For many years it was thought that these megafloods were caused by the release of a deep global hydrosphere in the Martian subsoil. However, the research conducted by J. P. Alexis Rodríguez of the Planetary Science Institute (PSI-USA), with the participation of Rogelio Linares and Mario Zarroca of the Department of Geology of the Universitat Autònoma de Barcelona (UAB), has revealed that their origin could have been vast quantities of sediment and ice deposited 450 million years before the floods.

The findings from this project, which was partially supported by NASA funding for the PSI under its Planetary Geology and Geophysics Program, are detailed in the study entitled “Martian outflow channels: How did their source aquifers form, and why did they drain so quickly?”

The article, co-authored by the UAB Geology Department members mentioned above, describes how the sediments carried by rivers and glaciers filled up enormous canyons below an ancient ocean located in the Northern Lowlands, and how it was the release of the water trapped in these buried sediments that caused the megafloods, whose effects we can observe in the present.

The canyons filled up, the ocean disappeared and the planet surface remained frozen for around 450 million years. Subsequently, 3200 million years ago, the heat from lava beneath the canyons thawed the ice trapped in the sediments and enormous rivers of subterranean water spread over hundreds of kilometres, before eventually bursting out on to the now-dry surface and causing the megafloods.

In the words of the Geology Department researchers, “Our research suggests that, given that the process was regional rather than global, there could still be large reservoirs of subterranean water trapped under the surface of Mars, in the areas around the old northern ocean, or in other parts of the planet where seas and lakes formed at the same time.” “Traces of ancient environments capable of sustaining life forms similar to those on Earth could have been preserved in sub-surface materials that are now exposed,” claim R. Linares and M. Zarroca. “The results obtained could have clear implications both for exobiological research and for future human activity on Mars.”

To illustrate the scale of the Martian megafloods, the UAB researchers have estimated the effect they would have on Europe, quantifying it as around 2,500,000 km².

Story Source:

The above post is reprinted from materials provided by Universitat Autònoma de Barcelona. Note: Materials may be edited for content and length.

Journal Reference:

1. J. Alexis P. Rodriguez, Jeffrey S. Kargel, Victor R. Baker, Virginia C. Gulick, Daniel C. Berman, Alberto G. Fairén, Rogelio Linares, Mario Zarroca, Jianguo Yan, Hideaki Miyamoto, Natalie Glines. Martian outflow channels: How did their source aquifers form, and why did they drain so rapidly?Scientific Reports, 2015; 5: 13404 DOI: 10.1038/srep13404
   

{ http://nationalufocenter.com/ }

For many years it was thought that these megafloods were caused by the release of a deep global hydrosphere in the Martian subsoil. However, the research conducted by J. P. Alexis Rodríguez of the Planetary Science Institute (PSI-USA), with the participation of Rogelio Linares and Mario Zarroca of the Department of Geology of the Universitat Autònoma de Barcelona (UAB), has revealed that their origin could have been vast quantities of sediment and ice deposited 450 million years before the floods.

The findings from this project, which was partially supported by NASA funding for the PSI under its Planetary Geology and Geophysics Program, are detailed in the study entitled “Martian outflow channels: How did their source aquifers form, and why did they drain so quickly?”

The article, co-authored by the UAB Geology Department members mentioned above, describes how the sediments carried by rivers and glaciers filled up enormous canyons below an ancient ocean located in the Northern Lowlands, and how it was the release of the water trapped in these buried sediments that caused the megafloods, whose effects we can observe in the present.

The canyons filled up, the ocean disappeared and the planet surface remained frozen for around 450 million years. Subsequently, 3200 million years ago, the heat from lava beneath the canyons thawed the ice trapped in the sediments and enormous rivers of subterranean water spread over hundreds of kilometres, before eventually bursting out on to the now-dry surface and causing the megafloods.

In the words of the Geology Department researchers, “Our research suggests that, given that the process was regional rather than global, there could still be large reservoirs of subterranean water trapped under the surface of Mars, in the areas around the old northern ocean, or in other parts of the planet where seas and lakes formed at the same time.” “Traces of ancient environments capable of sustaining life forms similar to those on Earth could have been preserved in sub-surface materials that are now exposed,” claim R. Linares and M. Zarroca. “The results obtained could have clear implications both for exobiological research and for future human activity on Mars.”

To illustrate the scale of the Martian megafloods, the UAB researchers have estimated the effect they would have on Europe, quantifying it as around 2,500,000 km².

Story Source:

The above post is reprinted from materials provided by Universitat Autònoma de Barcelona. Note: Materials may be edited for content and length.

