During the 13 years and 76 days that the Cassini mission spent around Saturn, the orbiter and its lander (the Huygens probe) revealed a great deal about Saturn and its systems of moons. This is especially true of Titan, Saturn’s largest moon and one of the most mysterious objects in the Solar System. As a result of Cassini’s many flybys, scientists learned a great deal about Titan’s methane lakes, nitrogen-rich atmosphere, and surface features.
Even though Cassini plunged into Saturn’s atmosphere on September 15th, 2017, scientists are still pouring over the things it revealed. For instance, before it ended its mission, Cassini captured an image of a strange cloud floating high above Titan’s south pole, one which is composed of toxic, hybrid ice particles. This discovery is another indication of the complex organic chemistry occurring in Titan’s atmosphere and on it’s surface.
Since this cloud was invisible to the naked eye, it was only observable thanks to Cassini’s Composite Infrared Spectrometer (CIRS). This instrument spotted the cloud at an altitude of about 160 to 210 km (100 to 130 mi), far above the methane rain clouds of Titan’s troposphere. It also covered a large area near the south pole, between 75° and 85° south latitude.
Using the chemical fingerprint obtained by the CIRS instrument, NASA researchers also conducted laboratory experiments to reconstruct the chemical composition of the cloud. These experiments determined that the cloud was composed of the organic molecules hydrogen cyanide and benzene. These two chemicals appeared to have condensed together to form ice particles, rather than being layered on top of each other.
For those who have spent more than the past decade studying Titan’s atmosphere, this was a rather interesting and unexpected find. As Carrie Anderson, a CIRS co-investigator at NASA’s Goddard Space Flight Center, said in a recent NASA press statement:
“This cloud represents a new chemical formula of ice in Titan’s atmosphere. What’s interesting is that this noxious ice is made of two molecules that condensed together out of a rich mixture of gases at the south pole.”
The presence of this cloud around Titan’s southern pole is also another example of the moon’s global circulation patterns. This involves currents of warm gases being sent from the hemisphere that is experiencing summer to the hemisphere experience winter. This pattern reverse direction when the seasons change, which leads to a buildup of clouds around whichever pole is experiencing winter.
When the Cassini orbiter arrived at Saturn in 20o4, Titan’s northern hemisphere was experiencing winter – which began in 2004. This was evidenced by the buildup of clouds around its north pole, which Cassini spotted during its first encounter with the moon later than same year. Similarly, the same phenomena was taking place around the south pole near the end of Cassini’s mission.
This was consistent with seasonal changes on Titan, which take place roughly every seven Earth years – a year on Titan lasts about 29.5 Earth years. Typically, the clouds that form in Titan’s atmosphere are structured in layers, where different types of gas will condense into icy clouds at different altitudes. Which ones condense is dependent on how much vapor is present and temperatures – which become steadily colder closer to the surface.
However, at times, different types of clouds can form over a range of altitudes, or co-condense with other types of clouds. This certainly appeared to be the case when it came to the large cloud of hydrogen cyanide and benzene that was spotted above the south pole. Evidence of this cloud was derived from three sets of Titan observations made with the CIRS instrument, which took place between July and November of 2015.
The CIRS instrument works by separating infrared light into its constituent colors, and then measures the strengths of these signals at the different wavelengths to determine the presence of chemical signatures. Previously, it was used to identify the presence of hydrogen cyanide ice clouds over the south pole, as well as other toxic chemicals in the moon’s stratosphere.
As F. Michael Flasar, the CIRS principal investigator at Goddard, said:
“CIRS acts as a remote-sensing thermometer and as a chemical probe, picking out the heat radiation emitted by individual gases in an atmosphere. And the instrument does it all remotely, while passing by a planet or moon.”
However, when examining the observation data for chemical “fingerprints”, Anderson and her colleagues noticed that the spectral signatures of the icy cloud did not match those of any individual chemical. To address this, the team began conducting laboratory experiments where mixtures of gases were condensed in a chamber that simulated conditions in Titan’s stratosphere.
After testing different pairs of chemicals, they finally found one which matched the infrared signature observed by CIRS. At first, they tried letting one gas condense before the other, but found that the best results were obtained when both gases were introduced and allowed to condense at the same time. To be fair, this was not the first time that Anderson and her colleagues had discovered co-condensed ice in CIRS data.
For example, similar observations were made near the north pole in 2005, about two years after the northern hemisphere experienced its winter solstice. At that time, the icy clouds were detected at a much lower altitude (below 150 km, or 93 mi) and showed chemical fingerprints of hydrogen cyanicide and caynoacetylene – one of the more complex organic molecules in Titan’s atmosphere.
This difference between this and the latest detection of a hybrid cloud, according to Anderson, comes down to differences in seasonal variations between the north and south poles. Whereas the northern polar cloud observed in 2005 was spotted about two years after the northern winter solstice, the southern cloud Anderson and her team recently examined was spotted two years before the southern winter solstice.
In short, it is possible that the mixture of the gases was slightly different in the two case, and/or that the northern cloud had a chance to warm slightly, thus altering its composition somewhat. As Anderson explained, these observations were made possible thanks to the many years that the Cassini mission spent around Saturn:
“One of the advantages of Cassini was that we were able to flyby Titan again and again over the course of the thirteen-year mission to see changes over time. This is a big part of the value of a long-term mission.”
