Tag: Astronomy

First Israeli Nanosatellite Designed to Communicate from Space with Optical Ground Station

Written by AUFTAU on 4 January 2023. Posted in Newsroom.

TAU Paves the Way – New Space & Nanosatellites

The researchers: “TAU leads Israel’s effort to create satellite communication channels based on optical and quantum technologies. To implement long-distance quantum communication over hundreds of kilometers or more we need to go into space. TAU-SAT3 is designed to pave the way toward demonstrating quantum communication via a quantum nanosatellite, to be built in the future at TAU.”

“TAU’s first two nanosatellites were designed to measure cosmic radiation around the Earth and test various means for protecting the electronic systems installed on satellites from this radiation,” explains Prof. Meir Ariel, Head of TAU’s Center for Nanosatellites. “To this end, the nanosatellites carried special payloads built in collaboration with various scientific institutions, including the SOREQ Nuclear Research Center. The third satellite, TAU-SAT3, was the first to be fully designed, developed, and built at TAU.”

Dean of the Faculty of Engineering, Prof. Noam Eliaz says, “the Faculty of Engineering at Tel Aviv University is proud of the TAUSAT3 nanosatellite’s successful launching. This is the third nanosatellite we have launched in less than two years. The launching is a result of research and development executed by the Nanosatellites Center at the Faculty of Engineering in collaboration with the QuanTAU Center. This nanosatellite realizes several milestones on our way to achieve quantum communication from space by the means of a quantum nanosatellite, which will be built in Tel Aviv University in the future.”

“Recently, we were the sole winners of a tender by the Ministry of Science and Technology of Israel to build and launch a fleet of satellites while making the field of New Space and building nanosatellites accessible to students in the periphery. As of today, the Faculty of Engineering at Tel Aviv University is the leader of this field in Israel and is a focal point for students, schoolchildren, research centers and industry in this field. “

The Satellite Team (Clockwise): Orly Blumberg, Prof. Ofer Amrani, Prof. Meir Ariel, Dr. Dolev Bashi & Idan Finkelstein

Will Orbit Earth for 5 Years

Launched to an altitude of 550 km, TAU-SAT3 is expected to orbit the earth for about five years and carry out several scientific tasks. It carries on board for the first-time batteries made by the Israeli company Epsilor that will provide it with energy for its entire life in orbit.

Its main mission will be to communicate with the new optical ground station set up on the roof of the Shenkar Physics Building on the TAU campus.

This is the first optical ground station in Israel, and one of very few worldwide, that can lock onto, track, and collect data from a nanosatellite which, viewed from Earth, is smaller than a single pixel. According to the researchers, this means that in the future it will be possible to build and launch nanosatellites for optical communication at a much lower cost compared to large satellites.

TAU-SAT3 will also conduct experiments in satellite communication at very high bit rates and in scenarios where satellite communication channels have been disrupted.

“The novelty in this project is the ability of the communication systems installed in both the nanosatellite and the ground station to reconstruct the lost data in real time using smart signal processing algorithms developed at TAU.” Prof. Meir Ariel

Reconstruct Lost Data in Real Time

“TAU-SAT3 is a 20cm nanosatellite carrying an optical device that is only a few centimeters long,” says Prof. Ariel. He explains that “when the satellite passes over Israel, the device will emit light at various wavelengths, and the telescope of the optical ground station will identify the tiny flash, lock onto it, and track it. The nanosatellite will simultaneously send both optical and radio signals back to earth.”

“However, when the optical device turns toward the optical ground station, the antenna will face in a different direction. As a result, a significant portion of the data might be lost. The novelty in this project is the ability of the communication systems installed in both the nanosatellite and the ground station to reconstruct the lost data in real time using smart signal processing algorithms developed at TAU.”

Prof. Yaron Oz, Head of TAU’s Center for Quantum Science and Technology and former Rector of TAU: “The principles of quantum mechanics enable an unconditionally secure encryption method. Whenever a hostile entity tries to intercept a transmitted message, the message immediately dissipates. Moreover, the interception attempt is detected – unlike current encryption methods, in which interceptions remain undetectable.”

TAU-SAT3

“We hope that TAU-SAT3 will for the first time enable communication between an optical ground station and a satellite, taking us a significant step forward with regard to demonstrating reliable quantum communication.” Prof. Yaron Oz

“Consequently, eavesdropping-proof quantum communication is today at the forefront of scientific research. Governments and giant organizations around the world are involved in a race for quantum encryption capabilities – especially since quantum computers are expected to crack today’s encryption algorithms. It’s an enormous effort – in terms of science, technology, and budgets.”

Prof. Oz adds: “It must be noted that beyond the encryption of security data, once current encryption methods are cracked by quantum computing, all data will be exposed – including personal medical and financial records, email and WhatsApp messages, etc. This makes quantum encryption highly relevant to protecting everyone’s privacy. Quantum communication is very sensitive to the medium through which it is transmitted, such as optical fibers or the atmosphere. We hope that TAU-SAT3 will for the first time enable communication between an optical ground station and a satellite, taking us a significant step forward with regard to demonstrating reliable quantum communication.”

