Posted on by Nancy Atkinson

Warm Poles Suggest Enceladus’ Liquid Water Near Surface

Saturn's moon Enceladus could harbor microbial life in the warm salty water thought to exist under its frozen surface. Respondents in the study seemed to like that possibility. Credits: NASA/JPL-Caltech/Space Science Institute

One of the biggest surprises from the Cassini mission to Saturn has been the discovery of active geysers at the south pole of the moon Enceladus. At only about 500 km (310 miles) in diameter, the bright and ice-covered moon should be too small and too far from the Sun to be active. Instead, this little moon is one of the most geothermally active places in the Solar System.

Now, a new study from Cassini data shows that the south polar region of Enceladus is even warmer than expected just a few feet below its icy surface. While previous studies have confirmed an ocean of liquid water inside Enceladus which fuels the geysers, this new study shows the ocean is likely closer to the surface than previously thought. Additionally – and most enticing – there has to be a source of heat inside the moon that is not completely understood.

“These observations provide a unique insight into what is going on beneath the surface,” said Alice Le Gall, who is part of the Cassini RADAR instrument team, from Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), and Université Versailles Saint-Quentin (UVSQ), France. “They show that the first few meters below the surface of the area that we investigated, although at a glacial 50-60 K, are much warmer than we had expected: likely up to 20 K warmer in some places. This cannot be explained only as a result of the Sun’s illumination and, to a lesser extent, Saturn’s heating so there must be an additional source of heat.”

Tiger stripes on the south pole of Enceladus. The region studied is indicated by the coloured band. NASA/JPL-Caltech/Space Science Institute; Acknowledgement: A. Lucas

Microwave data taken during a close flyby in 2011 shows there is excess heat at three fractures in the surface of Enceladus. While similar to the so-called “tiger-stripe” features on this moon that are actively venting ice and water molecules into space, these three fractures don’t appear to be active, at least not in 2011.

Scientists say the seemingly dormant fractures lying above the moon’s warm, underground sea point to the dynamic character of Enceladus’ geology, suggesting the moon might have experienced several episodes of activity, in different places on its surface.

The 2011 flyby provided the first – and unfortunately, the only — high-resolution observations of Enceladus’ south pole at microwave wavelengths.

It looked at a narrow, arc-shaped swathe of the southern polar region, about 25 km (15 miles) wide, and located just 30 km to 50 km (18-30 miles) north of the tiger-stripe fractures.

The heat that was detected appears to be lying under a much colder layer of frost.

Because of operational constraints of the 2011 flyby, it was not possible to obtain microwave observations of the active fractures themselves. But this allowed the scientists to observe that the thermally anomalous terrains of Enceladus extend well beyond the tiger stripes.

Cassini’s view down into a jetting “tiger stripe” in August 2010. Credit: NASA

Their findings show it is likely that the entire south pole region is warm underneath, meaning Enceladus’ ocean could be just 2 km under the moon’s icy surface in that area. The finding agrees with a 2016 study, led by another Cassini team member, Ondrej Cadek, which estimated the thickness of the crust on Enceladus’ south pole to be less than the rest of the moon. That study estimated the depth of the ice shell to be less than 5 km (1.2 miles) at the south pole, while average depth on other areas of Enceladus is between 18–22 km (11-13 miles).

What generates the internal heat at Enceladus? The main source of heat remains a mystery, but scientists think gravitational forces between Enceladus, Saturn, and another moon, Dione pull and flex Enceladus’ interior. Known as tidal forces, the tugging causes the moon’s interior to rub, creating friction and heat. It also creates stress compressions and deformations on the crust, leading to the formation of faults and fractures. This in turn creates more heat in the sub-surface layers. In this scenario, the thinner icy crust in the south pole region is subject to a larger tidal deformation that means more heat being created to help keep the underground water warm.

Dramatic plumes, both large and small, spray water ice out from many locations along the famed “tiger stripes” near the south pole of Saturn’s moon Enceladus. Credit: NASA/JPL/Space Science Institute

Since the geysers weren’t known until Cassini’s arrival at Saturn, the spacecraft didn’t have a specific payload to study them, but scientists used the instruments at their disposal to make the best observations they could, flying the spacecraft to within 49 km (30 miles) of the surface. To fully study the tidal heating — or to determine if there is another source of heat — scientists will continue to study the data already taken by various Cassini instruments. But since the mission will be ending in September 2017, it may require another mission to this intriguing moon to fully figure out this mystery.