Additional studies will certainly be needed to determine the structure of these icy clouds of mixed composition, and Anderson and her team already have some ideas on how they would look. For their money, the researchers expect these clouds to be lumpy and disorderly, rather than well-defined crystals like the single-chemical clouds.
In the coming years, NASA scientists are sure to be spending a great deal of time and energy sorting through all the data obtained by the Cassini mission over the course of its 13-year mission. Who knows what else they will detect before they have exhausted the orbiter’s vast collections of data?
Future Reading: NASA
The post Forecast for Titan: Cold, with a Chance of Noxious Ice Clouds appeared first on Universe Today.
In January of 2016, astronomers Mike Brown and Konstantin Batygin published the first evidence that there might be another planet in our Solar System. Known as “Planet 9” (“Planet X” to those who reject the controversial 2006 Resolution by the IAU), this hypothetical body was believed to orbit at an extreme distance from our Sun, as evidenced by the fact that certain Trans-Neptunian Objects (TNOs) all seem to be pointing in the same direction.
Since that time, more and more evidence has been produced that show how the presence of Planet 9 affected the evolution of the Solar System, leading it to become as it is today. For example, a recent study by a team of researchers from the University of Michigan has shown how Planet 9 may have kept certain TNOs from being destroyed or ejected from the Solar System over the course of billions of years.
The study, which was recently published in the Astronomical Journal under the title “Evaluating the Dynamical Stability of Outer Solar System Objects in the Presence of Planet Nine“, was led by Juliette Becker, a graduate student with the University of Michigan’s Department of Astronomy. It was supported by Professors David Gerdes and Fred Adams, as well as graduate and undergraduate students from UofM’s Depart of Physics.
For the sake of their study, Becker and her colleagues conducted a large set of computer simulations that examined the stability of Trans-Neptunian Objects (TNOs) who’s orbits are believed to have been influenced by Planet 9. In each simulation, the researchers tested a different version of Planet 9 to see if its gravitational influence would result in the Solar System as we know it today.
From this, they uncovered two key findings. First, the simulations showed that Planet 9 may have led to the current Solar System by preventing these TNOs from being destroyed or ejected from the Solar System. Second, the simulations indicated that TNOs can jump between stable orbits, a process they refer to as “resonance hoping”. This would prevent these same TNOs from being thrown out of the Kuiper Belt.
As Becker explained in a University of Michigan press statement:
“From that set of simulations, we found out that there are preferred versions of Planet Nine that make the TNO stay stable for longer, so it basically increases the probability that our solar system exists the way it does. Through these computer simulations, we were able to determine which realization of Planet Nine creates our solar system—the whole caveat here being, if Planet Nine is real.”
Next, Becker and her team examined the TNOs to see if they experienced resonance with Planet 9. This phenomena, which occurs as a result of objects exerting a gravitational influence on each other, causes them to line up in a pattern. What they found was that, on occasion, Neptune will push a TNOs out of its orbital resonance, but does not disturb it enough to send it towards the Sun.
A plausible explanation for this behavior was the gravitational influence of another object, which serves to catch any TNOs and confine them to a different resonance. In addition, the team also considered a newly-discovered TNO that was recently detected by The Dark Energy Survey collaboration – a group of 400 scientist from 26 institutions in seven countries, which includes several members from the University of Michigan.
This object has a high orbital inclination compared to the plane of the Solar System, where it is tilted at 54° relative to the Sun’s ecliptic. After analyzing this new object, Becker and team concluded that the object also experiences resonance hopping, which is consistent with the existence of Planet 9. This, along with other recent studies, are creating a picture where it is harder to imagine the Solar System without Planet 9 than with it.
As Becker explained, all that remains now is to observe Planet 9 directly.”The ultimate goal would be to directly see Planet Nine—to take a telescope, point it at the sky, and see reflected light from the sun bouncing off of Planet Nine,” she said. “Since we haven’t yet been able to find it, despite many people looking, we’re stuck with these kinds of indirect methods.”
On October 5th, 2017, Vice President Mike Pence announced the Trump administration’s plan to return astronauts to the Moon. Looking to the long-term, NASA and several other space agencies are also intent on establishing a permanent lunar base there. This base will not only provide opportunities for lunar science, but will facilitate missions to Mars and beyond.
The only question is, where should such a base be built? For many years, NASA, the ESA and other agencies have been exploring the possibility of stable lava tubes as a potential site. According to new study by a team of international scientists, the presence of such a tube has now been confirmed in the Marius Hills region. This location is likely to be the site of future lunar missions, and could even be the site of a future lunar habitat.
In 2009, data provided by the Terrain Camera aboard JAXA’s SELENE spacecraft indicated the presence of three huge pits on the Moon. These pits (aka. “skylights”) were of particular interest since they were seen as possible openings to subsurface lava channels. Since then, the Marius Hills region (where they were found) has been a focal point for astronomers and planetary scientists hoping to confirm the existence of lava tubes.
The recent study, titled “Detection of intact lava tubes at Marius Hills on the Moon by SELENE (Kaguya) Lunar Radar Sounder“, recently appeared in the journal Geophysical Research Letters. The team consisted of members from JAXA’s Institute of Space and Astronautical Science (ISAS), Purdue University, the University of Alabama, AstroLabs, the National Astronomical Observatory of Japan (NOAJ) and multiple Japanese Universities.
