Extraterrestrial Archives

December 11, 2017December 19, 2017 by Matt Williams

Breakthrough Listen is Going to Scan ‘Oumuamua, You Know, Just to be Sure it’s Just an Asteroid and Not a Spaceship.

Artist’s impression of the first interstellar asteroid/comet, "Oumuamua". This unique object was discovered on 19 October 2017 by the Pan-STARRS 1 telescope in Hawaii. Credit: ESO/M. Kornmesser

On October 19th, 2017, the Panoramic Survey Telescope and Rapid Response System-1 (Pan-STARRS-1) in Hawaii announced the first-ever detection of an interstellar asteroid, named 1I/2017 U1 (aka. ‘Oumuamua). Based on subsequent measurements of its shape (highly elongated and thin), there was some speculation that it might actually be an interstellar spacecraft (the name “Rama” ring a bell?).

For this reason, there are those who would like to study this object before it heads back out into interstellar space. While groups like Project Lyra propose sending a mission to rendezvous with it, Breakthrough Initiatives (BI) also announced its plans to study the object using Breakthrough Listen. As part of its mission to search for extra-terrestrial communications, this project will use the Greenbank Radio Telescope to listen to ‘Oumuamua for signs of radio transmissions.

Observations of ‘Oumuamua’s orbit revealed that it made its closest pass to our Sun back in September of 2017, and has been on its way back to interstellar space ever since. When it was observed back in October, it was passing Earth at a distance of about 85 times the distance between Earth and the Moon, and was traveling at a peak velocity of about 315,430 km/h (196,000 mph).

This indicated that, unlike the many Near-Earth Objects (NEOs) that periodically cross Earth’s orbit, this asteroid was not gravitationally bound to the Sun. In November, astronomers using the ESO’s Very Large Telescope (VLT) at the Paranal Observatory in Chile were also able to determine the brightness and color of the asteroid, which allowed for precise calculations of its size and shape.

Basically, they determined that it was 400 meters (1312 ft) long and very narrow, indicating that it was shaped somewhat like a cigar. What’s more, the idea of a cigar or needle-shaped spacecraft is a time-honored concept when it comes to science fiction and space exploration. Such a ship would minimize friction and damage from interstellar gas and dust, and could rotate to provide artificial gravity.

For all of these reasons, it is understandable why some responded to news of this asteroid by making comparisons to a certain science fiction novel. That would be Arthur C. Clarke’s Rendezvous with Rama, a story of a cylindrical space ship that travels through the Solar System while on its way to another star. While a natural origin is the more likely scenario, there is no consensus on what the origin this object might be – other than the theory that it came from the direction of Vega.

Hence why Breakthrough Listen intends to explore ‘Oumuamua to determine whether it is truly an asteroid or an artifact. Established in January of 2016, Listen is the largest scientific research program aimed at finding evidence of extra-terrestrial intelligence with established SETI methods. These include using radio observatories to survey 1,000,000 of the closest stars (and 100 of the closest galaxies) to Earth over the course of ten years.

*Breakthrough Listen will monitor the 1 million closest stars to Earth over a ten year period. Credit: Breakthrough Initiatives*

Listen’s observation campaign will begin on Wednesday, December 13th, at 3:00 pm EST (12:00 PST), using the Greenbank Radio Telescope. This 100-meter telescope is the world’s premiere single-dish radio telescope and is capable of operating at millimeter and submillimeter wavelengths. It is also the mainstay of the NSF-funded Green Bank Observatory, located in West Virginia.

The first phase of observations will last a total of 10 hours, ranging from the 1 to 12 GHz bands, and will broken down into four “epochs” (based on the object’s rotational period). At present, ‘Oumuamua is about 2 astronomical units (AUs) – or 299,200,000 km; 185,900,000 mi – away from Earth, putting it at twice the distance between the Earth and the Sun. This places it well beyond the orbit of Mars, and over halfway between Mars and Jupiter.

At this distance, the Green Bank Telescope will take less than a minute to detect an omni-directional transmitter with the power of a cellphone. In other words, if there is a alien signal coming from this object, Breakthrough Listen is sure to sniff it out in no time! As Andrew Siemion, Director of Berkeley SETI Research Center and a member of Breakthrough Listen, explained in a BI press statement:

“‘Oumuamua’s presence within our solar system affords Breakthrough Listen an opportunity to reach unprecedented sensitivities to possible artificial transmitters and demonstrate our ability to track nearby, fast-moving objects. Whether this object turns out to be artificial or natural, it’s a great target for Listen.”

Even if there are no signals to be heard, and no other evidence of extra-terrestrial intelligence is detected, the observations themselves are a opportunity for scientists and the field of radio astronomy in general. The project will observe ‘Oumuamua in portions of the radio spectrum that it has not yet been observed at, and is expected to yield information about the possibility of water ice or the presence of a “coma” (i.e. gaseous envelop) around the object.

During the previous survey, data gathered using the VLT’s FOcal Reducer and low dispersion Spectrograph (FORS) indicated that ‘Oumuamua was likely a dense and rocky asteroid with a high metal content and little in the way of water ice. Updated information provided by the Greenbank Telescope could therefore confirm or cast doubt on this, thus reopening the possibility that it is actually a comet.