Journal Reference:

1. J. Alexis P. Rodriguez, Jeffrey S. Kargel, Victor R. Baker, Virginia C. Gulick, Daniel C. Berman, Alberto G. Fairén, Rogelio Linares, Mario Zarroca, Jianguo Yan, Hideaki Miyamoto, Natalie Glines. Martian outflow channels: How did their source aquifers form, and why did they drain so rapidly?Scientific Reports, 2015; 5: 13404 DOI: 10.1038/srep13404

{ http://nationalufocenter.com/ }

Now, in a study in the journal Nature, astronomers at Columbia University provide additional evidence that a pair of closely orbiting black holes is causing the rhythmic flashes of light coming from quasar PG 1302-102.

Based on calculations of the pair’s mass–together, and relative to each other–the researchers go on to predict a smashup 100,000 years from now, an impossibly long time to humans but the blink of an eye to a star or black hole. Spiraling together 3.5 billion light-years away, deep in the Virgo constellation, the pair is separated by a mere light-week. By contrast, the closest previously confirmed black hole pair is separated by 20 light-years.

“This is the closest we’ve come to observing two black holes on their way to a massive collision,” said the study’s senior author, Zoltan Haiman, an astronomer at Columbia. “Watching this process reach its culmination can tell us whether black holes and galaxies grow at the same rate, and ultimately test a fundamental property of space-time: its ability to carry vibrations called gravitational waves, produced in the last, most violent, stage of the merger.”

At the center of most giant galaxies, including our own Milky Way, lies a supermassive black hole so dense that not even light can escape. Over time, black holes grow bigger–millions to billions times more massive than the sun–by gobbling up stars, galaxies and even other black holes.

A supermassive black hole about to cannibalize its own can be detected by the mysterious flickering of a quasar–the beacon of light produced by black holes as they burn through gas and dust swirling around them. Normally, quasars brighten and dim randomly, but when two black holes are on the verge of uniting, the quasar appears to flicker at regular intervals, like a light bulb on timer.

Recently, a team led by Matthew Graham, a computational astronomer at the California Institute of Technology, designed an algorithm to pick out repeating light signals from 247,000 quasars monitored by telescopes in Arizona and Australia. Of the 20 pairs of black hole candidates discovered, they focused on the most compelling bright quasar– PG 1302-102. In a January study in Nature, they showed that PG 1302-102 appeared to brighten by 14 percent every five years, indicating the pair was less than a tenth of a light-year apart.

Intrigued, Haiman and his colleagues wondered if they could build a theoretical model to explain the repeating signal. If the black holes were as close as predicted, one had to be circling a much larger counterpart at nearly a tenth of the speed of light, they hypothesized. At that speed, the smaller black hole would appear to brighten as it approached Earth’s line of sight under the relativistic Doppler beaming effect.

If correct, they predicted they would find a five-year cycle in the quasar’s ultraviolet emissions–only two-and-a-half times more variable in its intensity. Analyzing UV observations collected by NASA’s Hubble and GALEX space telescopes they found exactly that.

Previous explanations for the repeating signal include a warp in the debris disks orbiting the black holes, a wobble in the axis of one black hole and a lopsided debris disk formed as one black hole draws material off the other–all creating the impression of a periodic flicker from Earth.

The new study also offers a new technique for investigating other converging black holes, the researchers said. By estimating the combined and relative mass of PG 1302-102’s black holes, they narrow down the pair’s predicted crash time to between 20,000 and 350,000 years from now with a best estimate of 100,000 years. (The predicted crash time by Graham’s team was 10,000 to several million years from now with a best estimate of 250,000 years).

“We can start to put numbers on the rates that black holes come together and build up into larger black holes, and use what we’re learning to search for more black holes pairs,” said study coauthor David Schiminovich, an astronomer at Columbia.

An uptick in the number of black hole binary discoveries has made astronomers hopeful that a collision could be detected in the next decade. This summer, Graham and his colleagues reported another 90 candidates, while astronomers at Columbia expect to soon unveil discoveries of their own from data collected at California’s Palomar Observatory.

With more black holes to watch, the chance of witnessing a crash and the gravitational waves predicted, but not yet detected, by Einstein’s general theory of relativity, grows.

“The detection of gravitational waves lets us probe the secrets of gravity and test Einstein’s theory in the most extreme environment in our universe–black holes,” said the study’s lead author, Daniel D’Orazio, a graduate student at Columbia. “Getting there is a holy grail of our field.”

Story Source:

The above post is reprinted from materials provided by Columbia University. Note: Materials may be edited for content and length.

Journal Reference:

1. Daniel J. D’Orazio, Zoltán Haiman, David Schiminovich. Relativistic boost as the cause of periodicity in a massive black-hole binary candidate. Nature, 2015; 525 (7569): 351 DOI:10.1038/nature15262

{ http://nationalufocenter.com/ }

To obtain these highest-resolution radar images of the asteroid, scientists used the 230-foot (70-meter) DSS-14 antenna at Goldstone, California, to transmit high-power microwaves toward the asteroid. The signal bounced off the asteroid, and its radar echoes were received by the National Radio Astronomy Observatory’s (NRAO) 100-meter (330-foot) Green Bank Telescope in West Virginia. The radar images achieve a spatial resolution as fine as 13 feet (4 meters) per pixel.

