fine powder, although the extremely low gravity would probably interfere too much…)!
Enceladus silhouetted against the clouds and rings of Saturn in the background (the rings are edge-on in this view), image taken October 19, 2011. Credit: NASA/JPL-Caltech/Space Science Institute
Having a personal fascination with Enceladus, I was reminded of an older “Captain’s Log” entry on the CICLOPS web site (2006), by Cassini imaging team leader Carolyn Porco, after the initial discovery of the geysers. In part:
“Our detailed analyses of these images have led us to a remarkable conclusion, documented in a paper to be published in the journal SCIENCE tomorrow, that the jets are erupting from pockets of liquid water, possibly as close to the surface as ten meters… a surprising circumstance for a body so small and cold. Other Cassini instruments have found that the fractures on the surface and the plume itself contain simple organic materials, and that there is more heat on average emerging from the south polar terrain, per square meter, than from the Earth.
Gathering all the evidence and steeling ourselves for the “shockwave spread ’round the world”, we find ourselves staring at the distinct possibility that we may have on Enceladus subterranean environments capable of supporting life. We may have just stumbled upon the Holy Grail of modern day planetary exploration. It doesn’t get any more exciting than this.
A great deal more analysis and further exploration with Cassini must ensue before this implication becomes anything more than a suggestion. But at the moment, the prospects are staggering. Enceladus may have just taken center stage as the body in our solar system, outside the Earth, having the most easily accessible bodies of organic-rich water and, hence, significant biological potential.
Many years from now, it may well be that we and those who follow us will look back on these explorations of Saturn and take our discoveries on this otherwise cold little world to be the most wondrous of any we’ve ever made.
Future explorers of Saturn will have much to look forward to.”
And I agree with Cassini imaging team lead Carolyn Porco who said on Twitter of this image: “You’d have to be dead to tire of such magnificent vistas of alien worlds. Eerie Titan, the rings, Pan & Pandora. Glory!”
Titan is the largest in the background, and also the largest moon at 5,150 kilometres (3,200 miles) across, with Dione in front of it, which is 1,123 kilometres (698 miles) in diameter. Just to the right of the edge of the rings is Pandora, which is only about 81 kilometres (50 miles) in diameter. Tiny little Pan, only about 28 kilometres (17 miles) across, can just barely be seen as a speck inside the Encke Gap of the A ring on the left side of the image (look closely!).
Another amazing natural montage showing the alien beauty of the worlds in the Saturnian system. The full-size image can be seen here.
New Mexico Governor Susana Martinez and Sir Richard Branson pose for photographer on the balcony of the new Spaceport Hangar, Monday October 17, 2011 near Las Cruces, New Mexico.
It was part of a dedication and christening of the hangar to Virgin Galactic. Credit: Mark Greenberg
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Do you want to buy a ticket to outer space? Fly into orbit for the most breathtaking views of Earth possible? Well, those dreams for many took a step closer to reality yesterday as the world’s first commercial spaceport officially opened with dedication ceremonies for the new home of Virgin Galactic, Spaceport America, in New Mexico. It’s the beginning of a whole new space age…
With about 800 people attending, the terminal building was officially named “Virgin Galactic Gateway to Space” while its two spacecraft, WhiteKnightTwo and SpaceShipTwo, flew overhead. The ceremonies were overseen by Virgin Galactic’s founder Sir Richard Branson. New Mexico Governor Susana Martinez and Congressman Steve Pearce were also in attendance. The ceremonies even included a performance, (on the side of the building!) by the dance troupe Project Bandaloop (see video below).
“Today is another history-making day for Virgin Galactic,” said Sir Richard Branson. “We are here with a group of incredible people who are helping us lead the way in creating one of the most important new industrial sectors of the 21st century. We’ve never wavered in our commitment to the monumental task of pioneering safe, affordable and clean access to space, or to demonstrate that we mean business at each step along the way.”
This event marks a major milestone in the history of commercial spaceflight; once only the domain of NASA and other government space agencies, the space age is now finally really coming into its own, opening up the way for more ordinary citizens to leave Earth, at least to low-Earth orbit for now. Could space hotels be far behind?
“For me, my children and our ever growing community of future astronauts, many of whom are with us today, standing in front of the Virgin Galactic Gateway to Space as it glimmers majestically under the New Mexican sun brings our space adventure so close we can almost taste it,” said Sir Richard.
The cracked ice surface of Europa. Credit: NASA/JPL
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Until fairly recently, the search for life elsewhere in the solar system has focused primarily on Mars, as it is the most Earth-like of all the other planets in the solar system. The possibility of finding any kind of life farther out in the outer solar system was considered very unlikely at best; too cold, too little sunlight, no solid surfaces on the gas giants and no atmospheres to speak of on any of the moons apart from Titan.
