Titanium dioxide, ingredient in sunscreen, falls as snow on hot exoplanet

Understanding atmospheres of large exoplanets will help scientists better understand those of Earth-like worlds.

A hot Jupiter exoplanet discovered by NASA’s Kepler spacecraft has an unusually structured atmosphere from which titanium dioxide, one of the active ingredients in sunscreen, falls onto its surface as snow.

Located 1,730 light years away, Kepler-13Ab is in a close orbit around a star that is part of a triple-star system. It circles its star, Kepler-13A, once every 1.8 Earth days and is about six times more massive than Jupiter.

Because it orbits so close to its parent star, the planet is tidally locked, with a day side that always faces the star and a night side that always faces away from it.

Day side temperatures can reach nearly 5,000 degrees Fahrenheit (2,760 degrees Celsius), making Kepler-13Ab one of the hottest exoplanets ever discovered.

Hot Jupiters typically have gaseous titanium dioxide in the upper atmospheres of their day sides, which warms those day sides by absorbing starlight and subsequently radiating it out as heat.

In contrast, Kepler-13Ab has an unusual atmosphere in which the uppermost levels are cooler than the lower ones, the opposite of what occurs on similar worlds.

Scientists who studied the planet using NASA’s Hubble Space Telescope think high winds on its day side transport titanium dioxide to its night side, where the substance cools, condenses into clouds, and then falls into the lower atmosphere as snow.

Because of the planet’s extreme gravity, the “snow” stays in the lower atmosphere, further cooling it.

“These observations of Kepler-13Ab are telling us how condensates and clouds form in the atmospheres of very hot Jupiters, and how gravity will affect the composition of an atmosphere,” study lead author Thomas Beatty of Pennsylvania State University said in a public statement.

“When looking at these planets, you need to know not only how hot they are, but also what their gravity is like.”

This particular atmospheric process, known as a “cold trap,” has not been previously seen on any exoplanet.

Scientists view detailed studies of these giant planets’ atmospheres as tests for similar studies they hope to eventually conduct of the atmospheres of Earth-like exoplanets.

“Understanding more about the atmospheres of these planets and how they work will help us when we study smaller planets that are harder to see and have more-complicated features in their atmospheres,” Beatty noted.

A paper detailing the study has been published in the October 2017 issue of The Astronomical Journal.

Rosetta data sheds light on comet dust jets

In unprecedented observation, five science instruments studied a single dust jet for several hours.

In a stroke of good luck, five science instruments on board the European Space Agency’s (ESA) Rosetta spacecraft, which orbited Comet 67P/Churyumov-Gerasimenko from 2014-2016, successfully observed the surface location on the comet from which a dust jet erupted.

The multiple observations, which shed new light on the process by which comets emit dust into space, were unusual because dust jets are impossible to predict, and when they do occur, can usually be observed with just one instrument.

On July 3, 2016, Rosetta’s path took it directly through a cloud of dust the comet was emitting into space just as the Sun rose over its Imhotep region, warming up the surface and triggering the dust jet.

At that same time, the probe’s OSIRIS scientific camera system directly observed the surface region of the comet from which the dust was emitted.

Over the next several hours, an unprecedented five instruments on Rosetta studied multiple aspects of the dust jet.

The Grain Impact Analyzer and Dust Accumulator (GIADA) and the Cometary Secondary Ion Mass Analyzer (COSIMA) actually captured dust particles from the jet, enabling them to analyze the particles’ speeds, sizes, and densities.

For COSIMA, this was the first opportunity to study particles released from a single dust jet as opposed to those from multiple sources collected over several weeks.

COSIMA found the particles to be more fragile than typical dust particles released by comets.

“They must either be very fast or relatively loosely built,” said COSIMA Principal Investigator Martin Hilchenbach of the Max Planck Institute for Solar System Research (MPS) in Germany.

Alice, Rosetta’s spectrograph, recorded the brightness increase caused by the dust jet and identified tiny ice particles within the dust cloud.

One of Alice’s star sensors, which help the orbiter navigate its position in space, measured increased radiation levels from the comet’s coma over several hours.

High-resolution images of the surface location from which the jet originated allowed scientists to pinpoint a ten-meter-wide circular region containing frozen water as the jet’s source.

The most significant discovery of these observations is that dust jets such as the one emitted that day are not produced solely by the sublimation of frozen water as previously thought.

Because the jet contained far more dust than expected, scientists now believe it and jets like it are driven by another, energetic process just beneath the comet’s surface.

That process could be a release of compressed gas as the surface is warmed by the Sun, or a release of energy as subsurface ice transforms from an amorphous state to a crystallized one, also triggered by warmth from sunlight.