Together, they examined data from the SELENE mission’s Lunar Radar Sounder (LRS) from locations that were close to the Marius Hills Hole (MHH) to determine if the region hosted stable lava tubes. Such tubes are a remnant from the Moon’s past, when it was still volcanically active. These underground channels are believed to be an ideal location for a lunar colony, and for several reasons.
For starters, their thick roofs would provide natural shielding from solar radiation, cosmic rays, meteoric impacts, and the Moon’s extremes in temperature. These tubes, once enclosed, could also be pressurized to create a breathable environment. As such, finding an entrance to a stable lava tube would the first step towards selecting a possible site for such a colony.
As Junichi Haruyama, a senior researcher at JAXA and one of the co-authors on the study, explained in a University of Purdue press release:
“It’s important to know where and how big lunar lava tubes are if we’re ever going to construct a lunar base. But knowing these things is also important for basic science. We might get new types of rock samples, heat flow data and lunar quake observation data.”
Granted, the LRS was not specifically designed to detect lava tubes, but to characterize the origins of the Moon and its geologic evolution. For this reason, it did not fly close enough to the Moon to obtain extremely accurate information on the subsurface. Nevertheless, as SELENE passed near the Marius Hills Hole, the instrument picked up a distinctive echo pattern.
This pattern was characterized by a decrease in echo power followed by a large second echo peak. These two echoes correspond to radar reflections from the Moon’s surface, as well as the floor and ceiling of the open lava tube. When they analyzed this pattern, the research team interpreted it is evidence of a tube. They found similar echo patterns at several locations around the hole, which could indicate that there is more than one lava tube in the region.
To confirm their findings, the team also consulted data from NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission. Consisting of two spacecraft, this collaborative effort collected high-quality data on the Moon’s gravitational field between 2011 and 2012. By using GRAIL data that identified mass deficits under the surface, which are evidence of caverns, the team was able to narrow down their search.
Jay Melosh, a GRAIL co-investigator and Distinguished Professor of Earth, Atmospheric and Planetary Sciences at Purdue University, was also a co-author on the paper. As he explained:
“They knew about the skylight in the Marius Hills, but they didn’t have any idea how far that underground cavity might have gone. Our group at Purdue used the gravity data over that area to infer that the opening was part of a larger system. By using this complimentary technique of radar, they were able to figure out how deep and high the cavities are.”
On Earth, stable lava tubes have been found that can extend for dozens of kilometers. To date, the longest and deepest to be discovered is the Kazumura Cave in Hawaii, which is over a kilometer (3,614 feet) deep and 65.5 km (40.7 mi) long. On the Moon, however, lava tubes are much larger, due to the fact that the Moon has only a fraction of the Earth’s gravity (0.1654 g to be exact).
For a lava tube to be detecting using gravity data, it would need to be several kilometers in length and at least one kilometer in height and width. Since the tube in Marius Hills was detectable, it is likely big enough to house a major city. In fact, during a presentation at the 47th Lunar and Planetary Conference, researchers from Purdue University showed GRAIL data that indicated how the tube beneath the MHH could be large enough to house Philadelphia.
This most recent study was also the subject of a presentation at the 48th Lunar and Planetary Conference. Similar evidence of possible stable lava tubes in the Sea of Tranquility was also obtained by the Lunar Reconnaissance Orbiter (LRO) back in 2010. However, this latest combination of radar and gravity data has provided the clearest picture yet of what a stable lava tube looks like.
Similar evidence of lava tubes has also been discovered on Mars, and possible even Mercury. On Mars in particular, chains of pit craters, broad lava fans, skylights and partially collapsed lava tubes all indicate the presence of stable tubes. Based on this latest study, future mission to the Red Planet (which could include the creation of a habitat) might also entail the investigation of these features.
In fact, lava tubes could become the means through which a human presence is established throughout the Solar System someday!
The post Stable Lava Tube Could Provide a Potential Human Habitat on the Moon appeared first on Universe Today.
Today, there are multiple lines of evidence that indicate that during the Noachian period (ca. 4.1 to 3.7 billion years ago), microorganisms could have existed on the surface of Mars. These include evidence of past water flows, rivers and lakebeds, as well as atmospheric models that indicate that Mars once had a denser atmosphere. All of this adds up to Mars having once been a warmer and wetter place than it is today.
However, to date, no evidence has been found that life ever existed on Mars. As a result, scientists have been trying to determine how and where they should look for signs of past life. According to a new study by a team of European researchers, extreme lifeforms that are capable of metabolizing metals could have existed on Mars in the past. The “fingerprints” of their existence could be found by looking at samples of Mars’ red sands.
For the sake of their study, which recently appeared in the scientific journal Frontiers of Microbiology, the team created a “Mars Farm” to see how a form of extreme bacteria might fare in an ancient Martian environment. This environment was characterized by a comparatively thin atmosphere composed of mainly of carbon dioxide, as well as simulated samples of Martian regolith.
They then introduced a strain of bacteria known as Metallosphaera sedula, which thrives in hot, acidic environments. In fact, the bacteria’s optimal conditions are those where temperatures reach 347.1 K (74 °C; 165 °F) and pH levels are 2.0 (between lemon juice and vinegar). Such bacteria are classified as chemolithotrophs, which means that they are able to metabolize inogranic metals – like iron, sulfur and even uranium.
These stains of bacteria were then added to the samples of regolith that were designed to mimic conditions in different locations and historical periods on Mars. First, there was sample MRS07/22, which consisted of a highly-porous type of rock that is rich in silicates and iron compounds. This sample simulated the kinds of sediments found on the surface of Mars.
