Drops of Sciences

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Microplastics as an oceanic chemistry lab

As plastic continuously finds its way into the ocean it follows a long trip that weathers it down to smaller and smaller pieces. These pose a hazard to ocean environments and other aquatic habitats based on a new study published in Environmental Science & technology letters. Once below 5mm they fall into the category of microplastics with, as it seems, additional properties for chemical pollution besides the physical one. The surface of microplastics bonds optimally with heavy metals such as Cromium but also with organic components such as UV filters in sunscreens. In their study Kelvin Sze-Yin Leung and colleagues observed that the heavy metal substances where not only oxidised (rusted), but also hindered the growth of aquatic algal communities. In a continuous stream of pollution in the ocean, plastics do not only entrain into the tissue of fish and other animals as previous studies have shown, but also create a chemically hostile environment to the growth of aquatic ecosystems full of rust.

Image credit: 5Gyres, courtesy of Oregon State University, source: flickr

Source: phys.org

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ESA new astronaut class 2022

Today in the ESA ministerial conference in Paris the class of 2022 ESA astronauts was announced. The new class of 17 was divided in carreer astronauts and reserve astronauts. The carreer astronauts will be given a contract and start preparing for future missions, including among other language lessons! Meanwhile, the reserve astronauts will be considered for future missions and will continue their current day job. So what are the "flavours" of the new astronauts that were chosen among the diverse crowd of about 22,000 applicants of the last ESA call? For the carreer selection the following persons were chosen: one french woman carreer officer and helicopter test pilot, one spanish male aerospace engineer, a UK female astrophysics phd holder, a Belgium male biomedical engineer and neuroscientist, and a Swiss male medical doctor. A parastronaut with a physical disability was also among the chosen astronauts. Good luck new astronaut class!

Image credit: esa.web.tv

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Artemis - I launch - back to the Moon!

A mission destined for the Moon lifted off yesterday, November 16th from the Kennedy space center. This mission is Artemis - I, a first in a series of three launches that aim to bring the first woman and first person of colour back to the Moon by 2025. Artemis - I is an unmanned mission that composes of the SLS NASA rocket, the most powerful rocket ever built, and the European Service Module with the Orion capsule that hosts 4 astronaut seats. Even though the capsule has no astronauts, the service module carries the amount of food and water they would need for their short lunar trip. 240 kg of potable water, 90kg of oxygen and 8600 kg of usable propellant is among the payload. The module will propel an extra payload mass of up to 380 kg. Instead of humans the seats of the Orion capsule are occupied by 3 dummies with sensors to capture the stresses that the human body would be subjected to during the flight. First stop in the trajectory of the spacecraft will be a loop around the Earth, then a loop around the Moon with lunar gravity assist, then a retrograde loop around the Moon, a second flyby of our natural satellite and finally the home trip back to Earth. The capsule of Orion is planned to have a reentry into the atmosphere and a splash in the Pacific Ocean, thus safely returning the mockup crew to our planet on December 11th. The next mission with a human crew is planned for 2024 and will involve a lunar flyby and return to Earth. In 2025 Artemis - III mission will bring humans to land on the Moon, first time since the last Apollo mission in 1972. This series of missions builds incrementally but steadily towards a manned lunar base that will assist future trips to Mars, which is the ultimate aim of the collaborating space agencies of NASA, ESA, DLR, ASI, ISA, JAXA and partners such as Boeing and Space X. For the current Artemis - I mission ESA is providing the European Service Module for Orion, ASI and JAXA are providing cubesats that will be taking measurements around the quality of the mission, JAXA on top provides a lunar impactor and DLR and the Israel Space Agency are providing two of the three dummies that will measure the radiation environment during the flight. Besides them two celebrity fluffy heroes, Shaun the sheep and Snoopy the dog, are also hitchhiking their way to the Moon in the Orion capsule.

Image credit: NASA flickr, Artemis-I launch Sources: https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Orion/Artemis_I https://www.rmg.co.uk/stories/topics/nasa-moon-mission-artemis-program-launch-date https://it.usembassy.gov/international-cooperation-in-nasas-artemis-i-program/