“This discovery opens new perspectives to investigate the emergence of habitable conditions on the icy moons of the gas giant planets,” says Nicolas Altobelli, ESA’s Project Scientist for Cassini–Huygens. “If Enceladus’ underground sea is really as close to the surface as this study indicates, then a future mission to this moon carrying an ice-penetrating radar sounding instrument might be able to detect it.”

“Finding temperatures near these three inactive fractures that are unexpectedly higher than those outside them adds to the intrigue of Enceladus,” said Cassini Project Scientist Linda Spilker at the Jet Propulsion Laboratory. “What is the warm underground ocean really like and could life have evolved there? These questions remain to be answered by future missions to this ocean world.”

Feel free to submit your mission proposals in the comment section below…

An artist’s illustration of Cassini entering orbit around Saturn. Credit: NASA/JPL.

Sources: ESA
JPL
Paper: Thermally anomalous features in the subsurface of Enceladus’s south polar terrain” by A. Le Gall et al. (2017), published in Nature Astronomy

Posted on by Nancy Atkinson

Closest Star Around A Black Hole Discovered

This artist's impression depicts a white dwarf star found in the closest known orbit around a black hole. As the circle around each other, the black hole's gravitational pull drags material from the white dwarf's outer layers toward it. Astronomers found that the white dwarf in X9 completes one orbit around the black hole in less than a half an hour. They estimate the white dwarf and black hole are separated by about 2.5 times the distance between the Earth and Moon — an extraordinarily small span in cosmic terms. (Credit: NASA/CXC/M.Weiss)

Imagine being caught in the clutches of a black hole, being whirled around at dizzying speeds and having your mass slowly but continually sucked away. That’s the life of a white dwarf star that is doing an orbital dance with a black hole. And this dancing duo could be the first ultracompact black hole X-ray binary identified in our galaxy.

“This white dwarf is so close to the black hole that material is being pulled away from the star and dumped onto a disk of matter around the black hole before falling in,” said Arash Bahramian from the University of Alberta in Edmonton, Canada, and Michigan State University, first author of a new paper.

If you were the white dwarf in this predicament, you may wish for a quick end to it all. But somehow, the star does not appear to be in danger of falling in or being torn apart by the black hole.

“We don’t think it will follow a path into oblivion, but instead will stay in orbit,” Bahramian added.

Data from the Chandra X-ray Observatory, the NuSTAR mission and the Australian Telescope Compact Array (ATCA) shows evidence that this star whips around the black hole about twice an hour, and it may be the tightest orbital dance ever witnessed for a likely black hole and a companion star.

This seemingly unique binary system – with a great name, X9 — is located in the globular cluster 47 Tucanae, a dense cluster of stars in our galaxy about 14,800 light years from Earth.

Astronomers have been studying this system for a while.

“For a long time, it was thought that X9 is made up of a white dwarf pulling matter from a low mass Sun-like star,” Bahramian wrote in a blog post.

But 2015, radio observations with the ATCA showed the pair likely contains a black hole pulling material from a companion star called a white dwarf, a low-mass star that has exhausted most or all of its nuclear fuel.

“In 2015, Dr. Miller-Jones and collaborators observed strong radio emission from X9 indicating the presence of a black hole in this binary,” Bahramian continued. “They suggested that this might mean the system is made up of a black hole pulling matter from a white dwarf.”

Astronomers found an extraordinarily close stellar pairing in the globular cluster 47 Tucanae, a dense collection of stars located on the outskirts of the Milky Way galaxy, about 14,800 light years from Earth. Credit: X-ray: NASA/CXC/University of Alberta/A.Bahramian et al.

Looking at archived Chandra data, it showed changes in X-ray brightness in the same manner every 28 minutes, and Bahramian and his PhD supervisor Craig Heink think this is likely the length of time it takes the companion star to make one complete orbit around the black hole. Chandra data also shows evidence for large amounts of oxygen in the system, a characteristic feature of white dwarfs. They feel a strong case can be made that the companion star is a white dwarf. And this star would then be orbiting the black hole at just 2.5 times the distance between the Earth and the Moon.

