A common criticism of science is its quick decision to experiment, without thinking about whether or not it should. While many argue that philosophical implications do not belong within the realm of science, others argue that scientists should absolutely consider the broader implications of their results.
Now, neuro-psychologist Gabriel G. de la Torre from the University of Cádiz is questioning whether or not astronomers, who have previously only looked for signs of extraterrestrial life, should actively send messages from Earth.
The idea that we might not be alone in the universe has been around since at least the fifth century B.C., when the Greek philosopher Democritus posited innumerable worlds, none of which were devoid of life.
With the founding of NASA and other space agencies in the 20th century, human beings began to explore the solar system and actively search for alien life. The most ambitious search began in 1960, when astronomer Frank Drake pointed a radio telescope at two stars similar to our Sun and listened for a signature of intelligence.
Drake’s work inspired the Search for ExtraTerrestrial Intelligence (SETI) project, an initiative that began in the 70s with funding from NASA, but has now evolved toward the collaboration of millions of Internet users for the processing of data from the Arecibo Observatory.
But then there is “Active SETI — also known as METI (Messaging to Extra-Terrestrial Intelligence) — which is the attempt to send messages to potential ETs via radio signals. Some astrophysicists, such as Stephen Hawking, have already warned against the risk this implies for humanity. It would favor the arrival of beings with more advanced technology and unknown intentions.
So “can such a decision be taken on behalf of the whole planet?” asked De la Torre. “What would happen if it was successful and ‘someone’ received our signal? Are we prepared for this type of contact?”
To answer these questions, De la Torre surveyed 116 American, Italian and Spanish university students. The questionnaire assessed their knowledge of astronomy, their religious beliefs, and their beliefs on the likelihood of contact with extraterrestrial intelligent life.
The results indicate that as a species, humanity is still not ready to actively contact a supposed extraterrestrial civilization. The students lacked awareness on many astronomical aspects, despite the enormous progress of science and technology. It also revealed that they lack preparation and would instead rely on political and religious figures.
De la Torre encourages SETI researchers to look for alternative strategies until society can better prepare itself. “This pilot study demonstrates that the knowledge of the general public of a certain education level about the cosmos and our place within it is still poor,” said De la Torre. “Therefore, a cosmic awareness must be further promoted – where our mind is increasingly conscious of the global reality that surrounds us – using the best tool available to us: education.”
The paper has been published in the journal Acta Astronautica.
Artist's rendering of Kepler-186f (Credit: NASA Ames/SETI Institute/Caltech)
It’s truly a “eureka” moment for Kepler scientists: the first rocky Earth-sized world has been found in a star’s habitable “Goldilocks” zone, the narrow belt where liquid water could readily exist on a planet’s surface without freezing solid or boiling away. And while it’s much too soon to tell if this really is a “twin Earth,” we can now be fairly confident that they do in fact exist.
The newly-confirmed extrasolar planet has been dubbed Kepler-186f. It is the fifth and outermost planet discovered orbiting the red dwarf star Kepler-186, located 490 light-years away. Kepler-186f completes one orbit around its star every 130 days, just within the outer edge of the system’s habitable zone.
The findings were made public today, April 17, during a teleconference hosted by NASA.
“This is the first definitive Earth-sized planet found in the habitable zone around another star,” says lead author Elisa Quintana of the SETI Institute at NASA Ames Research Center. “Finding such planets is a primary goal of the Kepler space telescope. The star is a main-sequence M-dwarf, a very common type. More than 70 percent of the hundreds of billions of stars in our galaxy are M-dwarfs.”
A visualization of the many “unseen” red dwarfs in the night sky. (CLICK FOR ANIMATION) Credit: D. Aguilar & C. Pulliam (CfA)
Unlike our Sun, which is a G-type yellow dwarf, M-dwarf stars (aka red dwarfs) are much smaller and dimmer. As a result their habitable zones are much more confined. But, being cooler stars, M-dwarfs have long lifespans, offering planets in their habitable zones — like Kepler-186f — potentially plenty of time to develop favorable conditions for life.
In addition, M-dwarfs are the most abundant stars in our galaxy; 7 out of 10 stars in the Milky Way are M-dwarfs, although most can’t be seen by the naked eye. Finding an Earth-sized planet orbiting one relatively nearby has enormous implications in the hunt for extraterrestrial life.
“M dwarfs are the most numerous stars,” said Quintana. “The first signs of other life in the galaxy may well come from planets orbiting an M dwarf.”
Still, there are many more conditions on a planet that must be met for it to be actually habitable. But size, composition, and orbital radius are very important first steps.
“Some people call these habitable planets, which of course we have no idea if they are,” said Stephen Kane, an assistant professor of physics and astronomy at San Francisco State University in California. “We simply know that they are in the habitable zone, and that is the best place to start looking for habitable planets.”