Regardless of what it finds, this survey is likely to be a feather in the cap of Breakthrough Listen, which already demonstrated it’s worth in terms of non-SETI astronomy this past summer. At that time, and using the Green Bank Radio Telescope, the Listen science team at UC Berkeley observed 15 Fast Radio Bursts (FRBs) for the fist time coming from a dwarf galaxy three billion light-years from Earth.

Still, I think we can all agree that an extra-terrestrial spaceship would be the most exciting possibility (and perhaps the most frightening!). And it is very safe to say that some of us will be awaiting the results of the survey with baited breath. Luckily, we’ll only have to wait two more days to see if humanity is still alone in the Universe or not! Stay tuned!

Further Reading: Breakthrough Initiatives

December 3, 2017December 3, 2017 by Matt Williams

There Could be Hundreds More Icy Worlds with Life Than on Rocky Planets Out There in the Galaxy

The moons of Europa and Enceladus, as imaged by the Galileo and Cassini spacecraft. Credit: NASA/ESA/JPL-Caltech/SETI Institute

In the hunt for extra-terrestrial life, scientists tend to take what is known as the “low-hanging fruit approach”. This consists of looking for conditions similar to what we experience here on Earth, which include at oxygen, organic molecules, and plenty of liquid water. Interestingly enough, some of the places where these ingredients are present in abundance include the interiors of icy moons like Europa, Ganymede, Enceladus and Titan.

Whereas there is only one terrestrial planet in our Solar System that is capable of supporting life (Earth), there are multiple “Ocean Worlds” like these moons. Taking this a step further, a team of researchers from the Harvard Smithsonian Center for Astrophysics (CfA) conducted a study that showed how potentially-habitable icy moons with interior oceans are far more likely than terrestrial planets in the Universe.

The study, titled “Subsurface Exolife“, was performed by Manasvi Lingam and Abraham Loeb of the Harvard Smithsonain Center for Astrophysics (CfA) and the Institute for Theory and Computation (ITC) at Harvard University. For the sake of their study, the authors consider all that what defines a circumstellar habitable zone (aka. “Goldilocks Zone“) and likelihood of there being life inside moons with interior oceans.

*Cutaway showing the interior of Saturn’s moon Enceladus. Credit: ESA*

To begin, Lingam and Loeb address the tendency to confuse habitable zones (HZs) with habitability, or to treat the two concepts as interchangeable. For instance, planets that are located within an HZ are not necessarily capable of supporting life – in this respect, Mars and Venus are perfect examples. Whereas Mars is too cold and it’s atmosphere too thin to support life, Venus suffered a runaway greenhouse effect that caused it to become a hot, hellish place.

On the other hand, bodies that are located beyond HZs have been found to be capable of having liquid water and the necessary ingredients to give rise to life. In this case, the moons of Europa, Ganymede, Enceladus, Dione, Titan, and several others serve as perfect examples. Thanks to the prevalence of water and geothermal heating caused by tidal forces, these moons all have interior oceans that could very well support life.

As Lingam, a post-doctoral researcher at the ITC and CfA and the lead author on the study, told Universe Today via email:

“The conventional notion of planetary habitability is the habitable zone (HZ), namely the concept that the “planet” must be situated at the right distance from the star such that it may be capable of having liquid water on its surface. However, this definition assumes that life is: (a) surface-based, (b) on a planet orbiting a star, and (c) based on liquid water (as the solvent) and carbon compounds. In contrast, our work relaxes assumptions (a) and (b), although we still retain (c).”

As such, Lingam and Loeb widen their consideration of habitability to include worlds that could have subsurface biospheres. Such environments go beyond icy moons such as Europa and Enceladus and could include many other types deep subterranean environments. On top of that, it has also been speculated that life could exist in Titan’s methane lakes (i.e. methanogenic organisms). However, Lingam and Loeb chose to focus on icy moons instead.

*A “true color” image of the surface of Jupiter’s moon Europa as seen by the Galileo spacecraft. Image credit: NASA/JPL-Caltech/SETI Institute*

“Even though we consider life in subsurface oceans under ice/rock envelopes, life could also exist in hydrated rocks (i.e. with water) beneath the surface; the latter is sometimes referred to as subterranean life,” said Lingam. “We did not delve into the second possibility since many of the conclusions (but not all of them) for subsurface oceans are also applicable to these worlds. Similarly, as noted above, we do not consider lifeforms based on exotic chemistries and solvents, since it is not easy to predict their properties.”

Ultimately, Lingam and Loeb chose to focus on worlds that would orbit stars and likely contain subsurface life humanity would be capable of recognizing. They then went about assessing the likelihood that such bodies are habitable, what advantages and challenges life will have to deal with in these environments, and the likelihood of such worlds existing beyond our Solar System (compared to potentially-habitable terrestrial planets).