A large number of TAU faculty members took part in the groundbreaking project, including Prof. Ofer Amrani, the project’s Principal Investigator, Prof. Haim Suchowski, Head of the Femto-Nano Research Laboratory, and the students and researchers who developed the nanosatellite’s systems: Dr. Dolev Bashi, Idan Finkelstein, Michael Tzukran, Ofir Cohen, David Greenberg, Barak Levi, Alon Haramati, Onn Rengingad, Ofir Yafe, Shahar Morag, Ori Dagan, Elad Sagi and Orly Blumberg.

Researchers Characterize Earliest Galaxies in the Universe

Written by AUFTAU on 4 December 2022. Posted in Newsroom.

An international team of astrophysicists, including Prof. Rennan Barkana from Tel Aviv University’s Sackler School of Physics and Astronomy at Raymond & Beverly Sackler Faculty of Exact Sciences, has managed for the first time to statistically characterize the first galaxies in the Universe, which formed only 200 million years after the Big Bang.

According to the groundbreaking results, the earliest galaxies were relatively small and dim. They were fainter than present-day galaxies, and likely processed only 5% or less of their gas into stars. Moreover, the intensity of the radio waves emitted by the earliest galaxies wasn’t much higher than that of modern galaxies.

“We are trying to understand the epoch of the first stars in the Universe, known as the ‘cosmic dawn’, about 200 million years after the Big Bang.” Prof. Rennan Barkana

Researching the “Cosmic Dawn”

This new study, carried out together with the SARAS observation team, was led by the research group of Dr. Anastasia Fialkov from the University of Cambridge, England, a former PhD student of TAU’s Prof. Barkana. The results of this innovative study were published in the prestigious journal Nature Astronomy.

“This is a very new field and a first-of-its-kind study”, explains Prof. Barkana. “We are trying to understand the epoch of the first stars in the Universe, known as the ‘cosmic dawn’, about 200 million years after the Big Bang.”

“The James Webb Space Telescope, for example, can’t really see these stars. It might only detect a few particularly bright galaxies from a somewhat later period. Our goal is to probe the entire population of the first stars.”

“Since stellar radiation affects the light emitted by hydrogen atoms, we use hydrogen as a detector in our search for the first stars: if we can detect the effect of stars on hydrogen, we will know when they were born, and in what types of galaxies.” Prof. Rennan Barkana

Prof. Rennan Barkana from TAU’s Sackler School of Physics and Astronomy

Searching for the First Stars

According to the standard picture, before stars began to fuse heavier elements inside their cores, our Universe was nothing but a cloud of hydrogen atoms from the Big Bang (other than some helium and a lot of dark matter).

Today, the Universe is also filled with hydrogen, but in the modern Universe it is mostly ionized due to radiation from stars.

“Hydrogen atoms naturally emit light at a wavelength of 21cm, which falls within the spectrum of radio waves”, explains Prof. Barkana. “Since stellar radiation affects the light emitted by hydrogen atoms, we use hydrogen as a detector in our search for the first stars: if we can detect the effect of stars on hydrogen, we will know when they were born, and in what types of galaxies. I was among the first theorists to develop this concept 20 years ago, and now observers are able to implement it in actual experiments. Teams of experimentalists all over the world are currently attempting to discover the 21cm signal from hydrogen in the early Universe.”

One of these teams is EDGES, which uses a small radio antenna that measures the average intensity on the entire sky of radio waves arriving from different periods of the cosmic dawn. In 2018, the EDGES team announced that it had found the 21cm signal from ancient hydrogen.

“There was a problem with their findings, however,” says Prof. Barkana. “We could not be sure that the measured signal did indeed come from hydrogen in the early Universe. It could have been a fake signal produced by the electrical conductivity of the ground below the antenna. Therefore, we all waited for an independent measurement that would either confirm or refute these results.”

“Every year the experiments become more reliable and precise, and consequently we expect to find stronger upper limits, giving us even better constraints on the cosmic dawn.” Prof. Rennan Barkana

Setting Limits

“Last year, astronomers in India carried out an experiment called SARAS, in which the antenna was made to float on a lake, a uniform surface of water that could not mimic the desired signal. According to the results of the new experiment, there was a 95% probability that EDGES did not, in fact, detect a real signal from the early Universe.”

“SARAS found an upper limit for the genuine signal, implying that the signal from early hydrogen is likely significantly weaker than the one measured by EDGES. We modeled the SARAS result and worked out the implications for the first galaxies, i.e., what their properties were, given the upper limit determined by SARAS. Now we can say for the first time that galaxies of certain types could not have existed at that early time.”

Prof. Barkana concludes: “Modern galaxies, such as our own Milky Way, emit large amounts of radio waves. In our study we placed an upper limit on the star formation rate in ancient galaxies and on their overall radio emission. And this is only the beginning. Every year the experiments become more reliable and precise, and consequently we expect to find stronger upper limits, giving us even better constraints on the cosmic dawn. We hope that in the near future we will have not only limits, but a precise, reliable measurement of the signal itself.”