Scale comparison of the Kepler-186 system and the inner Solar System (NASA Ames/SETI Institute/Caltech)
As far as the planetary system’s age is concerned — which relates to how long life could have potentially had to evolve on Kepler-186f’s surface — that’s hard to determine… especially with M-dwarf stars. Because they are so stable and long-lived, once they’re formed M-dwarfs essentially stay the same throughout their lifetimes.
“We know it’s probably older than a few billion years, but after that it’s very difficult to tell,” BAERI/Ames scientist Tom Barclay told Universe Today. “That’s the problem with M-dwarfs.”
A comparison of the Kepler 186 and Solar systems (Presentation slide, NASA/Ames)
The exoplanet was discovered via the transit method used by NASA’s Kepler spacecraft, whereby stars’ brightnesses are continually monitored within a certain field of view. Any dips in luminance reveal the likely presence of a passing planet.
Because of its small size — just slightly over 1 Earth radius — and close proximity to its star, Kepler-186f can’t be observed directly with current telescope technology.
The Gemini North telescope on the summit of Mauna Kea (Gemini Observatory/AURA)
“However, what we can do is eliminate essentially all other possibilities so that the validity of these planets is really the only viable option,” said Steve Howell, Kepler project scientist and a co-author on the paper.
Using the latest advanced imaging capabilities of the Gemini North and Keck II observatories located atop Mauna Kea in Hawaii, astronomers were able to determine that the signals detected by Kepler were from a small orbiting planet and not something else, such as a background or companion star.
“The Keck and Gemini data are two key pieces of this puzzle,” Quintana said. “Without these complementary observations we wouldn’t have been able to confirm this Earth-sized planet.”
Kepler-186f joins the other 20 extrasolar worlds currently listed in the Habitable Exoplanets Catalog, maintained by the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo. To date 961 exoplanets have been confirmed through Kepler observations, with 1,696 total confirmed altogether. (Source)
Artist’s conception of the Kepler Space Telescope. Credit: NASA/JPL-Caltech
Whether Kepler-186f actually resembles Earth or not, this discovery provides more information on the incredible variety of planetary systems to be found even in our little corner of the galaxy.
“The diversity of these exoplanets is one of the most exciting things about the field,” Kane said. “We’re trying to understand how common our solar system is, and the more diversity we see, the more it helps us to understand what the answer to that question really is.”
The SETI Institute’s Allen Telescope Array has surveyed the Kepler-186 system for any potential signals but so far none has been detected. Further observations are planned.
“Kepler-186f is special because we already know that a planet of its size and distance is capable of supporting life.”
– Elisa Quintana, research scientist, SETI Institute
The team’s paper, “An Earth-sized Planet in the Habitable Zone of a Cool Star” by Elisa V. Quintana et al., will be published in the April 18 issue of Science.
This interview with Frank Drake — sometimes called the Father of the Search for Extraterrestrial Intelligence – was recorded in 2012 but not released until now to celebrate the beginning of the 30th year of the SETI Institute. As interviewer Andrew Fraknoi says, “I don’t think anyone had a conversation like this that was recorded with Galileo or William Herschel or Edwin Hubble, but I get to do it with Frank Drake!”
This is a great conversation that alternates between Drake’s current work with SETI and the history of his work that led to the famous Drake Equation. Fraknoi and Drake have an interesting exchange about the value of N, which is the number of civilizations in The Milky Way Galaxy whose electromagnetic emissions would be detectable.
It was recorded in June 2012 at an event called SETICon, which featured a series of talks, panels, and events featuring scientists, authors, futurists, and film-makers.
Discovering life beyond Earth might just be the holy grail of science. And even though we have yet to find evidence for little green men or blobs of bacteria, astronomers continue to search for elusive signs of life.
A novel strategy may help astronomers better target extraterrestrial intelligent life. Dr. Michael Gillon, of the University of Liege in Belgium, proposes an approach that would monitor the regions of nearby stars to search for interstellar communication devices.
The most common method in the search for extraterrestrial intelligence (abbreviated as SETI) is the use of giant radio dishes to scan the stars, listening for possible faint signals coming from distant civilizations.
While the SETI institute has been hard at work since 1959 we haven’t chanced upon a signal yet. But that doesn’t mean we’re alone or that we should stop looking.
Even without a confirmed extraterrestrial signal, most astronomers would argue that recent discoveries have strongly reinforced the hypothesis that extraterrestrial life may just be abundant in the Universe. With the help of the Kepler Space Telescope we have learned that planets are plentiful throughout the Milky Way. With most stars harboring at least one planet, it’s conceivable that a few of those planets will have the right conditions for life.
