The clouds that flow in the sky of Mars

After the postcards of blue sunsets and sunsets from Mars sent by NASA’s InSight mission, the extraordinary videos of the clouds moving in the Martian atmosphere, sent by the Curiosity rover, arrive. NASA’s robot lab has filmed the clouds with its Navcam navigation cameras on May 7 and May 12, 2019. In the images the filamentous clouds illuminated by the Sun, similar to the terrestrial cirrus clouds, which move in the sky of Mars driven by the wind. According to the American Space Agency they are probably clouds of water ice and are located about 31 kilometers from the surface.

Filming clouds for Curiosity is not a pastime between exploration and the other of the Gale crater, but an activity planned by researchers to study the dynamics of the atmosphere of Mars, especially after comparing Curiosity observations with those collected by the InSight lander which is about 600 kilometers away. This is because capturing the same clouds from two vantage points, for example, can help calculate their height.

Curiosity captured the images during a break from the drilling activity that engaged him a lot in May. Recently it has in fact drilled two rocks called ‘Aberlady’ and ‘Kilmarie’, collecting the greatest quantity of clay minerals ever found during the mission. The result shows that the region, located on one of the sides of Mount Sharp and called the Clay Unit, well deserved its name. The clay is formed in the presence of water and according to the researchers it is probable that the rocks in the area were formed in the mud layers of ancient lakes, where the water interacting with the sediments left an abundance of clay in the rocks.

ExoMars 2020, in Italy the control center of the rover for Mars

TURIN – The control center of the Exomars 2020 mission was inaugurated in Turin, organized by the European Space Agency (ESA) and the Russian Roscosmos. It is from here that the movements of the rover will be controlled which, with an Italian drill, will have to pierce the ground of Mars up to two meters deep in search of traces. F nter caption onte: Thales Alenia Spacedi past life.

Called Rover Operations and Control Center (Rocc), the center is located in the Altec facilities, the company born from the collaboration between Thales Alenia Space and the Italian Space Agency (ASI). Also present at the inauguration ceremony were the mayor of Turin, Chiara Appendino, in addition to the leaders of Altec, Thales Alenia Space, Esa.

“This is a strategic place on Earth, from which we will listen to the tools of the rover, we will see what Rosalind sees and we will send commands to look for obvious traces of life above and below the surface,” said Esa general manager Jan Wörner. The Rocc Center is also strategic for Italy: “it is the first step to nominate the structure for future missions for the study of Mars, but also for other celestial bodies”, said the president of ASI Giorgio Saccoccia.

The ExoMars 2020 mission foresees the launch, in July 2020, of a Descent Module on whose Landing Platform will be housed a Rover called Rosalind, in honor of the chemist Rosalind Franklin who discovered the DNA structure with James Watson and Francis Crick. The auger with which he will search for traces of life was built in Italy, in Leonardo’s Nerviano facilities.

Dark matter exists: the observations that questioned its presence in galaxies are denied

The old saying “we are dust of stars” has penetrated so deeply into our minds that we risk losing some of its poetry. Yes, elements heavier than hydrogen and helium in the earth’s environment have been forged by various ancient life cycles of generations of stars. Many of these cosmic furnaces have expelled their contents into the void, polluting our galaxy with traces of atomic nuclei that we call oxygen, carbon, iron and more. And in the course of the eons gravity has caused the re-condensation of this interstellar matter. As a result, the elements were separated, allowing star matter to become extraordinarily concentrated, creating new stars, planets, and clusters of heavy nuclei that make up human beings and their absurd complexity.

Di Paolo and his collaborators wanted to verify this relationship, analyzing the rotation curves of galaxies different from the “classic” spirals: 72 galaxies with low surface brightness (LSB) and 34

dwarf disk galaxies. They produced more extensive results, finding a relationship that, in addition to the total gravitational acceleration and its ordinary component, also involves the galactic radius and the morphology of the galaxies.

