February 10, 2017February 15, 2017 by Evan Gough

Time To Build A Venus Rover

The planet Venus, as imaged by the Magellan 10 mission. Credit: NASA/JPL — The planet Venus, as imaged by the Magellan 10 mission. The planet's inhospitable surface makes exploration extremely difficult. Credit: NASA/JPL

Venus is often described as being hell itself, because of its crushing pressure, acidic atmosphere, and extremely high temperatures. Dealing with any one of these is a significant challenge when it comes to exploring Venus. Dealing with all three is extremely daunting, as the Soviet Union discovered with their Venera landers.

Actually, dealing with the sulphuric rain is not too difficult, but the heat and the pressure on the surface of Venus are huge hurdles to exploring the planet. NASA has been working on the Venus problem, trying to develop electronics that can survive long enough to do useful science. And it looks like they’re making huge progress.

Scientists at the NASA Glenn Research Centre have demonstrated electronic circuitry that should help open up the surface of Venus to exploration.

The first color pictures taken of the surface of Venus by the Venera-13 space probe. Credit: NASA — The first color pictures taken of the surface of Venus by the Venera-13 space probe. The Venera 13 probe lasted only 127 minutes before succumbing to Venus’s extreme surface environment. Credit: NASA

“With further technology development, such electronics could drastically improve Venus lander designs and mission concepts, enabling the first long-duration missions to the surface of Venus,” said Phil Neudeck, lead electronics engineer for this work.

With our current technology, landers can only withstand surface conditions on Venus for a few hours. You can’t do much science in a few hours, especially when weighed against the mission cost. So increasing the survivability of a Venus lander is crucial.

With a temperature of 460 degrees Celsius (860 degrees Fahrenheit), Venus is almost twice as hot as most ovens. It’s hot enough to melt lead, in fact. Not only that, but the surface pressure on Venus is about 90 times greater than Earth’s, because the atmosphere is so dense.

To protect the electronics on previous Venus landers, they have been contained inside special vessels designed to withstand the pressure and temperature. But these vessels add a lot of mass to the mission, and make sending landers to Venus a very expensive proposition. So NASA’s work on robust electronics is super important when it comes to exploring Venus.

The team at the Glenn Research Centre has developed silicon carbide semiconductor integrated circuits (Si C IC) that are extremely robust. Two of the circuits were tested inside a special chamber designed to precisely reproduce the conditions on Venus. This chamber is called the Glenn Extreme Environments Rig (GEER.)

The GEER (Glenn Extreme Environments Rig) facility can recreate the conditions of any body in our Solar System. (No, not the Sun, obviously.) Image: NASA/Glenn Research Centre

GEER is a special chamber that can recreate the conditions on any body in our Solar System. It’s an 800 Litre (28 cubic foot) chamber that can simulate temperatures up to 500° C (932° F), and pressures from near-vacuum to over 90 times the surface pressure of Earth. GEER can also simulate exotic atmospheres with its precision gas-mixing capabilities. It can mix very specific quantities of gases down to parts per million accuracy. For these tests, that means the unit had to reproduce an accurate recipe of CO2, N2, SO2, HF, HCl, CO, OCS, H2S, and H2O, down to very tiny quantities. And the tests were a success.

“We demonstrated vastly longer electrical operation with chips directly exposed — no cooling and no protective chip packaging — to a high-fidelity physical and chemical reproduction of Venus’ surface atmosphere,” Neudeck said. “And both integrated circuits still worked after the end of the test.”

In fact, the two circuits not only functioned after the test was completed, but they withstood Venus-like conditions for 521 hours. That’s more than 100 times longer than previous demonstrations of electronics designed for Venus missions.

A before (top) and after (bottom) image of the electronics after being tested in Venus atmospheric conditions. Image: NASA

The circuits themselves were originally designed to operate in the extremely high temperatures inside aircraft engines. “This work not only enables the potential for new science in extended Venus surface and other planetary exploration, but it also has potentially significant impact for a range of Earth relevant applications, such as in aircraft engines to enable new capabilities, improve operations, and reduce emissions,” said Gary Hunter, principle investigator for Venus surface electronics development.”

The chips themselves were very simple. They weren’t prototypes of any specific electronics that would be equipped on a Venus lander. What these tests showed is that the new Silicon Carbide Integrated Circuits (Si C IC) can withstand the conditions on Venus.

A host of other challenges remains when it comes to the overall success of a Venus lander. All of the equipment that has to operate there, like sensors, drills, and atmospheric samplers, still has to survive the thermal expansion from exposure to extremely high temperature. Robust new designs will be required in many cases. But this successful test of electronics that can survive without bulky, heavy, protective enclosures is definitely a leap forward.

If you’re interested in what a Venus lander might look like, check out the Venus Sail Rover concept.

February 8, 2017February 15, 2017 by Evan Gough

The Magellenic Clouds Stay Connected By A String Of Stars

This image shows the two "bridges" that connect the Large and Small Magellanic Clouds. The white line traces the bridge of stars that flows between the two dwarf galaxies, and the blue line shows the gas. Image: V. Belokurov, D. Erkal and A. Mellinger

Astronomers have finally observed something that was predicted but never seen: a stream of stars connecting the two Magellanic Clouds. In doing so, they began to unravel the mystery surrounding the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC). And that required the extraordinary power of the European Space Agency’s (ESA) Gaia Observatory to do it.

The Large and Small Magellanic Clouds (LMC and SMC) are dwarf galaxies to the Milky Way. The team of astronomers, led by a group at the University of Cambridge, focused on the clouds and on one particular type of very old star: RR Lyrae. RR Lyrae stars are pulsating stars that have been around since the early days of the Clouds. The Clouds have been difficult to study because they sprawl widely, but Gaia’s unique all-sky view has made this easier.