Featured image: Earliest galaxies in the Universe (photo: NASA – James Webb Space Telescope)

Two New Planets Found in Milky Way

Written by AUFTAU on 11 July 2022. Posted in Newsroom.

TAU team leads discovery of giant planets, similar in size to Jupiter, in remote corner of the galaxy.

Tel Aviv University researchers led the recent discovery of two new planets in remote solar systems within the Milky Way galaxy. They identified the giant planets, named Gaia-1b and Gaia-2b, as part of a study in collaboration with teams from the European Space Agency (ESA) and the body’s Gaia spacecraft.

The development marks the first time that the Gaia spacecraft successfully detected new planets. Gaia is a star-surveying satellite on a mission to chart a 3D map of the Milky Way with unprecedented accuracy comparable to standing on Earth and identifying a 10-shekel coin (roughly the size of a U.S. nickel) on the Moon.

TAU’s Prof. Shay Zucker, Head of the Porter School of the Environment and Earth Sciences, and doctoral student Aviad Panhi from the Raymond and Beverly Sackler School of Physics & Astronomy led the initiative. The findings were published in the scientific journal Astronomy & Astrophysics.

More Discoveries on the Horizon

“The discovery of the two new planets was made in the wake of precise searches, using methods of artificial intelligence,” said Prof. Zucker. “We have also published 40 more candidates we detected by Gaia. The astronomical community will now have to try to corroborate their planetary nature, like we did for the first two candidates.”

The two new planets are referred to as “Hot Jupiters” due to their size and proximity to their host star: “The measurements we made with the telescope in the U.S. confirmed that these were in fact two giant planets, similar in size to the planet Jupiter in our solar system, and located so close to their suns that they complete an orbit in less than four days, meaning that each Earth year is comparable to 90 years of that planet,” he adds.

Giant Leaps for Astronomy

There are eight planets in our solar system. Less known are the hundreds of thousands of other planets in the Milky Way, which contains an untold number of solar systems. Planets in remote solar systems were first discovered in 1995 and have been an ongoing subject of astronomers’ research ever since, in hopes of using them to learn more about our own solar system.

To fulfill its mission, Gaia scans the skies while rotating around an axis, tracking the locations of about 2 billion suns, stars at the center of a solar system, in our galaxy with precision of up to a millionth of a degree. While tracking the location of the stars, Gaia also measures their brightness — an incomparably important feature in observational astronomy, since it relays significant information about the physical characteristics of celestial bodies around them. Changes documented in the brightness of the two remote stars were what led to the discovery. Aviad Panhi explains: “The planets were discovered thanks to the fact that they partially hide their suns every time they complete an orbit, and thus cause a cyclical drop in the intensity of the light reaching us from that distant sun.”

To confirm that the celestial bodies were in fact planets, the researchers performed tracking measurements with the Large Binocular Telescope, in Arizona, one of the largest telescopes in the world today. The telescope makes it possible to track small fluctuations in a star’s movement which are caused by the presence of an orbiting planet.

The discovery marks another milestone in the scientific contribution of the Gaia spacecraft’s mission, which has already been credited with a true revolution in the world of astronomy. Gaia’s ability to discover planets via the partial occultation method, which generally requires continuous monitoring over a long period of time, has been doubted up to now. The research team charged with this mission developed an algorithm specially adapted to Gaia’s characteristics, and searched for years for these signals in the cumulative databases from the spaceship.

Signs of Life?

What about the possibility of life on the surface of those remote new planets? “The new planets are very close to their suns, and therefore the temperature there is extremely high, about 1,000 degrees Celsius, so there is zero chance of life developing there,” explains Panhi. Still, he says, “I’m convinced that there are countless others that do have life on them, and it’s reasonable to assume that in the next few years we will discover signs of organic molecules in the atmospheres of remote planets. Most likely we will not get to visit those distant worlds any time soon, but we’re just starting the journey, and it’s very exciting to be part of the search.”

Diagnosing Diseases in Space

Written by AUFTAU on 6 July 2022. Posted in Newsroom.

If pursuing the unknown in space is on your bucket list, you can take comfort in knowing that TAU researchers recently conducted a unique experiment at the International Space Station to test genetic diagnosis under microgravity conditions. The researchers launched a kit together with Israeli astronaut Eytan Stibbe to space and proved that an existing technology based on a bacterial immune system against viruses, ‘CRISPR’, can be used to identify viruses and bacteria infecting crew members during space missions.

The study was led by Dr. Dudu Burstein from the Shmunis School of Biomedicine and Cancer Research, Tel Aviv University and Dr. Gur Pines from the Volcani Institute. The experiment was conducted by Stibbe as part of the “Rakia” mission in April, under the leadership of the Ramon Foundation and the Israel Space Agency.

Suited for Astronauts

CRISPR systems are the immune systems of bacteria from viruses. Bacteria use the CRISPR-Cas systems as a sort of molecular ‘search engine’ to locate viral sequences and cleave them to disable viruses.