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Growing data in plants

A collaboration between science and art is showing the way to cleaner data storage. That is achieved with using the DNA of plants to store data into. Everyday when we search for our data on the internet cloud we are performing a query in volumous data centers, buildings around the world full with wires and cooling systems that run heavily on electricity and produce CO2. The global consumption of these centers reaches the energy demand of the whole UK, while until 2030 this is projected to rise by 20%. This everincreasing consumption of energy is linked to the concept of data warming, where large volumes of data become responsible for part of the global warming of the planet. The "grow your own cloud" project explores an alternative future where data are stored in an organic environment that the community of citizens can cater to. Imagine a data center that does not run on electricity but only on water and CO2. With the help of biotechnologists at the University of Washington, data such as text, jpeg images and mp3 music files are sequenced not into bits of 0 and 1 as in classic digital data encoding, but into the alphabet of dna, the nucleobases Adenine, Thymine, Cytosine and Guanine. The data are then stored in the idle part of the DNA of plants. Since not all natural DNA sequencing corresponds to useful genes for the evolution of the plant, the DNA molecule chain provides a vast amount of free space to encode on by artificially rearranging nucleobases in it. In order to retrieve the information, one takes a liquid sample of plant DNA and inserts it into modern DNA decoding devices, that decipher the stored information and either project it onto screens or play it into speakers. This way the data storage becomes a local islet of O2 producing plants that combat global warming while the data format does not ever become obsolete, in contrast to the digital data storage.

The project won the prize in Falling Walls Berlin 2022 in the category science meets art.

sources: growyourown.cloud https://cyrus.website/data-garden/ Falling Walls Berlin, 7-9 November 2022

image credit: Grow Your own Cloud

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Wine crystals

A microscopic exploration of crystals in daily life substances. Transmitted light and polarizing filters are used to provide coloration to those transparent crystals in wine.

Image Credit: Jstor, Wellcome collection, Fernan Federici & Jim Haseloff, Creative commons by attribution

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Bees electrify the atmosphere

In a recent study, researchers of the University of Bristol and the University of Reading looked into a lively group of charge carriers in the atmosphere, the insects. It turns out that the swarms of insects that we find in the lowest 5 km of the atmospheric layer carry electric charge aloft. This biogenic electricity even compares to that of meteorological phenomena such as cloud electrification, aerosols and rain. The researchers were able to study the electric charge of a swarm of honeybees in a field in the UK and confirm its presence in the atmosphere. The denser the swarm, the higher the contribution to the electric field was. Researchers say that combining the two disciplines of biology and physics could be so important as to add this new component to weather prediction models, a unique link where the biosphere enters the physical world observables. This link could potentially explain gaps in the knowledge of how the atmosphere electrifies.

source: Observed electric charge of insect swarms and their contribution to atmospheric electricity, Ellard R.Hunting, Liam J.O’Reilly, R. Giles Harrison, Konstantine Manser, Sam J.England, Beth H.Harris and Daniel Robert, Iscience, October 2022

University of Bristol, news and features https://www.bristol.ac.uk/news/2022/october/insects-affect-electric-fields.html

Image credit: Iscience graphical abstract, Elsevier

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A blob of lava, followed

Let's follow a blob of lava in its journey out of a volcano. In the beginning it vertically uplifts out of the magma conduit, since it originates many meters below the surface deep into the Earth. Then, it overflows the mountain caldera and races along the slopes of the volcano creating short-lived rivers. The lava rivers eventually freeze into solid as they come in contact with the cold atmosphere; But not immediately. The do so slowly from the outside, while the inside keeps on being hot, liquid and rapidly flowing. There is our lava blob, pushing on and rolling towards the feet of the mountain protected by a solid wall around it. Once it reaches the bottom of the mountain it stops, but it has left an empty conduit in its trace. The result is a lava tube that will stay warm for years before we are able to visit it, an underground channel made out of frozen lava walls. The inside of these tunnels have walls that ressemble dark glass, with texture curved by the superheated gases that the lava exhausted. The gases also colour the mineral rocks with various colours due to the oxidation they cause. The tunnels have even solid structures of once dripping lava, similar to a natural cave's stalagmites and stalactites formed by dripping salty water. One can visit a lava tube in various volcanic hotspots around the Earth, such as Hawaii, La Reunion, Azores, Iceland and the Canary islands. Similar lava tubes are expected to exist also on the once volcanically active moon. They provide a hopeful location for humans to colonise and live inside, protected by the solar UV rays and other cosmic radiation. In volcanic places with lava tunnels on Earth, such as Iceland, researchers have already deployed analogue lunar habitats and test communications and mapping devices in preparation for a similar lunar mission: A pretty ambitious plan shaped by many small lava blobs.

Image credit: Athanasia Nikolaou, Inside a lava tube in La Reunion, 2017.

