Matt Williams, Author at Universe Today

November 15, 2017 by Matt Williams

Closest Potentially-Habitable World Found Around “Quiet” Star

This artist's impression shows the temperate planet Ross 128 b, with its red dwarf parent star in the background. Credit: ESO/M. Kornmesser

In August of 2016, the European Southern Observatory (ESO) announced the discovery of a terrestrial (i.e. rocky) extra-solar planet orbiting within the habitable zone of the nearby Proxima Centauri star system, just 4.25 light-years away. Naturally, news of this was met with a great deal of excitement. This was followed about six months later with the announcement of a seven-planet system orbiting the nearby star of TRAPPIST-1.

Well buckle up, because the ESO just announced that there is another potentially-habitable planet in our stellar neighborhood! Like Proxima b, this exoplanet – known as Ross 128b – is relatively close to our Solar System (10.8 light years away) and is believed to be temperate in nature. But on top of that, this rocky planet has the added benefit of orbiting a quiet red dwarf star, which boosts the likelihood of it being habitable.

The discovery paper, titled “A temperate exo-Earth around a quiet M dwarf at 3.4 parsecs“, was recently released by the ESO. The discovery team was led by Xavier Bonfils of the University of Grenoble Alpes, and included members from the Geneva Observatory, the National Scientific and Technical Research Council (CONICET), the University of Buenos Aires, the University of Laguna, the Instituto de Astrofísica de Canarias (IAC), and the University of Porto.

The discovery was made using the ESO’s High Accuracy Radial velocity Planet Searcher (HARPS), located at the La Silla Observatory in Chile. This observatory relies on measurements of a star’s Doppler shift in order to determine if it moving back and forth, a sign that it has a system of planets. Using the HARPS data, the team determined that a rocky planet orbits Ross 128 (an M-type red dwarf star) at a distance of about 0.05 AU with a period of 9.9 days.

Despite its proximity to its host star, Ross 128b receives only 1.38 times more irradiation than the Earth. This is due to the cool and faint nature of red dwarf stars like Ross 128, which has a surface temperature roughly half that of our Sun. From this, the discovery team estimated that Ross 128b’s equilibrium temperature is likely somewhere between -60 and 20°C – i.e. close to what we experience here on Earth.

As Nicola Astudillo-Defru of the Geneva Observatory – and a co-author on the discovery paper – indicated in an ESO press release:

“This discovery is based on more than a decade of HARPS intensive monitoring together with state-of-the-art data reduction and analysis techniques. Only HARPS has demonstrated such a precision and it remains the best planet hunter of its kind, 15 years after it began operations.”

But what is most encouraging is the fact that Ross 128 is the “quietest” nearby star that is also home to an exoplanet. Compared to other classes of stars, M-type red dwarfs are particularly low in mass, dimmer and cooler. They are also the most common type of star in the Universe, accounting for 70% of the stars in spiral galaxies and more than 90% of all stars in elliptical galaxies.

Unfortunately, they are also variable and unstable compared to other classes of star, which means they experience regular flare ups. This means that any planets which orbit them will be periodically subjected to deadly ultraviolet and X-ray radiation. In comparison, Ross 128 is much quieter, meaning it experiences less in the way of flare activity, and planets orbiting it are therefore exposed to less radiation over time.

This means that, relative to Proxima b or those planets located within TRAPPIST-1’s habitable zone – Ross 128b is more likely to retain an atmosphere and support life. For those who are engaged in searches for exoplanets around M-type stars – or are of the opinion that red dwarfs are the best bet for finding habitable worlds – this latest discovery would seem to confirm that they are looking in the right spots!

As noted, red dwarfs are the most common in the Universe, and in recent years, many rocky planets (sometimes even a multi-planet system) have been found orbiting these stars. Combined with their natural longevity – which can remain in their main sequence phase for up to 10 trillion years – red dwarf stars have understandably become a popular target for exoplanet-hunters.

In fact, lead author Xavier Bonfils named their HARPS program “The Shortcut to Happiness” for this very reason. As he and his colleagues indicated, it is easier to detect small cool planets of Earth around smaller, dimmer M-type stars than it is around stars that are more similar to the Sun.

However, many in the scientific community have remained skeptical about the likelihood that any of these planets could be habitable (again, due to their variable nature). But this most recent discovery, along with recent research that indicates how tidally-locked planets that orbit red dwarf stars could hold onto their atmospheres, is another possible indication that these fears may be for naught.

Being at a distance of about 11 light-years from Earth, Ross 128b is currently the second-closest exoplanet to our Sun. However, Ross 128 itself is slowly moving closer towards us and will become our nearest stellar neighbor in roughly 79,000 years. At this point, Ross 128b will replace Proxima b and become the closest exoplanet to Earth!

But of course, much remains to be found about this latest exoplanet. While the discovery team consider Ross 128b to be a temperate planet based on its orbit, it remains uncertain as to whether it lies within, beyond, or on the cusp of the star’s habitable zone. However, further studies are expected to shed more light on this and other questions relating this potentially-habitable world.

Astronomers also anticipate that more temperature exoplanets will be discovered in the coming years, and that future surveys will be able to determine a great deal more about their atmospheres, composition and chemistry. Instruments like the James Webb Space Telescope (JWST) and the ESO’s Extremely Large Telescope (ELT) are expected to play a major role.

Not only will these and other instrument help turn up more exoplanet candidates, they will also be used in the hunt for biosignatures in planet’s atmospheres (i.e. oxygen, nitrogen, water vapor, etc.). As Bonfils concluded:

“New facilities at ESO will first play a critical role in building the census of Earth-mass planets amenable to characterization. In particular, NIRPS, the infrared arm of HARPS, will boost our efficiency in observing red dwarfs, which emit most of their radiation in the infrared. And then, the ELT will provide the opportunity to observe and characterize a large fraction of these planets.”

At this juncture, the process of exoplanet discovery is moving beyond detection and getting into the process of characterization and detailed study. Even so, it is nice that we are still making groundbreaking discoveries in the field of detection. In the coming years, we may transition from looking for an Earth 2.0 to a point where weare actively studying several at once!