So why haven’t we detected extraterrestrial intelligent life? Why do we have this glaring Fermi Paradox — the apparent contradiction between the high probability of extraterrestrial civilizations’ existence and the lack of contact with such civilizations?
One hypotheses to explain the famous Fermi Paradox is that self-replicating probes could have explored the whole Galaxy, including our Solar System, but we just haven’t detected them yet. A self-replicating probe is one sent to a nearby planetary system where it would mine raw materials to create a replica of itself that would then head towards other nearby systems, continuing to replicate itself along the way.
While our own technological civilization is less than two hundred years old, we have already sent robotic probes to a large number of bodies in our Solar System and beyond. Our furthest-reaching probe, Voyager 1, just made it to interstellar space. But it took it over 40 years.
“We are still far from being able to build an actual self-replicating interstellar spaceship, but only because our technology is not mature enough, and not because of an obvious physical limitation,” Dr. Gillon told Universe Today.
While we cannot currently send self-replicating probes to the nearest stars in a reasonable amount of time, nothing excludes this as a reachable future project, or a project already completed by extraterrestrial intelligent life.
This study further proposes that probes from neighboring stellar systems could use the stars they orbit as gravitational lenses to communicate efficiently with each other.
The coordination of probes to explore the Galaxy would be very inefficient unless they had the ability to directly communicate with one another. The vastness and structure of the Milky Way makes this seemingly impossible. By the time a signal reached a very distant star it would be highly diluted.
However, any star is massive enough to bend and amplify light. This process, gravitational lensing, is extremely powerful. “It means that the Sun (and any other star) is an antenna much more powerful than we could ever build,” says Dr. Gillon.
Based on this method, interstellar communication devices will exist along the line that connects one star to another. We now know exactly where to look, and even where to send messages.
Could this novel idea provide a new mission for SETI?
“A negative result wouldn’t tell us very much,” explains Dr. Gillon. “But a positive result would represent one of the most important discoveries of all time.”
The paper has been accepted for publication in Acta Astronautica and is available for download here.
Neptune's system of moons and rings visualized. Credit: SETI
“That’s no moon…”
-B. Kenobi
But in this case, it is… a lost moon of Neptune not seen since its discovery in the late 1980’s.
A new announcement from the 45th Meeting of the Division for Planetary Sciences of the American Astronomical Society being held this week in Denver, Colorado revealed the recovery of a moon of Neptune that was only briefly glimpsed during the 1989 flyby of Voyager 2.
The re-discovery Naiad, the innermost moon of Neptune, was done by applying new processing techniques to archival Hubble images and was announced today by Mark Showalter of the SETI institute.
Collaborators on the project included Robert French, also from the SETI Institute, Dr. Imke de Pater of UC Berkeley, and Dr. Jack Lissauer of the NASA Ames Research Center.
The findings were a tour-de-force of new techniques applied to old imagery, and combined the ground-based 10 meter Keck telescope in Hawaii as well as Hubble imagery stretching back to December 2004.
The chief difficulty in recovering the diminutive moon was its relative faintness and proximity to the “dazzling” disk of Neptune. At roughly 100 kilometres in diameter and an apparent magnitude of +23.9, Naiad is over a million times fainter than +8th magnitude Neptune. It’s also the innermost of Neptune’s 14 known moons, and orbits once every 7 hours just 23,500 kilometres above the planet’s cloud tops. Neptune itself is about 49,000 kilometres in diameter, and only appears 2.3” in size from Earth. From our Earthly vantage point, Naiad only strays about arc second from the disk of Neptune, a tiny separation.
“Naiad has been an elusive target ever since Voyager left the Neptune system,” Showalter said in a recent SETI Institute press release. Voyager 2 has, to date, been the only mission to explore Uranus and Neptune.
To catch sight of the elusive inner moon, Showalter and team applied new analyzing techniques which filtered for glare and image artifacts that tend to “spill over” from behind the artificially occulted disk of Neptune.
Other moons, such as Galatea and Thalassa — which were also discovered during the 1989 Voyager 2 flyby — are also seen in the new images. In fact, the technique was also used to uncover the as of yet unnamed moon of Neptune, S/2004 N1 which was revealed earlier this year.
Naiad is named after the band of nymphs in Greek mythology who inhabited freshwater streams and ponds. The Naiads differed from the saltwater-loving Nereids of mythology fame, after which another moon of Neptune discovered by Gerard Kuiper in 1949 was named.
It’s also intriguing to note that Naiad was discovered in a significantly different position in its orbit than expected. Clearly, its motion is complex due to its interactions with Neptune’s other moons.
“We don’t quite have enough observations to establish a refined orbit,” Mr. Showalter told Universe Today, noting that there may still be some tantalizing clues waiting to be uncovered from the data.