“Eventually so much matter may be pulled away from the white dwarf that it ends up only having the mass of a planet,” said Heinke, also of the University of Alberta. “If it keeps losing mass, the white dwarf may completely evaporate.”

The researchers think this system would be a good candidate for future gravitational wave observatories to observe. It has to low of a frequency that is too low to be detected with Laser Interferometer Gravitational-Wave Observatory, LIGO, that made ground-breaking detections of gravitational waves last year. Systems like this could tell us more about gravitational waves, as well as providing more information about black hole binary systems.

“We’re going to watch this binary closely in the future, since we know little about how such an extreme system should behave”, said co-author Vlad Tudor of Curtin University and the International Centre for Radio Astronomy Research in Perth, Australia. “We’re also going to keep studying globular clusters in our galaxy to see if more evidence for very tight black hole binaries can be found.”

Further reading:
Chandra press release
ICRAR press release
Blog post
Paper: The ultracompact nature of the black hole candidate X-ray binary 47 Tuc X9

Posted on by Nancy Atkinson

Brightest ‘Spot’ on Ceres is Likely a Cryovolcano

False color mosaic showing parts of Occator crater, with a central pit containing the brightest material on Ceres. It measures 11 kilometers in diameter and in the middle of the pit a dome towers 400 meters high. The dome could be the remnant of a cryovolcano. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The bright regions on the dwarf planet Ceres have been some of the most talked about features in planetary science in recent years. While data from the Dawn spacecraft has shown these bright areas are salt deposits (alas, not lights of an alien city), the question remained of how these salts reached the surface.

Researchers with the Dawn mission say they have now thoroughly investigated the complex geological structures in Occator crater, the region with the brightest regions on Ceres. The scientists conclude that a bright dome-like feature called Cerealia Facula is the remnant of a cryovolcano — an ice volcano — that repeatedly and relatively recently spewed salty ice from within Ceres up to the surface.

“The age and appearance of the material surrounding the bright dome indicate that Cerealia Facula was formed by a recurring, eruptive process, which also hurled material into more outward regions of the central pit,” said Andreas Nathues, a Dawn scientist from the Max Planck Institute for Solar System Research. “A single eruptive event is rather unlikely.”

The bright central spots near the center of Occator Crater are shown in enhanced color in this view from NASA’s Dawn spacecraft. The view was produced by combining the highest resolution images taken in February 2016 (at image scales 115 feet (35 meters) per pixel of 35 meters with color images obtained in September 2015 at a lower resolution. Click for a highest-res view. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

Occator crater located in the northern hemisphere of Ceres measures 92 kilometers (57 miles) in diameter. In its center is a pit with a diameter of about 11 kilometers (7 miles). On some parts of its edges, jagged mountains and steep slopes rise up to 750 meters (820 yards) high. Within the pit a bright dome formed. It has a diameter of 3 km (1.8 miles), is 400 meters (437 yards) high, with prominent fractures.

In analyzing images from Dawn’s Framing Camera, Nathues and his team deduced that the central pit is a remnant of a former central mountain, formed from the impact that created Occator Crater about 34 million years ago. But with a method for estimating the age of a planet’s surface – called crater counting — the science team could determine the dome of bright material is only about four million years old.

This suggests, the team said, that Occator crater has been the scene of eruptive outbursts of subsurface brine over a long period and until almost recently.

Jupiter’s moons Callisto and Ganymede show similar types of domes, and researchers interpret them as signs of cryovolcanism. While Ceres is too far from the Sun to be warm enough for regular volcanic activity, it very likely has harbored cryovolcanic activity, and it may even be active today.


This 3d-anaglyph for the first time shows a part of Occator crater in a combination of anaglyphe and false-color image. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Images from the Hubble Space Telescope taken more than a decade ago hinted at the bright spots in Occator Crater, but as the Dawn spacecraft approached Ceres in 2015, new images showed the bright areas almost shining like “cosmic beacons, like interplanetary lighthouses drawing us forth,” as described by Marc Rayman, the chief engineer and mission director for Dawn, in an interview with me last year.

Dawn scientist had previously determined the bright areas were salts left over from subsurface briny water that had made its way to the surface, and in the vacuum of space, the water sublimated away, leaving behind the dissolved salts. These salts were determined to be sodium carbonate and ammonium chloride.