Then there was P-MRS, a sample that was rich in hydrated minerals, and the sulfate-rich S-MRS sample, which mimic Martian regolith that was created under acidic conditions. Lastly, there was the sample of JSC 1A, which was largely composed of the volcanic rock known as palagonite. With these samples, the team was able to see exactly how the presence of extreme bacteria would leave biosignatures that could be found today.
As Tetyana Milojevic – an Elise Richter Fellow with the Extremophiles Group at the University of Vienna and a co-author on the paper – explained in a University of Vienna press release:
“We were able to show that due to its metal oxidizing metabolic activity, when given an access to these Martian regolith simulants, M. sedula actively colonizes them, releases soluble metal ions into the leachate solution and alters their mineral surface leaving behind specific signatures of life, a ‘fingerprint’, so to say.”
The team then examined the samples of regolith to see if they had undergone any bioprocessing, which was possible thanks to the assistance of Veronika Somoza – a chemist from the University of Vienna’s Department of Physiological Chemistry and a co-author on the study. Using an electron microscope, combined with analytical spectroscopy technique, the team sought to determine if metals with the samples had been consumed.
In the end, the sets of microbiological and mineralogical data they obtained showed signs of free soluble metals, which indicated that the bacteria had effectively colonized the regolith samples and metabolized some of the metallic minerals within. As Milojevic indicated:
“The obtained results expand our knowledge of biogeochemical processes of possible life beyond Earth, and provide specific indications for detection of biosignatures on extraterrestrial material – a step further to prove potential extra-terrestrial life.”
In effect, this means that extreme bacteria could have existed on Mars billions of years ago. And thanks to the state of Mars today – with its thin atmosphere and lack of precipitation – the biosignatures they left behind (i.e. traces of free soluble metals) could be preserved within Martian regolith. These biosignatures could therefore be detected by upcoming sample-return missions, such as the Mars 2020 rover.
In addition to pointing the way towards possible indications of past life on Mars, this study is also significant as far as the hunt for life on other planets and star systems is concerned. In the future, when we are able to study extra-solar planets directly, scientists will likely be looking for signs of biominerals. Among other things, these “fingerprints” would be a powerful indicator of the existence of extra-terrestrial life (past or present).
Studies of extreme lifeforms and the role they play in the geological history of Mars and other planets is also helpful in advancing our understanding of how life emerged in the early Solar System. On Earth too, extreme bacteria played an important role in turning the primordial Earth into a habitable environment, and play an important role in geological processes today.
Last, but not least, studies of this nature could also pave the way for biomining, a technique where strains of bacteria extract metals from ores. Such a process could be used for the sake of space exploration and resource exploitation, where colonies of bacteria are sent out to mine asteroids, meteors and other celestial bodies.
The post Metal-Eating Bacteria Could Have Left their “Fingerprints” on Mars, Proving it Once Hosted Life appeared first on Universe Today.
Fraser Cain (universetoday.com / @fcain)
Dr. Paul M. Sutter (pmsutter.com / @PaulMattSutter)
Dr. Kimberly Cartier (KimberlyCartier.org / @AstroKimCartier )
Dr. Morgan Rehnberg (MorganRehnberg.com / @MorganRehnberg ChartYourWorld.org)
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The post Weekly Space Hangout – Oct 18, 2017: Weekly News Roundup appeared first on Universe Today.
Thanks to decades of exploration using robotic orbiter missions, landers and rovers, scientists are certain that billions of years ago, liquid water flowed on the surface of Mars. Beyond that, many questions have remained, which include whether or not the waterflow was intermittent or regular. In other words, was Mars truly a “warm and wet” environment billions of years ago, or was it more along the lines of “cold and icy”?
These questions have persisted due to the nature of Mars’ surface and atmosphere, which offer conflicitng answers. According to a new study from Brown University, it appears that both could be the case. Basically, early Mars could have had significant amounts of surface ice which experienced periodic melting, producing enough liquid water to carve out the ancient valleys and lakebeds seen on the planet today.
The study, titled “Late Noachian Icy Highlands Climate Model: Exploring the Possibility of Transient Melting and Fluvial/Lacustrine Activity Through Peak Annual and Seasonal Temperatures“, recently appeared in Icarus. Ashley Palumbo – a Ph.D. student with Brown’s Department of Earth, Environmental and Planetary Science – led the study and was joined by her supervising professor (Jim Head) and Professor Robin Wordsworth of Harvard University’s School of Engineering and Applied Sciences.
For the sake of their study, Palumbo and her colleagues sought to find the bridge between Mars’ geology (which suggests the planet was once warm and wet) and its atmospheric models, which suggest it was cold and icy. As they demonstrated, it’s plausible that during the past, Mars was generally frozen over with glaciers. During peak daily temperatures in the summer, these glaciers would melt at the edges to produce flowing water.
After many years, they concluded, these small deposits of meltwater would have been enough to carve the features observed on the surface today. Most notably, they could have carved the kinds of valley networks that have been observed on Mars southern highlands. As Palumbo explained in a Brown University press release, their study was inspired by similar climate dynamics that take place here on Earth:
“We see this in the Antarctic Dry Valleys, where seasonal temperature variation is sufficient to form and sustain lakes even though mean annual temperature is well below freezing. We wanted to see if something similar might be possible for ancient Mars.”