Further Reading: ESO, ESO (2)

November 14, 2017 by Matt Williams

NASA’s Next-Generation Spaceplane Passes Free Flight Test

Sierra Nevada Corp’s Dream Chaser lands on Edwards Air Force Base in California. The spacecraft went through preparations for flight at NASA’s Armstrong Flight Research Center. Credits: NASA/Carla Thomas

It’s called the Dream Chaser, a reusable spaceplane that will one day transport cargo and crews to the International Space Station. For the past ten years, the Sierra Nevada Corporation and NASA have been developing and testing this next-generation space vehicle. When it is ready, this vehicle will not only provide a more cost-effective way of servicing the ISS, it will also help restore domestic launch capability to the United States.

On Saturday, November 11th, the Dream Chaser passed an important milestone by conducting a successful free flight test. This took place at Edwards Air Force Base in California, and verified the spaceplane’s ability to glide and land autonomously. This, in addition to verifying several key avionic and flight systems, is a strong indication that the spaceplane will be capable of conducting runs to and from Low-Earth Orbit (LEO) in the near future.

This test involved the spaceplane being lifted to an altitude of 3,780 meters (12,400 feet) and then let go to glide freely. It then deployed its landing gears and touched down on the Edwards Air Force Base runway before coming to a full stop. This runway, it should be noted, is very similar to the Kennedy Space Center Shuttle Landing Facility runway that the Dream Chaser will land on once it is operational.

This flight test validated the performance of the Dream Chaser during what is arguably the most critical part of a mission – the approach and landing phase – which will be the final phase of future flights from the ISS. The ability to conduct automated landings is central to the spaceplane’s reusability, which operates in much the same way as the now-retired Space Shuttle did.

This process entails the craft being launched into orbit aboard a rocket (Atlas V or Ariane 5), maneuvering under its own power while in orbit so that it can dock with the ISS (or other orbiting facilities), and then re-entering the atmosphere and returning to a landing strip. As Mark Sirangelo, the corporate vice president of SNC’s Space System business area, said in a company press release:

“The Dream Chaser flight test demonstrated excellent performance of the spacecraft’s aerodynamic design and the data shows that we are firmly on the path for safe, reliable orbital flight.”

The flight test also helped advance the vehicle as part of NASA’s Commercial Crew Program and prepare it for service under Commercial Resupply Services 2 program. These programs consist of NASA working closely with private aerospace companies to develop new spacecraft and launch systems that will be capable of carrying crews to locations in LEO and to the ISS.

Front-end view of the Dream Chaser spaceplane. Credit: Sierra Nevada Corporation

This approach and landing test expands on the phase one flight test, which took place back in October of 2013. For this free-flight test, the vehicle was released from a “skycrane” helicopter and flew a short flight, touching down less than a minute later. Just prior to landing, the left main landing gear failed to deploy resulting in a crash landing. However, the vehicle and its crew compartment were left intact.

For the second flight test, SNC and NASA incorporated orbital vehicle avionics and flight software for the first time. The trajectory also included specific program test inputs which, together with the added software, provided validations for orbital vehicle operations. Over the coming days and weeks, SNC and NASA will be evaluating all the data obtained during the flight, which includes the Dream Chaser aerodynamic and integrated system performance.

The data that SNC gathers from this test campaign will help inform the final design of the cargo Dream Chaser, which will be capable of transporting crews of six astronauts to the ISS. As Fatih Ozmen, the CEO of SNC, exclaimed:

“I’m so proud of the Dream Chaser team for their continued excellence. This spacecraft is the future and has the ability to change the way humans interact with space, and I couldn’t be happier with SNC’s dedicated team and the results of the test.”

If all goes well, SNC and NASA are hoping to begin conducting cargo deliveries by 2019. By 2024, it is hoped that a total of six cargo delivery missions will take place. No indications have been given as to when the crewed variant could start bringing astronauts to the ISS. But once that is possible, NASA will no longer be forced to rely on Roscosmos and their fleet of Soyuz rockets to send astronauts into space.

Be sure to check out this video of the Dream Chaster Cargo System, courtesy of Sierra Nevada Corporation:

Further Reading: NASA, Sierra Nevada

November 14, 2017 by Matt Williams

Triton’s Arrival was Chaos for the Rest of Neptune’s Moons

Artist's impression of what the surface of Triton may look like. Credit: ESO

The study of the Solar System’s many moons has revealed a wealth of information over the past few decades. These include the moons of Jupiter – 69 of which have been identified and named – Saturn (which has 62) and Uranus (27). In all three cases, the satellites that orbit these gas giants have prograde, low-inclination orbits. However, within the Neptunian system, astronomers noted that the situation was quite different.

Compared to the other gas giants, Neptune has far fewer satellites, and most of the system’s mass is concentrated within a single satellite that is believed to have been captured (i.e. Triton). According to a new study by a team from the Weizmann Institute of Science in Israel and the Southwest Research Institute (SwRI) in Boulder, Colorado, Neptune may have once had a more massive systems of satellites, which the arrival of Triton may have disrupted.

The study, titled “Triton’s Evolution with a Primordial Neptunian Satellite System“, recently appeared in The Astrophysical Journal. The research team consisted of Raluca Rufu, an astrophysicist and geophysicist from the Weizmann Institute, and Robin M. Canup – the Associate VP of the SwRI. Together, they considered models of a primordial Neptunian system, and how it may have changed thanks to the arrival of Triton.

*Neptune and its large moon Triton as seen by Voyager 2 on August 28th, 1989. Credit: NASA*

For many years, astronomers have been of the opinion that Triton was once a dwarf planet that was kicked out of the Kuiper Belt and captured by Neptune’s gravity. This is based on its retrograde and highly-inclined orbit (156.885° to Neptune’s equator), which contradicts current models of how gas giants and their satellites form. These models suggest that as giant planets accrete gas, their moons form from a surrounding debris disk.

Consistent with the other gas giants, the largest of these satellites would have prograde, regular orbits that are not particularly inclined relative to their planet’s equator (typically less than 1°). In this respect, Triton is believed to have once been part of a binary made up of two Trans-Neptunian Objects (TNOs). When they swung past Neptune, Triton would have been captured by its gravity and gradually fell into its current orbit.