I know the burning question you have, and we had as well during the initial announcement today. Is it REALLY Naiad, or another unknown moon? Showalter notes that this possibility is unlikely, as both objects seen in the Hubble and Voyager data are the same brightness and moving in the same orbit. To invoke Occam’s razor, the simplest solution— that both sightings are one in the same object —is the most likely.
“Naiad is well inside Neptune’s Roche Limit, like many moons in the solar system,” Mr. Showalter also told Universe Today. Naiad is also well below synchronous orbit, and is likely subject to tidal deceleration and may one day become a shiny new ring about the planet.
The labeled ring arcs of Neptune as seen in newly processed data. The image spans 26 exposures combined into an equivalent 95 minute exposure. The ring trace and an image of the occulted planet Neptune is added for reference. (Credit: M. Showalter/SETI Institute).
And speaking of which, the tenuous rings of Neptune have also evolved noticeably since the 1989 Voyager flyby. First discovered from the ESO La Silla Observatory in 1984, data using the new techniques show that the knotted ring segments named the Adams and Le Verrier have been fading noticeably.
“In a decade or two, we may see an ‘arc-less’ ring,” Showalter noted during today’s Division for Planetary Sciences press conference. The two ring segments observed are named after Urbain Le Verrier and John Couch Adams, who both calculated the position of Neptune due to orbital perturbations of the position of Uranus. Le Verrier beat Adams to the punch, and Neptune was first sighted from the Berlin Observatory on the night of September 23rd, 1846. Observers of the day were lucky that both planets had undergone a close passage just decades prior, or Neptune may have gone unnoticed for considerably longer.
The rings of Neptune as seen from Voyager 2 during the 1989 flyby. (Credit: NASA/JPL).
Neptune has completed just over one 164.8 year orbit since its discovery. It also just passed opposition this summer, and is currently a fine telescopic object in the constellation Aquarius.
Unfortunately, there aren’t any plans for a dedicated Neptune mission in the future. New Horizons will cross the orbit of Neptune in August 2014, though it’s headed in the direction of Pluto, which is currently in northern Sagittarius. New Horizons was launched in early 2006, which gives you some idea of just how long a “Neptune Orbiter” would take to reach the outermost ice giant, given today’s technology.
This represents the first time that Naiad has been imaged from the vicinity of Earth, and demonstrates a new processing technique capable of revealing new objects in old Hubble data.
“We keep discovering new ways to push the limit of what information can be gleaned from Hubble’s vast collection of planetary images,” Showalter said in the SETI press release.
Congrats to Showalter and team on the exciting recovery… what other moons, both old and new, lurk in the archives waiting to be uncovered?
– Read today’s SETI Institute press release on the recovery of Naiad.
-Be sure to follow all the action at the 45th DPS conference in Denver this week!
Pi Sagittarii moments before it was occulted by the Moon on August 10th, 2011. (Photo by Author).
Heads up, North American residents: our Moon is about to blot out two naked eye stars on Friday and Saturday night.
Such an event is known as an occultation, an astronomical term that has its hoary roots in astronomy’s pseudoscience ancestor of astrology. An occultation is simply when one astronomical body passes in front of another from our line of sight. There’s nothing quite like watching a star disappear on the dark limb of the Moon. In a universe where events often transpire over periods of time longer than a human life span, occultations are abrupt affairs to witness.
Close double stars have also been teased out of occultation data, winking out in a quick, step-wise fashion. If an occultation such as the two this weekend occurs while the Moon is waxing towards Full, we get the added advantage of watching the action on the leading dark limb of the Moon during convenient early evening hours.
Beta Capricorni on the dark limb of the Moon Saturday night. (Created by the author using Starry Night).
First up is the occultation of the +3.9th magnitude star Rho Sagittarii on Friday night, October 11th. Central conjunction for this occultation occurs at 00:40 Universal Time (UT) early on the morning of the 12th. The Moon will be at a 51% illuminated waxing gibbous phase, having passed First Quarter just prior to the start of the occultation at 7:02 PM EDT/23:02 UT on the 11th. The sunset terminator line at the start of the occultation will bisect the central U.S., and observers east of the Mississippi will get to witness the entire event. The southern graze line will cross Cuba and Guatemala. Note that the Moon will also pass its most southern declination for this lunation just two days prior on October 9th at 23:00 UT/7:00 PM EDT, at a declination of -19.6 degrees. This is one of the Moon’s most southern journeys for 2013, meaning that it will still ride fairly far to the south in the sky during this weekend’s occultations.
The occultation of Rho Sagittarii by the Moon for the night of October 11th. the dashed line indicates where the occultation will occur in the daytime; east of this region, the occultation occurs after sunset. (rendered using Occult 4.1.02 software).