Small and Large Magellanic Clouds over Paranal Observatory Credit: ESO/J. Colosimo

The Mystery: Mass

The Magellanic Clouds are a bit of a mystery. Astronomers want to know if our conventional theory of galaxy formation applies to them. To find out, they need to know when the Clouds first approached the Milky Way, and what their mass was at that time. The Cambridge team has uncovered some clues to help solve this mystery.

The team used Gaia to detect RR Lyrae stars, which allowed them to trace the extent of the LMC, something that has been difficult to do until Gaia came along. They found a low-luminosity halo around the LMC that stretched as far as 20 degrees. For the LMC to hold onto stars that far away means it would have to be much more massive than previously thought. In fact, the LMC might have as much as 10 percent of the mass that the Milky Way has.

The Large Magellanic Cloud. Image: Public Domain, https://commons.wikimedia.org/w/index.php?curid=57110

The Arrival of the Magellanic Clouds

That helped astronomers answer the mass question, but to really understand the LMC and SMC, they needed to know when the clouds arrived at the Milky Way. But tracking the orbit of a satellite galaxy is impossible. They move so slowly that a human lifetime is a tiny blip compared to them. This makes their orbit essentially unobservable.

But astronomers were able to find the next best thing: the often predicted but never observed stellar stream, or bridge of stars, stretching between the two clouds.

A star stream forms when a satellite galaxy feels the gravitational pull of another body. In this case, the gravitational pull of the LMC allowed individual stars to leave the SMC and be pulled toward the LMC. The stars don’t leave at once, they leave individually over time, forming a stream, or bridge, between the two bodies. This action leaves a luminous tracing of their path over time.

The astronomers behind this study think that the bridge actually has two components: stars stripped from the SMC by the LMC, and stars stripped from the LMC by the Milky Way. This bridge of RR Lyrae stars helps them understand the history of the interactions between all three bodies.

A Bridge of Stars… and Gas

The most recent interaction between the Clouds was about 200 million years ago. At that time, the Clouds passed close by each other. This action formed not one, but two bridges: one of stars and one of gas. By measuring the offset between the star bridge and the gas bridge, they hope to narrow down the density of the corona of gas surrounding the Milky Way.

Mystery #2: The Milky Way’s Corona

The density of the Milky Way’s Galactic Corona is the second mystery that astronomers hope to solve using the Gaia Observatory.

The Galactic Corona is made up of ionised gas at very low density. This makes it very difficult to observe. But astronomers have been scrutinizing it intensely because they think the corona might harbor most of the missing baryonic matter. Everybody has heard of Dark Matter, the matter that makes up 95% of the matter in the universe. Dark Matter is something other than the normal matter that makes up familiar things like stars, planets, and us.

The other 5% of matter is baryonic matter, the familiar atoms that we all learn about. But we can only account for half of the 5% of baryonic matter that we think has to exist. The rest is called the missing baryonic matter, and astronomers think it’s probably in the galactic corona, but they’ve been unable to measure it.

A part of the Small Magellanic Cloud galaxy is dazzling in this image from NASA’s Great Observatories. The Small Magellanic Cloud is about 200,000 light-years way from our own Milky Way spiral galaxy. Credit: NASA.

Understanding the density of the Galactic Corona feeds back into understanding the Magellanic Clouds and their history. That’s because the bridges of stars and gas that formed between the Small and Large Magellanic Clouds initially moved at the same speed. But as they approached the Milky Way’s corona, the corona exerted drag on the stars and the gas. Because the stars are small and dense relative to the gas, they travelled through the corona with no change in their velocity.

But the gas behaved differently. The gas was largely neutral hydrogen, and very diffuse, and its encounter with the Milky Way’s corona slowed it down considerably. This created the offset between the two streams.

Eureka?

The team compared the current locations of the streams of gas and stars. By taking into account the density of the gas, and also how long both Clouds have been in the corona, they could then estimate the density of the corona itself.

When they did so, their results showed that the missing baryonic matter could be accounted for in the corona. Or at least a significant fraction of it could. So what’s the end result of all this work?

It looks like all this work confirms that both the Large and Small Magellanic Clouds conform to our conventional theory of galaxy formation.

Mystery solved. Way to go, science.

February 8, 2017February 15, 2017 by Evan Gough

31 Years After Disaster, Challenger Soccer Ball Finally Gets To Orbit

Astronaut Shane Kimbrough took this photo of the Challenger soccer ball floating in front of the ISS's cupola window to mark NASA's day of remembrance for the Challenger disaster. Image: NASA

The Challenger disaster is one of those things that’s etched into people’s memories. The launch and resulting explosion were broadcast live. Professional astronauts may have been prepared to accept their fate, but that doesn’t make it any less tragic.

There’ve been fitting tributes over the years, with people paying homage to the crew members who lost their lives. But a new tribute is remarkable for its simplicity. And this new tribute is all centred around a soccer ball.

Ellison Onizuka was one of the Challenger seven who perished on January 28, 1986, when the shuttle exploded 73 seconds into its flight. His daughter and other soccer players from Clear Lake High School, near NASA’s Johnson Space Center, gave Ellison a soccer ball to take into space with him. Almost unbelievably, the soccer ball was recovered among the wreckage after the crash.

Ellison Onizuka, one of the seven who perished in the Challenger accident, carried a soccer ball into space. The ball was given to him by his daughter and other soccer players at a local high school. Image: NASA

The soccer ball was returned to the high school, where it was on display for the past three decades, with its meaning fading into obscurity with each passing year. Eventually, the Principal of the high school, Karen Engle, learned about the significance of the soccer ball’s history.