As Dr. Rufu and Dr. Canup state in their study, the arrival of this massive satellite would have likely caused a lot of disruption in the Neptunian system and affected its evolution. This consisted of them exploring how interactions – like scattering or collisions – between Triton and Neptune’s prior satellites would have modified Triton’s orbit and mass, as well as the system at large. As they explain:

“We evaluate whether the collisions among the primordial satellites are disruptive enough to create a debris disk that would accelerate Triton’s circularization, or whether Triton would experience a disrupting impact first. We seek to find the mass of the primordial satellite system that would yield the current architecture of the Neptunian system.”

*Montage of Neptune’s largest moon, Triton and the planet Neptune showing the moon’s sublimating south polar cap (bottom) and enigmatic “cantaloupe terrain”. Credit: NASA*

To test how the Neptunian system could have evolved, they considered different types of primordial satellite systems. This included one that was consistent with Uranus’ current system, made up of prograde satellites with a similar mass ration as Uranus’ largest moons – Ariel, Umbriel, Titania and Oberon – as well as one that was either more or less massive. They then conducted simulations to determine how Triton’s arrival would have altered these systems.

These simulations were based on disruption scaling laws which considered how non-hit-and-run impacts between Triton and other bodies would have led to a redistribution of matter in the system. What they found, after 200 simulations, was that a system that had a mass ratio that was similar to the current Uranian system (or smaller) would have been most likely to produce the current Neptunian system. As they state:

“We find that a prior satellite system with a mass ratio similar to the Uranian system or smaller has a substantial likelihood of reproducing the current Neptunian system, while a more massive system has a low probability of leading to the current configuration.”

They also found that the interaction of Triton with an earlier satellite system also offers a potential explanation for how its initial orbit could have been decreased fast enough to preserve the orbits of small irregular satellites. These Nereid-like bodies would have otherwise been kicked out of their orbits as tidal forces between Neptune and Triton caused Triton to assume its current orbit.

*The moons of Uranus and Neptune as imaged during the 2011 opposition season. Credit: Rolf Wahl Olsen.*

Ultimately, this study not only offers a possible explanation as to why Neptune’s system of satellites differs from those of other gas giants; it also indicates that Neptune’s proximity to the Kuiper Belt is what is responsible. At one time, Neptune may have had a system of moons that were very much like those of Jupiter, Saturn, and Uranus. But since it is well-situated to pick up dwarf planet-sized objects that were kicked out of the Kuiper Belt, this changed.

Looking to the future, Rufu and Canup indicate that additional studies are needed in order to shed light on Triton’s early evolution as a Neptunian satellite. Essentially, there are still unanswered questions concerning the effects the system of pre-existing satellites had on Triton, and how stable its irregular prograde satellites were.

These findings were also presented by Dr, Rufu and Dr. Canup during the 48th Lunar and Planetary Science Conference, which took place in The Woodlands, Texas, this past March.

Further Reading: The Astronomical Journal, USRA

November 13, 2017 by Matt Williams

Dinosaur Killing Asteroid hit Earth in Exactly the Wrong Spot

Earth and possibly its Moon were hit by impactors that killed off the dinosaurs — Artistic rendition of the Chicxulub impactor striking ancient Earth, with Pterosaur observing. Could pieces of the same impact swarm have hit the Moon, too? Credit: NASA

Sixty-six million years ago, an asteroid struck Earth in what is now the Yucatan Peninsula in southern Mexico. This event, known as the Chicxulub asteroid impact, measured 9 km in diameter and caused extreme global cooling and drought. This led to a mass extinction, which not only claimed the lives of the dinosaurs, but also wiped out about 75% of all land and sea animals on Earth.

However, had this asteroid impacted somewhere else on the planet, things could have turned out very differently. According to a new study produced by a team of Japanese researchers, the destruction caused by this asteroid was due in large part to where it impacted. Had the Chicxulub asteroid landed somewhere else on the planet, they argue, the fallout would not have been nearly as severe.

The study, which recently appeared in the journal Scientific Reports, is titled “Site of asteroid impact changed the history of life on Earth: the low probability of mass extinction“, and was conducted by Kunio Kaiho and Naga Oshima of Tohoku University and the Meteorological Research Institute, respectively. For the sake of their study, the pair considered how geological conditions in the Yucatan region were intrinsic to mass extinction that happened 66 million years ago.

*Satellite views of the Chicxulub impact site in the Yucutan Peninsula, southern Mexico. Image credit: NASA/JPL*

Dr. Kaiho and Dr. Oshima began by considering recent studies that have shown how the Chicxulub impact heated the hydrocarbon and sulfur content of rocks in the region. This is what led to the formation of stratospheric soot and sulfate aerosols which caused the extreme global cooling and drought that followed. As they state in their study, it was this (not the impact and the detritus it threw up alone) that ensured the mass extinction that followed:

“Blocking of sunlight by dust and sulfate aerosols ejected from the rocks at the site of the impact (impact target rocks) was proposed as a mechanism to explain how the physical processes of the impact drove the extinction; these effects are short-lived and therefore could not have driven the extinction. However, small fractions of stratospheric sulfate (SO4) aerosols were also produced, which may have contributed to the cooling of the Earth’s surface.“

Another issue they considered was the source of the soot aerosols, which previous research has indicated were quite prevalent in the stratosphere during the Cretaceous/Paleogene (K–Pg) boundary (ca. 65 million years ago). This soot is believed to coincide with the asteroid impact since microfossil and fossil pollen studies of this period also indicate the presence of iridium, which has been traced to the Chicxulub asteroid.

Previously, this soot was believed to be the result of wildfires that raged in the Yucatan as a result of the asteroid impact. However, Kaiho and Oshima determined that these fires could not have resulted in stratospheric soot; instead positing that they could only be produced by the burning and ejecting of hyrdocarbon material from rocks in the impact target area.

When an asteroid struck the Yucatan region about 66 million years ago, it wiped out the dinosaurs, and most of life on Earth. If it had hit elsewhere, the dinosaurs might well have survived. Credit: NASA/Don Davis

The presence of these hydrocarbons in the rocks indicate the presence of both oil and coal, but also plenty of carbonate minerals. Here too, the geology of the Yucatan was key, since the larger geological formation known as the Yucatan Platform is known to be composed of carbonate and soluble rocks – particularly limestone, dolomite and evaporites.