Findings of the study have been published in the journal Monthly Notices of the Royal Astronomical Society.

Ocean model error shows climate change may be worse than expected

New research shows that ancient oceans may not have been as warm as models show.

Models used to estimate past ocean temperature may be flawed, which could call into question many current perceptions of climate change.

This new discovery comes from a team of European researchers, who found that our ancient seas may have been much cooler than previously estimated. That in turn means Earth’s current warming trends are much more powerful than scientists believe.

While researchers cannot definitively know the state of ancient oceans, they estimate them on the belief that their temperatures were preserved inside tiny marine organisms known as foraminifera. By looking at the ancient creatures, scientists determined that the deeper parts of the tropical oceans some 100 million years ago were about 60 degrees Fahrenheit warmer than they are today.

However, that may not be true.

“What appeared to be perfectly preserved fossils are in fact not,” said lead author Sylvain Bernard, a mineralogist from the French National Center for Scientific Research, in a statement.

The team found this discrepancy by analyzing how the chemistry of the calcite in the foraminifera’s shells could change over time. They did that by putting some of the organisms in artificial sea water that contained just isotopes of oxygen-18. Then, they raised the temperature and used a nanoscale secondary ion mass spectrometer to analyze changes in the calcite’s oxygen ratios.

That revealed the ratios did shift over time. As a result, any evidence based on the organisms may be incorrect. In fact, the new data shows that ancient waters were not much warmer than they are today. 

The new findings suggest Earth’s oceans are getting hotter at a faster rate than previously thought. Now that they know this, the team plans to go back to square one and take a look at existing data. They hope that will help them figure out what difference the changes make to historical records and give them a better idea of what shifts may occur in the future.

“To revisit the ocean’s paleotemperatures now, we need to carefully quantify this re-equilibration, which has been overlooked for too long,” said study co-author Anders Meibom, a geochemist from the Swiss Federal Institute of Technology in Lausanne, according to Science Alert“For that, we have to work on other types of marine organisms so that we clearly understand what took place in the sediment over geological time.”

The new findings are detailed in the journal Nature Communications.

Newly discovered dinosaur had a “bandit mask”

Researchers have uncovered the first dinosaur ever discovered with a raccoon-like mask.

A new dinosaur species unearthed in China had a “bandit mask” pattern on its face that is similar to modern day raccoons, a new study published in Current Biology reports.

The prehistoric reptile — known as Sinosauropteryx — existed between 133 and 120 million years ago in north-eastern China. It had feather, a long tail, and short arms.

Researchers from Bristol University made this discovery by analyzing three well-preserved fossil specimens. This revealed it had a banded tail and a specific color pattern known as “counter-shading,” meaning it was dark on top and lighter on the underside.

Such patterns are found in numerous modern species, including raccoons, badgers, and nuthatches. This is the first time it has been observed in a dinosaur, but scientists are not sure the reason behind the pattern because its use differs from species to species.

“In raccoons and badgers, it’s an advertisement of the fact that they’re aggressive,” explained lead author Fiann Smithwick, a paleontologist at the University of Bristol, according to BBC News. “If you’re a predator and you mess with them, they’re going to fight back. We think that’s probably unlikely in Sinosauropteryx because there’s no real anatomical evidence that it could have defended itself well. It’s a small dinosaur and quite gracile (lightly built).”

Rather, researchers believe the reptile’s mask served a function similar to ones noted in modern birds. Some avian species have patterns around their eyes in order to reduce glare from light reflected off of their feathers. That would have useful to Sinosauropteryx because it lived during a time with a lot of direct sunlight. In addition, there is a chance the mask could have helped camouflage the reptile as well.

The team discerned the dinosaur’s coloration by looking at fossilized pigmented feathers. They then used cross-polarizing filters — which reduce glare and reveal dark-pigmented areas — to capture high-resolution photos of the specimens.

Those methods revealed the unique patters and could give researchers insight into Sinosauropteryx’s habitat and behavior. The team plans to continue their research into the strange animals to see what they could tell them about other dinosaurs that lived during the same time.

 

“By reconstructing the color of these long-extinct dinosaurs, we have gained a better understanding of not only how they behaved and possible predator-prey dynamics, but also the environments in which they lived,” added Smithwick, according to USA Today.

Heart surgery may be safer in the afternoon, study reports

Researchers have found that the body’s internal clock could make afternoon heart surgery safer than morning procedures.

The body’s internal clock may make heart surgery safer in the afternoon than in the morning, a new study published in The Lancet reports.