To determine the link between the atmospheric models and geological evidence, Palumbo and her team began with a state-of-the-art climate model for Mars. This model assumed that 4 billion years ago, the atmosphere was primarily composed of carbon dioxide (as it is today) and that the Sun’s output was much weaker than it is now. From this model, they determined that Mars was generally cold and icy during its earlier days.
However, they also included a number of variables which may have also been present on Mars 4 billion years ago. These include the presence of a thicker atmosphere, which would have allowed for a more significant greenhouse effect. Since scientists cannot agree how dense Mars’ atmosphere was between 4.2 and 3.7 billion years ago, Palumbo and her team ran the models to take into account various plausible levels of atmospheric density.
They also considered variations in Mars’ orbit that could have existed 4 billion years ago, which has also been subject to some guesswork. Here too, they tested a wide range of plausible scenarios, which included differences in axial tilt and different degrees of eccentricity. This would have affected how much sunlight is received by one hemisphere over another and led to more significant seasonal variations in temperature.
In the end, the model produced scenarios in which ice covered regions near the location of the valley networks in the southern highlands. While the planet’s mean annual temperature in these scenarios was well below freezing, it also produced peak summertime temperatures in the region that rose above freezing. The only thing that remained was to demonstrate that the volume of water produced would be enough to carve those valleys.
Luckily, back in 2015, Professor Jim Head and Eliot Rosenberg (an undergraduate with Brown at the time) created a study which estimated the minimum amount of water required to produce the largest of these valleys. Using these estimates, along with other studies that provided estimates of necessary runoff rates and the duration of valley network formation, Palumbo and her colleagues found a model-derived scenario that worked.
Basically, they found that if Mars had an eccentricity of 0.17 (compared to it’s current eccentricity of 0.0934) an axial tilt of 25° (compared to 25.19° today), and an atmospheric pressure of 600 mbar (100 times what it is today) then it would have taken about 33,000 to 1,083,000 years to produce enough meltwater to form the valley networks. But assuming for a circular orbit, an axial tile of 25°, and an atmosphere of 1000 mbar, it would have taken about 21,000 to 550,000 years.
The degrees of eccentricity and axial tilt required in these scenarios are well within the range of possible orbits for Mars 4 billion years ago. And as Head indicated, this study could reconcile the atmospheric and geological evidence that has been at odds in the past:
“This work adds a plausible hypothesis to explain the way in which liquid water could have formed on early Mars, in a manner similar to the seasonal melting that produces the streams and lakes we observe during our field work in the Antarctic McMurdo Dry Valleys. We are currently exploring additional candidate warming mechanisms, including volcanism and impact cratering, that might also contribute to melting of a cold and icy early Mars.”
It is also significant in that it demonstrates that Mars climate was subject to variations that also happen regularly here on Earth. This provides yet another indication of how our two plane’s are similar in some ways, and how research of one can help advance our understanding of the other. Last, but not least, it offers some synthesis to a subject that has produced a fair share of disagreement.
The subject of how Mars could have experienced warm, flowing water on its surface – and at a time when the Sun’s output was much weaker than it is today – has remained the subject of much debate. In recent years, researchers have advanced various suggestions as to how the planet could have been warmed, ranging from cirrus clouds to periodic bursts of methane gas from beneath the surface.
While this latest study has not quite settled the debate between the “warm and watery” and the “cold and icy” camps, it does offer compelling evidence that the two may not be mutually exclusive. The study was also the subject of a presentation made at the 48th Lunar and Planetary Science Conference, which took place from March 20th to 24th in The Woodland, Texas.
The post Flowing Water on Mars Likely Cold and Frosty, Says New Study appeared first on Universe Today.
PORT CANAVERAL/KENNEDY SPACE CENTER, FL – The now twice flown SpaceX first stage booster that successfully delivered the SES-11 UHDTV satellite to orbit at sunset Wednesday, Oct 11, sailed proudly back home into Port Canaveral during a beautiful Sunday sunrise, Oct. 15 only three days after it safely landed on a tiny droneship at sea.
The booster arrival also took place just hours after a ULA Atlas launched the covert NROL-52 surveillance satellite for the US National Reconnaissance Office (NRO) – making for a nonstop day of space action on the Florida Space Coast.
The 156-foot-tall Falcon 9 booster accomplished a precision guided rocket assisted touchdown on the football field sized OCISLY droneship platform about 8 minutes after the dinnertime liftoff with the private SES-11/EchoStar 105 communications satellite on Oct. 11 at 6:53 p.m. EDT from seaside Launch Complex 39A at NASA’s Kennedy Space Center in Florida.
The 15 story tall first stage came to rest slightly tilted a few degrees, similar to at least two prior boosters that soft landed upright on OCISLY while prepositioned several hundred miles off shore of the Florida peninsula in the Atlantic Ocean.
The recycled booster was towed into Port Canaveral by a SpaceX contracted tugboat accompanied by a small fleet of pilot ships and support vessels.
The doubly used and doubly successful booster entered the mouth of Port Canaveral around 7:15 a.m. EDT Sunday under dawns delightful twilight I witnessed from Jetty Park and beach together with a few space media colleagues and a small crowd of onlookers with little fanfare.
Over the next hour it was hauled through the narrow channel as numerous vessels large and small and pleasure craft sailed by, likely wondering what they were looking it.
Finally the droneship platform was docked at SpaceX’s spot leased near the two huge shipping cranes dominating the scene across from popular portside restaurants – and also not far from humongous cruise ships dwarfing the booster in size.