This view of the whole Occator crater shows the brightly colored pit in its center and the cryovolcanic dome. The jagged mountains on the edge of the pit throw their shadows on parts of the pit. This image was taken from a distance of 1478 kilometers above the surface and has a resolution of 158 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

But don’t call these bright areas “spots,” said Rayman. “Some of these bright areas are miles across,” he said, “and just as if you were standing on salt flats on Earth that were several thousand acres, you wouldn’t say, ‘I’m standing on a spot.’ You are standing on a big area. But just to see the distribution of this material in the Dawn images shows there is something complex going on there.”

It is currently unknown if the region in Occator Crater is active, but there are hints it is, at least at a low level.

In 2014 the Herschel spacecraft detected water vapor above Occator, and images from Dawn’s cameras of the crater show a ‘haze’ when imaged at certain angles, and this has been explained as the sublimation of water.

Dawn scientists are also studying the large volcanic feature on Ceres, Ahuna Mons, to determine if it could be a cryovolcano, and will continue to study other bright areas on Ceres, as well.

Ceres’ lonely mountain, Ahuna Mons, is seen in this simulated perspective view. The elevation has been exaggerated by a factor of two. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

Further Reading: Max Planck Institute for Solar System Research

Posted on by Nancy Atkinson

What the Oldest Fossil on Earth Means for Finding Life on Mars

Microscopic iron-carbonate (white) rosette with concentric layers of quartz inclusions (grey) and a core of a single quartz crystal with tiny (nanoscopic) inclusions of red hematite from the Nuvvuagittuq Supracrustal Belt in Québec, Canada. These may have formed through the oxidation of organic matter derived from microbes living around vents. Credit: Matthew Dodd/UCL.

Scientists have found evidence that life existed on Earth much earlier than previously thought and they say this discovery has implications for life springing up on other planets, particularly Mars.

Fossils of microscopic bacteria were discovered in Quebec, Canada in the Nuvvuagittuq Supracrustal Belt, a formation which contains some of the oldest sedimentary rocks in the world. Scientists estimate the fossils are at least 3.7 billion years old, and could be as old as 4.28 billion years. This is hundreds of millions of years older than previously found specimens.

“The most exciting thing about this discovery is that we know life managed to get a grip and start on Earth at such an early time in Earth’s evolution, which gives us exciting questions as to whether we are alone in the solar system or in the universe,” said PhD student Matthew Dodd from University College London (UCL), who is the first author on a new paper about the finding in the journal Nature. “If life happened so quickly on Earth then could we expect it to be a simple process and start on other planets, or was Earth really just a special case?”

Hematite tubes from the hydrothermal vent deposits that represent the oldest microfossils and evidence for life on Earth. The remains are at least 3.7 billion years old. Credit: Matthew Dodd/UCL

The tiny fossils are the remains of microorganisms that are smaller than the width of a human hair. The Nuvvuagittuq rocks are thought to have formed in an iron-rich deep-sea hydrothermal vent system that provided a habitat for Earth’s first life forms. These rocks are mostly composed of silica and hematite.

“Our discovery supports the idea that life emerged from hot, seafloor vents shortly after planet Earth formed,” Dodd said in a press release. “This speedy appearance of life on Earth fits with other evidence of recently discovered 3,700 million year old sedimentary mounds that were shaped by microorganisms.”

Prior to this discovery, the oldest microfossils reported were found in Western Australia and were dated at 3.4 billion years old, leading scientists to speculate that life probably started around 3.7 billion years ago. But the new finding suggests that life existed as early as 4.5 billion years ago, just 100 million years after Earth formed.

“The microfossils we discovered are about 300 million years older than the previously thought oldest microfossils,” said Dr. Dominic Papineau, a professor of geochemistry and astrobiology at UCL, “so they are within a few hundred million years from within the accretion of the solar system and the planet Earth and the Sun and the Moon and so on.”

The Blueberries of Mars are actually concretions of iron rich minerals from water – ground or standing pools – created over thousands of years during periodic epochs of wet climates on Mars. (Photo Credits: NASA/JPL/Cornell)

Papineau said the structures in the rocks that contained the fossils were spheroids, and since they are made of hematite, they are reminiscent of the discovery in 2004 by the Mars Exploration Rover Opportunity of beds of rounded hematite concretions, that MER scientists called “blueberries.” These rounded concretions formed on Earth when significant volumes of groundwater flowed through permeable rock, and chemical reactions triggered minerals to precipitate and start forming a layered, spherical ball.