Sources: Heemskerk, M., Pouwels, C., Kerber, S., Downes, E., Heemskerk, R., and Foing, B.: CHILL-ICE: Construction of a Habitat Inside a Lunar-analogue Lava-tube: Iceland Campaign of EuroMoonMars, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-901

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The 2022 Nobel physics prize

When it comes to what was the Nobel prize in physics all about, the answer is a bit hazy. We know it was for quantum mechanics, but which aspect of it? In this post we try to elucidate it. It all started in 1935 with a paper that Einstein, Podolsky and Rosen (EPR) published and that was expressing concerns about how quantum mechanics is an incomplete theory of describing the real world. In the heart of quantum mechanics we find the uncertainty about the properties of a subatomic particle. According to its view the particle has more than one values simultaneously, each described by a probability through its wavefunction. It is only when we measure the particle that the wavefunction "collapses" to one of the values of the property and gives us a definite answer. But before the measurement, the particle is in a superposition of values, all true with a certain probability, all true at the same time.

For the rest we will focus on one property of the particles called the spin that can only take the values "up" or "down". Experimental apparatus are able to generate a pair of subatomic particles that have always opposite spins and when we measure the one the other collapses into the opposite value. Since the pair was generated in this "entangled" state, the measurement of opposite spins will be the same no matter how far away each particle is from each other, that is what quantum mechanics claims. Now to go back into what EPR claimed in 1935 is that this was impossible. The only reason to measure the spins and find them opposite to each other is because they were always constantly so, from the moment that they were generated, and not because the particles communicated with each other at distance in some "spooky action" and collapsed at the same time. They claimed that the particles' spin was never uncertain but was a hidden and constant variable of the system that we only uncovered when measuring. But proving the truth of this statement against quantum mechanics view was a philosophical conundrum until 1964 that Bell entered the discussion. How can we prove that the particles have a superposition of spins if our only tool is to measure them and at all times that we measure the particle collapses to one and single state? It is as if saying that "I have green eyes every time you don't look but when you look at me they become blue". There is no way to prove the existence of green eyes at me.

Einstein and colleagues were not convinced by quantum mechanics probabilistic image of the world and condensed their thoughts into the above thought experiment, but Bell went a step further in 1964 and transferred their views into inequalities. A simple representation of what he did was the following: Assume that the particles have up and down spins not in one axis but in three axes. Now the particle is described by three spin numbers, one for each axis. Assume that we have a machine that generates entangled particles (with opposite spins in all axes) and then sends them to opposite directions at some distance where we have two measurement devices, one for each particle. Then the devices will measure the spin of each arriving particle, one spin value for a given axis, and will give an answer of "up" or "down" spin. The devices can measure only one spin at the same time, but they do not have to measure the same axis spin. Therefore they will give opposite spins when they measure the same axis or combinations of axis, but they will sometimes give the same spin (up-up or down-down) if they measure a combination of different axis. If we combine all the different ways that the two measuring devices can spit an output we will find it is 9 different outputs in total and that the cases of opposite spins are 5 or higher. That gives us a probability that if we repeat the experiment many times we will find opposite spin at least 5/9 times. This is "a Bell inequality" on the probability of opposite spins in entangled particles and gives a lower limit for its value, the 5/9. It accepts the EPR view of the world, as if the spins are predefined hidden variables, in order to be true. More inequalities like this can be thought of.

The three nobelists: Alain Aspect, John Clauser and Anton Zeilinger devised and improved experiments that made use of these Bell inequalities showing that they were all violated by the quantum particles, in various settings. In other words, the deterministic EPR view of the hidden variables was not confirmed when faced with statistical experimental data using quantum particles. Entangled particles showed behaviour of telecommunicating their properties at large distances in an effect relevant to quantum teleportation. The research on quantum information and cryptography, even on the quantum computer, blossomed, having as a starting point these experiments; And the proven uncertain nature of quantum particles continues to challenge the view of the Newtonian world that with our senses we are used to.

sources: Brian Green, "Your daily equation", youtube https://www.youtube.com/watch?v=UZiwtfrisTQ Physics today, Hill and Grant, Demonstrations of quantum entanglement earn the 2022 Nobel prize in physics, October 2022

Image credit: Yay Media AS/Alamy, New Scientist

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Buckle up - turbulence ahead

What is turbulence in the air? It is without doubt a complex phenomenon that involves erratic air motion and currents. Once a plane is captured in it, it is up for a bumpy ride. Sometimes we can see it at the edge of curly clouds taking apart vapour traces, but sometimes turbulence is invisible to the eye. In that case we are talking about clear air turbulence (CAT). CAT is caused by invisible waves that break in the atmosphere, especially when two layers of air are sliding over each other at different speeds. It is typically found at the crusing altitude (10-12km) of airplanes and at the edges of the jetstream, a current of air that encircles the globe at mid-latitudes and that airplanes ride in order to travel faster. The onboard instruments of planes cannot detect CAT, that is why the passengers and crew are unprotected against it. It is responsible for many minor to severe in-flight accidents yearly. The naked eye may not see the CAT but numerical climate models can capture it. Thanks to modelling studies we can see what the CAT will look like in a warming planet in the future. With the expected warming of the climate, the intensity of CAT will double over mid-latitudes by the period 2050-2080 with an emphasis in the spring months. Therefore, with time, international long-haul aviation travel is set to become more bumpy.