The radar images were taken as the asteroid flew past Earth on October 31 at 1 p.m. EDT at about 1.3 lunar distances (300,000 miles, or 480,000 kilometers) from Earth. Asteroid 2015 TB145 is spherical in shape and approximately 2,000 feet (600 meters) in diameter.

“The radar images of asteroid 2015 TB145 show portions of the surface not seen previously and reveal pronounced concavities, bright spots that might be boulders, and other complex features that could be ridges,” said Lance Benner of NASA’s Jet Propulsion Laboratory in Pasadena, California, who leads NASA’s asteroid radar research program. “The images look distinctly different from the Arecibo radar images obtained on October 30 and are probably the result of seeing the asteroid from a different perspective in its three-hour rotation period.”

“Working with our observatory partners, we were able to get our resolution down to less than 13 feet (four meters) per pixel,” said Shantanu Naidu, a postdoctoral student at the California Institute of Technology in Pasadena, and a member of the radar team. “It is a truly remarkable achievement, one which we will later be able to apply when future flyby opportunities present themselves.”

The next time that asteroid 2015 TB145 will be in Earth’s neighborhood will be in September 2018, when it will make a distant pass at about 24 million miles (38 million kilometers), or about a quarter the distance between Earth and Sun.

Radar is a powerful technique for studying an asteroid’s size, shape, rotation, surface features and surface roughness, and for improving the calculation of asteroid orbits. Radar measurements of asteroid distances and velocities often enable computation of asteroid orbits much further into the future than would be possible otherwise.

The 100-meter GBT is the world’s largest fully steerable radio telescope. Its location in the National Radio Quiet Zone and the West Virginia Radio Astronomy Zone protects the incredibly sensitive telescope from unwanted radio interference, enabling it to perform unique observations.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Story Source:

The above post is reprinted from materials provided by National Radio Astronomy Observatory. Note: Materials may be edited for content and length.

{ http://nationalufocenter.com/ }

For many years it was thought that these megafloods were caused by the release of a deep global hydrosphere in the Martian subsoil. However, the research conducted by J. P. Alexis Rodríguez of the Planetary Science Institute (PSI-USA), with the participation of Rogelio Linares and Mario Zarroca of the Department of Geology of the Universitat Autònoma de Barcelona (UAB), has revealed that their origin could have been vast quantities of sediment and ice deposited 450 million years before the floods.

The findings from this project, which was partially supported by NASA funding for the PSI under its Planetary Geology and Geophysics Program, are detailed in the study entitled “Martian outflow channels: How did their source aquifers form, and why did they drain so quickly?”

The article, co-authored by the UAB Geology Department members mentioned above, describes how the sediments carried by rivers and glaciers filled up enormous canyons below an ancient ocean located in the Northern Lowlands, and how it was the release of the water trapped in these buried sediments that caused the megafloods, whose effects we can observe in the present.

The canyons filled up, the ocean disappeared and the planet surface remained frozen for around 450 million years. Subsequently, 3200 million years ago, the heat from lava beneath the canyons thawed the ice trapped in the sediments and enormous rivers of subterranean water spread over hundreds of kilometres, before eventually bursting out on to the now-dry surface and causing the megafloods.

In the words of the Geology Department researchers, “Our research suggests that, given that the process was regional rather than global, there could still be large reservoirs of subterranean water trapped under the surface of Mars, in the areas around the old northern ocean, or in other parts of the planet where seas and lakes formed at the same time.” “Traces of ancient environments capable of sustaining life forms similar to those on Earth could have been preserved in sub-surface materials that are now exposed,” claim R. Linares and M. Zarroca. “The results obtained could have clear implications both for exobiological research and for future human activity on Mars.”

To illustrate the scale of the Martian megafloods, the UAB researchers have estimated the effect they would have on Europe, quantifying it as around 2,500,000 km².

Story Source:

The above post is reprinted from materials provided by Universitat Autònoma de Barcelona. Note: Materials may be edited for content and length.