For starters, “Ocean Worlds” have several advantages when it comes to supporting life. Within the Jovian system (Jupiter and its moons) radiation is a major problem, which is the result of charged particles becoming trapped in the gas giants powerful magnetic field. Between that and the moon’s tenuous atmospheres, life would have a very hard time surviving on the surface, but life dwelling beneath the ice would fare far better.

“One major advantage that icy worlds have is that the subsurface oceans are mostly sealed off from the surface,” said Lingam. “Hence, UV radiation and cosmic rays (energetic particles), which are typically detrimental to surface-based life in high doses, are unlikely to affect putative life in these subsurface oceans.”

Artist rendering showing an interior cross-section of the crust of Enceladus, which shows how hydrothermal activity may be causing the plumes of water at the moon’s surface. Credits: NASA-GSFC/SVS, NASA/JPL-Caltech/Southwest Research Institute

“On the negative side,’ he continued, “the absence of sunlight as a plentiful energy source could lead to a biosphere that has far less organisms (per unit volume) than Earth. In addition, most organisms in these biospheres are likely to be microbial, and the probability of complex life evolving may be low compared to Earth. Another issue is the potential availability of nutrients (e.g. phosphorus) necessary for life; we suggest that these nutrients might be available only in lower concentrations than Earth on these worlds.”

In the end, Lingam and Loeb determined that a wide range of worlds with ice shells of moderate thickness may exist in a wide range of habitats throughout the cosmos. Based on how statistically likely such worlds are, they concluded that “Ocean Worlds” like Europa, Enceladus, and others like them are about 1000 times more common than rocky planets that exist within the HZs of stars.

These findings have some drastic implications for the search for extra-terrestrial and extra-solar life. It also has significant implications for how life may be distributed through the Universe. As Lingam summarized:

“We conclude that life on these worlds will undoubtedly face noteworthy challenges. However, on the other hand, there is no definitive factor that prevents life (especially microbial life) from evolving on these planets and moons. In terms of panspermia, we considered the possibility that a free-floating planet containing subsurface exolife could be temporarily “captured” by a star, and that it may perhaps seed other planets (orbiting that star) with life. As there are many variables involved, not all of them can be quantified accurately.”

Exogenesis — A new instrument called the Search for Extra-Terrestrial Genomes (STEG)
is being developed to find evidence of life on other worlds. Credit: NASA/Jenny Mottor

Professor Leob – the Frank B. Baird Jr. Professor of Science at Harvard University, the director of the ITC, and the study’s co-author – added that finding examples of this life presents its own share of challenges. As he told Universe Today via email:

“It is very difficult to detect sub-surface life remotely (from a large distance) using telescopes. One could search for excess heat but that can result from natural sources, such as volcanos. The most reliable way to find sub-surface life is to land on such a planet or moon and drill through the surface ice sheet. This is the approach contemplated for a future NASA mission to Europa in the solar system.”

Exploring the implications for panspermia further, Lingam and Loeb also considered what might happen if a planet like Earth were ever ejected from the Solar System. As they note in their study, previous research has indicated how planets with thick atmospheres or subsurface oceans could still support life while floating in interstellar space. As Loeb explained, they also considered what would happen if this ever happened with Earth someday:

“An interesting question is what would happen to the Earth if it was ejected from the solar system into cold space without being warmed by the Sun. We have found that the oceans would freeze down to a depth of 4.4 kilometers but pockets of liquid water would survive in the deepest regions of the Earth’s ocean, such as the Mariana Trench, and life could survive in these remaining sub-surface lakes. This implies that sub-surface life could be transferred between planetary systems.”

This study also serves as a reminder that as humanity explores more of the Solar System (largely for the sake of finding extra-terrestrial life) what we find also has implications in the hunt for life in the rest of the Universe. This is one of the benefits of the “low-hanging fruit” approach. What we don’t know is informed but what we do, and what we find helps inform our expectations of what else we might find.

And of course, it’s a very vast Universe out there. What we may find is likely to go far beyond what we are currently capable of recognizing!

Further Reading: arXiv

November 10, 2017 by Matt Williams

Life on Mars can Survive for Millions of Years Even Right Near the Surface

Researchers from Lomonosov MSU, Faculty of Soil Science, have studied the resistance microorganisms have against gamma radiation in very low temperatures. Credit: YONHAP/EPA

Mars is not exactly a friendly place for life as we know it. While temperatures at the equator can reach as high as a balmy 35 °C (95 °F) in the summer at midday, the average temperature on the surface is -63 °C (-82 °F), and can reach as low as -143 °C (-226 °F) during winter in the polar regions. Its atmospheric pressure is about one-half of one percent of Earth’s, and the surface is exposed to a considerable amount of radiation.

Until now, no one was certain if microorganisms could survive in this extreme environment. But thanks to a new study by a team of researchers from the Lomonosov Moscow State University (LMSU), we may now be able to place constraints on what kinds of conditions microorganisms can withstand. This study could therefore have significant implications in the hunt for life elsewhere in the Solar System, and maybe even beyond!

The study, titled “100 kGy gamma-affected microbial communities within the ancient Arctic permafrost under simulated Martian conditions“, recently appeared in the scientific journal Extremophiles. The research team, which was led by Vladimir S. Cheptsov of LMSU, included members from the Russian Academy of Sciences, St. Petersburg State Polytechnical University, the Kurchatov Institute and Ural Federal University.