Because of Clear Lake High School’s close proximity to the Johnson Space Center, another astronaut now has a son attending the same school. His name is Shane Kimbrough, and he offered to carry a memento from the high school into space. That’s when Principal Engle had the idea to send the soccer ball with Kimbrough on his mission to the International Space Station.

NASA astronaut Shane Kimbrough, who took the soccer ball into space. Image: NASA

The causes of the Challenger accident are well-known. An O-ring failed in the cold temperature, and pressurized burning gas escaped and eventually caused the failure of the external fuel tank. The resulting fiery explosion left no doubt about the fate of the people onboard the shuttle.

It’s poignant that the soccer ball got a second chance to make it into space, when the Challenger seven never will. This tribute is touching for its simplicity, and is somehow more powerful than other tributes made with fanfare and speeches.

It must be difficult for family members of the Challenger seven to see the photos and videos of the explosion. Maybe this simple image of a soccer ball floating in zero gravity will take the place of those other images.

The Challenger seven deserve to be remembered for their spirit and dedication, rather than for the explosion they died in.

These are the seven people who perished in the Challenger accident:

Ellison Onizuka
Francis R. Scobee
Michael J. Smith
Ronald McNair
Judith Resnik
Gregory Jarvis
Christa McAuliffe

February 7, 2017February 15, 2017 by Evan Gough

Cassini Images Of Enceladus Highlight Possible Cradle For Life

Saturn's moon Enceladus, in all its glory. Captured by the Cassini probe. Image: NASA/JPL-Caltech/Space Science Institute

During its long mission to Saturn, the Cassini spacecraft has given us image after spectacular image of Saturn, its rings, and Saturn’s moons. The images of Saturn’s moon Enceladus are of particular interest when it comes to the search for life.

At first glance, Enceladus appears similar to other icy moons in our Solar System. But Cassini has shown us that Enceladus could be a cradle for extra-terrestrial life.

Our search for life in the Solar System is centred on the presence of liquid water. Maybe we don’t know for sure if liquid H2O is required for life. But the Solar System is huge, and the effort required to explore it is immense. So starting our search for life with the search for liquid water is wise. And in the search for liquid water, Enceladus is a tantalizing target.

Cassini captured this image of Enceladus with Saturn’s rings. The vapor plumes are slightly visible at the south polar region (bottom of image). Image: NASA/JPL/Space Science Institute

Though Enceladus looks every bit like a frozen, lifeless world on its surface, it’s what lies beneath its frigid crust that is exciting. Enceladus appears to have a subsurface ocean, at least in it’s south polar region. And that ocean may be up to 10 km. deep.

Before we dive into that, (sorry), here are a few basic facts about Enceladus:

Enceladus is Saturn’s sixth largest moon
Enceladus is about 500 km in diameter (Earth’s Moon is 3,474 km in diameter)
Enceladus was discovered in 1789 by William Herschel
Enceladus is one of the most reflective objects in our Solar System, due to its icy surface

In 2005, Cassini first spied plumes of frozen water vapor erupting from the southern polar region. Called cryovolcanoes, subsequent study of them determined that they are the likely source of Saturn’s E Ring. The existence of these plumes led scientists to suspect that their source was a sub-surface ocean under Enceladus’ ice crust.

This close up image of Enceladus clearly shows multiple plumes erupting into space. Image: NASA/JPL/Space Science Institute

Finding plumes of water erupting from a moon is one thing, but it’s not just water. It’s salt water. Further study showed that the plumes also contained simple organic compounds. This advanced the idea that Enceladus could harbor life.

This image of Enceladus shows the features known as “Tiger stripes”. They are the source of the vapor plumes that erupt from the surface. Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

The geysers aren’t the only evidence for a sub-surface ocean on Enceladus. The southern polar region has a smooth surface, unlike the rest of the moon which is marked with craters. Something must have smoothed that surface, since it is next to impossible that the south polar region would be free from impact craters.

In 2005, Cassini detected a warm region in the south, much warmer than could be caused by solar radiation. The only conclusion is that Enceladus has a source of internal heating. That internal heat would create enough geologic activity to erase impact craters.

So now, two conditions for the existence of life have been met: liquid water, and heat.

In 2005, data from Cassini showed that the so-called “Tiger Stripe” features on Enceladus’ south pole region are warm spots. Image:NASA/JPL/GSFC/SwRI/SSI

The source of the heat on Enceladus was the next question facing scientists. That question is far from settled, and there could be several sources of heat operating together. Among all the possible sources for the heat, two are most intriguing when it comes to the search for life: tidal heating, and radioactive heating.

Tidal heating is a result of rotational and orbital forces. In Enceladus’ case, these forces cause friction which is dissipated as heat. This heat keeps the sub-surface ocean in liquid form, but doesn’t prevent the surface from freezing solid.

Radioactive heating is caused by the decay of radioactive isotopes. If Enceladus started out as a rocky body, and if it contained enough short-lived isotopes, then an enormous amount of heat would be produced for several million years. That action would create a rocky core surrounded by ice.

Then, if enough long-lived radioactive isotopes were present, they would continue producing heat for a much longer period of time. However, radioactive heating isn’t enough on its own. There would have to be tidal heating also.

Gravity measurements by NASA’s Cassini spacecraft and Deep Space Network suggest that Saturn’s moon Enceladus, which has jets of water vapor and ice gushing from its south pole, also harbors a large interior ocean beneath an ice shell, as this illustration depicts.
Image Credit:
NASA/JPL-Caltech

More evidence for a large, sub-surface ocean came in 2014. Cassini and the Deep Space Network provided gravitometric measurements showing that the ocean is there. Those measurements showed that there is likely a regional, if not global, ocean some 10 km thick. Measurements also showed that the ocean is under an ice layer 30 to 40 km thick.