But now, some of the places that were previously considered the least likely to hold life have turned out to be perhaps some of the most likely to provide habitable environments. Moons that were thought be cold and frozen for eons are now known to be geologically active, in surprising ways. One of them is the most volcanically active place known in the solar system. At least two others appear to have oceans of liquid water beneath their surfaces. That’s right, oceans. And geysers. On the surface, they are ice worlds, but below, they are water worlds. Then there’s the one with rain, rivers, lakes and seas, but made of liquid methane instead of water. Billions of kilometres farther out from the Sun than the Earth. Who would have thought? Let’s look at those last three in a bit more detail…
Ever since the film 2001: A Space Odyssey first came out, Europa has been the subject of fascination. A small, icy moon orbiting Jupiter, its depiction in that movie, as an inhabited world beneath its ice crust was like a sort of foreshadowing, before the Voyager and Galileo spacecraft gave us our first real close-up looks of this intriguing place. Its surface shell of ice is covered with long cracks and fissures, giving it an appearance much like ice floes at the poles on Earth. More surprising though, was the discovery that, also like on Earth, this ice cover most likely is floating on top of a deep layer of liquid water below. In Europa’s case though, the water layer appears to cover the entire moon, a global subsurface ocean. How is this possible? If there is liquid water, there must be heat (or high concentrations of salts or ammonia), and if you have water and heat, could there be something living in those waters? Gravitational tugging from Jupiter indeed appears to provide enough heat to keep the water liquid instead of frozen. The environment is now thought to be similar to ocean bottoms on Earth. No sunlight, but if there are volcanic vents generating heat and minerals, as on Earth, such a spot could be ideal for at least simple forms of life. On Earth, places like these deep in the oceans are brimming with organisms which don’t require sunlight to survive.
Water vapour geysers on Enceladus. Credit: NASA/JPL
Then there’s Enceladus. Another very small icy moon, orbiting Saturn. Geological activity was considered very unlikely on such a tiny world, only a few hundred kilometres in diameter. But then Cassini saw the geysers, plumes of material erupting from the south polar region through large, warmer cracks nicknamed “tiger stripes.” Cassini has now flown directly through the geysers, analyzing their composition, which is mostly water vapour, ice particles, salts and organics. The latest analysis based on the Cassini data indicates that they almost certainly originate from a sea or ocean of liquid water below the surface. Warm, salty water loaded with organics; could Enceladus be another possible niche for extraterrestrial life? As with Europa, only further missions will be able to answer these questions, but the possibilities are exciting.
Radar image of one of many methane lakes on Titan. Credit: NASA/JPL
Titan is even more fascinating in some ways, the largest moon of Saturn. It is perpetually shrouded in a thick smoggy atmosphere of nitrogen and methane, so the surface has never been visible until now, when Cassini, and its small lander probe Huygens, first looked below the smog and clouds. Titan is like an eerily alien version of Earth, with rain, rivers, lakes and seas, but being far too cold for liquid water (not much heat here), its “water cycle” is composed of liquid methane/ethane. Appearance-wise, the surface and geology look amazingly Earth-like, but the conditions are uniquely Titan. For that reason, it has long been considered that the chances of any kind of life existing here are remote at best. In the last few years however, some scientists are starting to consider the possibility of life forming in just such environments, using liquids other than water, even in such cold conditions. Could life occur in a liquid methane lake or sea? How would it differ from water-based life? Last year, a discovery was made which might be interpreted as evidence of methane-based life on Titan – a seeming disappearance of hydrogen from the atmosphere near the surface and a lack of acetylene on the surface. Previous theoretical studies had suggested that those two things, if ever found, could be evidence for methane-based lifeforms consuming the hydrogen and acetylene. All of this is still highly speculative, and while a chemical explanation is probably more likely according to the scientists involved, a biological one cannot be ruled out yet. Future proposed missions for Titan include a floating probe to land in one of the lakes and a balloon to soar over the landscape, pursuing such mysteries as never before. How cool is that?
Oh, and the moon that is the most volcanically active place in the solar system? Io, although with the only known forms of liquid there being extremely hot lavas on that sulfuric hothouse, the chances of life are still thought to be unbelievably slim. But that’s ok when you start to find out that worlds with oceans and lakes, etc. may be much more common than previously imagined…
When the first spacecraft flew by Mars in the 1960’s, the images returned revealed a relatively uninteresting-looking place, featureless in some areas and pockmarked with craters in most others. It looked a lot like the Moon. Later flybys and orbiting probes, however, gave us a closer look at other regions on the planet, providing a glimpse of what Mars is really like: a world of mountains, volcanoes, canyons, craters, old riverbeds and polar ice caps. It is little surprise then, that these striking geologic features captured scientists’ attention the most, and so areas like Hesperia Planum, a flat, relatively dull-looking plain, have received less attention over the years.
But there is a mystery in this region in the form of geologic features called rilles. No one has been able to figure out where they came from or how they formed.
The rilles in Herperia Planum are a series of about a dozen narrow, sinuous channels. They are up to a few hundred meters wide, and hundreds of kilometers long, but don’t appear to have any sources or destinations. The assumption has been that they were most likely created by lava flows, like their counterparts on the Moon. But apart from one very small volcano, there is little evidence of any volcanism in Hesperia Planum, which makes the appearance these rilles difficult to explain.
Another explanation could be water, but again, there are no obvious sources or other indications of past water in this region.
These enigmatic features have been the subject of study by scientists from the University at Buffalo, State University of New York. Geologist Tracy Gregg and her student Carolyn Roberts have been comparing them to rilles on the Moon, and their preliminary findings were presented today at the Annual Meeting of The Geological Society of America, in Minneapolis, and they hope to find some answers in further study and collaboration with other scientists.
“On the Moon we see these same kinds of features and we know that water couldn’t have formed them there,” Gregg said. “Everybody assumed these were huge lava flows, But if it turns out to be a lake deposit, it’s a very different picture of what Mars was doing at that time.”
So, were they formed by water, lava or something else? If it turned out to be water, that would of course be more interesting in terms of the search for possible habitable areas in Mars’ past.
Whichever explanation turns out to be correct, or even a different one, it will be one more piece of evidence which helps to further our understanding of this fascinating world, so much like our own in some ways, yet utterly alien in others
The paper is available here and additional photos are here.