The next step was for dock workers to hoist a cap and attach it to the top of the booster. This enabled it to eventually be carefully raised off the barge with a crane by about 1 p.m. and then slowly moved and swung over and affixed onto a restraining pedestal stand on land.
By the next evening Monday night, all 4 landing legs were still intact. After they are all detached the booster will be lowered horizontally aided by the cabling attached by the workers and placed on a flab bed transporter and trucked back to the Cape.
However the impact of developing and reusing ‘used’ rockets is leading to an era when re-flown rockets are offered as a ‘routine service’ rather than the exception.
Rocket reusability is at the heart of the extraordinary vision of billionaire entrepreneur and SpaceX CEO Elon Musk to drastically cut space launch costs and one day build a ‘City on Mars’.
And it represents a ‘major sea change getting closer’ to fruition with each passing day thanks to SpaceX, said SES CTO Martin Halliwell in an exclusive interview with Universe Today, following the stunning sunset blastoff of the SES-11 UHDTV commercial satellite on another ‘flight-proven’ Falcon 9 booster that also re-landed – thus completing another remarkable round of rocket recovery and recycling or ‘launch, land and relaunch!’
“As I’ve said before, I think in a couple years time you won’t even consider whether it’s a preflown rocket or a new rocket or a second time rocket,” SES Chief Technology Officer Martin Halliwell told Universe Today in a one-on-one post launch interview.
“It will just be a flight and you will buy a service to get to orbit – and that will be that!”
“It’s a major sea change,” Halliwell explained. “That’s absolutely true.”
“We’re getting closer to that every day. It’s exactly where we are going. There is no doubt about it.”
The launch of EchoStar 105/SES-11 counts as only the third recycled SpaceX Falcon 9 ever to be launched and is the third successful mission with a flight-proven orbital class rocket.
All three ‘flight-proven’ missions have lifted off from Pad 39A this year and all three have relanded.
The Falcon 9 first stage appeared to be in good shape upon its return to Port. I did not observe noticeable significant damage to the outside of the booster skin, grid fins or landing legs. Scorching seemed comparable to the first two reflown boosters.
This booster originally flew on the NASA Dragon CRS-10 resupply mission to the International Space Station in February of this year.
On arrival it was clearly anchored to the OCISLY droneship deck with multiple chains as previously done for droneship landings as well as with what appears to be several gripper arms.
OCISLY, which stands for “Of Course I Still Love You,” had departed Port Canaveral several days ahead of the Oct. 11 launch and was prepositioned in the Atlantic Ocean off the US East coast, just waiting for the boosters 2nd approach and pinpoint propulsive soft landing.
The booster was outfitted with four grid fins and four landing legs to accomplish the pinpoint touchdown on the barge at sea.
SES was the first company to ever fly a payload on a ‘flight-proven’ Falcon 9. The SES-10 satellite lifted off successfully this spring on March 30, 2017.
The second reflown booster successfully launched the BulgariaSat-1 a few months later.
NASA is also assessing whether to utilize a reflown booster on upcoming ISS resupply missions – starting with the next flight of the Dragon CRS-13 cargo ship which may liftoff as soon as early December.
Pad 39A has been repurposed by SpaceX from its days as a NASA shuttle launch pad.
To date SpaceX has accomplished 18 successful landings of a recovered Falcon 9 first stage booster by land and by sea.
Watch for Ken’s continuing onsite coverage of SpaceX SES-11, ULA NROL-52 and NASA and space mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Saturn’s largest moon, Titan, is a mysterious place; and the more we learn about it, the more surprises it seems to have in store. Aside from being the only body beyond Earth that has a dense, nitrogen-rich atmosphere, it also has methane lakes on its surface and methane clouds in its atmosphere. This hydrological-cycle, where methane is converted from a liquid to a gas and back again, is very similar to the water cycle here on Earth.
Thanks to the NASA/ESA Cassini-Huygens mission, which concluded on September 15th when the craft crashed into Saturn’s atmosphere, we have learned a great deal about this moon in recent years. The latest find, which was made by a team of UCLA planetary scientists and geologists, has to do with Titan’s methane rain storms. Despite being a rare occurrence, these rainstorms can apparently become rather extreme.
The study which details their findings, titled “Regional Patterns of Extreme Precipitation on Titan Consistent with Observed Alluvial Fan Distribution“, recently appeared in the scientific journal Nature Geoscience. Led by Saun P. Faulk, a graduate student at UCLA’s Department of Earth, Planetary, and Space Sciences, the team conducted simulations of Titan’s rainfall to determine how extreme weather events have shaped the moon’s surface.
What they found was that the extreme methane rainstorms may imprint the moon’s icy surface in much the same way that extreme rainstorms shape Earth’s rocky surface. On Earth, intense rainstorms play an important role in geological evolution. When rainfall is heavy enough, storms can trigger large flows of water that transport sediment into low lands, where it forms cone-shaped features known as alluvial fans.
During it’s mission, the Cassini orbiter found evidence of similar features on Titan using its radar instrument, which suggested that Titan’s surface could be affected by intense rainfall. While these fans are a new discovery, scientists have been studying the surface of Titan ever since Cassini first reached the Saturn system in 2006. In that time, they have noted several interesting features.