To test just how important the local geology was to the mass extinction that followed, Kaiho and Oshima conducted a computer simulation that took into account where the asteroid struck and how much aerosols and soot would be produced by an impact. Ultimately, they found that the resulting ejecta would have been sufficient to trigger global cooling and drought; and hence, an Extinction Level Event (ELE).

This sulfur and carbon-rich geology, however, is not something the Yucatan Peninsula shares with most regions on the planet. As they state in their study:

“Here we show that the probability of significant global cooling, mass extinction, and the subsequent appearance of mammals was quite low after an asteroid impact on the Earth’s surface. This significant event could have occurred if the asteroid hit the hydrocarbon-rich areas occupying approximately 13% of the Earth’s surface. The site of asteroid impact, therefore, changed the history of life on Earth.”

*Mass extinction only occurred when the asteroid having 9-km diameter hit the orange areas. Credit: Kunio Kaiho*

Basically, Kaiho and Oshima determined that 87% of Earth would not have been able to produce enough sulfate aerosols and soot to trigger a mass extinction. So if the Chicxulub asteroid struck just about anywhere else on the planet, the dinosaurs and most of the world’s animals would have likely survived, and the resulting macroevolution of mammals probably would not have taken place.

In short, modern hominids may very well owe their existence to the fact that the Chicxulub asteroid landed where it did. Granted, the majority of life in the Cretaceous/Paleogene (K–Pg) was wiped out as a result, but ancient mammals and their progeny appear to have lucked out. The study is therefore immensely significant in terms of our understanding of how asteroid impacts affect climatological and biological evolution.

It is also significant when it comes to anticipating future impacts and how they might affect our planet. Whereas a large impact in a sulfur and carbon-rich geological region could lead to another mass extinction, an impact anywhere else could very well be containable. Still, this should not prevent us from developing appropriate countermeasures to ensure that large impacts don’t happen at all!

Further Reading: Science Reports

November 11, 2017 by Matt Williams

NASA Moving Ahead with Deployment of Orion Capsule and Space Launch System

Artist concept of NASA’s Space Launch System (SLS) on the left, and the Orion Multi-Purpose Crew Vehicle (right). Credit: NASA

On October 11th, 2010, Congress signed the bipartisan NASA Authorization Act, which allocated the necessary funding for the space agency to commence preparations for its “Journey to Mars“. For the sake of mounting the first crewed missions to the Red Planet, several components were designated as being crucial. These included the Space Launch System (SLS) and the Orion Multi-Purpose Crew Vehicle.

Despite a recent announcement that NASA would be prioritizing a return to the Moon in the coming years, both the SLS and Orion are on track with the eventual goal of mounting crewed missions to Mars. In recent weeks, NASA conducted critical assessments of both components and their proposed launch schedules, and determined that they will be launched together in 2020 for the sake of conducting Exploration Mission-1 (EM-1).

This test flight, which will be uncrewed, will test both systems and lay the foundations for the first crewed mission of the SLS and Orion. Known as Exploration Mission- 2 (EM-2), which was originally scheduled for 2021, this flight is now expected to take place in 2023. EM-1 will also serve to establish a regular cadence of mission launches that will take astronauts back to the Moon and eventually on to Mars.

*NASA’s Orion spacecraft will carry astronauts further into space than ever before using a module based on Europe’s Automated Transfer Vehicles (ATV). Credit: NASA*

The recent review came on the heels of an earlier assessment where NASA evaluated the cost, risk and technical factors of adding crew to the mission. This review was initiated as a result of the crew study and the challenges related to building the core stage of the SLS. Foremost among these was the recent tornado damage caused to the Michoud Assembly Facility in New Orleans, where the SLS is currently being built.

On top of that, there are also the challenges related to the manufacture and supply of the first Orion Service Module. This module, which is being developed by the European Space Agency (ESA), serves as the Orion’s primary power and propulsion component, until it is discarded at the end of each mission. During the summer of 2016, the design of the Service Module was also the subject of a critical design review, and passed.

After conducting their review, NASA reaffirmed the original plan to fly the EM-1 uncrewed. As acting NASA Administrator Robert Lightfoot announced in a recent NASA press release:

“While the review of the possible manufacturing and production schedule risks indicate a launch date of June 2020, the agency is managing to December 2019. Since several of the key risks identified have not been actually realized, we are able to put in place mitigation strategies for those risks to protect the December 2019 date.”

In addition, NASA has established new production performance milestones to address a key issue identified by the review, which was scheduling risks. Based on lesson learned from first-time builds, NASA and its contractors have adopted new measures to optimize building plans which will ensure flexibility – specifically if contractors are unable to deliver on schedule.

At this juncture, NASA is on track to develop the new deep space exploration systems that will take astronauts back to the Moon and beyond. Cost assessments for EM-1, which include the SLS and ground systems, are currently within their original targets. By June 2020, NASA estimates that cost overruns will remain within a 15% limit for the SLS and just slightly above for the ground systems.

As part of the review, NASA also considered when the test of the Orion’s launch abort system (which needs to happen ahead of EM-1) would take place – which they chose to move up to April 2019. Known as Ascent-Abort 2, this test will validate the launch abort system’s ability to land the crew safely during descent, and ensure that the agency can remain on track for a crewed flight in 2023.

To build the SLS and Orion, NASA is relying on several new and advanced manufacturing techniques. These include additive manufacturing (3-D printing), which is being used to fashion more than 100 parts for the Orion spacecraft. NASA is also using a technique known as self-reaction friction stir welding to join the two largest core stages of the rocket, which are the thickest structures ever joined using this technique.

*Space Launch System (SLS) Block 1 Expanded View. Credit: NASA*

Integration of the first service module is well under way in Bremen, Germany, with work already starting on the second. This is taking place at the Airbus integration room, where crews on eight-hour shifts are busy installing more than 11 km (6.8 mi) of cables that will connect the module’s central computers to everything from solar planes and fuel systems to the module’s engines and air and water systems.

These crews also finished installing the Orion’s 24 orientation thrusters recently, which complement the eight larger engines that will back up the main engine. The complex design of the module’s propulsion system requires that some 1100 welds be completed, and only 173 remain. At present, the ESA crews are aiming to finish work on the Orion and ship it to the USA by the summer of 2018.