This close up image of Enceladus show the variability of its icy features. The dark spots were originally called “Dalmatian” terrain when first imaged in 2005. There exact nature remained a mystery until ten years later, when Cassini flybys showed that they are actually blocks of bedrock ice scattered along a ridge. The blocks range in size from tens to hundreds of meters. Image: NASA/JPL/Cal-Tech.

The discovery of a warm, salty ocean containing organic molecules is very intriguing, and has expanded our idea of what the habitable zone might be in our Solar System, and in others. Enceladus is much too distant from the Sun to rely on solar energy to sustain life. If moons can provide their own heat through tidal heating or radioactive heating, then the habitable zone in any solar system wouldn’t be determined by proximity to the star or stars at the centre.

Cassini’s mission is nearing its end, and it won’t fly by Enceladus again. It’s told us all it can about Enceladus. It’s up to future missions to expand our understanding of Enceladus.

Numerous missions have been talked about, including two that suggest flying through the plumes and sampling them. One proposal has a sample of the plumes being returned to Earth for study. Landing on Enceladus and somehow drilling through the ice remains a far-off idea better left to science fiction, at least for now.

Whether or not Enceladus can or does harbor life is a question that won’t be answered for a long time. In fact, not all scientists agree that there is a liquid ocean there at all. But whether it does or doesn’t harbor life, Cassini has allowed us to enjoy the tantalizing beauty of that distant object.

Enceladus. Cassini Imaging Team, SSI, JPL, ESA, NASA

February 2, 2017February 15, 2017 by Evan Gough

Meteorite Confirms 2 Billion Years of Volcanic Activity on Mars

Color Mosaic of Olympus Mons on Mars — Olympus Mons on Mars is the largest volano in our Solar System. Analysis of a Martian meteorite that fell to Earth in 2012 confirms that Mars also has the longest-lived volcanoes in our Solar System. Image: NASA/JPL

Mars is renowned for having the largest volcano in our Solar System, Olympus Mons. New research shows that Mars also has the most long-lived volcanoes. The study of a Martian meteorite confirms that volcanoes on Mars were active for 2 billion years or longer.

A lot of what we know about the volcanoes on Mars we’ve learned from Martian meteorites that have made it to Earth. The meteorite in this study was found in Algeria in 2012. Dubbed Northwest Africa 7635 (NWA 7635), this meteorite was actually seen travelling through Earth’s atmosphere in July 2011.

A sample from the meteorite Northwest Africa 7635. Image: Mohammed Hmani

The lead author of this study is Tom Lapen, a Geology Professor at the University of Houston. He says that his findings provide new insights into the evolution of the Red Planet and the history of volcanic activity there. NWA 7635 was compared with 11 other Martian meteorites, of a type called shergottites. Analysis of their chemical composition reveals the length of time they spent in space, how long they’ve been on Earth, their age, and their volcanic source. All 12 of them are from the same volcanic source.

Mars has much weaker gravity than Earth, so when something large enough slams into the Martian surface, pieces of rock are ejected into space. Some of these rocks eventually cross Earth’s path and are captured by gravity. Most burn up, but some make it to the surface of our planet. In the case of NWA 7635 and the other meteorites, they were ejected from Mars about 1 million years ago.

“We see that they came from a similar volcanic source,” Lapen said. “Given that they also have the same ejection time, we can conclude that these come from the same location on Mars.”

Taken together, the meteorites give us a snapshot of one location of the Martian surface. The other meteorites range from 327 million to 600 million years old. But NWA 7635 was formed 2.4 billion years ago. This means that its source was one of the longest lived volcanoes in our entire Solar System.

This false color X-ray of NWA 7635 shows the meteorite’s mineralogy mineral textures. O, olivine; P, plagioclase (maskelynite); C, clinopyroxene (augite). Chemical compositions: Fe (purple), Mg (green), Ca (blue), Ti (magenta), and S (yellow). Purple colors in the mesostasis represent Fe-rich augite. You’re welcome, mineral nerds. Image: Lapen et. al.

Volcanic activity on Mars is an important part of understanding the planet, and whether it ever harbored life. It’s possible that so-called super-volcanoes contributed to extinctions here on Earth. The same thing may have happened on Mars. Given the massive size of Olympus Mons, it could very well have been the Martian equivalent of a super-volcano.

The ESA’s Mars Express Orbiter sent back images of Olympus Mons that showed possible lava flows as recently as 2 million years ago. There are also lava flows on Mars that have a very small number of impact craters on them, indicating that they were formed recently. If that is the case, then it’s possible that Martian volcanoes will be visibly active again.

A colorized image of the surface of Mars taken by the Mars Reconnaissance Orbiter. The line of three volcanoes is the Tharsis Montes, with Olympus Mons to the northwest. Valles Marineris is to the east. Image: NASA/JPL-Caltech/ Arizona State University

Continuing volcanic activity on Mars is highly speculative, with different researchers arguing for and against it. The relatively crater-free, smooth surfaces of some lava features on Mars could be explained by erosion, or even glaciation. In any case, if there is another eruption on Mars, we would have to be extremely lucky for one of our orbiters to see it.

But you never know.

February 1, 2017February 15, 2017 by Evan Gough

Preleminary Results In NASA Twins Study Released

NASA's astronauts twins, Scott Kelly (l) and Mark Kelly (r). Image: NASA — NASA's astronaut twins, Scott Kelly (l) and Mark Kelly (r). Image: NASA

In 1996, something remarkable happened at NASA. Twin brothers Mark and Scott Kelly were accepted into NASA; Mark as a shuttle pilot, and Scott into technical operations on the ground, at least initially. Eventually, both brothers became astronauts. They are the only siblings to have both been in space.