As part of their scientific vision, the researchers hypothesized that genetic diagnostics using this method, which requires minimal and easily operated equipment, could be suitable for long space missions: “Conditions in space are extremely problematic,” explains Burstein. “Treatment methods are limited, so it is essential to identify pathogens [= a microorganism that can cause disease] in a rapid, reliable, and straightforward method.” The method stands in contrast to tests like PCR (which we are now all familiar with due to Covid-19), which Burstein notes require trained personnel and relatively complex equipment.”

Researchers discussing the experimental design. From left to right: Dan Alon, Dr. David Burstein, Dr. Gur Pines (Photo: Ella Rannon)

Burstein outlines the process: “First, the DNA is amplified: each targeted DNA molecule is repeatedly duplicated many times. Then the CRISPR-Cas goes into action: If it identifies the target DNA, it activates a fluorescent molecular marker. The fluorescence lets us know whether the bacteria or viruses of interest are indeed present in the sample. This whole process can be conducted in one tiny test tube, so it is well suited for the astronauts’ needs.”

Zero Gravity? No problem!

Dr. Burstein describes the preparation for the space experiment: “Doctoral student Dan Alon and Dr. Karin Mittelman planned the experiment in detail and conducted it countless times in the lab under various conditions. After reaching the desired result, they prepared a kit, including the CRISPR-Cas system and the other components required for detection. Eventually, the kit was launched with Eytan Stibbe to the International Space Station.”

The experiments conducted by Stibbe were very successful, and proved that it is indeed possible to perform precise and sensitive CRISPR-based diagnosis – even in an environment with virtually no gravity.

What now? “This is the first step towards the simple and rapid diagnosis of diseases and pathogens on space missions,” says Burstein, adding that there is still some work to do on the next stages, including, “simple extraction of DNA from samples, making the system more efficient, so that it will be able to test a variety of organisms in one test tube, and diagnosis of more complex samples.”

“It was inspiring to see our test kit in Eytan’s hands at the Space Station, and we’re even more excited by the possibility that such kits will help future astronauts on their extraterrestrial missions,” he concludes.

Eytan Stibbe executing the experiment on the International Space Station (Photo: the Ramon Foundation and the Israel Space Agency)

Featured image: International space station on orbit of planet Earth

The “COTS-Capsule” that protects electronic systems from hazardous radiation effects in space

Written by AUFTAU on 18 January 2022. Posted in Newsroom, Press release.

An Innovative Technology has been Launched into Space…

Tel Aviv University recently launched TauSat-3 satellite to space. TauSat-3 is a technological demonstrator of the COTS-Capsule, an innovative space mechanism for detecting and mitigating cosmic-rays induced damage to space systems. The satellite was launched from the Kennedy Space Center in Florida, onboard a Falcon 9 rocket as part of the SpaceX CRS-24 mission. It was then transferred, via the Cargo Dragon C209 spacecraft to the International Space Station (ISS). The satellite was successfully installed and put into operation at the International Space Station. The satellite connected via the ISS datalink network and communicated successfully with ground stations.

TauSat-3, which is approximately the size of a shoebox, was carefully designed and built by the University’s team of experts and will examine the performance of a novel radiation detecting and active protective mechanism to guard electronics from cosmic radiation induced hazardous phenomena. The “COTS-Capsule” will allow the use of modern commercial electronic systems in space, by incorporating them into the protected environment inside the “COTS-Capsule” and operating them in that environment. According to the researchers, this is a mechanism that has revolutionary potential in the field of satellites and space-systems as well as a significant economic impact.

The “COTS-Capsule”. Courtesy of Tel Aviv University

The study was headed by doctoral candidate Yoav Simhony, from the School of Electrical Engineering, together with the head of the School of Physics and Astronomy, Prof. Erez Etzion and Prof. Ofer Amrani from the Iby and Aladar Fleischman Faculty of Engineering, head of the Small Satellite Laboratory.

It is noteworthy that the “COTS-Capsule” is expected to be included in the series of groundbreaking experiments that are to be conducted as part of the “Rakia” [Sky] mission guided by the Ramon Foundation and the Israel Space Agency.

Eytan Stibbe, the second Israeli in space, will be launched for a mission at the International Space Station this coming February. Stibbe is expected to conduct dozens of experiments for leading researchers from a number of universities and commercial companies in Israel.

Prof. Etzion and Prof. Amrani explain: “Integration of the “COTS-Capsule” mission as part of the national “Rakia” mission will provide a rare opportunity to examine the building blocks of this technology in space. In addition to the academic research, the space mission is leveraging and promoting an educational-scientific program in the field of space and radiation.”

PhD student and principal investigator Yoav Simhony adds: “Currently, electronic equipment sent to space must be specifically modified to prevent cosmic radiation induced effects. The protection provided by the “COTS-Capsule” will enable the use of commercial off the shelf components in space, thus opening the door to the use of advanced electronic components, while significantly shortening both development times and reducing the costs of space products.”