The concretions may bear on the search for evidence of past life on Mars because bacteria on Earth can make concretions form more quickly, according to previous research.

“The origin of this structure is not fully understood even on Earth where we find them,” Papineau said. “We don’t know really how organic matter can potentially be involved in making these structures.”

Both the MER rovers, Opportunity and Spirit, as well as the Curiosity rover have all found evidence of past water on Mars. In addition, Curiosity has identified traces of elements like carbon, hydrogen, nitrogen, oxygen, and more — the basic building blocks of life. It also found sulfur compounds in different chemical forms, a possible energy source for microbes. If Mars really was warmer and wetter in the past, as the evidence seems to point, Mars would have been the perfect spot for living organisms.

While the finding of ancient fossils on Earth doesn’t necessarily mean there is past or present life on Mars, in conjunction with the Curiosity rover finding of the raw ingredients for life, it is enticing to know that the environment on early Mars was likely very similar to early Earth, where life did spring up.

You can see details and hear the researchers talk about their findings in the video below:

Source: EurekAlert

Posted on by Nancy Atkinson

You Can’t See the Great Wall of China From Space, But You Can See Their Giant Solar Farm

A view from Earth orbit of the Longyangxia Dam Solar Park in China. Credit: NASA/Landsat 8.

While the Great Wall of China is not readily visible from space (we debunked that popular myth here) there are several other human-built structures that actually can be seen from space. And that list is growing, thanks to the large solar farms being built around the world.

The solar farm with the current distinction of being the largest in the world — as of February 2017 – is the Longyangxia Dam Solar Park in China. These new images from NASA’s Landsat 8 satellite show the farm’s blue solar panels prominently standing out on the brown landscape of the western province of Qinghai, China. Reportedly, the solar farm covers 27 square kilometers (10.42 square miles), and consists of nearly 4 million solar panels.

You can see in the image below from 2013 that the farm has been growing over the years. The project has cost the amount of 6 billion yuan ($889.5 million).

The orbital view from April 16, 2013
of the Longyangxia Dam Solar Park in China. Credit: NASA/Landsat 8.

China wants to shed its title of the biggest polluter in the world and is now investing in clean, renewable energy. It has a goal of producing 110 GW of solar power and 210 GW of wind power by the year 2020. That sounds like a lot, but in a country of 1.4 billion people that relies heavily on coal, it amounts to less than 1 percent of the country’s more than 1,500 gigawatts of total power generation capacity, says Inside Climate News.

According to NASA, China is now the world’s largest producer of solar power, however Germany, Japan, and the United States produce more solar power per person.

China has another solar farm in the works that will have a capacity of 2,000 MW when it is finished.

Here’s another wider-angle view from Landsat 8 of the Longyangxia Dam and lake near the solar farm.

The Longyangxia Dam Solar Park as seen from orbit on January 5, 2017. Credit: NASA/Landsat 8.

Source: Landsat

Posted on by Nancy Atkinson

Supernova Blast Wave Still Visible After 30 Years

To celebrate 30 years since Supernova 1987A was spotted, a new composite image shows the most recent images of the object, and contains X-rays from NASA's Chandra X-ray Observatory (blue), visible light data from NASA's Hubble Space Telescope (green), and submillimeter wavelength data from the international Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile (red).

30 years ago today, a supernova explosion was spotted in the southern hemisphere skies. The exploding star was located in the Large Magellanic Cloud — a satellite galaxy of the Milky Way – and Supernova 1987A was the brightest and nearest supernova explosion for modern astronomers to observe. This has provided an amazing opportunity to study the death of a star.

Telescopes around the world and in space have been keeping an eye on this event, and the latest images show the blast wave from the original explosion is still expanding, and it has plowed into a ring expelled by the pre-supernova star. The latest images and data reveal the blast is now moving past the ring.

Got a 3-D printer? You can print out your own version of SN1987A! Find the plans here.

Two different versions of 3-D printed models of SN1987A. Credit: Salvatore Orlando (INAF-Osservatorio Astronomico di Palermo) & NASA/CXC/SAO/A.Jubett et al.