Our internal clock — also known as circadian rhythm — drives large changes in the way the body works. It is the reason we sleep at night, and it also drives certain biological changes throughout the day. In the new study, a group of researchers from the Institut Pasteur de Lille also proved that it could make the heart stronger and more able to withstand surgery during the afternoon.

In order to perform operations on the heart, doctors typically need to stop the organ. This reduces oxygen flow to the tissue and puts the heart under an enormous amount of stress.

To get an idea of how that stress is linked to time, the team looked at how complications — including heart attacks, heart failure, or death after surgery — changed from morning to afternoon to night. This showed that 54 out of 298 morning patients had adverse events, compared to just 28 out of 298 afternoon patients. In addition, patients who went into surgery during the afternoon had half the risk of complications.

While the team does not want to discourage people from having life-saving surgery, they do hope to make doctors more aware of the best times to operate.

“If we can identify patients at highest risk, they will definitely benefit from being pushed into the afternoon and that would be reasonable,” study co-author Bart Staels, a researcher at the Institut Pasteur de Lille, told BBC News.

Previous research has already shown that heart health fluctuates throughout the day. The risk of a heart attack or stroke is highest first thing in the morning, while the heart and lungs work at their peak in the afternoon.

While some people speculate that surgeons being tired in the morning is the reason for those differences, the team showed that was not the cause. Not only did they analyze DNA samples to show different genes changed throughout the day, but they also altered the activity of one of those genes in mice, which reduced the risk of death.

However, while this is compelling evidence, more research needs to be done before the link between heart surgery and time of day can be confirmed. There are many factors at play and scientists hope they can better narrow it down for future study.

“What this research suggests is that an intrinsic body clock within cells of the heart may render these cells more susceptible to injury during cardiac surgery in the morning versus the afternoon,” said Bryan Williams, chair of medicine at University College London who was not involved in the study, according to The Guardian. “This would be needed to change practice because the logistical implications of doing so would be huge and require definitive proof that there is a real benefit.”

Irrigation drives urban cooling, study reports

A new study shows that irrigation and farmland greatly affect urban cooling.

While climate scientists fear global warming will cause cities to become much hotter than rural areas, new research from researchers at Purdue University suggests some urban regions may experience a cooling effect instead.

In the study, researchers found that over 60 percent of urban areas in India experience a day-time cooling effect. While the process has been noted in past research, this is the first time scientists have been able to identify the cause: lack of moisture and vegetation in non-urban areas surrounding the city.

“When the areas around cities are running low on water and they aren’t being irrigated, they turn into hot, dry, barren fields,” said study co-author Matthew Huber, a professor of earth, atmospheric, and planetary sciences at Purdue University, according to Phys.org. “When that happens, there’s actually more water available to evaporate in the cities than the surrounding countryside. It’s like the cities are sweating.”

Typically, the so-called “heat island” effect causes cities to be warmer than their rural surroundings. This occurs because cities lose vegetation as they develop. Without that shade and moisture, the regions become hotter over time.

However, the findings show that is not always the case.

In the study, the team collected temperature data from 89 cities in India and then used a climate model to determine the effects of irrigation. This showed that urban temperatures are largely driven by both agriculture and moisture availability from irrigation. Season and region play big factors in regional heating or cooling as well.

However, while most of the urban centers looked at in the study cooled during the day, almost all of them became warmer at night. The effects of night-time warming were especially intense in the semi-arid western region of India.

This is important because intense warming can be deadly. In May of 2015, a massive heat wave led to over 2,000 deaths, and such temperature spikes are expected to become more frequent as time moves on.

The team hopes their new findings will show officials how to use land in a way that will create cooling effects. That could then lead to more effective urban planning and improve public health. 

“[T]hat has implications for water use,” added Huber. “Are you going to impoverish the countryside and leave those areas barren, and the cities lush? These are the kinds of questions we’re asking: what are the tradeoffs?”

This research is detailed in Scientific Reports.

Unusual object likely originated outside the solar system

First interstellar object to pass through solar system is now on one-way trip out.

A small object in an extreme orbit that flew closest to the Sun in September likely originated outside the solar system, according to astronomers who have observed its trajectory over the last few weeks.

Less than a quarter of a mile (400 meters) wide and either an asteroid or comet, the object, designated A/2017 U1, is traveling at 27 miles (44 km) per second and is now on its way out of the solar system.

Worldwide, scientists are aiming telescopes at the object as it departs, in the hope of obtaining data that might provide clues as to its origin.

Using the Pan-STARRS 1 telescope in Hawaii, which searches for near-Earth asteroids and comets, Rob Weryk of the University of Hawaii’s Institute for Astronomy (IfA) first observed A/2017 U1 on the night of October 19.