Journal Reference:

1. J. Alexis P. Rodriguez, Jeffrey S. Kargel, Victor R. Baker, Virginia C. Gulick, Daniel C. Berman, Alberto G. Fairén, Rogelio Linares, Mario Zarroca, Jianguo Yan, Hideaki Miyamoto, Natalie Glines. Martian outflow channels: How did their source aquifers form, and why did they drain so rapidly?Scientific Reports, 2015; 5: 13404 DOI: 10.1038/srep13404

{ http://nationalufocenter.com/ }

The story that has unfolded is a wet one: Mars appears to have had a more massive atmosphere billions of years ago than it does today, with an active hydrosphere capable of storing water in long-lived lakes. The MSL team has concluded that this water helped to fill Gale Crater, the MSL rover Curiosity’s landing site, with sediment deposited as layers that formed the foundation for the mountain found in the middle of the crater today.

Curiosity has been exploring Gale Crater, which is estimated to be between 3.8 billion and 3.6 billion years old, since August 2012. In mid-September 2014, the rover reached the foothills of Aeolis Mons, a three-mile-high layered mountain nicknamed “Mount Sharp” in honor of the late Caltech geologist Robert Sharp. Curiosity has been exploring the base of the mountain since then.

“Observations from the rover suggest that a series of long-lived streams and lakes existed at some point between 3.8 billion to 3.3 billion years ago, delivering sediment that slowly built up the lower layers of Mount Sharp,” says Ashwin Vasavada (PhD ’98), MSL project scientist. “However, this series of long-lived lakes is not predicted by existing models of the ancient climate of Mars, which struggle to get temperatures above freezing,” he says.

This mismatch between the predictions of Mars’s ancient climate that arise from models developed by paleoclimatologists and indications of the planet’s watery past, as interpreted by geologists, bears similarities to a century-old scientific conundrum–in this case, about Earth’s ancient past.

At the time, geologists first began to recognize that the shapes of the continents matched each other, almost like scattered puzzle pieces, explains John Grotzinger, Caltech’s Fletcher Jones Professor of Geology, chair of the Division of Planetary and Geological Sciences, and lead author of the paper. “Aside from the shapes of the continents, geologists had paleontological evidence that fossil plants and animals in Africa and South America were closely related, as well as unique volcanic rocks suggestive of a common spatial origin. The problem was that the broad community of earth scientists could not come up with a physical mechanism to explain how the continents could plow their way through Earth’s mantle and drift apart. It seemed impossible. The missing component was plate tectonics,” he says. “In a possibly similar way, we are missing something important about Mars.”

As Curiosity has trekked across Gale Crater, it has stopped to examine numerous areas of interest. All targets are imaged, and soil samples have been scooped from some; the rocks in a select few places have been drilled for samples. These samples are deposited into the rover’s onboard laboratories. Using data from these instruments, as well as visual imaging from the onboard cameras and spectroscopic analyses, MSL scientists have pieced together an increasingly coherent and compelling story about the evolution of this region of Mars.

Before Curiosity landed on Mars, scientists proposed that Gale Crater had filled with layers of sediments. Some hypotheses were “dry,” implying that the sediments accumulated from wind-blown dust and sand, whereas others focused on the possibility that sediment layers were deposited in ancient streams and lakes. The latest results from Curiosity indicate that these wetter scenarios were correct for the lower portions of Mount Sharp. Based on the new analysis, the filling of at least the bottom layers of the mountain occurred mostly by ancient rivers and lakes.

“During the traverse of Gale, we have noticed patterns in the geology where we saw evidence of ancient fast-moving streams with coarser gravel as well as places where streams appear to have emptied out into bodies of standing water,” Vasavada says. “The prediction was that we should start seeing water-deposited, fine-grained rocks closer to Mount Sharp. Now that we’ve arrived, we’re seeing finely laminated mudstones in abundance.” These silty layers in the strata are interpreted as ancient lake deposits.

“These finely laminated mudstones are very similar to those we see on Earth,” says Woody Fischer, professor of geobiology at Caltech and coauthor of the paper. “The scale of lamination–which occurs both at millimeter and centimeter scale–represents the settling of plumes of fine sediment through a standing body of water. This is exactly what we see in rocks that represent ancient lakes on Earth. “The mudstone indicates the presence of bodies of standing water in the form of lakes that remained for long periods of time, possibly repeatedly expanding and contracting during hundreds to millions of years. These lakes deposited the sediment that eventually formed the lower portion of the mountain.

“Paradoxically, where there is a mountain today there was once a basin, and it was sometimes filled with water,” says Grotzinger. “Curiosity has measured about 75 meters of sedimentary fill, but based on mapping data from NASA’s Mars Reconnaissance Orbiter and images from Curiosity’s cameras, it appears that the water-transported sedimentary deposition could have extended at least 150-200 meters above the crater floor, and this equates to a duration of millions of years in which lakes could have been intermittently present within the Gale Crater basin” Grotzinger says. Furthermore, the total thickness of sedimentary deposits in Gale Crater that indicate interaction with water could extend higher still–up to perhaps 800 meters above the crater floor, and possibly representing tens of millions of years.