Whether it was intentional or not, having twin brothers gave NASA an important opportunity. They could use one twin as a control group, and send the other on a prolonged mission into space. That allowed NASA to carry out important research on the effects of space travel on the human body.

In March 2016, Scott Kelly returned from a year long (340 days) mission aboard the International Space Station, while his brother Mark stayed on Earth. Genetic samples were taken from each brother before and after Scott’s time aboard the ISS. Now, NASA has released the preliminary results of this unprecedented opportunity.

Expedition 46 Commander Scott Kelly of NASA is seen after returning to Ellington Field, Thursday, March 3, 2016 in Houston, Texas after his return to Earth the previous day. Kelly and Flight Engineers Mikhail Kornienko and Sergey Volkov of Roscosmos landed in their Soyuz TMA-18M capsule in Kazakhstan on March 1 (Eastern time).

NASA’s Human Research Program did the study, and the results were released at their Investigator’s Workshop on the week of January 23rd. The theme of that workshop was A New Dawn: Enabling Human Space Exploration. Though the studies are on-going, these initial results are interesting.

Omics

Mike Snyder, who is the Integrated Omics investigator, reported his findings. He found an altered level of lipids in Scott, the flight twin, which indicates inflammation. He also found increased 3-indolepropionic (IPA) in Mark, the ground twin. IPA is a potential brain antioxidant therapeutic, and also helps maintain normal insulin levels, to stabilize blood sugar after meals.

Telomeres and Telomerase

Telomeres and Telomerase are part of the chromosomal system in the human body. Susan Bailey reported that for Scott, the flight twin, the length of his white blood cell’s telomeres increased while in space. Typically, they decrease as a person ages. Once on Earth, they began to shorten again.

Telomerase, an enzyme that repairs telomeres, increased in both brothers in November, which could be related to a stressful family event at that time.

The Soyuz TMA-18M spacecraft is seen as it lands with Expedition 46 Commander Scott Kelly of NASA and Russian cosmonauts Mikhail Kornienko and Sergey Volkov in Kazakhstan on Wednesday, March 2, 2016. Photo Credit: (NASA/Bill Ingalls)

Cognitive Performance in Spaceflight

Mathias Basner is studying Cognitive Performance in Spaceflight, especially the difference in cognition between a 12-month mission and a six-month mission. Though he found a slight decrease in speed and accuracy after the mission, he found no real difference in cognition between 6 month and 12 month missions.

Biochemistry

Scott Smith’s investigation into biochemistry showed a decrease in bone density during the second half of Scott’s mission. Scott also had increased levels of a biochemical marker for inflammation once he returned to Earth.

Microbiome in the Gastro-Intestinal Tract

Fred Turek reported preliminary results of his investigation into the bacteria in the GI (microbiome) tract that help digestion. There were many differences in the twins’ biomes, but that was expected because of their different diets and environments. There were interesting differences in Scott’s biome between his time in space and his time on the ground. The ratio between two dominant bacterial groups shifted during his flight time compared to his ground time.

Immunome Studies

Emmanuel Mignot investigated changes in the bodies of both twins before and after a flu vaccine was given. Both twins showed increased levels of T-cell receptors after the vaccine, which was the expected immune response.

Genome Sequencing

Chris Mason is performing Genome Sequencing on the DNA and RNA contained within the twins’ white blood cells with his investigation. RNA sequencing showed that over 200,000 RNA molecules were expressed differently between the twins. Mason will look closer to see if a “space gene” could have been activated while Scott was in space.

Epigenomics

Andy Feinberg studies how the environment regulates our gene expression, which is known as epigenomics. Scott’s white blood cell DNA showed decreased levels of chemical modification while in flight, and a return to normal once back on Earth. The same level in Mark (the ground twin) increased midway through the study, but then returned to normal. There was variability between the twins, called epigenetic noise. This noise was higher in Scott during his spaceflight, and returned to baseline levels once back on Earth. This could indicate that some genes are more sensitive to the changing environment of spaceflight than others.

There’s a lot more research required to truly understand these results. Once they’re looked at in coordination with other physiological, psychological, and technological investigations, the picture will become clearer. Later in 2017, there will be a joint publication of further results, as well as individual research papers.

NASA’s goal is to make space travel safer for astronauts, and to make missions more effective and efficient. With all the talk of missions to Mars in the next decade, these results are arriving at the perfect time.

January 31, 2017February 15, 2017 by Evan Gough

Vortex Coronagraph A Game Changer For Seeing Close In Exoplanets

The vortex coronagraph at the Keck Observatory captured this image of the protoplanetary disk surrounding the young star HD 141569. which is about 380 light years from Earth. Image: NASA/JPL-Caltech — The vortex coronagraph at the Keck Observatory captured this image of the protoplanetary disk surrounding the young star HD 141569, which is about 380 light years from Earth. Image: NASA/JPL-Caltech

The study of exoplanets has advanced a great deal in recent years, thanks in large part to the Kepler mission. But that mission has its limitations. It’s difficult for Kepler, and for other technologies, to image regions close to their stars. Now a new instrument called a vortex coronagraph, installed at Hawaii’s Keck Observatory, allows astronomers to look at protoplanetary disks that are in very close proximity to the stars they orbit.

The problem with viewing disks of dust, and even planets, close to their stars is that stars are so much brighter than objects that orbit them. Stars can be billions of times brighter than the planets near them, making it almost impossible to see them in the glare. “The power of the vortex lies in its ability to image planets very close to their star, something that we can’t do for Earth-like planets yet,” said Gene Serabyn of NASA’s Jet Propulsion Laboratory (JPL). “The vortex coronagraph may be key to taking the first images of a pale blue dot like our own.”

“The power of the vortex lies in its ability to image planets very close to their star, something that we can’t do for Earth-like planets yet.” – Gene Serabyn, JPL.