*Image taken by the Viking 1 orbiter in June 1976, showing Mars thin atmosphere and dusty, red surface. Credits: NASA/Viking 1*

For the sake of their study, the research team hypothesized that temperature and pressure conditions would not be the mitigating factors, but rather radiation. As such, they conducted tests where microbial communities contained within simulated Martian regolith were then irradiated. The simulated regolith consisted of sedimentary rocks that contained permafrost, which were then subjected to low temperature and low pressure conditions.

As Vladimir S. Cheptsov, a post-graduate student at the Lomonosov MSU Department of Soil Biology and a co-author on the paper, explained in a LMSU press statement:

“We have studied the joint impact of a number of physical factors (gamma radiation, low pressure, low temperature) on the microbial communities within ancient Arctic permafrost. We also studied a unique nature-made object—the ancient permafrost that has not melted for about 2 million years. In a nutshell, we have conducted a simulation experiment that covered the conditions of cryo-conservation in Martian regolith. It is also important that in this paper, we studied the effect of high doses (100 kGy) of gamma radiation on prokaryotes’ vitality, while in previous studies no living prokaryotes were ever found after doses higher than 80 kGy.”

To simulate Martian conditions, the team used an original constant climate chamber, which maintained the low temperature and atmospheric pressure. They then exposed the microorganisms to varying levels of gamma radiation. What they found was that the microbial communities showed high resistance to the temperature and pressure conditions in the simulated Martian environment.

Spirit Embedded in Soft Soil on Mars — *Image of Martian soils, where the Spirit mission embedded itself. Credit: NASA/JPL*

However, after they began irradiating the microbes, they noticed several differences between the irradiated sample and the control sample. Whereas the total count of prokaryotic cells and the number of metabolically active bacterial cells remained consistent with control levels, the number of irradiated bacteria decreased by two orders of magnitude while the number of metabolically active cells of archaea also decreased threefold.

The team also noticed that within the exposed sample of permafrost, there was a high biodiversity of bacteria, and this bacteria underwent a significant structural change after it was irradiated. For instance, populations of actinobacteria like Arthrobacter – a common genus found in soil – were not present in the control samples, but became predominant in the bacterial communities that were exposed.

In short, these results indicated that microorganisms on Mars are more survivable than previously thought. In addition to being able to survive the cold temperatures and low atmospheric pressure, they are also capable of surviving the kinds of radiation conditions that are common on the surface. As Cheptsov explained:

“The results of the study indicate the possibility of prolonged cryo-conservation of viable microorganisms in the Martian regolith. The intensity of ionizing radiation on the surface of Mars is 0.05-0.076 Gy/year and decreases with depth. Taking into account the intensity of radiation in the Mars regolith, the data obtained makes it possible to assume that hypothetical Mars ecosystems could be conserved in an anabiotic state in the surface layer of regolith (protected from UV rays) for at least 1.3 million years, at a depth of two meters for no less than 3.3 million years, and at a depth of five meters for at least 20 million years. The data obtained can also be applied to assess the possibility of detecting viable microorganisms on other objects of the solar system and within small bodies in outer space.”

*Future missions could determine the presence of past life on Mars by looking for signs of extreme bacteria. Credit: NASA.*

This study was significant for multiple reasons. On the one hand, the authors were able to prove for the first time that prokaryote bacteria can survive radiation does in excess of 80 kGy – something which was previously thought to be impossible. They also demonstrated that despite its tough conditions, microorganisms could still be alive on Mars today, preserved in its permafrost and soil.

The study also demonstrates the importance of considering both extraterrestrial and cosmic factors when considering where and under what conditions living organisms can survive. Last, but not least, this study has done something no previous study has, which is define the limits of radiation resistance for microorganisms on Mars – specifically within regolith and at various depths.

This information will be invaluable for future missions to Mars and other locations in the Solar System, and perhaps even with the study of exoplanets. Knowing the kind of conditions in which life will thrive will help us to determine where to look for signs of it. And when preparing missions to other words, it will also let scientists know what locations to avoid so that contamination of indigenous ecosystems can be prevented.

Further Reading: Lomonsonov Moscow State University, Extremophiles

October 12, 2017October 12, 2017 by Matt Williams

Ancient Hydrothermal Vents Found on Mars, Could Have Been a Cradle for Life

MOLA topographic data, colorized to show the maximum (1,100?m) and minimum (700?m) level of an ancient sea. Credit: NASA/Joseph R. Michalski (et al.)/Nature Communications

It is now a well-understood fact that Mars once had quite a bit of liquid water on its surface. In fact, according to a recent estimate, a large sea in Mars’ southern hemisphere once held almost 10 times as much water as all of North America’s Great Lakes combined. This sea existed roughly 3.7 billion years ago, and was located in the region known today as the Eridania basin.