But layers deposited above that level do not require water as an agent of deposition or alteration. “Above 800 meters, Mount Sharp shows no evidence of hydrated strata, and that is the bulk of what forms Mount Sharp. We see another 4,000 meters of nothing but dry strata,” Grotzinger says. He suggests that perhaps this segment of the crater’s history may have been dominated by eolian, or wind-driven, deposition, as was once imagined for the lower part explored by Curiosity. This occurred after the wet period that built up the base of the mountain.

A lingering question surrounds the original source of the water that carried sediment into the crater. For flowing water to have existed on the surface, Mars must have had a thicker atmosphere and warmer climate than has been theorized for the time frame bookending the intense geological activity in Gale Crater. Evidence for this ancient, wetter climate exists in the rock record. However, current models of this paleoclimate–factoring in estimates of the early atmosphere’s mass, composition, and the amount of energy it received from the sun–come up, quite literally, dry. Those models indicate that the atmosphere of Mars could not have sustained large quantities of liquid water.

Yet the rock record discovered at Gale Crater suggests a different scenario. “Whether it was snowfall or rain, you have geologic evidence for that moisture accumulating in the highlands of the Gale Crater rim,” Grotzinger says. In the case of Gale Crater, at least some of the water was supplied by the highlands that form the crater rim, but groundwater discharge–a standard explanation to reconcile wet geologic observations with dry paleoclimatic predictions–is unlikely in this area. “Right on the other side of Gale’s northern rim are the Northern Plains. Some have made the argument that there was a northern ocean sitting out there, and that’s one way to get the moisture that you need to match what we are seeing in the rocks.” Pinpointing the possible location of an ocean, however, does not help to explain how that water managed to exist as a liquid for extended periods of time on the surface.

As climatologists try to develop new atmospheric models, help should be coming from the continuing explorations by Curiosity. “There are still many kilometers of Mars history to explore,” says Fischer. He thinks that some of the most exciting data yet may come in the next few years as Curiosity climbs higher on Mount Sharp. “The strata will reveal Gale’s early history, its story. We know there are rocks that were deposited underwater, in the lake. What is the chemistry of these rocks? That lake represented an interface between the water and the atmosphere, and should tell us important things about the environment of the time.”

“We have tended to think of Mars as being simple,” adds Grotzinger. “We once thought of the earth as being simple, too. But the more you look into it, questions come up because you’re beginning to fathom the real complexity of what we see on Mars. This is a good time to go back to reevaluate all our assumptions. Something is missing somewhere.”

Story Source:

The above post is reprinted from materials provided by California Institute of Technology. Note: Materials may be edited for content and length.

Journal Reference:

1. J. P. Grotzinger, S. Gupta, M. C. Malin, D. M. Rubin, J. Schieber, K. Siebach, D. Y. Sumner, K. M. Stack, A. R. Vasavada, R. E. Arvidson, F. Calef, L. Edgar, W. F. Fischer, J. A. Grant, J. Griffes, L. C. Kah, M. P. Lamb, K. W. Lewis, N. Mangold, M. E. Minitti, M. Palucis, M. Rice, R. M. E. Williams, R. A. Yingst, D. Blake, D. Blaney, P. Conrad, J. Crisp, W. E. Dietrich, G. Dromart, K. S. Edgett, R. C. Ewing, R. Gellert, J. A. Hurowitz, G. Kocurek, P. Mahaffy, M. J. McBride, S. M. McLennan, M. Mischna, D. Ming, R. Milliken, H. Newsom, D. Oehler, T. J. Parker, D. Vaniman, R. C. Wiens, S. A. Wilson. Deposition, exhumation, and paleoclimate of an ancient lake deposit, Gale crater, Mars. Science, 2015; 350 (6257): aac7575 DOI: 10.1126/science.aac7575

Now, in a study in the journal Nature, astronomers at Columbia University provide additional evidence that a pair of closely orbiting black holes is causing the rhythmic flashes of light coming from quasar PG 1302-102.

Based on calculations of the pair’s mass–together, and relative to each other–the researchers go on to predict a smashup 100,000 years from now, an impossibly long time to humans but the blink of an eye to a star or black hole. Spiraling together 3.5 billion light-years away, deep in the Virgo constellation, the pair is separated by a mere light-week. By contrast, the closest previously confirmed black hole pair is separated by 20 light-years.

“This is the closest we’ve come to observing two black holes on their way to a massive collision,” said the study’s senior author, Zoltan Haiman, an astronomer at Columbia. “Watching this process reach its culmination can tell us whether black holes and galaxies grow at the same rate, and ultimately test a fundamental property of space-time: its ability to carry vibrations called gravitational waves, produced in the last, most violent, stage of the merger.”