These included the vast sand dunes that dominate Titan’s lower latitudes and the methane lakes and seas that dominate it’s higher latitudes – particularly around the northern polar region. The seas – Kraken Mare, Ligeia Mare, and Punga Mare – measure hundreds of km across and up to several hundred meters deep, and are fed by branching, river-like channels. There are also many smaller, shallower lakes that have rounded edges and steep walls, and are generally found in flat areas.
In this case, the UCLA scientists found that the alluvial fans are predominantly located between 50 and 80 degrees latitude. This puts them close to the center of the northern and southern hemispheres, though slightly closer to the poles than the equator. To test how Titan’s own rainstorms could cause these features, the UCLA team relied on computer simulations of Titan’s hydrological cycle.
What they found was that while rain mostly accumulates near the poles – where Titan’s major lakes and seas are located – the most intense rainstorms occur near 60 degrees latitude. This corresponds to the region where alluvial fans are most heavily concentrated, and indicates that when Titan does experience rainfall, it is quite extreme – like a seasonal monsoon-like downpour.
As Jonathan Mitchell – a UCLA associate professor of planetary science and a senior author of the study – indicated, this is not dissimilar to some extreme weather events that were recently experienced here on Earth. “The most intense methane storms in our climate model dump at least a foot of rain a day, which comes close to what we saw in Houston from Hurricane Harvey this summer,” he said.
The team also found that on Titan, methane rainstorms are rather rare, occurring less than once per Titan year – which works out to 29 and a half Earth years. But according to Mitchell, who is also the principal investigator of UCLA’s Titan climate modeling research group, this is more often than they were expecting. “I would have thought these would be once-a-millennium events, if even that,” he said. “So this is quite a surprise.”
In the past, climate models of Titan have suggested that liquid methane generally concentrates closer to the poles. But no previous study has investigated how precipitation might cause sediment transport and erosion, or shown how this would account for various features observed on the surface. As a result, this study also suggests that regional variations in surface features could be caused by regional variations in precipitation.
On top of that, this study is an indication that Earth and Titan have even more in common than previously thought. On Earth, contrasts in temperature are what lead to intense seasonal weather events. In North America, tornadoes occur during the early to late Spring, while blizzards occur during the winter. Meanwhile, temperature variations in the Atlantic ocean are what lead to hurricanes forming between the summer and fall.
Similarly, it appears that on Titan, serious variations in temperature and moisture are what triggers extreme weather. When cooler, wetter air from the higher latitudes interacts with warmer, drier air from the lower latitudes, intense rainstorms result. These findings are also significant when it comes to other bodies in our Solar System that have alluvial fans on them – such as Mars.
In the end, understanding the relationship between precipitation and planetary surfaces could lead to new insights about the impact climate change has on Earth and the other planets. Such knowledge would also go a long way towards helping us mitigate the effects it is having here on Earth, where the changes are only unnatural, but also sudden and very hazardous.
And who knows? Someday, it could even help us to alter the environments on other planets and bodies, thus making them more suitable for long-term human settlement (aka. terraforming)!
The post Scientists Find Evidence of Extreme Methane Storms On Titan appeared first on Universe Today.
About 130 million years ago, in a galaxy far away, two neutron stars collided. The cataclysmic crash produced gravitational waves, ripples in the fabric of space and time. This event is now the 5th observation of gravitational waves by the Laser Interferometer Gravitational wave Observatory (LIGO) and Virgo collaboration, and the first detected that was not caused by the collision of two black holes.
But this event — called a kilonova — produced something else too: light, across multiple wavelengths.
For the first time in history, an astronomical phenomenon has been first observed through gravitational waves and then seen with telescopes. In an incredibly collaborative effort, over 3,500 astronomers using 100 instruments on over 70 telescopes around the world and in space worked with physicists from the LIGO and Virgo collaboration.
Scientists call this “multimessenger astronomy.”
“Together, all these observations are bigger than the sum of their parts,” said Laura Cadonati, LIGO’s Deputy Spokesperson at a briefing today. “We are now learning about the physics of the universe, about the elements we are made of, in a way that no one has ever done before.”
“It will give us insight into how supernova explosions work, how gold and other heavy elements are created, how the nuclei in our body works and even how fast the universe is expanding,” said Manuela Campanelli, from the Rochester Institute of Technology. “Multimessenger astronomy demonstrates how we can combine the old way with the new. It has changed the way astronomy is done.”
Neutron stars are the crushed leftover cores of massive stars that long ago exploded as supernovae. The two stars, located near each other in a galaxy called NGC 4993, started out between 8-20 times the mass of our sun. Then with their supernovas, each condensed down to about 10 miles in diameter, the size of a city. These are stars composed entirely of neutrons and are in-between normal stars and black holes in size and density — just a teaspoon of neutron star material would weigh 1 billion tons.
They spun around each other in a cosmic dance until their mutual gravity caused them to collide. That collision produced a fireball of astronomical proportions and the repercussions of that event arrived at Earth 130 million years later.
“While this event took place 130 million years ago, we only found out about this on Earth on August 17, 2017, just before the solar eclipse,” said Andy Howell from the Las Cumbres Observatory, speaking at a press briefing today. “We’ve been keeping this secret the whole time and we’re about to bust!”
At 8:41 am EDT, LIGO and Virgo felt the early tremors of the ripples of spacetime, gravitational waves. Just two seconds later, a bright flash of gamma rays was detected by NASA’s Fermi space telescope. This allowed researchers to quickly pinpoint the direction from which the waves were coming.