“The vortex coronagraph allows us to peer into the regions around stars where giant planets like Jupiter and Saturn supposedly form,” said Dmitri Mawet, research scientist at NASA’s Jet Propulsion Laboratory and Caltech, both in Pasadena. “Before now, we were only able to image gas giants that are born much farther out. With the vortex, we will be able to see planets orbiting as close to their stars as Jupiter is to our sun, or about two to three times closer than what was possible before.”

Rather than masking the light of stars, like other methods of viewing exoplanets, the vortex coronagraph redirects light away from the detectors by combining light waves and cancelling them out. Because there is no occulting mask, the vortex coronagraph can capture images of regions much closer to stars than other coronagraphs can. Dmitri Mawet, research scientist who invented the new coronagraph, compares it to the eye of a storm.

The vortex mask shown at left is made out of synthetic diamond. When viewed with a scanning electron microscope, right, the "vortex" microstructure of the mask is revealed. Image credit: University of Liège/Uppsala University — The vortex mask shown at left is made out of synthetic diamond. When viewed with a scanning electron microscope, right, the “vortex” microstructure of the mask is revealed. Image credit: University of Liège/Uppsala University

“The instrument is called a vortex coronagraph because the starlight is centered on an optical singularity, which creates a dark hole at the location of the image of the star,” said Mawet. “Hurricanes have a singularity at their centers where the wind speeds drop to zero — the eye of the storm. Our vortex coronagraph is basically the eye of an optical storm where we send the starlight.”

The results from the vortex coronagraph are presented in two papers (here and here) published in the January 2017 Astronomical Journal. One of the studies was led by Gene Serabyn of JPL, who is also head of the Keck vortex project. That study presented the first direct image of HIP79124 B, a brown dwarf that is 23 AU from its star, in the star-forming region called Scorpius-Centaurus.

The vortex coronagraph captured this image of the brown dwarf PIA21417. Image: NASA/JPL-Caltech

“The ability to see very close to stars also allows us to search for planets around more distant stars, where the planets and stars would appear closer together. Having the ability to survey distant stars for planets is important for catching planets still forming,” said Serabyn.

“Having the ability to survey distant stars for planets is important for catching planets still forming.” – Gene Serabyn, JPL.

The second of the two vortex studies presented images of a protoplanetary disk around the young star HD141569A. That star actually has three disks around it, and the coronagraph was able to capture an image of the innermost ring. Combining the vortex data with data from the Spitzer, WISE, and Herschel missions showed that the planet-forming material in the disk is made up pebble-size grains of olivine. Olivine is one of the most abundant silicates in Earth’s mantle.

“The three rings around this young star are nested like Russian dolls and undergoing dramatic changes reminiscent of planetary formation,” said Mawet. “We have shown that silicate grains have agglomerated into pebbles, which are the building blocks of planet embryos.”

These images and studies are just the beginning for the vortex coronagraph. It will be used to look at many more young planetary systems. In particular, it will look at planets near so-called ‘frost lines’ in other solar systems. The is the region around star systems where it’s cold enough for molecules like water, methane, and carbon dioxide to condense into solid, icy grains. Current thinking says that the frost line is the dividing line between where rocky planets and gas planets are formed. Astronomers hope that the coronagraph can answer questions about hot Jupiters and hot Neptunes.

Hot Jupiters and Neptunes are large gaseous planets that are found very close to their stars. Astronomers want to know if these planets formed close to the frost line then migrated inward towards their stars, because it’s impossible for them to form so close to their stars. The question is, what forces caused them to migrate inward? “With a bit of luck, we might catch planets in the process of migrating through the planet-forming disk, by looking at these very young objects,” Mawet said.

December 6, 2016December 18, 2016 by Evan Gough

Cassini’s First Ring-Grazing Orbit A Success

This graphic shows the closest approaches of Cassini's final two orbital phases. Ring-grazing orbits are shown in gray (at left); Grand Finale orbits are shown in blue. The orange line shows the spacecraft's Sept. 2017 final plunge into Saturn. Credit: NASA/JPL-Caltech

The Cassini-Huygens mission is coming to an end.

Cassini was launched in 1997 and reached Saturn in 2004. It will end its mission by plunging into the gas giant. But before then, it will dive through Saturn’s rings a total of 20 times.

An artist's illustration of Cassini entering orbit around Saturn. Public Domain, https://commons.wikimedia.org/w/index.php?curid=626636 — An artist’s illustration of Cassini entering orbit around Saturn. Public Domain, https://commons.wikimedia.org/w/index.php?curid=626636

The first dive through the rings was just completed, and represents the beginning of Cassini’s final mission phase. On December 4th at 5:09 PST the 2,150 kg, plutonium-powered probe, crossed through a faint and dusty ring created by the moons Janus and Epimetheus. This brought it to within 11,000 km of Saturn’s F-ring.

Though the end of a mission might seem sad, people behind the mission are excited about this final phase, a series of close encounters with the most iconic structures in our Solar System: Saturn’s glorious rings.

“This is a remarkable time in what’s already been a thrilling journey.” – Linda Spilker, NASA/JPL

“It’s taken years of planning, but now that we’re finally here, the whole Cassini team is excited to begin studying the data that come from these ring-grazing orbits,” said Linda Spilker, Cassini project scientist at JPL. “This is a remarkable time in what’s already been a thrilling journey.”

Even casual followers of space news have enjoyed the steady stream of eye candy from Cassini. But this first orbit through Saturn’s rings is more about science than pictures. The probe’s cameras captured images 2 days before crossing through the plane of the rings, but not during the closest approach. In future ring-grazing orbits, Cassini will give us some of the best views yet of Saturn’s outer rings and some of the small moons that reside there.