At the center of most giant galaxies, including our own Milky Way, lies a supermassive black hole so dense that not even light can escape. Over time, black holes grow bigger–millions to billions times more massive than the sun–by gobbling up stars, galaxies and even other black holes.

A supermassive black hole about to cannibalize its own can be detected by the mysterious flickering of a quasar–the beacon of light produced by black holes as they burn through gas and dust swirling around them. Normally, quasars brighten and dim randomly, but when two black holes are on the verge of uniting, the quasar appears to flicker at regular intervals, like a light bulb on timer.

Recently, a team led by Matthew Graham, a computational astronomer at the California Institute of Technology, designed an algorithm to pick out repeating light signals from 247,000 quasars monitored by telescopes in Arizona and Australia. Of the 20 pairs of black hole candidates discovered, they focused on the most compelling bright quasar– PG 1302-102. In a January study in Nature, they showed that PG 1302-102 appeared to brighten by 14 percent every five years, indicating the pair was less than a tenth of a light-year apart.

Intrigued, Haiman and his colleagues wondered if they could build a theoretical model to explain the repeating signal. If the black holes were as close as predicted, one had to be circling a much larger counterpart at nearly a tenth of the speed of light, they hypothesized. At that speed, the smaller black hole would appear to brighten as it approached Earth’s line of sight under the relativistic Doppler beaming effect.

If correct, they predicted they would find a five-year cycle in the quasar’s ultraviolet emissions–only two-and-a-half times more variable in its intensity. Analyzing UV observations collected by NASA’s Hubble and GALEX space telescopes they found exactly that.

Previous explanations for the repeating signal include a warp in the debris disks orbiting the black holes, a wobble in the axis of one black hole and a lopsided debris disk formed as one black hole draws material off the other–all creating the impression of a periodic flicker from Earth.

The new study also offers a new technique for investigating other converging black holes, the researchers said. By estimating the combined and relative mass of PG 1302-102’s black holes, they narrow down the pair’s predicted crash time to between 20,000 and 350,000 years from now with a best estimate of 100,000 years. (The predicted crash time by Graham’s team was 10,000 to several million years from now with a best estimate of 250,000 years).

“We can start to put numbers on the rates that black holes come together and build up into larger black holes, and use what we’re learning to search for more black holes pairs,” said study coauthor David Schiminovich, an astronomer at Columbia.

An uptick in the number of black hole binary discoveries has made astronomers hopeful that a collision could be detected in the next decade. This summer, Graham and his colleagues reported another 90 candidates, while astronomers at Columbia expect to soon unveil discoveries of their own from data collected at California’s Palomar Observatory.

With more black holes to watch, the chance of witnessing a crash and the gravitational waves predicted, but not yet detected, by Einstein’s general theory of relativity, grows.

“The detection of gravitational waves lets us probe the secrets of gravity and test Einstein’s theory in the most extreme environment in our universe–black holes,” said the study’s lead author, Daniel D’Orazio, a graduate student at Columbia. “Getting there is a holy grail of our field.”

Story Source:

The above post is reprinted from materials provided by Columbia University. Note: Materials may be edited for content and length.

Journal Reference:

1. Daniel J. D’Orazio, Zoltán Haiman, David Schiminovich. Relativistic boost as the cause of periodicity in a massive black-hole binary candidate. Nature, 2015; 525 (7569): 351 DOI:10.1038/nature15262

The story that has unfolded is a wet one: Mars appears to have had a more massive atmosphere billions of years ago than it does today, with an active hydrosphere capable of storing water in long-lived lakes. The MSL team has concluded that this water helped to fill Gale Crater, the MSL rover Curiosity’s landing site, with sediment deposited as layers that formed the foundation for the mountain found in the middle of the crater today.

Curiosity has been exploring Gale Crater, which is estimated to be between 3.8 billion and 3.6 billion years old, since August 2012. In mid-September 2014, the rover reached the foothills of Aeolis Mons, a three-mile-high layered mountain nicknamed “Mount Sharp” in honor of the late Caltech geologist Robert Sharp. Curiosity has been exploring the base of the mountain since then.

“Observations from the rover suggest that a series of long-lived streams and lakes existed at some point between 3.8 billion to 3.3 billion years ago, delivering sediment that slowly built up the lower layers of Mount Sharp,” says Ashwin Vasavada (PhD ’98), MSL project scientist. “However, this series of long-lived lakes is not predicted by existing models of the ancient climate of Mars, which struggle to get temperatures above freezing,” he says.

This mismatch between the predictions of Mars’s ancient climate that arise from models developed by paleoclimatologists and indications of the planet’s watery past, as interpreted by geologists, bears similarities to a century-old scientific conundrum–in this case, about Earth’s ancient past.