In addition, partners to the success of the project are: from Tel Aviv University – Dolev Bashi, Elad Sagi, Dr. Yan Benhammou, Dr. Igor Zolkin, Dr. Meir Ariel, Baruch Meirovich and the workshop staff, Orly Bloomberg, Edward Karat, Lily Almog and the procurement team, Yasmin Miller Zangi and the legal team, and several students of electrical engineering, software and physics. From Afeka College – Dr. Alex Segal, the IAI, the International Space Station deployment opportunity being made available by Nanoracks through its Space Act Agreement with NASA’s U.S. National Lab, the Ehrlich law firm, Samuel Berkowitz and the law firm of Herzog, Fox and Ne’eman, the ARotec company and Tal Ahituv.

Featured image: The Launch of the “COTS-Capsule” on top of the Cargo Dragon C209 spacecraft. Courtesy of NASA.

For the 1st time at an Israeli university: Air and Space Power Center

Written by AUFTAU on 5 January 2022. Posted in Newsroom, Press release.

Tel Aviv University and the Israeli Air Force establish a joint center that will harness the world of civilian research and knowledge to advance various areas related to policymaking and strategic thinking on issues of air and space.

On Thursday Dec. 30, Tel Aviv University and the Israeli Air Force launched the Air and Space Power Center at TAU, named the Elrom Center. The new Center, which is the first of its kind in Israel, will harness the world of research and knowledge to advance various areas related to air and space power in Israel.

The ceremony, held at TAU, was led by TAU President Prof. Ariel Porat, in the presence of Air Force Commander Aluf Amikam Norkin.

At the ceremony Prof. Porat and Aluf Norkin signed a joint document emphasizing that “a framework has been formed for multidisciplinary research promoting theoretical and practical knowledge on air and space power, as well as fruitful ties between academia and a range of other sectors, including industry, nonprofits and organizations, government agencies, and Israel’s security forces, to develop education and cultivate a cadre of future researchers in this important field.”

The new Center adds one more layer to TAU’s vision of advancing groundbreaking multidisciplinary research that brings together the university’s finest researchers, the hi-tech industry, and the community. The Center joins several other multidisciplinary centers established at TAU over the past year, including the Center for Combating Pandemics, the Center for Climate Change Action, the Center for Artificial Intelligence and Data Science, and the Center for Aging.

The center is also an important addition to the vision of the Israeli Air Force – to establish a national research and academic foundation in the field of Air and Space Power, in order to harness scientific knowledge for the benefit of the Air Force, encouraging creative and critical thinking and accelerating the incorporation of innovation into world views of the Air Force.

The new Center will be headed by Prof. Eviatar Matania of the Blavatnik Interdisciplinary Cyber Research Center, formerly founding Head of the Israel National Cyber Bureau and currently Head of the International Cyber Politics & Government Program at TAU. Combining theoretical and applied research, it will operate within the Gordon Faculty of Social Sciences but will also involve researchers from Engineering, Exact Sciences, and Medicine, and serve as a foundation for advancing multidisciplinary research on air and space.

In this context the Center will develop a cadre of future researchers and establish systematic academic activity in this area in Israel. It will encourage students to specialize in air & space power – both students who belong to nonprofits and organizations, government agencies and the security forces, and students looking to develop a career in industry in these important fields.

In the Israeli Air Force, the Air and Space Power Center will support the development of a foundation of academic knowledge. The academic research carried out at the Center can help in the development and adaptation of the Air Force’s operational concepts, combat doctrines, and power- building processes. Methodological tools for professional, abstract, and practical thinking developed by the Center’s researchers will also be beneficial. In the foreseeable future the Center will serve as a hub for international research collaboration with academic institutions, research institutes and air forces around the world.

Aluf Amikam Norkin & Prof. Ariel Porat (Photo credit: Israel Hadari.)

TAU President Prof. Ariel Porat: “The field of Air and Space Power is important and promising, both socially and scientifically. Many researchers at TAU address this subject from different angles, and the new Center will contribute a great deal to the advancement and development of both research and education in this area. Tel Aviv University conducts many research collaborations with industry and public organizations, which upgrade our research and make it more relevant. At the newly established Center, many more participants from industry and academia, both in Israel and worldwide, will become involved, advancing Air and Space Power research.”

Israeli Air Force Commander, Aluf Amikam Norkin: “Today we are groundbreaking pioneers in a vast range of operational issues which have grown in response to the challenges of our Middle-Eastern neighborhood. Thus, together with the IDF’s intelligence operations, air power has become the main answer to the country’s security challenges. Fighting terrorism from the air, air supremacy, remotely piloted aircraft, the most advanced air defense in the world, and three F-35 squadrons – are only some of the aspects in which the Israeli Air Force, together with Israel’s defense industries, are leaders and pioneers.

Ben Gurion’s vision, and his understanding that ‘the air is a new kingdom we must conquer’, has become a reality. But we must not rest on our laurels. Only in-depth investigation of ongoing operations will keep us sharp and ready. Yet as we look toward the coming decades, we need more than excellent inquiry. We must expand our activities into the academic arena, to include research methods developed in Israeli academia, at Tel Aviv University. We must set in motion both military and civilian research on air and space power, that will open new horizons to which we may aspire.