As far as the assembly of the SLS is concerned, NASA has completed welding on all the major structures to the rocket stages is on track to assemble them together. Once that is complete, they will be able to complete an engine test that will fire up the four RS-25 engines on the core stage simultaneously – the EM-1 “green run”. When EM-1 takes place, the launch will be supported by ground systems and crews at NASA’s Kennedy Space Center in Florida.

The agency is also developing a Deep Space Gateway (DSG) concept with Roscosmos and industry partners like Boeing and Lockheed Martin. This space station, which will be placed in orbit around the Moon, will facilitate missions to the lunar surface, Mars, and other locations deeper into the Solar System. Other components currently under consideration include the Deep Space Transport, and the Martian Basecamp and Lander.

These latter two components are what will allow for missions beyond the Earth-Moon system. Whereas the combination of the SLS, Orion and the DSG will allow for renewed lunar missions (which have not taken place since the Apollo Era) the creation of a Deep Space Transport and Martian Basecamp are intrinsic to NASA’s plans to mount a crewed mission to the Red Planet by the 2030s.

But in the meantime, NASA is focused on the first test flight of the Orion and the SLS, which will pave the way towards a crewed mission in a few years’ time. As William Gerstenmaier, the associate administrator for NASA’s Human Exploration and Operations Mission Directorate, indicated:

“Hardware progress continues every day for the early flights of SLS and Orion. EM-1 will mark a significant achievement for NASA, and our nation’s future of human deep space exploration. Our investments in SLS and Orion will take us to the Moon and beyond, advancing American leadership in space.”

For almost forty years, no crewed spaceflights have been conducted beyond Low-Earth Orbit. And with the retiring of the Space Shuttle Program in 2011, NASA has lost the ability to conduct domestic launches. For these reasons, the past three presidential administrations have indicated their commitment to develop the necessary tools to return to the Moon and send astronauts to Mars.

Not only will this restore the United State’s leadership in space exploration, it also will open up new venues for human exploration and create new opportunities for collaboration between nations and between federal agencies and industry partners. And be sure to check out this video showcases NASA’s plans for Deep Space Exploration:

Further Reading: ESA, NASA

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

November 9, 2017November 10, 2017 by Matt Williams

Building Electronics That Can Work on Venus

Artist's impression of the surface of Venus, showing its lightning storms and a volcano in the distance. Credit and ©: European Space Agency/J. Whatmore

The weather on Venus is like something out of Dante’s Inferno. The average surface temperature – 737 K (462 °C; 864 °F) – is hot enough to melt lead and the atmospheric pressure is 92 times that of Earth’s at sea level (9.2 MPa). For this reason, very few robotic missions have ever made it to the surface of Venus, and those that have did not last long – ranging from about 20 minutes to just over two hours.

Hence why NASA, with an eye to future missions, is looking to create robotic missions and components that can survive inside Venus’ atmosphere for prolonged periods of time. These include the next-generation electronics that researchers from NASA Glenn Research Center (GRC) recently unveiled. These electronics would allow a lander to explore Venus surface for weeks, months, or even years.

In the past, landers developed by the Soviets and NASA to explore Venus – as part of the Venera and Mariner programs, respectively – relied on standard electronics, which were based on silicon semiconductors. These are simply not capable of operating in the temperature and pressure conditions that exist on the surface of Venus, and therefore required that they have protective casings and cooling systems.

Naturally, it was only a matter of time before these protections failed and the probes stopped transmitting. The record was achieved by the Soviets with their Venera 13 probe, which transmitted for 127 minutes between its descent and landing. Looking ahead, NASA and other space agencies want to develop probes that can gather as much information as they can on Venus’s atmosphere, surface, and geological history before they time out.

To do this, a team from NASA’s GRC has been working to develop electronics that rely on silcon carbide (SiC) semiconductors, which would be capable of operating at or above Venus’ temperatures. Recently, the team conducted a demonstration using the world’s first moderately-complex SiC-based microcircuits, which consisted of tens or more transistors in the form of core digital logic circuits and analog operation amplifiers.

These circuits, which would be used throughout the electronic systems of a future mission, were able to operate for up to 4000 hours at temperatures of 500 °C (932 °F) – effectively demonstrated that they could survive in Venus-like conditions for prolonged periods. These tests took place in the Glenn Extreme Environments Rig (GEER), which simulated Venus’ surface conditions, including both the extreme temperature and high pressure.

Back in April of 2016, the GRC team tested a SiC 12-transistor ring oscillator using the GEER for a period of 521 hours (21.7 days). During the test, they raised they subjected the circuits to temperatures of up to 460 °C (860 °F), atmospheric pressures of 9.3 MPa and supercritical levels of CO² (and other trace gases). Throughout the entire process, the SiC oscillator showed good stability and kept functioning.

*SiC high-temperature electronics before and after testing in Venus surface conditions (rugged operation for extended durations). Credits: Marvin Smith/David Spry/NASA GRC*

This test was ended after 21 days due to scheduling reasons, and could have gone on much longer. Nevertheless, the duration constituted a significant world record, being orders of magnitude longer than any other demonstration or mission that has been conducted. Similar tests have shown that ring oscillator circuits can survive for thousands of hours at temperatures of 500 °C (932 °F) in Earth-air ambient conditions.

Such electronics constitute a major shift for NASA and space exploration, and would enable missions that were previously impossible. NASA’s Science Mission Direction (SMD) plans to incorporate SiC electronics on their Long-Life In-situ Solar System Explorer (LLISSE). A prototype is currently being developed for this low-cost concept, which would provide basic, but highly valuable scientific measures from the surface of Venus for months or longer.

Other plans to build a survivable Venus explorer include the Automaton Rover for Extreme Environments (AREE), a “steampunk rover” concept that relies on analog components rather than complex electronic systems. Whereas this concepts seeks to do away with electronics entirely to ensure a Venus mission could operate indefinitely, the new SiC electronics would allow more complex rovers to continue operating in extreme conditions.

Beyond Venus, this new technology could also lead to new classes of probes capable of exploring within gas giants – i.e. Jupiter, Saturn, Uranus and Neptune – where temperature and pressure conditions have been prohibitive in the past. But a probe that relies on a hardened shell and SiC electronic circuits could very well penetrate deep into the interior of these planets and reveal startling new things about their atmospheres and magnetic fields.