“We have studied the relationship between total acceleration and its ordinary component in 106 galaxies, obtaining different results than previously observed,” explains Paolo Salucci, professor of astrophysics at SISSA and among the authors of the research. “This not only demonstrates the inaccuracy of the previously described empirical relationship but eliminates doubts about the existence of dark matter in galaxies. Furthermore, the new report found could provide crucial information for understanding the nature of this indefinite component “.

Cuttlefish and squid inspire space blankets and smart clothes

Octopus, cuttlefish and squid have provided the inspiration for an innovative material, destined to become space blankets, “smart” clothes and much more: the particular characteristics of the skin of these sea creatures, in fact, have been exploited by researchers at the University from California to Irvine, to make a fabric that can regulate the body temperature of the wearer, controlling the amount of heat trapped or released. 

The study, published in the journal Nature Communications, could also be applied to thermally insulate buildings and camping tents. The two researchers, Erica Leung and Alon Gorodetsky, took the idea by looking at cuttlefish, squid and octopus: these animals have the ability to rapidly change color by changing the shape of skin cells. “We used a similar concept for our work, where we have layers of small metal ‘islands’ that border on each other,” explains Leung. “Under normal conditions, the islands touch and then the material reflects and traps heat – he continues – while when it is stretched the islands move away from each other, allowing the heat to escape”.

The ultra-light space blankets have been there for decades, like those in which athletes who participate in a marathon wrap around to prevent the rapid lowering of body temperature after the race, but these are non-adaptable materials. “Our version is able to change its properties,” says Gorodetsky. “We could make clothes that fit everyone’s needs – he adds – and this could lead to savings of 30% -40% for heating and air conditioning in closed rooms”.

Ready the touch file for future robots

The most complete archive of touch-based data available to future robots is ready. It was developed at the Massachusetts Institute of Technology (Mit), storing in an artificial intelligence system the sensations recorded through gloves equipped with special sensors. The details of the archive, published in the magazine Nature, will allow to build robots with a sense of touch similar to the human one and to design wearable computers and prostheses with a greater sensitivity.

The starting point of the project, coordinated by Subramanian Sundaram, were hi-tech gloves scattered with about 550 sensors, tested on 26 objects of different shapes and weights, from scissors to tennis balls, from cans to pens. In this way, a unique sensory archive has been obtained, which will allow artificial intelligence systems to recognize and classify objects with the sole sense of touch, without having to observe their images.

In the first tests performed at MIT, the touch archive allowed an artificial intelligence system to identify objects with an accuracy of 76%, predicting their correct weight with a margin of error of about 60 grams. “This information – concluded the authors of the study – will help robots to identify and manipulate objects, and to design future robotic prostheses.

Gravitational waves, nuclear fire, rocks and love

The old saying “we are stardust” is so penetrated into our mind that we risk losing part of his poetry. Yes, elements heavier than hydrogen and helium present in the terrestrial environment have been forged by various ancient life cycles of generations of stars. Many of these cosmic furnaces have expelled their contents into the void, polluting our galaxy with traces of the atomic nuclei we call oxygen, carbon, iron and more. And in the course of the aeons gravity has caused the recondensation of this interstellar matter. As a result, the elements have been separated, allowing the star matter to become extraordinarily concentrated, creating new stars, planets, and clusters of heavy nuclei that make up human beings and their absurd complexity.

Gravitational waves, nuclear fire, rocks and love
Artistic representation of the collision between two neutron stars. (Courtesy Dana Berry, SkyWorks Digital, Inc.)

This is fantastic, but repeat the story a great many times and it will start to sound a little trivial. Part of the reason is that the narrative can become vague – from speaking in general terms of previous generations of stars now invisible to our extensive descriptions of the nature of interstellar matter. It’s a bit like when an elderly relative tells you about the family tree of your family up to the fifth generation. There may be little to identify with, even if we would like to do so. 

The story becomes much more interesting when you look closer. First, not all elements are produced in the same way. Perhaps the most interesting example is that of the elements of the so-called ” process r “.

These elements have heavier nuclei than iron and are built by a mechanism called rapid neutron capture. Such as

 the name suggests, something is needed to capture neutrons in the form of “seed” nuclei, and a tremendous neutron flux is needed, which is fast enough to go and form nuclei beyond any highly unstable intermediate configuration. 