The establishment of the Air and Space Power Center, bringing together experts from academia and the Air Force, transforms a vision into reality. This is a real need arising from the constantly rising complexity of the battlefield and operational challenges, requiring ever greater and deeper military knowledge – in order to ensure the position of the Israeli Air Force as one of the leading forces in the world.”

Featured image: (left to right) Prof. Eviatar Matania, Prof. Ariel Porat, Dafna Meitar-Nechmad & Aluf Amikam Norkin (Photo credit: Israel Hadari.)

Out of This World

Written by AUFTAU on 5 January 2022. Posted in Newsroom.

A new star and satellite observatory is currently being set up on the roof of TAU’s Shenkar building, and is set to become one of the most sophisticated labs in the world.

If you’d like to take a look at the positioning of the receivers at the International Space Station or see how TAU’s own Nano-satellite, TAU SAT-1 (which has been orbiting the Earth for almost a year now) is doing, we’re here to tell you that you will soon be able to do so. A new state-of-the-art optical ground station is currently being built on the roof of Raymond & Beverly Sackler School of Physics & Astronomy. The new optical ground station will allow us to observe tiny details far above us.

The optical ground station will be used for advanced communication with satellites and other spacecraft and tracking of relatively close-up celestial bodies, but also stars that are millions of light-years away. At a later stage, the station will serve as a tool for quantum encryption in space, one that will allow us to best encrypt any type of information.

Moments before the most sophisticated telescope in Israel will be installed here at Tel Aviv University, we met with Prof. Yaron Oz, Head of the Quantum Center; Prof. Haim Suchowski from the School of Physics and Astronomy, and Michael Tzukran, a professional astronomy photographer who will be operating the new station, for a light conversation about, you know, the usual: quantum optical communication, space photography and surprise meetings that would lead to groundbreaking projects.

Replacing Light Pollution

Prof. Suchowski’s department, together with the University’s Engineering and Maintenance Division and partial funding from the Quantum Center, are currently working on making the Tel Aviv University campus free of celestial light pollution. This is a side-project that was born in conjunction with the construction of the new observation station. In the coming months, all polluting lighting on campus will be replaced with ecological lighting fixtures, making Tel Aviv University the first University in Israel to be free of light pollution.

Where it all started: Michael Tzukran in the old observatory on the roof of the Shenkar building the non-linear interaction of light with various materials in nature. In recent years, I’ve also been involved in the intensive activities at the Nano-Satellite Center and the new Quantum Center that have started operating on campus. What we’re dealing with on the roof these days is a combination of all these things,” he explains.

“The field of space once ‘belonged’ exclusively to NASA and very specific bodies, such as the aerospace industry in the case of Israel. Today, even high school students can send satellites into space,” explains Suchowski. “The New Space Revolution allows private companies to send and operate relatively affordable Nano-satellites into space and has changed our lives. Over the past 15 years, universities have been sending their own Nano-satellites as well.”

The University’s own Nano-satellite, TAU SAT-1, was devised, developed, assembled and tested under the leadership of Dr. Meir Ariel, Dr. Ofer Amrani of The Iby and Aladar Fleischman Faculty of Engineering and Prof. Colin Price of the Porter School of the Environment and Earth Sciences. The satellite, which carries scientific experiments, was launched about a year ago.

Up until now, the project has consisted in building a standard radio communication ground station to communicate with the launched satellite. According to Suchowski, one of the next projects will be to create optical communication through space, and thereafter quantum optical communication through space, which is a new and evolving field.

Quantum-Encrypted Communication Satellites

Information encryption is an essential subject with many applied meanings, and quantum mechanics is changing the rules of the game in this regard.

“Today, we encrypt our information based on complex mathematical algorithms, and assume that computers will take a long time to solve these problems and therefore the information is secure,” explains Prof. Yaron Oz, Chairman of the Tel Aviv University Quantum Science and Technology Center. “Quantum computers, however, are based on a different computational paradigm and can change the picture. Decomposing an integer into its primary factors – the complexity of which protects encryption algorithms that are widely used today – will be quickly solved by a quantum computer. Therefore, it is important to depict what the encrypted methods will be in the age of quantum computers.”

“Quantum systems have exceptional encrypted information transfer capabilities due to the fact that quantum mechanics do not allow information to be copied. Any attempt to copy or modify it destroys the original information. As a result, a quantum communication line is completely safe from eavesdropping. Transmitting a cipher key in a quantum communication network is completely secure, and indeed quantum optical encryption already exists via fiber optics,” he says.

Today, this type of encryption is possible, but limited to a distance of 150-200 km. Prof. Oz tells us that such communication networks already aid financial sectors in Switzerland. However, the transfer of information between continents (for example from New York to London) in this way is not yet possible.

Prof. Yaron Oz

Prof. Oz explains that in Israel there’s an understanding of the need to move in the direction of encrypting information on a satellite quantum communications network, and here at Tel Aviv University we have decided to take steps at the operational and research level. The new lab with the telescope on the roof is thereby about to take part in the future satellite project of the Nano-Satellite center.

