A drone for ultrafast transitions between air and water

The new drone with a fish-inspired suction disc hitchhikes on moving objects to save power and can quickly transition between air and water.
Illustration: Beihang University / Science Robotics

A new robot is capable of switching from an underwater drone to an aerial vehicle in less than one second. The robot also features a suction disc inspired by the remora fish, which enables it to hitchhike on wet or dry moving objects to significantly reduce its power consumption. It is designed for biological and environmental monitoring in marine ecosystems such as surveying ocean pollution in the open sea as the scientist of Beihang University, Imperial College London and Empa point out in a new study published in Science Robotics.

The ultrafast transition from underwater drone to aerial vehicle in less than one second is based on a new propeller design – making this transition between the different mediums faster than most prior aerial-aquatic robots. Designed by a team of scientists from China, the United Kingdom and Switzerland, the versatile robot and its bio-inspired adhesive disc could be adapted for open-environment aerial and aquatic surveillance research.

Travelling with whales

The robot features a suction pad inspired by remora fish.
Image: Beihang University / Science Robotics

It’s well known that untethered drones can help research expeditions and wildlife surveys in expansive or remote environments such as the open sea, but some constraints remain. For example, untethered drones are not the best choice to use during lengthier missions because they have no external power sources to fall back on if their battery fails. To address this limitation, scientists 3D-printed an aerial-aquatic untethered robot that reduces its power consumption through hitchhiking. The robot features a suction pad inspired by remora fish – a family of species known for their adhesive discs, which help them catch a ride on marine creatures including whales and sharks. The remote-controlled robot’s disc can stick to wet and dry surfaces with different textures, even on moving objects.

In tests, the robot hitched a ride on a swimming host vehicle to obtain seabed images of hermit crabs, scallops, and seaweed. „Our study shows how we can take inspiration from the adhesion mechanism of the Remora and combine it with aerial robotics systems to achieve novel mobility methods for robotics“, says Mirko Kovac, who heads both Empa's Materials and Technology Center of Robotics and the Aerial Robotics Lab at Imperial College.

During the process, the hitchhiking robot consumed almost 20-times less energy than it would have using self-propulsion. Through their outdoor experiments, the team could show that the robot can hitchhike, record video during air-water transitions, and perform cross-medium retrieval operations in both freshwater and saltwater environments.

Ultrafast transition between water and air – the new bioinspired robot. 

Video: Empa / Source: Beihang University / Science Robotics

Source/Credit: EMPA

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Astronauts may one day drink water from ancient moon volcanoes

Scientists believe that the moon's snakelike
Schroeter's Valley was created by lava flowing over the surface.
Credit: NASA Johnson

Billions of years ago, a series of volcanic eruptions broke loose on the moon, blanketing hundreds of thousands of square miles of the orb’s surface in hot lava. Over the eons, that lava created the dark blotches, or maria, that give the face of the moon its familiar appearance today.

New research from CU Boulder suggests that volcanoes may have left another lasting impact on the lunar surface: sheets of ice that dot the moon’s poles and, in some places, could measure dozens or even hundreds of feet thick.

“We envision it as a frost on the moon that built up over time,” said Andrew Wilcoski, lead author of the new study and a graduate student in the Department of Astrophysical and Planetary Sciences (APS) and the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder.

He and his colleagues published their findings this month in The Planetary Science Journal.

The researchers drew on computer simulations, or models, to try to recreate conditions on the moon long before complex life arose on Earth. They discovered that ancient moon volcanoes spewed huge amounts of water vapor, which then settled onto the surface—forming stores of ice that may still be hiding in lunar craters. If any humans had been alive at the time, they may even have seen a sliver of that frost near the border between day and night on the moon's surface.

It’s a potential bounty for future moon explorers who will need water to drink and process into rocket fuel, said study co-author Paul Hayne.

“It’s possible that 5 or 10 meters below the surface, you have big sheets of ice,” said Hayne, assistant professor in APS and LASP.

Tooth unlocks mystery of Denisovans in Asia

Views of the TNH2-1 specimen
Credit: Flinders University

What links a finger bone and some fossil teeth found in a cave in the remote Altai Mountains of Siberia to a single tooth found in a cave in the limestone landscapes of tropical Laos?