Rho Sagittarii is an F-type star 122 light years distant. Stick around until February 23rd, 2046, and you’ll get to see an even rarer treat, when the planet Venus occults the very same star. Just south of the Rho Sagittarii pair lies the region from which the Wow! Signal was detected in 1977.
The Moon moves at an average speed of just over a kilometre a second in its orbit about the Earth, and traverses roughly the apparent distance of its angular size of 30’ in one hour. The duration of occultations as seen from their center line take about an hour from ingress to egress, though its much tougher to watch a star reappear on the bright limb of the Moon!
And the night of Saturday, October 12th finds the 62% illuminated waxing gibbous Moon occulting an even brighter star across roughly the same region. The star is +3.1 magnitude Beta Capricorni, which also goes by the Arabic name of Dabih, meaning “the butcher.” Dabih is also an interesting double star with a +6th magnitude component 3.5’ away from the +3rd magnitude primary. Dabih is an easy split with binoculars, and it will be fun to watch the two components pass behind the Moon Saturday night. This occultation also occurs the night of October 12th which is traditionally Fall Astronomy Day. If you’re hosting a star party this coming Saturday night, be sure to catch the well-timed occultation of Beta Capricorni! The central conjunction for this event occurs at 01:27 UT on the morning of the 13th, and North American observers east of the Rockies will get to see the entire event.
The occultation footprint of Beta Capricorni for the night of October 12th. (Rendered using Occult 4.1.0.2 software).
Beta Capricorni is 328 light years distant, putting the physical separation of the B component at about a third of a light year away from the primary star at 21,000 astronomical units distant. “Beta B” thus takes about 700,000 years to orbit its primary! It’s also amazing to think that those fusion-born photons took over three centuries to get here, only to be rudely “interrupted” by the bulk of our Moon in the very last second of their journey.
And be sure to keep an eye on the primary star as it winks out, as it’s a known spectroscopic triple star with unseen companions in respective 9 and 1374 day orbits. Dabih may just appear to “hang” on the jagged lunar limb as those close companions wink out in a step-wise fashion.
Both occultations are bright enough to watch with the naked eye, although a standard set of 10x 50 binoculars will provide a fine view. The ingress of an occultation is also an excellent event to catch on video, and if you’ve got WWV radio running audio in the background, you can catch the precise time that the star disappears from your locale.
Note: WWV radio is still indeed broadcasting through the ongoing U.S. government shutdown, though they’re operated by NOAA & the NIST.
The International Occultation and Timing Association is always interested in reports of occultations carried out by amateur astronomers. Not only can this reveal or refine knowledge of close double stars, but a series of occultation observations from precisely known locations can map the profile of the lunar limb.
Be sure to catch both events this U.S. Columbus Day/Canadian Thanksgiving Day weekend, and send those pics in to Universe Today!
Precise timings for the ingress and egress of each lunar occultations for major North American cities can be found at the following pages:
Our Universe is big, and it’s been around for a long time. So why don’t we see any evidence of aliens? If they are out there, why haven’t they contacted us, and how do we contact them? What methods might they use to try and contact us?
Where do we look for signs of alien civilizations?
The search for extraterrestrial intelligence, otherwise known as SETI, are the methods that scientists have proposed to discover evidence of aliens in the Universe.
Perhaps the most famous method is listening for their signals. Here on Earth, we have exploited the radio spectrum to send signals through the air. We even use it to communicate with spacecraft in the Solar System.
So, since it works so well for us, it makes sense that aliens might use radio waves to communicate from star to star. If there’s an alien civilization out there beaming a signal directly at the Sun, our largest radio telescopes should be able to pick up their signal.
The problem is that the galaxy is huge, with hundreds of billions of stars. Any one of which could be the world where the aliens live. Furthermore, we don’t know which frequency the aliens might use to communicate with us.
Even though the search for ET has been going for many years, we’ve only explored a fraction of the millions of available stars and frequencies on the radio spectrum.
So far, no definitive signal has been discovered.
Gieren et al. used the 8.2-m Very Large Telescope (Yepun) to image M33, and deduce the distance to that galaxy (image credit: ESO).Another possibility is that aliens are using lasers to communicate with us. An alien could target an incredibly powerful laser at our star, and it would be detectable with our large optical telescopes. There have been a few dedicated searches for laser communication, and scientists have proposed we could search for these alien signals at the same time we’re searching for extrasolar planets.
Again, so far nothing has turned up.
View from inside the Borexino neutrino detector. Image Credit: Borexino CollaborationIt’s possible that aliens use a more exotic method of communication, like neutrinos.
Neutrinos are generated in high energy collisions, and can pass right through planets with ease. They would be incredibly difficult to detect with our current technology, but maybe advances in the future will make that a possible communication method.