*AREE is a clockwork rover inspired by mechanical computers. A JPL team is studying how this kind of rover could explore extreme environments, like the surface of Venus. Credit: NASA/JPL-Caltech*

The surface of Mercury could also be accessible to rovers and landers using this new technology – even the day-side, where temperatures reach a high of 700 K (427 °C; 800 °F). Here on Earth, there are plenty of extreme environments that could now be explored with the help of SiC circuits. For example, drones equipped with SiC electronics could monitor deep-sea oil drilling or explore deep into the Earth’s interior.

There are also commercial applications involving aeronautical engines and industrial processors, where extreme heat or pressure traditionally made electronic monitoring impossible. Now such systems could be made “smart”, where they are capable of monitoring themselves instead of relying on operators or human oversight.

With extreme circuits and (someday) extreme materials, just about any environment could be explored. Maybe even the interior of a star!

Further Reading: NASA

November 8, 2017November 8, 2017 by Matt Williams

A Brown Dwarf Prevented a Regular Star from Going Through its Full Life Cycle

A team of Brazilian scientists recently observed a binary star system consisting of a white dwarf and a brown dwarf companion. Credit: FAPESP

Eclipsing binary star systems are relatively common in our Universe. To the casual observer, these systems look like a single star, but are actually composed of two stars orbiting closely together. The study of these systems offers astronomers an opportunity to directly measure the fundamental properties (i.e. the masses and radii) of these systems respective stellar components.

Recently, a team of Brazilian astronomers observed a rare sight in the Milky Way – an eclipsing binary composed of a white dwarf and a low-mass brown dwarf. Even more unusual was the fact that the white dwarf’s life cycle appeared to have been prematurely cut short by its brown dwarf companion, which caused its early death by slowly siphoning off material and “starving” it to death.

The study which detailed their findings, titled “HS 2231+2441: an HW Vir system composed by a low-mass white dwarf and a brown dwarf“, was recently published the Monthly Notices of the Royal Astronomical Society. The team was led by Leonardo Andrade de Almeida, a postdoctoral fellow from the University of São Paolo’s Institute of Astronomy, Geophysics, and Atmospheric Sciences (IAG-USP), along with members from the National Institute for Space Research (MCTIC), and the State University of Feira de Santana.

*The Observatorio del Roque de los Muchachos, located on the island of La Palma. Credit: IAC*

For the sake of their study, the team conducted observations of a binary star system between 2005 and 2013 using the Pico dos Dias Observatory in Brazil. This data was then combined with information from the William Herschel Telescope, which is located in the Observatorio del Roque de los Muchachos on the island of La Palma. This system, known as of HS 2231+2441, consists of a white dwarf star and a brown dwarf companion.

White dwarfs, which are the final stage of intermediate or low-mass stars, are essentially what is left after a star has exhausted its hydrogen and helium fuel and blown off its outer layers. A brown dwarf, on the other hand, is a substellar object that has a mass which places it between that of a star and a planet. Finding a binary system consisting of both objects together in the same system is something astronomers don’t see everyday.

As Leonardo Andrade de Almeida explained in a FAPESP press release, “This type of low-mass binary is relatively rare. Only a few dozen have been observed to date.”

This particular binary pair consists of a white dwarf that is between twenty to thirty percent the Sun’s mass – 28,500 K (28,227 °C; 50,840 °F) – while the brown dwarf is roughly 34-36 times that of Jupiter. This makes HS 2231+2441 the least massive eclipsing binary system studied to date.

*This artist’s impression shows an eclipsing binary star system. Credit: ESO/L. Calçada.*

In the past, the primary (the white dwarf) was a normal star that evolved faster than its companion since it was more massive. Once it exhausted its hydrogen fuel, its formed a helium-burning core. At this point, the star was on its way to becoming a red giant, which is what happens when Sun-like stars exit their main sequence phase. This would have been characterized by a massive expansion, with its diameter exceeding 150 million km (93.2 million mi).

At this point, Almeida and his colleagues concluded that it began interacting gravitationally with its secondary (the brown dwarf). Meanwhile, the brown dwarf began to be attracted and engulfed by the primary’s atmosphere (i.e. its envelop), which caused it it lose orbital angular momentum. Eventually, the powerful force of attraction exceeded the gravitational force keeping the envelop anchored to its star.

Once this happened, the primary star’s outer layers began to be stripped away, exposing its helium core and sending massive amounts of matter to the brown dwarf. Because of this loss of mass, the remnant effectively died, becoming a white dwarf. The brown dwarf then began orbiting its white dwarf primary with a short orbital period of just three hours. As Almeida explained:

“This transfer of mass from the more massive star, the primary object, to its companion, which is the secondary object, was extremely violent and unstable, and it lasted a short time… The secondary object, which is now a brown dwarf, must also have acquired some matter when it shared its envelope with the primary object, but not enough to become a new star.”

*Artist’s impression of a brown dwarf orbiting a white dwarf star. Credit: ESO*

This situation is similar to what astronomers noticed this past summer while studying the binary star system known as WD 1202-024. Here too, a brown dwarf companion was discovered orbiting a white dwarf primary. What’s more, the team responsible for the discovery indicated that the brown dwarf was likely pulled closer to the white dwarf once it entered its Red Giant Branch (RGB) phase.

At this point, the brown dwarf stripped the primary of its atmosphere, exposing the white dwarf remnant core. Similarly, the interaction of the primary with a brown dwarf companion caused premature stellar death. The fact that two such discoveries have happened within a short period of time is quite fortuitous. Considering the age of the Universe (which is roughly 13.8 billion years old), dead objects can only be formed in binary systems.

In the Milky Way alone, about 50% of low-mass stars exist as part of a binary system while high mass stars exist almost exclusively in binary pairs. In these cases, roughly three-quarters will interact in some way with a companion – exchanging mass, accelerating their rotations, and eventually en merging.

As Almeida indicated, the study of this binary system and those like it could seriously help astronomers understand how hot, compact objects like white dwarfs are formed. “Binary systems offer a direct way of measuring the main parameter of a star, which is its mass,” he said. “That’s why binary systems are crucial to our understanding of the life cycle of stars.”

It has only been in recent years that low-mass white dwarf stars were discovered. Finding binary systems where they coexist with brown dwarfs – essentially, failed stars – is another rarity. But with every new discovery, the opportunities to study the range of possibilities in our Universe increases.