With the help of various bodies here at TAU, the Quantum Center in particular, and with the support of Prof Erez Etzion, Head of the School of Physics and Astronomy, budget and space was ensured to build the advanced observatory and buy the massive equipment. With a telescope with a 24-inch mirror, the precise and huge robot will be able to track stars, galaxies, nebulae and other bodies. The robot, which weighs 300 kg, can move at an angular speed of up to 50 degrees per second and accurately track moving satellites at low altitudes, as well as lower flying aircraft. “We are already doing preliminary experiments in optical communication. With the level of accuracy of the new telescope we’ll be the only ones in Israel with such equipment,” promises Prof. Suchowski.

The construction of the new ground station, as documented in Michael Tzukran’s Instagram account

The Stargazer

Quite by chance, another actor entered the picture and helped Prof. Suchowski leverage the idea into practice: Michael Tzukran, a world expert in astronomical and satellite photography and research observatory construction consultant.

“As a seasoned astronomy photographer, I wanted to challenge myself and photograph the International Space Station. I needed an open roof close to the space station’s orbit as it passes over the skies of Israel. And so I simply asked whether it could be done here.” Tzukran brought his own equipment and took one of the most detailed photos ever taken of the space station from Earth. During the photography, the space station was flying at a speed of close to 28,000 km per hour. No big deal.

Passing at a speed of close to 28,000 km/h. The space station, photographed by Michael Tzukran

Michael’s specialty is to adjust and control the sophisticated robot, monitor the satellites and photograph them according to requests from researchers. With the new equipment, he plans to document satellites like they’ve never been observed before from Earth.

Prof. Ady Arie from the Faculty of Engineering and doctoral students Dolev Bashi, Georgi Gary Rosenman, Yonatan Piasetski, Sahar Shahaf, Tomer Nahum and Yuval Reches are also working on the establishment of the technological system for laboratory quantum optical communication.

Prof. Suchowski estimates that various industries, such as security and other universities, will be interested in using the new platform in the future: “This is a national resource. I believe it will become instrumental in promoting applied and basic research in Israel and the world,” he concludes.

When the stars aligned: A star in a distant galaxy blew up in a powerful explosion, solving an astronomical mystery from the 11th century

Written by AUFTAU on 16 July 2021. Posted in Newsroom, Press release.

Las Cumbres Observatory and Hubble Space Telescope color composite of the electron-capture supernova 2018zd (the large white dot on the right) and the host starburst galaxy NGC 2146 (toward the left).

Giant Explosion in Space Illuminates Thousand-Year Mystery.

Dr. Iair Arcavi.
Credit: Israel Hadari

Dr. Iair Arcavi, a Tel Aviv University researcher at the Raymond and Beverly Sackler Faculty of Exact Sciences, participated in a study that discovered a new type of stellar explosion – an electron-capture supernova. While they have been theorized for 40 years, real-world examples have been elusive. Such supernovas arise from the explosions of stars 8-9 times the mass of the sun. The discovery also sheds new light on the thousand-year mystery of the supernova from A.D. 1054 that was seen by ancient astronomers, before eventually becoming the Crab Nebula, that we know today.

A supernova is the explosion of a star following a sudden imbalance between two opposing forces that shaped the star throughout its life. Gravity tries to contract every star. Our sun, for example, counter balances this force through nuclear fusion in its core, which produces pressure that opposes the gravitational pull. As long as there is enough nuclear fusion, gravity will not be able to collapse the star. However, eventually, nuclear fusion will stop, just like gas runs out in a car, and the star will collapse. For stars like the sun, the collapsed core is called a white dwarf. This material in white dwarfs is so dense that quantum forces between electrons prevent further collapse.

For stars 10 times more massive than our sun, however, electron quantum forces are not enough to stop the gravitational pull, and the core continues to collapse until it becomes a neutron star or a black hole, accompanied by a giant explosion. In the intermediate mass range, the electrons are squeezed (or more accurately, captured) onto atomic nuclei. This removes the electron quantum forces, and causes the star to collapse and then explode.

Historically, there have been two main supernova types. One is a thermonuclear supernova — the explosion of a white dwarf star after it gains matter in a binary star system. These white dwarfs are the dense cores of ash that remain after a low-mass star (one up to about 8 times the mass of the sun) reaches the end of its life. Another main supernova type is a core-collapse supernova where a massive star — one more than about 10 times the mass of the sun — runs out of nuclear fuel and has its core collapsed, creating a black hole or a neutron star. Theoretical work suggested that electron-capture supernovae would occur on the borderline between these two types of supernovae.

That’s the theory that was developed in the 1980’s by Ken’ichi Nomoto of the University of Tokyo, and others. Over the decades, theorists have formulated predictions of what to look for in an electron-capture supernova. The stars should lose a lot of mass of particular composition before exploding, and the supernova itself should be relatively weak, have little radioactive fallout, and produce neutron-rich elements.