But maybe Instead of searching for signals, we could look for their artifacts.
If the energy of transmitting signals across the vast reaches of space is too much, it might make more sense for aliens to construct self-replicating probes and let them journey from star to star.
These probes could leave behind an obvious alien-made structure which we could discover once we become a true spacefaring species.
We could also detect aliens by their impact on their home planets. With a large enough space telescope, we should be able to study the atmosphere of planets orbiting nearby stars. An industrialized civilization would probably be polluting its atmosphere with various gases — just like we have — which would be detectable.
Finally, we could search for evidence of aliens through their structures.
If a civilization starts building megastructures which block off a large portion of their star’s light, we should be able to detect evidence through our search for extrasolar planets.
A Star Trek-inspired space station.A gigantic space station would give off a much different light signature than a nice spherical planet as it passes in front of its star.
There have been a few attempts to reach out to other worlds directly, transmitting signals out into space. It’s unlikely that these signals will actually reach any other civilization, and some scientists are concerned about the wisdom of this kind of communication.
Do we really want to alert potentially hostile aliens to our location in the Milky Way?
It’s exciting to think that there are other alien civilizations around us in the Milky Way, and with a little more work, we could discover their location and maybe even communicate with them.
An artist's concept of a rocky world orbiting a red dwarf star. (Credit: NASA/D. Aguilar/Harvard-Smithsonian center for Astrophysics).
Hunters of alien life may have a new and unsuspected niche to scout out.
A recent paper submitted by Associate Professor of Astronomy at Columbia University Kristen Menou to the Astrophysical Journal suggests that tidally-locked planets in close orbits to M-class red dwarf stars may host a very unique hydrological cycle. And in some extreme cases, that cycle may cause a curious dichotomy, with ice collecting on the farside hemisphere of the world, leaving a parched sunward side. Life sprouting up in such conditions would be a challenge, experts say, but it is — enticingly — conceivable.
The possibility of life around red dwarf stars has tantalized researchers before. M-type dwarfs are only 0.075 to 0.6 times as massive as our Sun, and are much more common in the universe. The life span of these miserly stars can be measured in the trillions of years for the low end of the mass scale. For comparison, the Universe has only been around for 13.8 billion years. This is another plus in the game of giving biological life a chance to get underway. And while the habitable zone, or the “Goldilocks” region where water would remain liquid is closer in to a host star for a planet orbiting a red dwarf, it is also more extensive than what we inhabit in our own solar system.
Gliese 581- an example of a potential habitable zone around a red dwarf star contrasted with our own solar system. (Credit: ESO/Henrykus under a Wikimedia Creative Commons Attribution 3.0 Unported license).
But such a scenario isn’t without its drawbacks. Red dwarfs are turbulent stars, unleashing radiation storms that would render any nearby planets sterile for life as we know it.
But the model Professor Menou proposes paints a unique and compelling picture. While water on the permanent daytime side of a terrestrial-sized world tidally locked in orbit around an M-dwarf star would quickly evaporate, it would be transported by atmospheric convection and freeze out and accumulate on the permanent nighttime side. This ice would only slowly migrate back to the scorching daytime side and the process would continue.
Could these types of “water-locked worlds” be more common than our own?
The type of tidal locking referred to is the same as has occurred between the Earth and its Moon. The Moon keeps one face eternally turned towards the Earth, completing one revolution every 29.5 day synodic period. We also see this same phenomenon in the satellites for Jupiter and Saturn, and such behavior is most likely common in the realm of exoplanets closely orbiting their host stars.
The study used a dynamical model known as PlanetSimulator created at the University of Hamburg in Germany. The worlds modeled by the author suggest that planets with less than a quarter of the water present in the Earth’s oceans and subject to a similar insolation as Earth from its host star would eventually trap most of their water as ice on the planet’s night side.
Kepler data results suggest that planets in close orbits around M-dwarf stars may be relatively common. The author also notes that such an ice-trap on a water-deficient world orbiting an M-dwarf star would have a profound effect of the climate, dependent on the amount of volatiles available. This includes the possibility of impacts on the process of erosion, weathering, and CO2 cycling which are also crucial to life as we know it on Earth.
Thus far, there is yet to be a true “short list” of discovered exoplanets that may fit the bill. “Any planet in the habitable zone of an M-dwarf star is a potential water-trapped world, though probably not if we know the planet possesses a thick atmosphere.” Professor Menou told UniverseToday. “But as more such planets are discovered, there should be many more potential candidates.”
Hard times in harsh climes-an artist’s conception of the daytime side of a world orbiting a red dwarf star. (Credit: NASA/JPL-Caltech).
Being that red dwarf stars are relatively common, could this ice-trap scenario be widespread as well?