Below is the latest image of this supernova, as seen by the Hubble Space Telescope. You can see it in the center of the image among a backdrop of stars, and the supernova is surrounded by gas clouds.

This new image of the supernova remnant SN 1987A was taken by the NASA/ESA Hubble Space Telescope in January 2017 using its Wide Field Camera 3 (WFC3). Credit: NASA, ESA, and R. Kirshner (Harvard-Smithsonian Center for Astrophysics and Gordon and Betty Moore Foundation) and P. Challis (Harvard-Smithsonian Center for Astrophysics)

Hubble launched in 1990, just three years after the supernova was detected, so Hubble has a long history of observations. In addition, the Chandra X-ray telescope – launched in 1999 – has been keeping an eye on the explosion too.

Here are a few animations and images of SN1987A over the years:

This scientific visualization, using data from a computer simulation, shows Supernova 1987A, as the luminous ring of material we see today.
Credits: NASA, ESA, and F. Summers and G. Bacon (STScI); Simulation Credit: S. Orlando (INAF-Osservatorio Astronomico di Palermo)
This montage shows the evolution of the supernova SN 1987A between 1994 and 2016, as seen by the NASA/ESA Hubble Space Telescope. Credit:
NASA, ESA, and R. Kirshner (Harvard-Smithsonian Center for Astrophysics and Gordon and Betty Moore Foundation) and P. Challis (Harvard-Smithsonian Center for Astrophysics)

Here’s a link to the original astronomer’s telegram announcing the detection.

Astronomers estimate that the ring material was was ejected about 20,000 years before the actual explosion took place. Then, the initial blast of light from the supernova illuminated the rings. They slowly faded over the first decade after the explosion, until the shock wave of the supernova slammed into the inner ring in 2001, heating the gas to searing temperatures and generating strong X-ray emission.

The observations by Hubble, Chandra and telescopes around the world has shed light on how supernovae can affect the dynamics and chemistry of their surrounding environment, and continue to shape galactic evolution.

See additional images and animations at the Chandra website, ESA’s Hubble website , and NASA.

Posted on by Nancy Atkinson

NASA Fires a Rocket into the Northern Lights, for Science!

A NASA Black Brant IX sounding rocket soars skyward into an aurora over Alaska during the launch on 5:13 a.m. EST, Feb. 22, 2017. Credit: NASA/Terry Zaperach

Not only is it aurora season in Alaska, its sounding rocket season! NASA started launching a series of five sounding rockets from the Poker Flat Research Range in Alaska to study the aurora. The first of these rockets for this year, a Black Brant IX, was launched in the early morning hours of February 22, 2017.

The instrument on board was an Ionospheric Structuring: In Situ and Groundbased Low Altitude StudieS (ISINGLASS) instrumented payload, which studies the structure of an aurora.

The Black Brant IX sounding rocket carried instruments to an altitude of 225 miles as part of the Ionospheric Structuring: In Situ and Groundbased Low Altitude StudieS or ISINGLASS mission. Credit: NASA/Terry Zaperach.

This is not the first sounding rocket flight from Poker Flats to launch into an aurora. Starting in 2009, this research has been taking place to help refine current models of aurora structure, and provide insight on the high-frequency waves and turbulence generated by aurorae. This helps us to better understand the space weather caused by the charged particles that come from the Sun and how it impacts Earth’s lower atmosphere and ionosphere.

“The visible light produced in the atmosphere as aurora is the last step of a chain of processes connecting the solar wind to the atmosphere,” said Kristina Lynch, ISINGLASS principal investigator from Dartmouth College. “We are seeking to understand what structure in these visible signatures can tell us about the electrodynamics of processes higher up.”

While humans don’t feel any of these effects directly, the electronic systems in our satellites do, and as our reliance on satellite technologies grow, researchers want to have all the data they can to help avert problems than can be caused by space weather.

The rocket sent a stream of real-time data back before landing about 200 miles downrange shortly after the launch.

The launch window for the remaining rockets runs through March 3. ISINGLASS will fly into what is known as a dynamic Alfenic curtain, which is a form of electromagnetic energy thought to be a key driver of “discrete” aurora – the typical, well-defined band of shimmering lights about six miles thick and stretching east to west from horizon to horizon.