At the time, geologists first began to recognize that the shapes of the continents matched each other, almost like scattered puzzle pieces, explains John Grotzinger, Caltech’s Fletcher Jones Professor of Geology, chair of the Division of Planetary and Geological Sciences, and lead author of the paper. “Aside from the shapes of the continents, geologists had paleontological evidence that fossil plants and animals in Africa and South America were closely related, as well as unique volcanic rocks suggestive of a common spatial origin. The problem was that the broad community of earth scientists could not come up with a physical mechanism to explain how the continents could plow their way through Earth’s mantle and drift apart. It seemed impossible. The missing component was plate tectonics,” he says. “In a possibly similar way, we are missing something important about Mars.”

As Curiosity has trekked across Gale Crater, it has stopped to examine numerous areas of interest. All targets are imaged, and soil samples have been scooped from some; the rocks in a select few places have been drilled for samples. These samples are deposited into the rover’s onboard laboratories. Using data from these instruments, as well as visual imaging from the onboard cameras and spectroscopic analyses, MSL scientists have pieced together an increasingly coherent and compelling story about the evolution of this region of Mars.

Before Curiosity landed on Mars, scientists proposed that Gale Crater had filled with layers of sediments. Some hypotheses were “dry,” implying that the sediments accumulated from wind-blown dust and sand, whereas others focused on the possibility that sediment layers were deposited in ancient streams and lakes. The latest results from Curiosity indicate that these wetter scenarios were correct for the lower portions of Mount Sharp. Based on the new analysis, the filling of at least the bottom layers of the mountain occurred mostly by ancient rivers and lakes.

“During the traverse of Gale, we have noticed patterns in the geology where we saw evidence of ancient fast-moving streams with coarser gravel as well as places where streams appear to have emptied out into bodies of standing water,” Vasavada says. “The prediction was that we should start seeing water-deposited, fine-grained rocks closer to Mount Sharp. Now that we’ve arrived, we’re seeing finely laminated mudstones in abundance.” These silty layers in the strata are interpreted as ancient lake deposits.

“These finely laminated mudstones are very similar to those we see on Earth,” says Woody Fischer, professor of geobiology at Caltech and coauthor of the paper. “The scale of lamination–which occurs both at millimeter and centimeter scale–represents the settling of plumes of fine sediment through a standing body of water. This is exactly what we see in rocks that represent ancient lakes on Earth. “The mudstone indicates the presence of bodies of standing water in the form of lakes that remained for long periods of time, possibly repeatedly expanding and contracting during hundreds to millions of years. These lakes deposited the sediment that eventually formed the lower portion of the mountain.

“Paradoxically, where there is a mountain today there was once a basin, and it was sometimes filled with water,” says Grotzinger. “Curiosity has measured about 75 meters of sedimentary fill, but based on mapping data from NASA’s Mars Reconnaissance Orbiter and images from Curiosity’s cameras, it appears that the water-transported sedimentary deposition could have extended at least 150-200 meters above the crater floor, and this equates to a duration of millions of years in which lakes could have been intermittently present within the Gale Crater basin” Grotzinger says. Furthermore, the total thickness of sedimentary deposits in Gale Crater that indicate interaction with water could extend higher still–up to perhaps 800 meters above the crater floor, and possibly representing tens of millions of years.

But layers deposited above that level do not require water as an agent of deposition or alteration. “Above 800 meters, Mount Sharp shows no evidence of hydrated strata, and that is the bulk of what forms Mount Sharp. We see another 4,000 meters of nothing but dry strata,” Grotzinger says. He suggests that perhaps this segment of the crater’s history may have been dominated by eolian, or wind-driven, deposition, as was once imagined for the lower part explored by Curiosity. This occurred after the wet period that built up the base of the mountain.

A lingering question surrounds the original source of the water that carried sediment into the crater. For flowing water to have existed on the surface, Mars must have had a thicker atmosphere and warmer climate than has been theorized for the time frame bookending the intense geological activity in Gale Crater. Evidence for this ancient, wetter climate exists in the rock record. However, current models of this paleoclimate–factoring in estimates of the early atmosphere’s mass, composition, and the amount of energy it received from the sun–come up, quite literally, dry. Those models indicate that the atmosphere of Mars could not have sustained large quantities of liquid water.

Yet the rock record discovered at Gale Crater suggests a different scenario. “Whether it was snowfall or rain, you have geologic evidence for that moisture accumulating in the highlands of the Gale Crater rim,” Grotzinger says. In the case of Gale Crater, at least some of the water was supplied by the highlands that form the crater rim, but groundwater discharge–a standard explanation to reconcile wet geologic observations with dry paleoclimatic predictions–is unlikely in this area. “Right on the other side of Gale’s northern rim are the Northern Plains. Some have made the argument that there was a northern ocean sitting out there, and that’s one way to get the moisture that you need to match what we are seeing in the rocks.” Pinpointing the possible location of an ocean, however, does not help to explain how that water managed to exist as a liquid for extended periods of time on the surface.