“In short, yes,” Professor Menou said to Universe Today. “It also depends on the frequency of planets around such stars (indications suggest it is high) and on the total amount of water at the surface of the planet, which some formation models suggest should indeed be small, which would make this scenario more likely/relevant. It could, in principle, be the norm rather than the exception, although it remains to be seen.”
Of course, life under such conditions would face the unique challenges. The daytime side of the world would be subject to the tempestuous whims of its red dwarf host sun in the form of frequent radiation storms. The cold nighttime side would offer some respite from this, but finding a reliable source of energy on the permanently shrouded night side of such as world would be difficult, perhaps relying on chemosynthesis instead of solar-powered photosynthesis.
On Earth, life situated near “black smokers” or volcanic vents deep on the ocean floor where the Sun never shines do just that. One could also perhaps imagine life that finds a niche in the twilight regions of such a world, feeding on the detritus that circulates by.
Some of the closest red dwarf stars to our own solar system include Promixa Centauri, Barnard’s Star and Luyten’s Flare Star. Barnard’s star has been the target of searches for exoplanets for over a century due to its high proper motion, which have so far turned up naught.
The closest M-dwarf star with exoplanets discovered thus far is Gliese 674, at 14.8 light years distant. The current tally of extrasolar worlds as per the Extrasolar Planet Encyclopedia stands at 919.
Searching for and identifying ice-trapped worlds may prove to be a challenge. Such planets would exhibit a contrast in albedo, or brightness from one hemisphere to the other, but we would always see the ice-covered nighttime side in darkness. Still, exoplanet-hunting scientists have been able to tease out an amazing amount of information from the data available before- perhaps we’ll soon know if such planetary oases exist far inside the “snowline” orbiting around red dwarf stars.
Read the paper on Water-Trapped Worlds at the following link.
Artist's rendition of a Moon Base. Credit: John Spencer/Space Tourism Society.
In Star Trek lore, money doesn’t exist in the 24th century. But sometime in the 21st century, when we (hopefully) can go to a Bigelow orbiting space hotel or spend a weekend at a colony on the Moon, how are we going to pay for it? Global e-commerce company PayPal has a plan. They’ve teamed up with SETI and other space folks to launch PayPal Galactic, an initiative that PayPal says will address the issues to help make universal space payments a reality.
While this doesn’t seem to be an immediate need, PayPal wants to be ready … I presume. But as of this writing, the PayPal Galactic website doesn’t seem to be up and running yet.
The launch of PayPal Galactic is in conjunction with PayPal’s 15th anniversary, as well as a new crowdfunding campaign for SETI, called Curiosity Movement.
“PayPal and the SETI Institute are well-matched to work on PayPal Galactic because together we can create a recipe for innovation,” said Jill Tarter, from the SETI Institute. “PayPal envisions exploring possibilities in space the way that we do, breaking boundaries to make real progress. When the SETI Institute succeeds in its exploration of the universe, and as we find our place among the stars, PayPal will be there to facilitate commerce, so people can get what they need, and want, to live outside of our planet.”
Apollo 11’s Buzz Aldrin even was part of a webcast to launch PayPal Galactic.
“Trips to Mars, the moon, even orbit will require we provide astronauts and astro-tourists with as many comforts from home as possible, including how to pay each other,” said astronaut and author Buzz Aldrin, who is on-board with PayPal’s plans. “Whether it’s paying a bill, or even helping a family member on Earth, we’ll need access to money. I think humans will reach Mars, and I would like to see it happen in my lifetime. When that happens I won’t be surprised if people use PayPal Galactic for the little things and the big ones.”
PayPal’s President David Marcus (no, not THAT David Marcus from Star Trek) says that as space travel opens to ‘the rest of us’, this drives questions about the commercialization of space.
“We are launching PayPal Galactic, in conjunction with leaders in the scientific community, to increase public awareness of the important questions that need to be addressed,” he said in a press release. “We may not answer these questions today or even this year, but one thing is clear, we won’t be using cash in space. PayPal has already pushed payments onto the Internet, onto mobile phones and across terrestrial borders. We now look forward to pushing payments from our world to the next, and beyond.”
These are the questions PayPal hopes to answer:
• What will our standard currency look like in a truly cash-free interplanetary society?
• How will the banking systems have to adapt?
• How will risk and fraud management systems need to evolve?
• What regulations will we have to conform with?
• How will our customer support need to develop?
PayPal says this system could even help astronauts on the International Space Station be able to pay their bills back on Earth or be able to pay for e-books or online music.
But check out SETI’s Curiosity Movement, which hopes to “unite with curious thinkers across the globe in helping to expand our research and continue the search for answers on Earth and beyond.”
The Jamesburg Earth Station radio dish in Carmel, California will be used to send the Lone Signal messages to space. Image via Lone Signal.