NASA says that the five launches in the 2017 sounding rocket campaign will add to our body of information about this space through which our spacecraft and astronauts travel near Earth. By studying the interaction of the sun and its solar wind with Earth’s upper atmosphere, scientists are also able to apply the knowledge to other planetary bodies — helping us understand these interactions throughout the universe as well.

Here’s an infographic from NASA about the 2017 sounding rocket launches from Poker Flats:

Read more: NASA

Posted on by Nancy Atkinson

Planet 9 Can’t Run Forever. Two Asteroids Give Up Some Clues

The six most distant known objects in the solar system with orbits exclusively beyond Neptune (magenta) all mysteriously line up in a single direction. Also, when viewed in three dimensions, they tilt nearly identically away from the plane of the solar system. Batygin and Brown show that a planet with 10 times the mass of the earth in a distant eccentric orbit anti-aligned with the other six objects (orange) is required to maintain this configuration. Credit: Caltech/R. Hurt (IPAC); [Diagram created using WorldWide Telescope.]

Last year, Caltech astronomers Mike Brown and Konstantin Batygin found indirect evidence for the existence of a large planet in the outer reaches of our Solar System — likely located out past Pluto — and since then, the search has been on. The latest research continues to show signs of an unseen planet, the hypothetical Planet 9.

Astronomers using the Gran Telescopio CANARIAS (GTC) in the Canary Islands looked at two distant asteroids called Extreme Trans Neptunian Objects’ (ETNOs), and spectroscopic observations show and their present-day orbits could be the result of a past interaction with a large “superearth”-type object orbiting the Sun at a distance between 300 to 600 AU.

Researchers say the orbits of asteroids 2004 VN112 and 2013 RF98 suggest that the two were once a binary asteroid which separated after an encounter a large body, with a mass of between 10 and 20 Earth masses.

“The similar spectral gradients observed for the pair 2004 VN112 – 2013 RF98 suggests a common physical origin,” said Julia de León, the first author of a new paper, and who is an astrophysicist at the Instituto de Astrofísica de Canarias (IAC). “We are proposing the possibility that they were previously a binary asteroid which became unbound during an encounter with a more massive object.”

Sequence of images taken with the Gran Telescopio CANARIAS (GTC) to identify one of the ETNO´s studied in this article, 2013 RF98, where one can see how it moves during four consecutive nights. Below, right, visible spectra obtained with the GTC of the two objects 2004 VN112 and 2013 RF98. The red lines show the gradients of the spectra. Credit: Julia de León (IAC).

To test their hypothesis, the team performed thousands of simulations to see how the poles of the orbits would separate as time went on. The results of these simulations suggest that a possible Planet 9 could have separated the pair of asteroids around 5 to 10 million years ago.

de León said this could explain, in principle, how these two asteroids, starting as a pair orbiting one another, became gradually separated in their orbits after an encounter with a much more massive object at a particular moment in time.

The tale of Planet 9 started in 2014, when astronomers Chad Trujillo and Scott Shepard were studying the motions of large objects in the Kuiper Belt and realized that a large planet in the outer Solar System must be altering orbits of several ETNOs the in Kuiper Belt.

Brown and Batygin were looking to verify or refute the research of Trujillo and Shepard, and they painstakingly analyzed the movement of various KBOs. They found that six different objects all seem to follow a very similar elliptical orbit that points back to the same region in space.

All the bodies were found to be inclined at a plane of about 30-degrees different from almost everything else in the Solar System. Brown said the odds of these orbits all occurring randomly are about 1 in 100.

But calculations revealed the orbits could be influenced by a massive planet way out beyond the orbit of Pluto, about 200 times further than the distance from the Sun to the Earth. This planet would be Neptune-sized, roughly 10 times more massive than Earth.

It hasn’t been found yet, but the hunt is on by large telescopes around the world, and a new citizen science project allows people around the world to join in the search.

The latest findings of by de León and team could help point the way to where Planet 9 might be lurking.

Source: PhysOrg

Posted on by Nancy Atkinson

Here’s Something We Never Thought We’d See on a Comet: Shifting Dunes

Features in the Hapi region show evidence of local gas-driven transport producing dune-like ripples (left) and boulders with ‘wind-tails’ (right) – where the boulder has acted as a natural obstacle to the direction of the gas flow, creating a streak of material ‘downwind’ of it. The images were taken with the OSIRIS narrow-angle camera on 18 September 2014. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

The Rosetta mission’s close-up views of the curiously-shaped Comet 67P/Churyumov-Gerasimenko have already changed some long-held ideas about comets. But here’s more: there’s a ‘wind’ blowing across the comet’s surface, creating moving shifting dunes.