As climatologists try to develop new atmospheric models, help should be coming from the continuing explorations by Curiosity. “There are still many kilometers of Mars history to explore,” says Fischer. He thinks that some of the most exciting data yet may come in the next few years as Curiosity climbs higher on Mount Sharp. “The strata will reveal Gale’s early history, its story. We know there are rocks that were deposited underwater, in the lake. What is the chemistry of these rocks? That lake represented an interface between the water and the atmosphere, and should tell us important things about the environment of the time.”

“We have tended to think of Mars as being simple,” adds Grotzinger. “We once thought of the earth as being simple, too. But the more you look into it, questions come up because you’re beginning to fathom the real complexity of what we see on Mars. This is a good time to go back to reevaluate all our assumptions. Something is missing somewhere.”

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The above post is reprinted from materials provided by California Institute of Technology. Note: Materials may be edited for content and length.

Journal Reference:

1. J. P. Grotzinger, S. Gupta, M. C. Malin, D. M. Rubin, J. Schieber, K. Siebach, D. Y. Sumner, K. M. Stack, A. R. Vasavada, R. E. Arvidson, F. Calef, L. Edgar, W. F. Fischer, J. A. Grant, J. Griffes, L. C. Kah, M. P. Lamb, K. W. Lewis, N. Mangold, M. E. Minitti, M. Palucis, M. Rice, R. M. E. Williams, R. A. Yingst, D. Blake, D. Blaney, P. Conrad, J. Crisp, W. E. Dietrich, G. Dromart, K. S. Edgett, R. C. Ewing, R. Gellert, J. A. Hurowitz, G. Kocurek, P. Mahaffy, M. J. McBride, S. M. McLennan, M. Mischna, D. Ming, R. Milliken, H. Newsom, D. Oehler, T. J. Parker, D. Vaniman, R. C. Wiens, S. A. Wilson. Deposition, exhumation, and paleoclimate of an ancient lake deposit, Gale crater, Mars. Science, 2015; 350 (6257): aac7575 DOI: 10.1126/science.aac7575

In a contract signed with the Breakthrough Prize Foundation, significant funding — approximately $2 million per year for 10 years — will go to the GBT to participate in this exhilarating journey of discovery.

“Beginning early next year, approximately 20 percent of the annual observing time on the GBT will be dedicated to searching a staggering number of stars and galaxies for signs of intelligent life via radio signals,” said Tony Beasley, director of the National Radio Astronomy Observatory, which operates the GBT and other world-class radio astronomy facilities. “We are delighted to play such a vital role in hopefully answering one of the most compelling questions in all of science and philosophy: are we alone in the Universe?”

In addition to the GBT, the Parkes Telescope in Australia will also be involved in this endeavor.

Breakthrough Listen will be the biggest scientific search ever undertaken for signs of intelligent life beyond Earth. It will be 50 times more sensitive and cover 10 times more of the sky than previous searches. In tandem with this radio search, the Automated Planet Finder Telescope at Lick Observatory in California will undertake the world’s deepest and broadest search for optical laser transmissions, a tantalizing complementary approach to searching the cosmos for extraterrestrial intelligence.

The $100 million Breakthrough Listen initiative was announced today at the Royal Society in London.

The program will include a survey of the one million closest stars to Earth. It will scan the center of our Galaxy and the entire galactic plane. Beyond the Milky Way, it will search for messages from the 100 closest galaxies. If a civilization based around one of the 1,000 nearest stars transmits to us with the power of common aircraft radar, the GBT and the Parkes Telescope could detect it.

The program will generate vast amounts of data; all of which will be open to the public. This will likely constitute the largest amount of scientific data ever made publicly available. The Breakthrough Listen team will use and develop the most powerful software for sifting and searching this flood of data. All software will be open source. Both the software and the hardware used in the Breakthrough Listen project will be compatible with other telescopes around the world, so that they could join the search for intelligent life. As well as using the Breakthrough Listen software, scientists and members of the public will be able to add to it, developing their own applications to analyze the data.

Breakthrough Listen will also be joining and supporting SETI@home, the University of California, Berkeley ground-breaking distributed computing platform, with 9 million volunteers around the world donating their spare computing power to search astronomical data for signs of life. Collectively, they constitute one of the largest supercomputers in the world.

The 100-meter Green Bank Telescope is the world’s largest fully steerable radio telescope. Its location in the National Radio Quiet Zone and the West Virginia Radio Astronomy Zone protects the incredibly sensitive telescope from unwanted radio interference, enabling it to perform unique observations.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

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The above post is reprinted from materials provided by National Radio Astronomy Observatory. Note: Materials may be edited for content and length.

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