The new study, published in Nature Astronomy, focuses on the supernova SN2018zd, discovered in 2018 by Japanese amateur astronomer Koihchi Itagaki. Dr. Iair Arcavi, of the astrophysics department at Tel Aviv University, also took part in the study. This supernova, located in the galaxy NGC 2146, has all of the properties expected from an electron-capture supernova, which were not seen in any other supernova. In addition, because the supernova is relatively nearby – only 31 million light years away – the researchers were able to identify the star in pre-explosion archival images taken by the Hubble Space Telescope. Indeed, the star itself also fits the predictions of the type of star that should explode as an electron-capture supernovae, and is unlike stars that were seen to explode as the other types of supernovae.

From left: Japanese amateur astronomer Koichi Itagaki (who discovered the supernova), Tel Aviv University researcher Dr. Iair Arcavi (who participated in the study), and University of California graduate student Daichi Hiramatsu (lead author of the study), at one of Itagaki’s telescopes in Japan.

While some supernovae discovered in the past had a few of the indicators predicted for electron-capture supernovae, only SN2018zd had all six – a progenitor star that fits within the expected mass range, strong pre-supernova mass loss, an unusual chemical composition, a weak explosion, little radioactivity, and neutron-rich material. “We started by asking ‘what’s this weirdo?’” said Daichi Hiramatsu of the University of California Santa Barbara and Las Cumbres Observatory, who led the study. “Then we examined every aspect of SN 2018zd and realized that all of them can be explained in the electron-capture scenario.”

The new discoveries also illuminate some mysteries of one of the most famous supernovae of the past. In A.D. 1054 a supernova happened in our own Milky Way Galaxy, and according to Chinese and Japanese records, it was so bright that it could be seen in the daytime and cast shadows at night. The resulting remnant, the Crab Nebula, has been studied in great detail, and was found to have an unusual composition. It was previously the best candidate for an electron-capture supernova, but this was uncertain partly because the explosion happened nearly a thousand years ago. The new result increases the confidence that the historic 1054 supernova was an electron-capture supernova.

“It’s amazing that we can shed light on historical events in the Universe with modern instruments,” says Dr. Arcavi. “Today, with robotic telescopes that scan the sky in unprecedented efficiency, we can discover more and more rare events which are critical for understanding the laws of nature, without having to wait 1000 years between one event and the next.”

Dr. Arcavi is a member of the Global Supernova Project, and makes use of the Las Cumbres telescope network to study rare transient phenomena like supernovae, neutron star mergers, and stars torn apart by black holes.

Link to the original article: https://www.nature.com/articles/s41550-021-01384-2

What Disrupted A Giant Black Hole’s Feast?

Written by AUFTAU on 11 August 2020. Posted in Newsroom.

A new, revolutionary way to simplify complex scientific calculations

Written by AUFTAU on 7 December 2019. Posted in Newsroom.

Researchers at Prof. Roy Beck’s lab have figured out a simple and accessible solution to a problem that even supercomputers struggle with: measuring entropy, the level of molecular disorder or randomness in a complext system. In complex physical systems, the interaction of internal elements is unavoidable, rendering entropy calculation a computationally demanding, and often impractical, task. The tendency of a properly folded protein to unravel, for example, can be predicted using entropy calculations. Now, a new Tel Aviv University study proposes a radically simple and efficient way of calculating entropy — and it probably exists on your own computer. “We discovered a way to calculate entropy using a standard compression algorithm like the zip software we all have on our computers,” explains Prof. Roy Beck of TAU’s School of Physics and Astronomy. “Supercomputers are used today to simulate the folding or misfolding of proteins in diseased states. Our study demonstrated that by using a standard compression algorithm, we can provide new insights into the physical properties of these proteins by calculating their entropy values using a compression algorithm.

A veriety of new solutions

“Having the ability to calculate entropy meets an urgent need to harness the incredible power of computer simulations to address urgent, timely problems in science and medicine,” Prof. Beck adds. The research was led by him and conducted by TAU PhD students Ram Avinery and Micha Kornreich. According to Prof. Beck, the research has endless applications. From biomedical simulations to basic research conducted in physics, chemistry or material science, the new algorithm would be simple to use on any computer. “A high school student used our concept to calculate the entropy of a complex physical system — the XY model,” says Prof. Beck. “Although this is considered a challenging problem with regard to entropy, the student accomplished it with very little guidance. This demonstrates how easily this method can be used by almost anybody to solve very interesting problems.”

A by-the-way discovery

The idea for the computational method first came about when Prof. Beck’s students, Avinery and Kornreich, discussed entropy from the point of view of information theory. They wondered how well this idea might work in practice rather than in theory. “They simulated a few standard physical systems with entropy values they can compare to,” says Prof. Beck. “Soon they found that the simulation data file size after compression rises and falls just as the expected entropy should. Shortly after that, they realized they could convert the compressed file size into a usable value — the physical entropy. Surprisingly, the simple conversion they used was valid for all the systems studied.” The researchers are currently expanding the application of their methodology to a wide and varied selection of systems. “Since we started working and talking about our work, we have been approached by many researchers from very different fields, asking us to help them calculate entropy from their data,” concludes Prof. Beck. “For now, we are concentrating on simulation of protein folding, a timely and urgent topic that can benefit tremendously from our discovery.”

Tag: Astronomy

First Israeli Nanosatellite Designed to Communicate from Space with Optical Ground Station