However, a new study based on data from NASA’s Mars Reconnaissance Orbiter (MRO) detected vast mineral deposits at the bottom of this basin, which could be seen as evidence of ancient hot springs. Since this type of hydrothermal activity is believed to be responsible for the emergence of life on Earth, these results could indicate that this basin once hosted life as well.

The study, titled “Ancient Hydrothermal Seafloor Deposits in Eridania Basin on Mars“, recently appeared in the scientific journal Nature Communications. The study was led by Joseph Michalski of the Department of Earth Sciences and Laboratory for Space Research at the University of Hong Kong, along with researchers from the Planetary Science Institute, the Natural History Museum in London, and NASA’s Johnson Space Center.

*The Eridania basin of southern Mars is believed to have held a sea about 3.7 billion years ago, with seafloor deposits likely resulting from underwater hydrothermal activity. Credit: NASA*

Together, this international team used data obtained by the MRO’s Compact Reconnaissance Spectrometer for Mars (CRISM). Since the MRO reached Mars in 2006, this instrument has been used extensively to search for evidence of mineral residues that form in the presence of water. In this respect, CRISM was essential for documenting how lakes, ponds and rivers once existed on the surface of Mars.

In this case, it identified massive mineral deposits within Mars’ Eridania basin, which lies in a region that has some of the Red Planet’s most ancient exposed crust. The discovery is expected to be a major focal point for scientists seeking to characterize Mars’ once-warm and wet environment. As Paul Niles of NASA’s Johnson Space Center said in a recent NASA press statement:

“Even if we never find evidence that there’s been life on Mars, this site can tell us about the type of environment where life may have begun on Earth. Volcanic activity combined with standing water provided conditions that were likely similar to conditions that existed on Earth at about the same time — when early life was evolving here.”

Today, Mars is a cold, dry place that experiences no volcanic activity. But roughly 3.7 billion years ago, the situation was vastly different. At that time, Mars boasted both flowing and standing bodies of water, which are evidenced by vast fluvial deposits and sedimentary basins. The Gale Crater is a perfect example of this since it was once a major lake bed, which is why it was selected as the landing sight for the Curiosity rover in 2012.

*Illustrates showing the origin of some deposits in the Eridania basin of southern Mars resulting from seafloor hydrothermal activity more than 3 billion years ago. Credit: NASA*

Since Mars had both surface water and volcanic activity during this time, it would have also experienced hydrothermal activity. This occurs when volcanic vents open into standing bodies of water, filling them with hydrated minerals and heat. On Earth, which still has an active crust, evidence of past hydrothermal activity cannot be preserved. But on Mars, where the crust is solid and erosion is minimal, the evidence has been preserved.

“This site gives us a compelling story for a deep, long-lived sea and a deep-sea hydrothermal environment,” Niles said. “It is evocative of the deep-sea hydrothermal environments on Earth, similar to environments where life might be found on other worlds — life that doesn’t need a nice atmosphere or temperate surface, but just rocks, heat and water.”

Based on their study, the researchers estimate that the Eridania basin once held about 210,000 cubic km (50,000 cubic mi) of water. Not only is this nine times more water than all of the Great Lakes combined, it is as much as all the other lakes and seas on ancient Mars combined. In addition, the region also experienced lava flows that existed after the sea is believed to have disappeared.

From the CRISM’s spectrometer data, the team identified deposits of serpentine, talc and carbonate. Combined with the shape and texture of the bedrock layers, they concluded that the sea floor was open to volcanic fissures. Beyond indicating that this region could have once hosted life, this study also adds to the diversity of the wet environments which are once believed to have existed on Mars.

A scale model compares the volume of water contained in lakes and seas on the Earth and Mars to the estimated volume of water contained in an ancient Eridania sea. Credit: JJoseph R. Michalski (et al.)/Nature Communications

Between evidence of ancient lakes, rivers, groundwater, deltas, seas, and volcanic eruptions beneath ice, scientists now have evidence of volcanic activity that occurred beneath a standing body of water (aka. hot springs) on Mars. This also represents a new category for astrobiological research, and a possible destination for future missions to the Martian surface.

The study of hydrothermal activity is also significant as far as finding sources of extra-terrestrial, like on the moons of Europa, Enceladus, Titan, and elsewhere. In the future, robotic missions are expected to travel to these worlds in order to peak beneath their icy surfaces, investigate their plumes, or venture into their seas (in Titan’s case) to look for the telltale traces of basic life forms.

The study also has significance beyond Mars and could aid in the study of how life began here on Earth. At present, the earliest evidence of terrestrial life comes from seafloor deposits that are similar in origin and age to those found in the Eridania basin. But since the geological record of this period on Earth is poorly preserved, it has been impossible to determine exactly what conditions were like at this time.

Given Mars’ similarities with Earth, and the fact that its geological record has been well-preserved over the past 3 billion years, scientists can look to mineral deposits and other evidence to gauge how natural processes here on Earth allowed for life to form and evolve over time. It could also advance our understanding of how all the terrestrial planets of the Solar System evolved over billions of years.