Alerted by an Astronomers Telegram, thousands of astronomers around the world scrambled to make observations and begin collecting additional data from the neutron star merger.
This animation shows how LIGO, Virgo, and space- and ground-based telescopes zoomed in on the location of gravitational waves detected August 17, 2017 by LIGO and Virgo. By combining data from the Fermi and Integral space missions with data from LIGO and Virgo, scientists were able to confine the source of the waves to a 30-square-degree sky patch. Visible-light telescopes searched a large number of galaxies in that region, ultimately revealing NGC 4993 to be the source of gravitational waves.
“This event has the most precise sky localization of all detected gravitational waves so far,” Jo van den Brand, spokesperson for the Virgo collaboration, said in a statement. “This record precision enabled astronomers to perform follow-up observations that led to a plethora of breathtaking results.”
This provides the first real evidence that light and gravitational waves travel at the same speeds – near the speed of light — as Einstein predicted.
Observatories from the very small to the most well-known were involved, quickly making observations. While bright at first, the event faded in less than 6 days. Howell said the observed light was 2 million times brighter than the Sun over the coarse of the first few hours, but it then faded over a few days.
The Dark Energy Camera (DECam), which is mounted on the Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory in the Chilean Andes was one of the instruments that helped localize the source of the event.
“The challenge that we face every time that the LIGO collaboration issues a new observational trigger is how do we search for a source that is rapidly fading, was possibly faint to begin with, and is located somewhere over there,” said Marcelle Soares-Santos, from Brandeis University at the briefing. She is the first author on the paper describing the optical signal associated with the gravitational waves. “It’s the classical challenge of finding a needle in a haystack with the added complication that the needle is far away and haystack is moving.”
With the DECam, they were quickly able to determine the source galaxy, and rule out 1500 other candidates that were present in that haystack.
“Things that look like needles are very common, so we need to make sure we have the right one. Today, we are certain we have,” Soares-Santos added.
In the very small department, a small robotic 16-inch telescope called PROMPT (Panchromatic Robotic Optical Monitoring and Polarimetry Telescope) — which astronomer David Sand from the University of Arizona described at “basically a souped-up amateur telescope,” — also helped determine the source. Sand said this proves that even small telescopes can play a roll in multimessenger astronomy.
The well known is led by Hubble and several other NASA and ESA space observatories, such as the Swift, Chandra and Spitzer missions. Hubble captured images of the galaxy in visible and infrared light, witnessing a new bright object within NGC 4993 that was brighter than a nova but fainter than a supernova. The images showed that the object faded noticeably over the six days of the Hubble observations. Using Hubble’s spectroscopic capabilities the teams also found indications of material being ejected by the kilonova as fast as one-fifth of the speed of light.
“This is a game-changer for astrophysics,” said Howell. “A hundred years after Einstein theorized gravitational waves, we’ve seen them and traced them back to their source to find an explosion with new physics of the kind we only dreamed about before.”
Here are just a few of insights this single event created, using multimessenger astronomy:
* Gamma rays: These flashes of light are now definitively associated with merging neutron stars and will help scientists figure out how supernova explosions work, explained Richard O’Shaughnessy, also from Rochester Institute of Technology and a member of the LIGO team. “The initial gamma-ray measurements, combined with the gravitational-wave detection, further confirm Einstein’s general theory of relativity, which predicts that gravitational waves should travel at the speed of light,” he said.
* The source of gold and platinum: “These observations reveal the direct fingerprints of the heaviest elements in the periodic table,” said Edo Berger, from the Harvard Smithsonian Center for Astrophysics, speaking at the briefing. “The collision of the two neutron stars produced 10 times of mass of Earth in gold and platinum alone. Think about how as these materials are flying out of this event, they eventually combine with other elements to form stars, planets, life … and jewelry.”
Berger added something else to think about: the original supernova explosions of these stars produced all the heavy elements up to iron and nickel. Then in the kilonova in this one system, we can see the complete history of how the periodocial table of the heavy elements came to being.
Howell said that when you split the signatures of the heavy elements into a spectrum, you create a rainbow. “So there really was a pot of gold at the end of the rainbow, at least a kilonova rainbow,” he joked.
* Nuclear physics astronomy: “Eventually, more observations like this discovery will tell us how the nuclei in our body works,” O’Shaughnessy said. “The effects of gravity on neutron stars will tell us how big balls of neutrons behave, and, by inference, little balls of neutrons and protons — the stuff inside of our body that makes up most of our mass”; and
* Cosmology:- “Scientists now can independently measure how fast the universe is expanding by comparing the distance to the galaxy containing the bright flare of light and distance inferred from our gravitational wave observation,” said O’Shaughnessy.
“The ability to study the same event with both gravitational waves and light is a real revolution in astronomy,” said astronomer Tony Piro from the CfA. “We can now study the universe with completely different probes, which teaches things we could never know with only one or the other.”
“For me, what made this event so amazing is that not only did we detect gravitational waves, but we saw light across the electromagnetic spectrum, seen by 70 observatories around the world,” said David Reitz, scientific spokesman for LIGO, at today’s press briefing. “This is the first time the cosmos has provided to us the equivalent of movies with sound. The video is the observational astronomy across various wavelengths and the sound is gravitational waves.”
The post First Cosmic Event Observed in Both Gravitational Waves and Light appeared first on Universe Today.
This week’s Carnival of Space is hosted by Brad Rogers at The Evolving Planet blog.
And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to email@example.com, and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.