But where do you find such environments? 

In 2017, observers of gravitational waves LIGO and Virgo caused a sensation by detecting the signature of a fusion of two neutron stars. Two stellar mass spheres of nuclear material spiraled towards one another with a cry of space-time oscillations of increasing intensity.

Unlike the fusion of a binary black hole, that event produced a prodigious amount of electromagnetic radiation in the so-called kilonova (literally, a thousand times the emission of a normal nova star). The kilonova’s telescopic study has provided convincing support for the idea that the neutron star fusone represents a paradise for the r process. This suggests that these cataclysmic events play an important role in supplying our galactic landscape with some of the heavier elements. From gold, platinum and iridium to thorium and uranium, up to short-lived elements such as plutonium. 

Now, new research by Bartos and Marka, published in recent days on “Nature”, offers a creative and rather surprising view of the origins of the elements of the r-process in our solar system. The researchers combined two key analyzes. One of the data on meteorites that preserve evidence of the mix of elements in our solar system in formation, about 4.6 billion years ago. The other is an ingenious statistical model of the history of neutron star fusions in the galaxy. 

Research indicates that at the dawn of our local cosmic history a very close neutron star collision occurred. Traces of this unique event seem to be present in the details of the radioisotopes due to the r process that sprayed our system in formation after the collision of neutron stars.

Gravitational waves, nuclear fire, rocks and love
The nucleosynthesis of some elements can occur within the stars, but even more energetic processes are needed for the elements heavier than iron. (© Science Photo Library / AGF)

Reaching this conclusion requires some mental flexibility and hard work. Neutron star fusions are cosmically rare in the Milky Way, ranging from one to one hundred events per million years in all its extension. Some elements of the r process, such as the actinides (including curio-247, plutonium-244 and iodine-129), have relatively short half-lives, in the order of tens of millions of years, but have left specific traces in the meteorite material of the ancient solar system, which allow us to measure their original abundances.

Therefore, the quantity of these elements that existed during the time window in which our solar system was forming offers a tool to evaluate not only the era in which those elements were forged, but also the distance at which the element must have been forge. 

By building a simulation of neutron star fusions in our galaxy, in the course of its history up to the formation of our solar system (in the approximately 9 billion years of existence of the Milky Way), Bartos and Marka have been able to examine which scenarios could have produced the mixture of actinides obtained from meteorite analysis.

From the result of the analysis it seems that there was only one kilonova produced by a fusion of neutron stars that would be verified within 80 million years (more or less 40) by the formation of the solar system and about a thousand light years away. The researchers estimate that a kilonova event so close would have hidden all the night sky for over a day. Four and a half billion years ago, when the newly generated elements of the fusion were projected outside and spread in interstellar space, about 10 ^ 20 kilograms of them ended up depositing in our young system.

From there you can understand how much of the terrestrial deposit of elements of the process came from that one event. For example, the equivalent of an eyelash of iodine in your body will have come from those neutron stars. A Tesla Model 3 car contains a total of about 5 grams of the nuclei generated by this specific neutron star fusion. A modern fission reactor, which uses enriched uranium, will contain about 200 kilograms of material that was produced in that one cosmic explosion.

Significantly, the study also seems to exclude that among the primary producers of process elements r throughout the galaxy there have been events such as nuclear collapse supernovae, linked to the implosion of massive stars. Those events, which occur hundreds or even thousands of times more frequently than neutron star mergers, do not seem to match the data. 

Overall, it seems that we can update the story of our origins from “stardust”. Not only are we indebted to an even more exotic and extreme physics than perhaps we imagined, but now we have to place two very specific members of our ancestral tribe on the family tree: a pair of lovers neutron stars, whose embrace was literally on fire.

Molecular machines as revolutionary as planes

Nobel Stoddart, useful for new materials, batteries and even in medicine

A technological revolution equal to that brought about by the invention of the plane: this is what is being prepared thanks to molecular machines, the smallest machines in the world produced in the laboratory imitating those present in nature, even in the cells of the human body. Made by gears, switches, pumps and rotors a few millionths of a millimeter in size, they can move, transport drugs or be controlled remotely, and thanks to their properties can make a radical change in medicine and in the development of new materials, also useful to produce the batteries of the future. Word of the 2016 Nobel Prize for Chemistry James Fraser Stoddart, guest at the Politecnico di Milano for a lectio magistralis followed by more than 300 students and teachers.