Further Reading: NASA

August 30, 2017September 1, 2017 by Matt Williams

Breakthrough Detects Repeating Fast Radio Bursts Coming from Distant Galaxy

The Karl G. Jansky Very Large Array, located in central New Mexico. Credit: NRAO

In July of 2015, Russian billionaire Yuri Milner announced the creation of Breakthrough Listen, a decade-long project that would conduct the largest survey to date for signs of extra-terrestrial communications (ETI). As part of his non-profit organization, Breakthrough Initiatives, this survey would rely on the latest in instrumentation and software to observe the 1,000,000 closest stars and 100 closest galaxies.

Using the Green Bank Radio Telescope in West Virginia, the Listen science team at UC Berkeley has been observing distant stars for over a year now. And less than a week ago, they observed 15 Fast Radio Bursts (FRBs) coming from a dwarf galaxy located three billion light-years away. According to a study that described their findings, this was the first time that repeating FRBs have been seen coming from this source at these frequencies.

The team’s study, titled “FRB 121102: Detection at 4 – 8 GHz band with Breakthrough Listen backend at Green Bank“, was recently published in The Astronomers Telegraph. Led by Dr. Vishal Gajjar – a postdoctoral researcher at the University of California, Berkeley – the team conducted a detailed survey of FRB 121102. This repeating FRB source is located in a dwarf galaxy in Auriga constellation, some 3 billion light-years from Earth.

*The NSF’s Arecibo Observatory, which is located in Puerto Rico, is the world largest radio telescope. Credit: NAIC*

To clarify, FRBs are brief, bright pulses of radio waves that are periodically detected coming from distant galaxies. This strange astronomical phenomena was first detected in 2007 by Duncan Lorimer and David Narkovic using the Parkes Telescope in Australia. To honor their discovery, FRBs are sometimes referred to as “Lorimer Bursts”. Many FRB sources have been confirmed since then, some of which were found repeating.

The source known as FRB 121101 was discovered back on November 2nd, 2012, by astronomers using the Arecibo radio telescope. At the time, it was the first FRB to be discovered; and by 2015, it became the first FRB to be seen repeating. This effectively ruled out the possibility that repeating FRBs were caused by catastrophic events, which had previously been theorized.

And in 2016, FRB 121102 was the first FRB to have its location pinpointed to such a degree that its host galaxy could be identified. As such, the Listen science team at UC Berkeley was sure to add FRB 121102 to their list of targets. And in the early hours of Saturday, August 26th, Dr. Vishal Gajjar – a postdoctoral researcher at UC Berkeley – observed FRB 121102 using the Green Bank Radio Telescope (GBRT) in West Virginia.

Using the Digital Backend instrument on the GBRT, Dr. Gajjar and the Listen team observed FRB 121102 for five hours. From this, they accumulating 400 terabytes of data in the entire 4 to 8 GHz frequency band which they then analyzed for signs of short pulses over a broad range of frequencies. What they found was evidence of 15 new pulses coming from FRB 121102, which confirmed that it was in a newly active state.

*The Green Bank Telescope, located in West Virginia. Credit: NRAO*

In addition, their observations revealed that the brightest of these 15 emissions occurred at around 7 GHz. This was higher than any repeating FRBs seen to date, which indicated for the first time that they can occur at frequencies higher than previously thought. Last, but not least, the high-resolution data the Listen team collected is expected to yield valuable insights into FRBs for years to come.

This was made possible thanks to the Digital Backend instrument on the GBRT, which is able to record several GHz of bandwidth simultaneously and split the information into billions of individuals channels. This enables scientists to study the proprieties and the frequency spectrum of FRBs with greater precision, and should lead to new theories about the causes of these radio emissions.

So even if these particular signals should prove to not be an indication of extra-terrestrial intelligence, Listen is still pushing the boundaries of what is possible with radio astronomy. And given that Breakthrough Listen is less than two years into its proposed ten-year survey, we can expect many more sources to be observed and studied in the coming years. If there’s evidence of ETI to be found, we’re sure to find out about it sooner or later!

And be sure to check out this video of the Green Bank Telescope and the surveys it allows for, courtesy of Berkeley SETI:

Further Reading: Breakthrough Initiatives

July 20, 2017April 14, 2020 by Matt Williams

Advanced Civilizations Could Build a Galactic Internet with Planetary Transits

In a series of papers, Professor Loeb and Michael Hippke indicate that conventional rockets would have a hard time escaping from certain kinds of extra-solar planets. Credit: NASA/Tim Pyle

Decades after Enrico Fermi’s uttered his famous words – “Where is everybody?” – the Paradox that bears his name still haunts us. Despite repeated attempts to locate radio signals coming from space and our ongoing efforts to find visible indications of alien civilizations in distant star systems, the search extra-terrestrial intelligence (SETI) has yet to produce anything substantive.

June 13, 2017April 14, 2020 by Matt Williams

What is the Drake Equation?

Is there life out there in the Universe? That is a question that has plagued humanity long before we knew just how vast the Universe was – i.e. before the advent of modern astronomy. Within the 20th century – thanks to the development of modern telescopes, radio astronomy, and space observatories – multiple efforts have been made in the hopes of finding extraterrestrial intelligence (ETI).