Source: Luke N. Storer, Paul D. Williams, Manoj M. Joshi, Global Response of Clear-Air Turbulence to Climate Change, Geophys. Res. Let. 2017

Image credit: Peter Hoor, imaggeo.egu.eu

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Water on the Sun

What is the most curious place that you would expect to find water? We know it exists on the surface of our planet, in the atmosphere, also deep into the Earth in aquifers, even in ices on the Moon and Mars. It turns out, it also exists on our host star, the Sun! More specifically it is found in the dark and cooler areas of the Sun, the sunspots. The scientists were able to isolate spectra from those regions of around 3000 K temperature. The surrounding photosphere has a temperature of 5777K. There, water has already dissociated into ions and is not a molecule anymore, but only exists as free hydrogen (H) and hydroxyl (OH). But that is not the case in the sunspots. The water there may be superheated but its molecule rotates and vibrates absorbing energy. Each of these motions then contributes with various lines to the sunspots' absorption spectra. For years the astronomers collected the sunspots light but could not decipher the information in it. In order to map the spectra of the superheated water in those extreme temperature conditions, scientists used theory, and specifically quantum calculations. Then they compared the observed absorption spectra of the solar spots to that of the theoretical calculations of water and found that the main features matched each other. Modern large databases of absorption lines in each frequency of the electromagnetic light allow for these comparisons. It is notable that we only know of the existence of superheated water in the Sun after many years of collecting spectral information and aided by the quantum theory tools that were not discovered but at the beginning of the 20th century.

Image credit: Sunspots in January 2014 and Earth size for comparison. Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams

Source: Water on the Sun: The Sun yields more secrets to spectroscopy Jonathan Tennyson & Oleg L. Polyansky, Contemporary physics, Pages 283-294, 1998

Wikipedia, Solar photosphere

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Partial solar eclipse on the 25th of October

Get prepared to see the partial solar eclipse tomorrow if you are on the northern hemisphere. The eclipse will be visible in most parts of Europe, Northern/East Africa and South/West Asia. The moon disc will start casting its shadow over the solar disc at 8:58 UTC, will cover its maximum at 11:00 UTC and will finish at 13:02 UTC. A quick guide to convert to your own local time is that for local Greece time the time zone is UTC+3h and for Central Europe it corresponds to UTC+2h. Wherever you are, it is important to protect your eyes and never watch the sun directly during an eclipse. A good solution is to follow a live stream like this one from the Royal observatory of Greenwich: https://www.youtube.com/watch?v=2FKh2xLo4Ek . This is the second eclipse of 2022, the first took place on 30th of April and swept over the Southern hemisphere while the next one will not take place until the 20th of April 2023.

Image credit: timeanddate.com The point of maximum eclipse (82%) of the solar disc will take place over the North Pole. The rest of the locations will see a smaller portion of the solar disc covered.

Source: timeanddate.com, space.com

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The aftermath of the DART mission

The pinnacle of DART mission took place recently, on the 27th of September. A spacecraft weighing 360 kg impacted with a speed of 6.6 km/second on asteroid Dimorfos that was orbiting the larger asteroid Didymos with a period of 11 hours and 55 minutes. Did however the scientists manage to alter its orbit? After data analysis sent by the spacecraft LICIAcube of the Italian Space Agency ASI it turns out that yes. The LICIAcube spacecraft accompanied the impacting mission and recorded the motion of the double asteroid system before and after the impact. The orbital time of Dimorfos was reduced by 32 minutes, much above the initial aim of the mission that was 10 minutes. We therefore have the first successful effort of humanity altering the orbit of a solar system body, that makes already part of the history of the solar system exploration.

Image credit: NASA/ESA Hubble telescope, debris of Dimorfos impact as seen on 11th October.

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Απολογισμός της αποστολής DART

Eικόνα: NASA-ESA Hubble telescope, ουρά από την σκόνη που προκάλεσε η σύγκρουση του DART με τον αστεροειδή Δίμορφο, 11 Οκτωβρίου.