“The approach to comet 67P/Churyumov–Gerasimenko by the spacecraft Rosetta has revealed the presence of astonishing dune-like patterns,” wrote Philippe Claudin, of the Institute of Industrial Physics and Chemistry, Paris, France, in his new paper, noting the unusual and unexpected conditions found on Comet 67P.

Left, an image of comet Chury showing outgassing of water vapor, which entrains dust (© ESA/Rosetta/NAVCAM). Right, the neck region, between the comet’s two lobes. Various types of relief can be seen, including the dunes, at bottom left (circled in red), in the sandy region. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA).

Images from Rosetta’s cameras revealed the dusty covering of the comet may be several meters thick in places, which was surprising. But even more surprising was seeing active dunes that are changing. The dunes were seen on both of the ‘lobes’ of the comet as well as on the neck that connects them. Comparisons images taken 16 months of the same region shows evidence that the dunes moved, and are therefore active.

Claudin and his team said that the formation of sedimentary dunes requires the presence of grains and of winds that are strong enough to transport them along the ground. However, comets do not have a dense, permanent and active atmosphere like Earth does. Also, Comet 67P’s gravity is so weak – only about 1/50,000 that of Earth’s – that fast moving grains might be ‘launched’ into space.

What could be creating a wind strong enough that not only moved the grains, but also some boulders up to a meter wide?

There is indeed a wind blowing along the comet’s surface, said Claudin, coming from gases that escape from the surface.
Gases escape at ‘sunset’ on the comet, caused by the pressure difference between the sunlit side, where the surface ice can sublimate due to the energy provided by the sunlight, and the night side.

“This transient atmosphere is still extremely tenuous, with a maximum pressure at perihelion, when the comet is closest to the Sun, 100,000 times lower than on Earth,” the team said in a press release. “However, gravity on the comet is also very weak, and an analysis of the forces exerted on the grains at the comet’s surface shows that these thermal winds can transport centimeter-scale grains, whose presence has been confirmed by images of the ground. The conditions required to allow the formation of dunes, namely winds able to transport the grains along the ground, are thus met on Chury’s surface.”

Summary of properties of Comet 67P/Churyumov–Gerasimenko, as determined by Rosetta’s instruments during the first few months of its comet encounter. Credit: ESA.

The transportation of dust has created dune-like ripples, and boulders with ‘wind-tails’ – the boulders act as natural obstacles to the direction of the gas flow, creating streaks of material ‘downwind’ of them.

Claudin said this finding represents a step forward in understanding the various processes at work on cometary surfaces, and also shows the Rosetta mission still has many surprises and discoveries in store.

Paper: Giant ripples on comet 67P/Churyumov–Gerasimenko sculpted by sunset thermal wind

Press release

Posted on by Nancy Atkinson

Drone Captures Amazing Footage of Falcon 9 Landing

The Falcon 9 first stage touches down at Cape Canaveral on February 19, 2017. Credit: SpaceX.

Let’s just take a moment to admire how amazing it is when science fiction becomes routinely real:

https://www.instagram.com/p/BQtNTk4Brqp/

SpaceX CEO Elon Musk shared this amazing drone footage of the Falcon 9 rocket’s first stage returning for a perfect landing after the launch of the Dragon capsule to the International Space Station. It drops flawlessly through the clouds, easy as pie, touching down at SpaceX’s Landing Zone 1 at Cape Canaveral.

As cool as the first stage landing was, the launch had a notable starting place. As our Ken Kremer reported yesterday, “the era of undesired idleness for America’s most famous launch pad was broken at last by the rumbling thunder of a SpaceX Falcon 9.” The SpaceX launch took place on the historic Launchpad 39-A, the same spot where Apollo astronauts began their journey to the Moon and space shuttles set off on their missions.

Here’s another view of drone footage of the landing:

SpaceX’s CRS-10 resupply mission to the International Space Station was the second successful launch for the commercial space company since the launch pad explosion in September 2016. Dragon will rendezvous and be docked to the ISS, on Wednesday, March 22, bringing about 5,500 pounds of supplies and experiments.