June 6, 2017August 28, 2020 by Matt Williams

Maybe the Aliens Aren’t Hiding, they’re Sleeping, Waiting for the Universe to Get Better

A new study has offered a new take on the Fermi Paradox - alien civilizations are not visible to us because they are sleeping. Credit and Copyright: Kevin M. Gill

When you consider that age of the Universe – 13.8 billion years by our most recent counts – and that which is “observable” to us measures about 93 billion light-years in diameter, you begin to wonder why we haven’t found signs of extra-terrestrial intelligence (ETI) beyond our Solar System. To paraphrase Enrico Fermi, the 20th-century physicists who advanced the famous Fermi Paradox – “where the heck are all the aliens?”

Naturally, Fermi’s Paradox has attracted a lot of theoretical explanations over the years – which include ETI being very rare, humanity being early to the Universe, and the aliens being extinct! But a new study by a team of scientists from the Future of Humanity Institute (FHI) offers a different take on this age-old paradox. According to their study, the key to answering this question is to consider the possibility that the aliens are engaged in “aestivation”.

June 1, 2017June 1, 2017 by Matt Williams

Are Aliens Communicating with Neutrino Beams?

One of the Daya Bay detectors. Roy Kaltschmidt, Lawrence Berkeley National Laboratory

It is no easy thing to search for signs of intelligent life beyond our Solar System. In addition to the incredible distances involved and the fact that we really only have indirect methods at our disposal, there is also the small problem of not knowing exactly what to look for. If intelligent life does exist beyond our Solar System, would they even communicate as we do, using radio transmitters and similar forms of technology?

Such has been the preoccupation of groups like the Search for Extra Terrestrial Intelligence (SETI) Institute and, more recently, organizations like Messaging Extraterrestrial Intelligence (METI) International. A non-profit dedicated to communicating with extra-terrestrial intelligence (ETI), the organization recently suggested that looking for neutrinos and other exotic particles could help us find signals as well.

First, some clarification should be made as to what SETI and METI are all about it and what sets them apart. The term METI was coined by Russian scientist Alexander Zaitsev, who sought to draw a distinction between SETI and METI. As he explained in a 2006 paper on the subject:

“The science known as SETI deals with searching for messages from aliens. METI science deals with the creation of messages to aliens. Thus, SETI and METI proponents have quite different perspectives. SETI scientists are in a position to address only the local question “does Active SETI make sense?” In other words, would it be reasonable, for SETI success, to transmit with the object of attracting ETI’s attention? In contrast to Active SETI, METI pursues not a local and lucrative impulse, but a more global and unselfish one – to overcome the Great Silence in the Universe, bringing to our extraterrestrial neighbors the long-expected annunciation ‘You are not alone!'”

*One of the 42 dishes in the Allen Telescope Array that searches for signals from space. Credit: Seth Shostak/SETI Institute.*

In short, METI looks for ways in which we might be able to contact aliens instead of waiting to hear from them. However, this does not mean that organizations like METI International are without ideas on how me might better listen to our (potential) alien neighbors. After all, communication goes beyond mere messages, and also requires that a medium exist with which to convey the message.

Such is the recommendation put forth by Dr. Morris Jones, a space analyst and writer who serves on the METI advisory council. In a recent article published on METI International’s website, he addressed the two main challenges when it comes to looking for ETI. On the one hand, you have the need for multiple methodologies to increase the odds of finding something. But as he indicates, there’s also the problem of knowing what to look for:

“We are not really sure of how extraterrestrials would communicate with us. Would they use radio waves, lasers, or something more exotic? Perhaps the universe is awash in extraterrestrial signals that we cannot even receive. SETI and METI practitioners spend a lot of time wondering how a message would be encoded in terms of language and content. It’s also important to consider the medium of transmission.”

In the past, says Jones, SETI searches were based on radio astronomy because that was the only practical means of doing so. Since then, efforts have expanded to include optical telescopes and the search for laser signals. This is due to the fact that in the past few decades, human beings have developed the technology to use laser for the sake of communications.

An artist’s illustration of a light-sail powered by a radio beam (red) generated on the surface of a planet. Could the part of the beam that misses the sail be our mysterious Fast Radio Bursts? Image Credit: M. Weiss/CfA

In a 2016 SETI paper, Dr. Philip Lubin of the University of California, Santa Barbara, explained how the development of directed-energy propulsion could help us search for evidence of aliens. As one of the scientific minds behind Breakthrough Starshot – a laser-driven lightsail that would be fast enough to make the trip to Alpha Centauri in just 20 years – he believes it’s a safe bet that ETI could be using similar technology to travel or communicate.

In addition, Dr. Avi Loeb from the Harvard-Smithsonian Center for Astrophysics (also one of the minds behind Starshot) has also suggested that fast-radio bursts (FRBs) could be evidence of alien activity. FRBs have been a subject of fascination to scientists since they were first detected in 2007 (the “Lorimer Burst“), and could also be a sign of alien communications or a means of propulsion.