Cassini is about more than just beautiful images though. It’s a vital link in a series of missions that have opened up our understanding of the Solar System we inhabit. Here are some of Cassini’s important discoveries:

New Moons

The Cassini mission discovered 7 new moons orbiting Saturn. Methone, Pallene and Polydeuces were all discovered in 2004. Daphnis, Anthe, and Aegaeon were discovered between 2005 and 2009. The final moon is currently named S/2009 S 1.

This image shows the moon Daphnis in the Keeler gap in Saturn's A ring. The moon's gravity causes the wave shapes in the rings. By NASA/JPL/Space Science Institute - http://www.esa.int/SPECIALS/Cassini-Huygens/SEM1XQ5TI8E_1.html, Public Domain, https://commons.wikimedia.org/w/index.php?curid=17953334 — This image shows the moon Daphnis in the Keeler gap in Saturn’s A ring. The moon’s gravity causes the wave shapes in the rings. By NASA/JPL/Space Science Institute – http://www.esa.int/SPECIALS/Cassini-Huygens/SEM1XQ5TI8E_1.html, Public Domain, https://commons.wikimedia.org/w/index.php?curid=17953334

In 2014, NASA reported that yet another new moon may be forming in Saturn’s A ring.

This Cassini image shows what might be a new moon forming in Saturn's rings. The new moon, if it is one, is only about 1 km in diameter. By NASA/JPL-Caltech/Space Science Institute - http://photojournal.jpl.nasa.gov/jpeg/PIA18078.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=32184174 — This Cassini image shows what might be a new moon forming in Saturn’s rings. The new moon, if it is one, is only about 1 km in diameter. By NASA/JPL-Caltech/Space Science Institute – http://photojournal.jpl.nasa.gov/jpeg/PIA18078.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=32184174

Huygens lands on Titan

The Huygens lander detached from the Cassini orbiter on Christmas Day 2004. It landed on the frigid surface of Saturn’s moon Titan after a 2 1/2 hour descent. The lander transmitted 350 pictures of Titan’s descent to the surface. An unfortunate software error caused the loss of another 350 pictures.

The first-ever images of the surface of a new moon or planet are always exciting. This image was taken by the Huygens probe at its landing site on Titan. Image Credit: ESA/NASA/JPL/University of Arizona

Enceladus Flyby

Cassini performed several flybys of the moon Enceladus. The first was in 2005, and the last one was in 2015. The discovery of ice-plumes and a salty liquid ocean were huge for the mission. The presence of liquid water on Enceladus makes it one of the most likely places for microbial life to exist in our Solar System.

In 2005 Cassini discovered jets of water vapor and ice erupting form the surface of Enceladus. The water could be from an subsurface sea. Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Each of Cassini’s final ring-grazing orbits will last one week. Cassini’s final orbit will bring it close to Saturn’s moon Titan. That encounter will change Cassini’s path. Cassini will leap over the rings and make the first of 22 plunges through the gap between Saturn and its rings.

In September 2017, the Cassini probe will finally reach the end of its epic mission. In order to prevent any possible contamination of Saturn’s moons, the probe will make one last glorious plunge into Saturn’s atmosphere, transmitting data until it is destroyed.

The Cassini mission is a joint mission between the European Space Agency, NASA, and the Italian Space Agency.

November 28, 2016December 18, 2016 by Evan Gough

Sentinel-1 Satellites Confirm San Francisco’s Millenium Tower Is Sinking

The Millennium Tower luxury skyscraper in San Francisco is sinking and tilting. Image by MichaelTG - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=51657571

The Millennium Tower is a luxury skyscraper in San Francisco. It has been sinking and tilting since it’s construction 8 years ago. In fact, the 58 story building has sunk 8 inches, and tilted at least 2 inches. San Francisco is experiencing a building boom, and planners and politicians want to know why the Millennium Tower is having these problems.

Now they’re getting a little help from space.

The European Space Agency’s (ESA) Copernicus Sentinel-1 satellites have trained their radar on San Francisco. They’ve found that the Millennium Tower is sinking, or subsiding, at the alarming rate of almost 50 mm per year. Although the exact cause is not yet known for sure, it’s suspected that the building’s supporting piles are not resting on solid bedrock.

An artist's illustration of the Sentinel-1. Image: ESA/ATG Medialab — An artist’s illustration of the Sentinel-1. Image: ESA/ATG Medialab

The Sentinel-1 satellites are part of the ESA’s Copernicus Program. There are two of the satellites in operation, and two more are on the way. They employ Synthetic Aperture Radar to provide continuous imagery during the day, during the night, and through any kind of weather.

The satellites have several applications:

Monitoring sea ice in the arctic
Monitoring the arctic environment and other marine environments
Monitoring land surface motion
Mapping land surfaces, including forest, water, and soil
Mapping in support of humanitarian aid in crisis situations

Though the Sentinels were not specifically designed to monitor buildings, they’re actually pretty good at it. Buildings like the Millennium Tower are especially good at reflecting radar. When multiple passes are made with the satellites, they provide a very accurate measurement of ground subsidence.

Radar data from Sentinel-1 shows the displacement in San Francisco's Bay Area. Yellow-red areas are sinking, while blue areas are rising. Green areas are not moving. Image: ESA SEOM INSARAP study / PPO.labs / Norut / NGU — Radar data from Sentinel-1 shows the displacement in San Francisco’s Bay Area. Yellow-red areas are sinking, while blue areas are rising. Green areas are not moving. Image: ESA SEOM INSARAP study / PPO.labs / Norut / NGU

The Millennium Tower is not the only thing in San Francisco Bay Area that Sentinel-1 can see moving. It’s also spotted movement in buildings along the Hayward Fault, an area prone to earthquakes, and the sinking of reclaimed land in San Rafael Bay. It’s also spotted some rising land near the city of Pleasanton. The recent replenishing of groundwater is thought to be the cause of the rising land.