The answer to this question has been established by an international team of researchers from Laos, Europe, the US and Australia.

The human tooth was chanced upon during an archaeological survey in a remote area of Laos. The scientists have shown it originated from the same ancient human population first recognized in Denisova Cave (dubbed the Denisovans), in the Altai Mountains of Siberia (Russia).

The research team made the significant discovery during their 2018 excavation campaign in northern Laos. The new cave Tam Ngu Hao 2, also known as Cobra Cave, is located near to the famous Tam Pà Ling Cave where another important 70,000-year-old human (Homo sapiens) fossils had been previously found.

The international researchers are confident the two ancient sites are linked to Denisovans occupations despite being thousands of kilometers apart.

How ice clouds develop – Asian monsoon influences large parts of the Northern Hemisphere

Air pollutants form the condensation nuclei for ice clouds or cirrus clouds (here: Cirrus spissatus). When ammonia, nitric acid and sulfuric acid are present together, they form such condensation nuclei particularly effectively.
Credit: Joachim Curtius, Goethe-University Frankfurt

Atmospheric researchers from the international CLOUD consortium have discovered a mechanism that allows nuclei for ice clouds to form and rapidly grow in the upper troposphere. The discovery is based on cloud chamber experiments to which a team from Goethe University contributed highly specialized measurements. Although the conditions for nucleus formation are only fulfilled in the Asian monsoon region, the mechanism is expected to have an impact on ice cloud formation across large parts of the Northern Hemisphere. 

The Asian monsoon transports enormous amounts of air from atmospheric layers close to Earth's surface to a height of around 15 kilometers. Like in a gigantic elevator, human-induced pollutants also end up in the upper troposphere in this way. A research team from the CLOUD consortium (Cosmics Leaving Outdoor Droplets), including atmospheric researchers from Goethe University in Frankfurt, have reproduced the conditions prevailing there, among them cosmic radiation, in their experimental chamber at the CERN particle accelerator center in Geneva.

Biological crusts influence the climate

Biological soil crusts strengthen the soil and ensure that less sand is stirred up and thus fewer dust particles are released into the atmosphere.
Credit: Emilio Rodriguez-Caballero

A surface layer of bacteria, fungi and lichen amongst others reduces the amount of dust stirred up into the atmosphere

When bacteria, fungi, mosses, lichens and algae combine on dry land, they form so-called biological soil crusts. These cover about twelve percent of the total global land surface, and up to one third of the surface in dry areas. Biological soil crusts play an important role in consolidating soils, making them more stable and less likely to be stirred up by the wind. Since dust particles in the atmosphere have an impact on the climate, soil crusts fulfil an important function in several respects. An international team of researchers around biologist Bettina Weber of the University of Graz and research associate of the Max Planck Institute for Chemistry provide, for the first time, comprehensive facts and figures on the importance of biological soil crusts for the regional and global dust cycle, both under current and future conditions.

The dwarf planet Ceres was formed in the coldest zone of Solar System and thrust into Asteroid Belt

The dwarf planet Ceres in an image captured by NASA’s Dawn Mission. The bright white spot is a reflection of sunlight from ice deposits at the bottom of the crater
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

In an article published in the journal Icarus, researchers at São Paulo State University (UNESP) and collaborators report the findings of a study reconstituting the formation of the dwarf planet Ceres.

The research was conducted by Rafael Ribeiro de Sousa, a professor in the program of graduate studies in physics on the Guaratinguetá campus. The co-authors of the article are Ernesto Vieira Neto, who was Ribeiro de Sousa’s PhD thesis advisor, and researchers affiliated with Côte d’Azur University in France, Rice University in the United States, and the National Observatory in Rio de Janeiro.

Ceres is the largest object in the Asteroid Belt, a collection of celestial bodies located between the orbits of Mars and Jupiter. It is roughly spherical and comprises a third of the Asteroid Belt’s total mass, with a diameter of almost 1,000 km, less than a third of the Moon’s.

Its orbit around the Sun is almost perfectly circular, with 0.09 eccentricity, and an inclination of 9.73° to the invariable plane of the Solar System, much greater than Earth’s, which is 1.57°.