While searching Pan-STARRS archives, he found images of it captured the previous night but more importantly discovered its highly unusual orbit.

“Its motion could not be explained using either a normal solar system asteroid or comet orbit,” he noted.

Fellow IfA graduate Marco Micheli, who took his own followup images of the object using the European Space Agency’s (ESA) Canary Islands telescope on Tenerife when contacted by Weryk, agreed that it originated from beyond the solar system.

Scientists at NASA’s Center for Near-Earth Object Studies (CNEOS) at the Jet Propulsion Laboratory (JPL) analyzed the path taken by the object and found it is leaving the solar system and will not return.

“This is the most extreme orbit I have ever seen. It is going extremely fast and on such a trajectory that we can say with confidence that this object is on its way out of the solar system and not coming back,” noted CNEOS scientist Davide Farnocchia.

Having come toward our solar system from almost directly above the plane of Earth’s orbit, known as the ecliptic, A/2017 U1 originated from the direction of the constellation Lyra, travelling at 15.8 miles (25.5 km) per second.

It did not interact with any solar system planets, and on September 2, within the orbit or Mercury, it dipped beneath the ecliptic, coming closest to the Sun one week later.

Tugged at by the Sun’s gravity, A/2017 U1 then essentially made a U-turn, flying within 15 million miles (24 million km) of the Earth beneath its orbit, before heading back above the ecliptic. It is currently traveling in the direction of the constellation Pegasus.

“We have long suspected that these objects should exist, because during the process of planet formation, a lot of material should be ejected from planetary systems,” said IfA astronomer Karen Meech, who specializes in small objects such as comets and asteroids.

“What’s most surprising is that we’ve never seen an interstellar object pass through before,” she emphasized.

Studies show new evidence of ancient subsurface ocean on Ceres

Dwarf planet appears to have had strong crust with deformable material beneath it.

Two separate studies analyzing data returned by NASA’s Dawn mission about the surface and sub-surface of dwarf planet Ceres suggest the small world may have once had a global underground ocean.

Some subsurface liquid water from that ocean may still be present today, adding Ceres to the growing category of solar system worlds with underground oceans that could potentially host microbial life.

Minerals containing water are ubiquitous on Ceres’ surface, suggesting an ocean once existed and may still exist today.

In the first study, researchers led by Anton Ermakov of NASA’s Jet Propulsion Laboratory (JPL) analyzed small changes in Dawn’s orbit around Ceres using NASA’s Deep Space Network.  These changes enabled them to obtain data on Ceres’s shape and gravity, which in turn helped them better estimate both the structure and composition of its interior.

They discovered gravity anomalies, or discrepancies between computer models of Ceres’ gravity and actual observations by Dawn at four sites–the dwarf planet’s sole high mountain, Ahuna Mons, and Occator, Kerwan, and Yalode craters.

The findings indicate Ceres is currently geologically active or was geologically active in its past.

“Ceres has an abundance of gravity anomalies associated with outstanding geologic features,” Ermakov said. Anomalies seen at Ahuna Mons and Occator Crater suggest both are products of cryovolcanism, he added.

Also puzzling is the low density of Ceres’ crust, which is more akin to that of ice than of rock. A separate study conducted by Dawn guest scientist Michael Bland of the US Geological Survey found Ceres to have a crust far too strong to be composed largely of ice.

Findings of the study by Ermakov and colleagues are published in the Journal of Geophysical Research.

The second study centered on determining the strength and composition of both Ceres’ crust and its deeper interior through analysis of its surface topography.

Tracing the evolution of topography on a planet’s surface enables scientists to identify its interior composition. Strong, rocky crusts likely experienced little or no change since the solar system’s formation.

On the other hand, weak crusts with high levels of ices and salts likely underwent significant deformation.

Study leader Roger Fu of Harvard University and his colleagues modeled the flow of Ceres’ crust based on Dawn data, and identified the crust as a mix of ice, salts, rock, and clathrate hydrate. The latter is made of water molecules that surround a gas molecule and is up to 1,000 times stronger than water ice.

Based on their findings, the researchers believe ancient Ceres had significantly more surface features that were subsequently smoothed out, meaning it had to have a strong crust on top of a weaker layer, the latter of which could have been an ocean.

Although they believe most of that ocean has since frozen, with its components left in Ceres’ crust, they acknowledge some subsurface liquid could remain, as indicated by thermal evolution models of the planet.

The second study was published in the journal Earth and Planetary Science Letters.

 

Robotic “bees” are able dive in and out water, study reports

Researchers from Harvard have developed a robot that is able to both go underwater and come back out of the liquid without breaking.