Further Reading: São Paulo Research Foundation, MNRAS

November 8, 2017 by Matt Williams

Astronomers Practice Responding to a Killer Asteroid”

Artist's concept of a large asteroid passing by the Earth-Moon system. Credit: A combination of ESO/NASA images courtesy of Jason Major/Lights in the Dark.

Beyond the Earth-Moon system, thousands of asteroids known as Near-Earth Objects (NEOs) are known to exist. These rocks periodically cross Earth’s orbit and make close a flyby of Earth. Over the course of millions of years, some even collide with the Earth, causing mass extinctions. Little wonder then why NASA’s Center for Near Earth Object Studies (CNEOS) is dedicated to monitoring the larger objects that occasionally come close to our planet.

One of these objects is 2012 TC4, a small and oblong-shaped NEO that was first spotted in 2012 during a close flyby of Earth. During its most recent flyby – which took place on Thursday, October 12th,2017 – an international team of astronomers led by NASA scientists used the opportunity to conduct the first international exercise to test global responses to an impending asteroid strike.

This exercise was known as the “TC4 Observation Campaign“, which began this past July and concluded with the asteroid flyby. It all began when astronomers at the European Southern Observatory’s (ESO) Paranal Observatory in Chile used the Very Large Telescope (VLT) to recover 2012 TC4. When the asteroid made its final close approach to Earth in mid-October, it passed Earth by at a distance of 43,780 km (27,200 mi).

*Diagram showing 2012 TC4’s heliocentric orbit, which has changed due to the 2012 and 2017 close encounters with Earth. Credit: NASA/JPL-Caltech*

The goal of this exercise was simple: recover, track and characterize a real asteroid as if it were likely to collide with Earth. In addition, the exercise was an opportunity to test the International Asteroid Warning Network, which conducts observations of potentially hazardous asteroids, attempts to model their behavior, make predictions, and share these findings with institutions around the world.

On Oct. 12th, TC4 flew by Earth at roughly 0.11 times the distance between Earth and the Moon. In the months leading up to the flyby, astronomers from the US, Canada, Columbia, Germany, Israel, Italy, Japan, the Netherlands, Russia and South Africa tracked TC4 from the ground. At the same time, space-based telescopes studied the asteroid’s orbit, shape, rotation and composition.

Detlef Koschny is the co-manager of the Near-Earth Object segment in the European Space Agency (ESA)’s Space Situational Awareness program. As he was quoted in a recent NASA press release:

“This campaign was an excellent test of a real threat case. I learned that in many cases we are already well-prepared; communication and the openness of the community was fantastic. I personally was not prepared enough for the high response from the public and media – I was positively surprised by that! It shows that what we are doing is relevant.”

Asteroid 2012 TC4 appears as a dot at the center of this composite of 37 individual 50-second exposures obtained on Aug. 6, 2017 by the European Southern Observatory’s Very Large Telescope. Credit: *NASA/JPL-Caltech*

Based on their observations, scientists at CNEOS – which is located at the Jet Propulsion Laboratory in Pasadena, California – were able to determine all the necessary characteristics of TC4. This included its precise orbit, the distance it would pass by Earth on Oct. 12th, and discern if there was any possibility of a future impact. As Davide Farnocchia, a member of CNEOS who led the effort to determine the asteroid’s orbit, explained:

“The high-quality observations from optical and radar telescopes have enabled us to rule out any future impacts between the Earth and 2012 TC4. These observations also help us understand subtle effects such as solar radiation pressure that can gently nudge the orbit of small asteroids.”

Multiple observatories also dedicated their optical telescopes to studying how fast TC4 rotates. As Eileen Ryan – the director of the Magdalena Ridge Observatory, which conducted observations of the asteroids rotation – indicated, “The rotational campaign was a true international effort. We had astronomers from several countries working together as one team to study TC4’s tumbling behavior.”

What they found that the small asteroid rotated slowly, which was rather surprising. Whereas small asteroids typically rotate very quickly, TC4 had a rotational period of just 12 minutes, and also appeared to be tumbling. Other observations revealed some interesting things about the shape of TC4.

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

These were conducted by astronomers using NASA’s Goldstone Deep Space Network antenna in California, and the National Radio Astronomy Observatory‘s Green Bank Telescope in West Virginia. Their reading helped refine size estimates of the asteroid, indicating that it is elongated and measures approximately 15 meters (50 ft) long and 8 meters (25 feet) wide.

Determining TC4’s composition was more challenging. Due to unfavorable weather conditions that coincided with the flyby, instruments like NASA’s Infrared Telescope Facility (IRTF) at the Mauna Kea Observatory in Hawaii were unable to get a good look at the asteroid. However, spectra was obtained on the asteroid that indicated that it has a rocky body, which means it is an S-type asteroids.

Typically, ground-based elements determine an asteroid’s composition based on their color. Whereas dark asteroids are known for being carbon-rich (C-type), bright asteroids are predominantly composed of silicate minerals (S-type). As Lance Benner, who led the radar observations at JPL, explained:

“Radar has the ability to identify asteroids with surfaces made of highly reflective rocky or metallic materials. We were able to show that radar scattering properties are consistent with a bright rocky surface, similar to a particular class of meteorites that reflect as much as 50 percent of the light falling on them.”

In addition to the observation campaign, NASA used TC4’s latest flyby as an opportunity to test communications between observatories, as well as the internal messaging and communications system that is currently in place. This network connects various government agencies and the executive branch and would come into play in the event of a predicted impact emergency.

*Asteroid 2012 TC4 projected flyby of the Earth-Moon system, which was calculated well before it took place. Credits: NASA/JPL-Caltech*

According to Vishnu Reddy, an assistant professor from the University of Arizona’s Lunar and Planetary Laboratory who led the observation campaign, this aspect of the exercise “demonstrated that we could organize a large, worldwide observing campaign on a short timeline, and communicate results efficiently.”Michael Kelley, the TC4 exercise lead at NASA Headquarters in Washington, added,”We are much better prepared today to deal with the threat of a potentially hazardous asteroid than we were before the TC4 campaign.”