Another means involves searching for artefacts – i.e. looking for evidence of physical infrastructure in other star systems. Case in point, since 2015, astronomers have been seeking to determine what is responsible for the periodic dimming of KIC 8462852 (aka. Tabby’s Star). Whereas most studies have sought to explain this in terms of natural causes, others have suggested it could be evidence of an alien megastructure.

To this array of search methods, Dr. Jones offers a few other possibilities. One way is to look for neutrinos, a type of subatomic particle that is produced by the decay of radioactive elements and interacts with matter very weakly. This allows them to pass through solid matter and also makes them very difficult to detect. Neutrinos are produced in large quantities by our Sun and astronomical sources, but they can also be produced artificially by nuclear reactors.

*Ever since it was first announced in 2015, there has been speculation as to what could account for the dimming of KIC 8462852. Credit: SentientDevelopments.com*

These, claims Jones, could be used for the sake of communications. The only problem is that looking for them would require some specialized equipment. Currently, all means of detecting neutrinos involve expensive facilities that have to be built either underground or in extremely isolated locations to ensure that they are not subject to any kind of electromagnetic interference.

These include the Super-Kamiokande facility, the world’s largest neutrino detector which is located under Mt. Ikeno in Japan. There’s also the IceCube Neutrino Observatory, located at the Amundsen–Scott South Pole Station in Antarctica and operated by the University of Wisconsin–Madison; and the Sudbury Neutrino Observatory, located in a former mine complex near Sudbury, Ontario, and operated by SNOLAB.

Another possibility is searching for evidence of communications that rely on gravitational waves. Predicted by Einstein’s Theory of General Relativity, the first detection of these mysterious waves was first made in February 2016. And in the coming years and decades, it is expected that gravitational wave observatories will be established so the presence of these “ripples” in spacetime can be visualized.

However, compared to neutrinos, Jones admits that this seems like a long shot. “It’s hard to conceive with our current grasp of physics,” he writes. “They are extremely difficult to generate at a detectable level. You would need abilities similar to those of superheroes, and be able to smash neutron stars and black holes together at will. There are probably easier ways to get a message across the stars.”

Beyond these, there is the even more exotic possibility of “Zeta Rays”, which Dr. Jones is not prepared to rule out. Basically, “Zeta Rays” is a term used by physicists to describe physics that go beyond the Standard Model. As scientists are currently looking for evidence of new particles with the Large Hadron Collider and other particle accelerators, it stands to reason that anything they discover will be the added to the SETI and METI search manifest.

But could such physics entail new forms of communication? Hard to say, but definitely worth considering. After all, the physics that power our current technology certainly existed before we did. Or as Jones put it:,

“Is it possible to transmit with something better than we already have? Until we know a lot more physics, we just won’t know. Humanity in the twenty-first century could be like an isolated tribe in the Amazon jungle a century ago, unaware that the air around them was filled with radio signals. SETI uses the science and technology provided to us by other disciplines. Thus, we must wait until physics itself makes some more major breakthroughs. Only then can we consider such exotic methods of searching. We think a lot about the message. But we should also think about the medium.”

Other projects that are dedicated to METI include Breakthrough Listen, a ten-year initiative launched by Breakthrough Initiatives to conduct the largest survey to date for extraterrestrial communications – encompassing the 1,000,000 closest stars and 100 closest galaxies. Back in April of 2017, the scientists behind this project shared their analysis of the first year of Listen data. No definitive results have been announced yet, but they are just getting started!

Ever since Drake proposed his famous equation, human beings have eagerly sought to find evidence of extra-terrestrial intelligence. Unfortunately, all of our efforts have been haunted by Fermi’s equally-famous paradox! But of course, as space exploration goes, we’ve really only begun to scratch the surface of our Universe. And the only way we can ever expect to find evidence of intelligent life out there is to keep looking.

And with greater knowledge and increasingly sophisticated methods at our disposal, we can be sure that if intelligent life is out there somewhere, we will find it eventually. One can always hope, right? And be sure to check out this video of Dr. Jones 2014 presentation at the SETI Institute, titled “A Journalistic Perspective on SETI-Related Message Composition“:

Further Reading: METI

May 20, 2017October 26, 2019 by Matt Williams

The Star That Probably Doesn’t Have an Alien Megastructure (But Maybe it Does) is Dimming Again

Artist's concept of KIC 8462852, which has experienced unusual changes in luminosity over the past few years. Credit: NASA, JPL-Caltech

In September of 2015, scientists announced that the star known as KIC 8462852 (aka. “Tabby’s Star” or “Boyajian’s Star”) was experiencing a strange dip in luminosity. At the time, astronomers indicated that this mysterious behavior could be the result of comets transiting in front of the star, but other (perhaps more hopeful) individuals claimed that it could also be the result of an alien megastructure.

This led to a flurry of studies and articles that sought to offer entirely natural explanations for what has been observed. Even SETI weighed in, indicating that they would begin searching for indications of radio signals coming this mysterious star. But after two years and multiple studies that offer explanations other an alien Dyson Sphere (or some other type of megastructure), the star is at it again! Continue reading “The Star That Probably Doesn’t Have an Alien Megastructure (But Maybe it Does) is Dimming Again”