Although scientists have been listening for years to search for indications of other sentient life in the Universe, just a few efforts have been made by humans to purposefully send out messages to the cosmos. Called METI (Messaging to Extraterrestrial Intelligence) or Active SETI (Search for Extraterrestrial Intelligence), these messages have so far been just one-time bursts of info – or “pulses in time” said Dr. Jacob Haqq-Misra.
Haqq-Misra is leading a team of scientists and entrepreneurs who are launching a new initiative called “Lone Signal” which will send the first continuous mass “hailing messages” out into space, starting later this month. They’ll be specifically targeting one star system, Gliese 526, which has been identified as a potentially habitable solar system.
And yes, the general public can participate.
“From the start we wanted to be an experiment where anyone on Earth could participate,” said Haqq-Misra during a press event on June 11, 2013, announcing the project.
“Our scientific goals are to discover sentient beings outside of our solar system,” said Lone Star co-founder Pierre Fabre, also speaking at the event. “But an important part of this project is to get people to look beyond themselves and their differences by thinking about what they would say to a different civilization. Lone Signal will allow people to do that.”
Lone Signal will be using the recommissioned radio dish at the Jamesburg Earth Station in Carmel, California, one of the dishes used to carry the Apollo Moon landings live to the world.
Timelapse of the Jamesburg Earth Station
Lone Signal will be sending two signals: one is a continuous wave (CW) signal, a hailing message that sends a slow binary broadcast to provide basic information about Earth and our Solar System using an encoding system created by astrophysicist and planetary scientist Michael W. Busch. The binary code is based on mathematical “first principles” which reflect established laws that, theoretically, are relatively constant throughout the universe; things like gravity and the structure of the hydrogen atom, etc.
“This hailing message is a language we think could be used to instigate communication,” said Haqq-Misra, “and is the most advanced binary coding currently in use.”
The second signal, embedded in the first signal, will be messages from the people of Earth.
Strength of various signals from Earth. Graph courtesy of Dr. Haqq-Misra.
Since Gliese 526 is 17.6 light years from Earth, the messages will be beamed to the coordinates of where the star will be in 17.6 years from now. Even though no planets have been found yet in this system, the Lone Signal team said they are confident planets exist there since missions like Kepler and Corot have found that most stars host multiple planets.
The Lone Signal team is allowing anyone with access to the internet to send the equivalent of one free text message or Twitter message — a 144-character text-based message — into space. The team said they want to have messages sent from people all around the world to provide messages that are “representative of humanity.”
Anything additional, like more messages, images, etc., will cost money, but those funds will help support the project.
“In effect we are doing our own Kickstarter and doing the crowdfunding on our own,” said Lone Signal CEO Jamie King. “Long Signal would not be possible without crowd sourcing support, which will be used for maintaining the millions of dollars in equipment, powering the dish, running the web portal and other critical tech that makes the project possible.”
If you want to be part of the project and be a “beamer” you can currently sign up at the Lone Signal website –which currently doesn’t have much information. But on June 18th their public site will go live and ‘beamers will be able to submit messages as well as:
• Share Beams / Track Beams – Once signed in, users can see how far their beam has traveled from Earth as well as share it with the beaming community.
• Dedicate Beams – Parents, friends and loved ones can dedicate a beam to others.
• Explore – The Explore section gives beamers current data on the Lone Signal beam, who is sending messages, from where on Earth, overall stats, etc.
• Blog / Twitter – Via their blog and Twitter, the Lone Signal science team and other contributors will be posting opinion articles on associated topics of interest as well as sharing the latest science news and updates.
One you submit your “beam” you’ll be able to “echo” it on your Facebook and Twitter accounts.
After a user sends their initial free message, Lone Signal will be offering paid credit packages for purchase that allow users to transmit and share longer messages as well as images using credits in the following USD price structure:
• $0.99 buys 4 credits.
• $4.99 buys 40 credits.
• $19.99 buys 400 credits.
• $99.99 buys 4000 credits.
Following the initial free message, each subsequent text-based message costs 1 credit. Image-based messages cost 3 credits.
The team said that each message will be sent as an individual packet of information and won’t be bunched with other messages.
While some scientists have indicated that sending messages out into space might pose a hazard by attracting unwanted attention from potentially aggressive extraterrestrial civilizations, Haqq-Misra thinks the benefits outweigh the potential hazards. In fact, he and his team have written a paper about the concept.
“We want to inspire passion for the space sciences in people young and old, encourage citizens of Earth to think about their role in the Universe, and inspire the next generation of scientists and astronauts,” said Lone Signal chief marketing officer Ernesto Qualizza. “We’re really excited to find out what people will want to say, and the science of METI allows people to do this – to think about more than their own backyard.”