Last, but not least, was the way the exercise brought scientists and institutions from all around the world together for a single purpose. As Boris Shustov – the science director for the Institute of Astronomy at the Russian Academy of Sciences, who was also part of the exercise – indicated, the exercise was an excellent way to test how the world’s scientific institutions would go about prepping for a possible asteroid impact:

“The 2012 TC4 campaign was a superb opportunity for researchers to demonstrate willingness and readiness to participate in serious international cooperation in addressing the potential hazard to Earth posed by NEOs. I am pleased to see how scientists from different countries effectively and enthusiastically worked together toward a common goal, and that the Russian-Ukrainian observatory in Terskol was able to contribute to the effort. In the future I am confident that such international observing campaigns will become common practice.”

In the event that a Near-Earth asteroid might actually pose a threat the Earth, it is good to know that all the tracking, monitoring and alert systems we have in place are in good working order. If we are going to trust the fate of human civilization (and possibly all life on Earth) to an advanced warning system, it just makes sense to have all the bugs worked out beforehand!

The TC4 Observation Campaign is sponsored by NASA’s Planetary Defense Coordination Office, which in turn is managed by the Planetary Science Division of the Science Mission Directorate at NASA Headquarters in Washington, D.C.

Further Reading: NASA

November 7, 2017November 30, 2017 by Matt Williams

Proxima Centauri has a Cold Dust Belt that Could Indicate Even More Planets

This artist’s impression shows how the newly discovered belts of dust around the closest star to the Solar System, Proxima Centauri, may look. Credit: ESO/M. Kornmesser

Proxima Centauri, in addition to being the closest star system to our own, is also the home of the closest exoplanet to Earth. The existence of this planet, Proxima b, was first announced in August of 2016 and then confirmed later that month. The news was met with a great deal of excitement, and a fair of skepticism, as numerous studies followed t were dedicated to determining if this planet could in fact be habitable.

Another important question has been whether or not Proxima Centauri could have any more objects orbiting it. According to a recent study by an international team of astronomers, Proxima Centauri is also home to a belt of cold dust and debris that is similar to the Main Asteroid Belt and Kuiper Belt in our Solar System. The existence of this dusty belt could indicate the presence of more planets in this star system.

The study, titled “ALMA Discovery of Dust Belts Around Proxima Centauri“, recently appeared online and is scheduled to appear in the Monthly Notices of the Astronomical Society. The study was led by Guillem Anglada from the Astrophysical Institute of Andalusia (CSIS), and included members from the Institute of Space Sciences (IEEC), the European Southern Observatory (ESO), the Joint ALMA Observatory, and multiple universities.

*View of the Atacama Large Millimeter/submillimeter Array (ALMA) site in the Atacama Desert of northern Chile. Credit: A. Marinkovic/X-Cam/ALMA (ESO/NAOJ/NRAO)*

For their study, the team relied on data obtained by the Atacama Large Millimeter/submillimter Array (ALMA) at the ALMA Observatory in Chile. These observations revealed the glow of a cold dust belt that is roughly 1 to 4 AUs from Proxima Centauri – one to four times the distance between the Earth and the Sun. This puts it significantly further out than Proxima b, which orbits its sun at a distance of 0.0485 AU (~5% of Earth’s distance from the Sun).

Dust belts are essentially the leftover material that did not form into larger bodies withing a star system. The particles of rock and ice in these belts vary in size from being smaller than a millimeter across to asteroids that are many kilometers in diameter. Based on their observations, the team estimated that the belt in Proxima Centauri has a total mass that is about one-hundredth the mass of Earth.

The team also estimated that this belt experiences temperatures of about 43 K (-230°C; -382 °F), making it as cold as the Kuiper Belt. As Dr. Anglada explained the significance of these findings in a recent ESO press release:

“The dust around Proxima is important because, following the discovery of the terrestrial planet Proxima b, it’s the first indication of the presence of an elaborate planetary system, and not just a single planet, around the star closest to our Sun.”

*This infographic compares the orbit of the planet around Proxima Centauri (Proxima b) with the same region of the Solar System. Credit: ESO*

The ALMA data also provided indications that Proxima Centauri might also have another belt located about ten times further out. In other words, Proxima Centauri may have two belts, just like our Solar System. If confirmed, this could indicate that this neighboring star also has a system of planets that fall within and between belts of unconsolidated material, which in turn is leftover from the early days of planet formation. As Dr. Anglada explained:

“This result suggests that Proxima Centauri may have a multiple planet system with a rich history of interactions that resulted in the formation of a dust belt. Further study may also provide information that might point to the locations of as yet unidentified additional planets.”

The very cold environment of this outer belt could also have some interesting implications, since its parent star is much dimmer than our own. Pedro Amado, who also hails from the Astrophysical Institute of Andalusia, was similarly enthusiastic about these findings. As he indicated, they are just the beginning of what is sure to be a long process of discovery about this system.

“These first results show that ALMA can detect dust structures orbiting around Proxima,” he said. “Further observations will give us a more detailed picture of Proxima’s planetary system. In combination with the study of protoplanetary discs around young stars, many of the details of the processes that led to the formation of the Earth and the Solar System about 4600 million years ago will be unveiled. What we are seeing now is just the appetiser compared to what is coming!”

*Project Starshot, an initiative sponsored by the Breakthrough Foundation, is intended to be humanity’s first interstellar voyage. Credit: breakthroughinitiatives.org*

This study is also likely to be of interest to those planning on conducting direct observations of the Alpha Centauri system, such as Project Blue. In the coming years, they hope to deploy a space telescope that will observe Alpha Centauri directly to study any exoplanets it may have. With a slight adjustment, this telescope could also take a gander at Proxima Centauri and aid in the hunt for a system of planets there.

And then there’s Breakthrough Starshot, the first proposed interstellar voyage which hopes to send a laser sail-driven nanocraft to Alpha Centauri in the coming decades. Recently, the scientists behind Starshot discussed the possibility of extending the mission to include a stopover in Proxima Centauri. Before such a mission can take place, the planners need to know what kind of dusty environment awaits it.

And of course, future studies will benefit from the deployment of next-generation instruments, like the James Webb Space Telescope (scheduled for launch in 2019) and the ESO’s Extremely Large Telescope (ELT) – which is expected to collect its first light in 2024.

Further Reading: ESO, arXiv