Now other parts of the world, especially in Europe, are poised to benefit from Sentinel-1’s newfound prowess at reading the ground. In Oslo, Norway, the train station is built on reclaimed land. Newer buildings have proper foundations right on solid bedrock, but the older parts of the station are experiencing severe subsidence.

Sentinel-1 data shows that the Oslo train station, the red/yellow area in the center of the image, is sinking at the rate of 12-18mm per year. Image: Copernicus Sentinel data (2014–16) / ESA SEOM INSARAP study / InSAR Norway project / NGU / Norut / PPO.labs

John Dehls is from the Geological Survey of Norway. He had this to say about Sentinel: “Experience and knowledge gained within the ESA’s Scientific Exploitation of Operational Missions programme give us strong confidence that Sentinel-1 will be a highly versatile and reliable platform for operational deformation monitoring in Norway, and worldwide.”

As for the Millennium Tower in San Francisco, the problems continue. The developer of the building is blaming the problems on the construction of a new transit center for the city. But the agency in charge of that, the Transbay Joint Powers Authority, denies that they are at fault. They blame the developer’s poor structural design, saying that it’s not properly built on bedrock.

Now, the whole thing is before the courts. A $500 million class-action lawsuit has been filed on behalf of the residents, against the developer, the transit authority, and other parties.

It’s a good bet that data from the Sentinel satellites will be part of the evidence in that lawsuit.

November 23, 2016November 26, 2016 by Evan Gough

‘Global Warming Hiatus’ Not Good News For Planet Earth

Research into the temporary slowdown of the global mean surface temperature has revealed that the world's oceans have absorbed the "missing heat." Image: Flickr user Brian Richardson, CC by 2.0

A reprieve from Global Warming? A hiatus? That would be nice, wouldn’t it? But in this case, a hiatus is not quite what it seems.

Everybody knows that global warming is partly caused by human activities, largely our use of fossil fuels. We understand how it works and we fear for the future. But there’s been a slowdown in the global mean surface temperature increase between 1998 to 2013. We haven’t lowered our emissions of greenhouse gases (GHGs) significantly during that time, so what happened?

Fossil fuels: we just can't get enough of them. Image: a petrochemical refinery in Scotland. Credit: User:John from wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2459867 — Fossil fuels: we just can’t get enough of them. Image: a petrochemical refinery in Scotland. Credit: User:John from wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2459867

A new multi-institutional study involving NASA’s Jet Propulsion Laboratory (JPL), the National Oceanographic and Atmospheric Institute, and others, concludes that Earth’s oceans have absorbed the heat. So instead of the global mean surface temperature rising at a steady rate, the oceans have taken on the job as global heat sink. But what’s the significance of this?

“The hiatus period gives scientists an opportunity to understand uncertainties in how climate systems are measured, as well as to fill in the gap in what scientists know.” -Xiao-Hai Yan, University of Delaware, Newark

In terms of the on-going rise in the temperature of the globe, the hiatus is not that significant. But in terms of the science of global warming, and how well we understand it, the hiatus gives scientists an opportunity.

The new paper, titled “The Global Warming Hiatus: Slowdown or Redistribution?” grew out of the U.S. Climate Variability and Predictability Program (CLIVAR) panel session at the 2015 American Geophysical Union fall meeting. From those discussions, scientists reached consensus on three key points:

From 1998 to 2013, the rate of global mean surface warming slowed, which some call the “global warming hiatus.”
Natural variability plays a large role in the rate of global mean surface warming on decadal time scales.
Improved understanding of how the ocean distributes and redistributes heat will help the scientific community better monitor Earth’s energy budget. Earth’s energy budget is a complex calculation of how much energy enters our climate system from the sun and what happens to it: how much is stored by the land, ocean or atmosphere.

This graph shows the yearly global ocean heat content. The dashed line shows the 1958-65 average. Image: Balmaseda et al., 2013

The paper is a reminder that climate science is complex, and that the oceans play a big part in global warming. As Yan says, “To better monitor Earth’s energy budget and its consequences, the ocean is most important to consider because the amount of heat it can store is extremely large when compared to the land or atmospheric capacity.”

“…”arguably, ocean heat content — from the surface to the seafloor — might be a more appropriate measure of how much our planet is warming.” – from the paper “The Global Warming Hiatus: Slowdown or Redistribution?”

The team behind this new research suggests that saying there’s been a hiatus in global warming is confusing. They suggest “global warming hiatus” be replaced with “global surface warming slowdown.”

There’s a danger in calling it a “global warming hiatus.” Those opposed to climate change and who think it’s a hoax can use that term to discredit climate science. They’ll claim that the “hiatus” shows we don’t understand climate change and the Earth may have stopped warming. But in any case, it’s the long-term trend—change over the course of a century or more—that defines “global warming,” not the change from year to year or even decade to decade.

There’s much more to learn about the oceans’ role in global warming. Research shows that some ocean areas absorb heat much faster than others. But whatever the fine detail of it is, there is broad agreement in the scientific community that the global surface warming slowdown was caused by an increased uptake of heat energy by the world’s oceans.

A screenshot from the "NASA's Eyes" app. The app allows anyone to check Earth's vital signs. Image: NASA/JPL — A screenshot from the “NASA’s Eyes” app. The app allows anyone to check Earth’s vital signs. Image: NASA/JPL

NASA uses a lot of tools to monitor the Earth’s temperature. For an interesting look at the Earth’s vital signs, check out Nasa’s Eyes. This easy to use visualization tool lets you take a closer look at the Earth’s temperature, CO2 levels, soil moisture levels, sea levels, and other things.