A group of scientists from Harvard University have developed a robotic “bee” that can fly, swim underwater, and then move back up into the air.

The machine — which is apart of the latest generation of so-called RoboBees — is a big breakthrough. Not only can it do things past models were not capable of, but it is 1,000 times lighter than any previous aerial-to-aquatic robot.

“This is the first microrobot capable of repeatedly moving in and through complex environments,” explained lead author Yufeng Chen, a researcher at Harvard University, according to International Business Times. “We designed new mechanisms that allow the vehicle to directly transition from water to air, something that is beyond what nature can achieve in the insect world.”

While the new design is effective, creating a robot that can move in and out of water is not easy. That is because water is 1,000 times more dense than air, which means the machine need to flap their wings at different speeds depending on which medium they are in. If they flap too slowly they will not be able to fly, but if their wings move too fast they will break while submerged. 

In the study, the team used a combination of computer modelling and experimental data to get the robots to flap their wings between 9 and 13 hertz in water and 220 to 300 hertz in in the air.

Once that problem was solved, they next needed to design the machines in a way that would allow them to dive into water and bring themselves back out.

Past studies have shown that a powerful impact and sharp objects can help machines pierce through the surface of water. However, moving from the liquid — which has a surface tension that is more than 10 times the weight of the robot and three times its maximum lift — is a much more difficult process.

To overcome that, scientists fitted the RoboBee with four flotation devices and a special gas chamber filled with combustible fuel. The flotation devices first push the robot up to the surface so that its wings are out of water, and from there a spark ignites the gas to move it out the rest of the way. 

“Because the RoboBee has a limited payload capacity, it cannot carry its own fuel, so we had to come up with a creative solution to exploit resources from the environment,” said study co-author Elizabeth Helbling, a researcher at Harvard University, according to Tech Radar. “Surface tension is something that we have to overcome to get out of the water, but is also a tool that we can utilize during the gas collection process.”

This new design allows the devices to lift more than three times the amount of past models. That enables them to carry the gas chamber, the sparker, and buoyant outriggers. While they are still in early testing, the team hopes the machines will have a wide range of applications across different fields. Not only could they be used for search-and-rescue operations, but they could aid environmental monitoring and biological studies as well.

The study is outlined in the journal Science Robotics.

Ancient skull may have belonged to oldest tsunami victim on record

Researchers believe they may have found a skull from the oldest known tsunami victim.

A 6,000-year-old partial skull found in what is now Papua New Guinea could be the earliest tsunami victim ever found, a new study in PLOS ONE reports.

For years, researchers have suspected there was something unusual about the sedimentary deposits around where the skull was first discovered in 1929. To elaborate on that, a team of international scientists recently visited the site to look into the dirt where the skull was buried.

This revealed that certain patterns in the sediments displayed many characteristics of an ancient tsunami. Not only does the team believe the large wave carried the skull to where it was found, they also think it may have taken the person’s life.

When a tsunami sweeps over the coast, it carries with it mud, plants and sea life from the bottom of the ocean. Researchers can look at such debris to figure out when and where past tsunamis occurred. In addition, the phenomena surge and ebb quickly. That means the layers of sediment they deposit have different patterns than other layers that formed slowly over time.

In the case of the skull, scientists were able to tell that the land around it had been scoured by large waves.

Though the ancient bone has been well-studied, little is known about the area where it was found. The team tried to shed light on the region by taking dirt samples from the site in 2014. They then used radiocarbon dating to examine the size and chemical composition of sediment grains, and studied the fossils of microscopic organisms in greater detail than ever before.

This showed that a tsunami likely created the deposits. In addition, the event corresponded with the age of the skull, suggesting that the individual could have been a victim of the natural disaster.

“After considering a range of possible scenarios, we believe that, on the balance of the evidence, the individual was either killed directly in the tsunami, or was buried just before it hit and the remains were redeposited,” said study lead author James Goff, a professor at the School of Biological, Earth and Environmental Sciences at the University of New South Wales in Sydney, in a statement.

Earth underwent a series of rapid environmental changes some 3,000 to 7,000 years ago. Those affected many different coastal societies and threatened different populations. Researchers hope that learning more about such regions could help them better understand the way ancient humans mitigated or adapted to different environmental risks and allow them to better prepare for modern coastal changes. 

“This is a story that has thousands of years of history that we’re still seeing today,” said study co-author Mark Golitko, an assistant professor in the Department of Anthropology at the University of Notre Dame, according to Live Science. “It’s a great place to live on one hand, and it’s a really bad place to live on another — and that’s something that has a resonant message for the modern age.”