Το αποκορύφωμα της αποστολής DART της ΝASA έλαβε χώρα πρόσφατα, στις 27 Σεπτεμβρίου. Ένα διαστημόπλοιο έπεσε με ταχύτητα 6.6 χιλιομέτρων τo δευτερόλεπτο πάνω στον αστεροδειδή Δίμορφο που περιφερόταν γύρω από τον μεγαλύτερο αστεροειδή Δίδυμο με περίοδο 11 ώρες και 55 λεπτά. Κατάφεραν όμως οι επιστήμονες να αλλάξουν την τροχιά του; Μετά από ανάλυση των δεδομένων από το διαστημόπλοιο LICIAcube της ιταλικής διαστημικής εταιρείας ASI προέκυψε πως ναι. Το διαστημόπλοιο LICIAcube συνόδεψε την βαλλιστική αποστολή DART και κατέγραψε τις κινήσεις του συστήματος Δίμορφου-Δίδυμου πριν και μετα τη σύγκρουση. Ο χρόνος περιφοράς του Δίμορφου μειώθηκε κατα 32 λεπτά, πολύ παραπάνω από τον στόχο της αποστολής που ήταν τα 10 λεπτά. Έχουμε λοιπόν την πρώτη επιτυχή αποστολή αλλαγής της τροχιάς ενός ουράνιου σώματος με ανθρώπινη παρέμβαση η οποία πέρασε ήδη στην ιστορία της εξερεύνησης του διαστήματος.

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Cryobots

A new generation of robots called 'cryobots' are prepared to explore subsurface ocean worlds in our solar system for signs of extraterrestrial life. The term came from the Keck Institute for Space Studies report in 2017 which examined the possibiity of their exploration with the current technical means. The largest challenge for the cryobot is to operate in very cold temperatures, below 0 C and to then dig to get access to the oceans below the icy surfaces while keeping on communicating with an orbiting satellite. Two of the solar system moons, Europa and Enceladus are the focus of subsurface ocean worlds that the space agencies aim to send cryobots to. There is already a mission in preparation with a lander for Europa that would excavate up to 10 cm through the water icy crust. But recently the moon of Neptune Triton gained renewed interest among the scientific community as a subsurface ocean world. We have not visited Triton since the Voyager 2 mission in 1989. Since then we found that it is geologically active, exhibitting geysers and a crust of Nitrogen. Therefore a potential cryobot for this body would have to dig through not water ice but nitrogen ice. For now and for the coming decade the studies for cryobots are continuing and they are tested in the polar regions of our planet before they meet with our solar system's exotic ices.

Image Credit: Krajewski et al. JPL. AbScicon 2019, ICEE-2 project for a lander on Europa.

Sources: https://d2pn8kiwq2w21t.cloudfront.net/documents/02-AbsSciCon-Mission-Overview-13Jun2019-no-BU.pdf https://oceanworlds.space/wp-content/uploads/sites/22/2020/07/Ocean-Worlds-Exploration-and-the-Search-for-Life.pdf https://solarsystem.nasa.gov/moons/neptune-moons/triton/in-depth/ https://d2pn8kiwq2w21t.cloudfront.net/documents/03-ICEE2-Overview-at-AbSciCon-2019-Krajewski.pdf

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Pillars of creation nebula image as taken by Hubble (left) and James Webb telescopes (right). We revisited this spot and saw many more stars being formed in the region. The added features in the image are due to James Webb’s infrared channels that can pierce trough the dust and uncover the light of stars behind it. Image credit: NASA/ESA https://www.flickr.com/photos/nasawebbtelescope/

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Mπιλιάρδο με τους αστεροειδείς - αποστολή DART

Σε μια προσπάθεια να αποδείξουν τις ικανότητες της τεχνολογίας προχώρησαν οι επιστήμονες της ΝΑΣΑ στις 27 Σεπτεμβρίου οδηγώντας ένα διαστημόπλοιο σε σύγκρουση με τον αστεροειδή Δίμορφο. Ο αστεροειδής Δίμορφος έχει μέγεθος 160 μέτρα/ και το στοιχημα ήταν αν θα μπορεσουμε να εκτρέψουμε την τροχιά του κατά μερικές δεκάδες μέτρα στρέφοντας πάνω του ένα διαστημόπολοιο που κινείται με ταχύτητα 6,6 χλμ το δευτερόλεπτο. Το αποτέλεσμα θα το γνωρίζουν οι επιστημονες αφού εξετάσουν τα δεδομένα αυτού του ιδιόμορφου "μπιλιάρδου" στις αρχές Οκτώβρη. Αν αυτή η προσπάθεια είναι επιτυχημένη κανουμε ένα μεγαλο βήμα προς την προστασία του πλανήτη μας απο μελλοντικους αστεροειδείς μικρού μεγέθους που θα ήταν σε τροχιά σύγκρουσης με τη γη.