“In our body there are many molecular machines that allow us to live: to move the arm, for example, I’m using a molecular machine made from a protein that walks on top of the other”, explains Stoddart, who arrived in Italy to participate in the international congress of chemistry Ismsc 2019 that the Politecnico di Milano organizes in Lecce from 2 to 6 June. “What I did with the other two Nobel Prize winners, Jean-Pierre Sauvage and Bernard L. Feringa, was nothing more than designing and synthesizing artificial molecular machines. Although invisible to the naked eye, these machines “are beginning to be a reality: there are already the first applications, but it will take years, perhaps decades, to exploit their full potential,” explains the British chemist who works in the United States at Northwestern University. “It’s going to be a new technological revolution, as with planes,” explains Nobel Prize winner Stoddart.

“We’ve always seen birds and insects fly, but it’s only in the last century that we humans have managed to do that, turning flying into a practice that has since become commercial and accessible to a growing number of people. With molecular machines, it will be the same. The revolution will, first of all, bring new materials. “On the market there are already scratch-resistant polymers based on simple molecular machines, which are used for example in Japan for the covers of smartphones, but in the future we can also have more efficient batteries: there is already a study in the literature that shows the best performance and durability of lithium-ion batteries that contain a special polymer. Even more impressive are the possible applications in medicine, “because we will have molecular machines capable of interacting with human cells, so – concludes Stoddart – we can imagine new and more efficient systems to convey drugs.

Notre Dame, his virtual 3D copy will help rebuild it

The hopes of rebuilding Notre Dame are not burned together with the historic cathedral: in 2015 an accurate 3D virtual copy accurate to the millimeter was made, thanks to a laser scan of the entire building that was saved in a digital archive. The work done by a group of historians who studied the architecture of the great Gothic cathedrals for the National Geographic, was led by Andrew Tallon of Vassar College, United States, who “recorded” every extraordinary detail with a margin of error of a few millimeters, providing a map to follow for the reconstruction of the church.

The scan was done by putting together the data taken from 50 different locations, inside and outside Notre Dame, which produced the impressive figure of a billion measurements. For each scan, the laser scoured the area in every direction, recording the exact position of all the surfaces encountered, from the buttresses to the columns. The result is millions of colored dots that combine to form a perfect three-dimensional replica of the cathedral.

Tallon’s work has also revealed all the secrets used in the construction of Notre Dame, which took place between 1163 and 1345, such as the design of its very high arches. The efforts to rebuild the church have already begun: thanks to donations, more than 450 million dollars have already been collected. Despite the extensive damage, most of the extraordinary works of art and stone structures have remained intact. But only time will tell if the building can be restored to its ancient and beloved splendor.

The secret of the fuels of the future eats methane in bacteria

In methane-eating bacteria, they promise to be the key to the fuels of the future. After years in which their mechanism of operation has remained mysterious, a group of Northwestern University has identified the precise point in which the enzyme responsible for the conversion of methane into ethanol enters into action. 

It is a point where there is only one ion (that is, an atom that has sold or acquired one or more electrons) of copper. The discovery, published in the journal Science, could lead to the design of new catalysts, capable of converting methane (a powerful greenhouse gas) into methanol (used in fuels) that can be quickly reused, using the same mechanism as bacteria.

“The identity and structure of the metal ions responsible for catalysis have remained elusive for years, but we have made an important step forward in understanding how these bacteria work,” noted Amy Rosenzweig, co-author of the study. 

Current industrial processes to trigger a methane-methanol reaction require very high pressures and extreme temperatures, which can exceed 1,300 degrees. With these bacteria, on the other hand, the reaction takes place at room temperature and is free. “If we could completely understand how these bacteria develop conversion under mild conditions, we could optimize our catalysis,” says another of the researchers, Matthew O. Ross.