Researchers developed invisible, machine-washable solar cell technology for clothing

The Sun-powered Textiles project looked for ways to seamlessly combine solar cells and textiles. Photo: Anne Kinnunen/Aalto University

The discrete nature of the cells protects them – and makes the clothes more attractive, the physics and design researchers say. Promising applications include work and outdoor clothing, and curtains which react to changes in the amount of light.

Lasting power and efficient recycling

Any solar cell placed under the textile it adheres to has to have a significantly larger surface area than a cell that’s placed on top. A piece of regular fabric eats up roughly 70 percent of a cell’s capacity - with a more porous fabric the percentage is smaller.

Key factors in the ability of textiles to let light through them include the material, transparency and crosscut of the fiber, structure of the threads, thickness and weave of the fabric, colors and the finish. Light colors transmit light better than dark colors, but a pitch-black and completely opaque fabric can also work.

The commercial solar cells used in the study comprised of a single crystal and were made of silicon. They can detect light that is invisible to the naked eye, which is what most sunlight actually is. Infrared is an example of such invisible light.

Mystery of seafloor metamorphosis unlocked

An adult tubeworm, in its tube, with its plume of tentacles extended.
Photo credit: Freckelton et al. 2022

Most bottom-dwelling marine invertebrate animals, such as sponges, corals, worms and oysters, produce tiny larvae that swim in the ocean prior to attaching to the seafloor and transforming into juveniles. A study published in the Proceedings of the National Academy of Sciences and led by University of Hawaiʻi at Mānoa researchers revealed that a large, complex molecule, called lipopolysaccharide, produced by bacteria is responsible for inducing larval marine tubeworms, Hydroides elegans, to settle to the seafloor and begin the complex processes of metamorphosis.

“This is a major milestone in understanding the factors that determine where larvae of bottom-living invertebrates settle and metamorphose,” said Michael Hadfield, senior author on the paper and emeritus professor in the UH Mānoa School of Ocean and Earth Science and Technology (SOEST). “It is the key to understanding how benthic (underwater) communities are established and maintained on all surfaces under salt water, that is, on 71% of Earth’s surface.”

Scientists 'see' puzzling features deep in Earth’s interior

Etna Volcano Eruption January 12th 2011
Credit: gnuckx

New research led by the University of Cambridge is the first to obtain a detailed 'image' of an unusual pocket of rock at the boundary layer with Earth’s core, some three thousand kilometers beneath the surface.

The enigmatic area of rock, which is located almost directly beneath the Hawaiian Islands, is one of several ultra-low velocity zones – so-called because earthquake waves slow to a crawl as they pass through them.

The research, published in Nature Communications, is the first to reveal the complex internal variability of one of these pockets in detail, shedding light on the landscape of Earth’s deep interior and the processes operating within it.

“Of all Earth’s deep interior features, these are the most fascinating and complex. We’ve now got the first solid evidence to show their internal structure - it’s a real milestone in deep earth seismology,” said lead author Zhi Li, PhD student at Cambridge’s Department of Earth Sciences.

“Natural Immunity” from Omicron is Weak and Limited

The new study shows that infection with Omicron does not protect against other variants of COVID-19. In this photo, clear zones on the purple background show the SARS-CoV-2 virus escaping from neutralizing antibodies in patient blood samples.
Credit: Gladstone Institutes

In unvaccinated people, infection with the Omicron variant of SARS-CoV-2 provides little long-term immunity against other variants, according to a new study by researchers at Gladstone Institutes and UC San Francisco (UCSF), published today in the journal Nature.

In experiments using mice and blood samples from donors who were infected with Omicron, the team found that the Omicron variant induces only a weak immune response. In vaccinated individuals, this response—while weak—helped strengthen overall protection against a variety of COVID-19 strains. In those without prior vaccination, however, the immune response failed to confer broad, robust protection against other strains.

“In the unvaccinated population, an infection with Omicron might be roughly equivalent to getting one shot of a vaccine,” says Melanie Ott, MD, PhD, director of the Gladstone Institute of Virology and co-senior author of the new work. “It confers a little bit of protection against COVID-19, but it’s not very broad.”