Maria Gritsevich

University of Helsinki | HY · Department of Physics

As fireball networks grow, the number of events observed becomes unfeasible to manage by manual efforts. Reducing and analysing big data requires automated data pipelines. Triangulation of a fireball trajectory can swiftly provide information on positions and, with timing information, velocities. However, extending this pipeline to determine the te...

Knowing the optical properties of a sample is important in many scientific fields, such as space science, climate studies, and medicine. In many of these applications, the samples are fragile, unique or available in limited quantities, and have to be subsequently studied by additional techniques, implying that sample preservation is important. Esta...

When an object enters the atmosphere it may be detected as a meteor. A bright meteor, called a fireball, may be a sign of a meteorite fall. Instrumentally observed meteorite falls provide unique opportunities to recover and analyse unweathered planetary samples supplemented with the knowledge on the Solar System orbit they had. To recover a meteori...

The massive outburst of the comet 17P/Holmes in October 2007 is the largest known outburst by a comet thus far. We present a new comprehensive model describing the evolution of the dust trails produced in this phenomenon. The model comprises of multiparticle Monte Carlo approach including the solar radiation pressure effects, gravitational disturba...

Atmospheric halos are a light scattering phenomenon caused by airborne ice crystals in the atmosphere. Halos can be seen by the naked eye. They provide the observer the information on the kinds of ice crystals present in the sky during a halo display. A combination of ice crystals’ shape, their orientation, and light ray paths through the crystals...

A bright fireball observed on 2020 November 7, over Scandinavia, produced the first iron meteorite with a well-determined pre-atmospheric trajectory. We calculated the orbit of this meteoroid and found that it demonstrates no close affinity with the orbit of any known asteroid. We found that the meteoroid (or its parent body) most probably entered...

This is reminder for International Conference on Recent Trends in Geoscience Research and Applications 2023 Belgrade, Serbia & virtual 23-27 October 2023

We study the axisymmetric, wide gap, spherical Couette flow in the presence of noise in numerical simulations and experiments. Such studies are important because most of the flows in nature are subjected to random fluctuations. Noise is introduced into the flow by adding fluctuations to the inner sphere rotation which are random in time with zero m...

The present white paper is submitted as part of the "Snowmass" process to help inform the long-term plans of the United States Department of Energy and the National Science Foundation for high-energy physics. It summarizes the science questions driving the Ultra-High-Energy Cosmic-Ray (UHECR) community and provides recommendations on the strategy t...

Meteor observations provide information about Solar System constituents and their influx onto Earth, their interaction processes in the atmosphere, as well as the neutral dynamics of the upper atmosphere. This study presents optical, radar, and infrasound measurements of a daytime fireball that occurred on 4 December 2020 at 13:30 UTC over Northeas...

The present white paper is submitted as part of the “Snowmass” process to help inform the long-term plans of the United States Department of Energy and the National Science Foundation for high-energy physics. It summarizes the science questions driving the Ultra-High-Energy Cosmic-Ray (UHECR) community and provides recommendations on the strategy t...

Cosmic Probes of Fundamental Physics take two primary forms: Very high energy particles (cosmic rays, neutrinos, and gamma rays) and gravitational waves. Already today, these probes give access to fundamental physics not available by any other means, helping elucidate the underlying theory that completes the Standard Model. The last decade has witn...

We present a database of the absolute magnitudes of asteroids named the Kharkiv Asteroid Absolute Magnitude Database (KhAAMD). The database includes a homogeneous set of the absolute magnitudes for about 400 asteroids in the new $HG_{1}G_{2}$ magnitude system. We performed a comparative analysis of the asteroid absolute magnitudes between the Khark...

Some of the fields of research that have captured the persistent interest of both scientists and the general public are meteor phenomena. The main goal in the study of meteoroid impacts into Earth’s atmosphere is the recovery of the remnant matter after the ablation in the form of meteorites. This is a complementary approach, yet cheap alternative,...

We have developed a scattering model allowing to study interaction of light with particles populating the near-Earth environment: satellite explosion remnants, collisional debris, particles detached from peeling paint surfaces, and ejecta resulting from micrometeorite bombardment. In its present configuration the model accounts for rough needles, g...

The present white paper is submitted as part of the "Snowmass" process to help inform the long-term plans of the United States Department of Energy and the National Science Foundation for high-energy physics. It summarizes the science questions driving the Ultra-High-Energy Cosmic-Ray (UHECR) community and provides recommendations on the strategy t...

Ultrasound provides a way to clean fouled pipes in industrial settings without interrupting the production. Ultrasonic clamp-on cleaners are used to clean pipes, but they typically cannot focus the cleaning power. This leads to insufficient cleaning results in cases where the fouling is localized to certain parts of the pipe. To solve this issue, w...

The massive outburst of the comet 17P/Holmes in October 2007 is the largest known outburst by a comet thus far. We present a new comprehensive model describing the evolution of the dust trails produced in this phenomenon. The model comprises of multiparticle Monte Carlo approach including the solar radiation pressure effects, gravitational disturba...

The Earth’s spherical albedo describes the ratio of light reflected from the Earth to that incident from the Sun, an important variable for the Earth’s radiation balance. The spherical albedo has been previously estimated from satellites in low-Earth orbits, and from light reflected from the Moon. We developed a method to derive the Earth’s spheric...

Boulders on the surfaces of planets, satellites and small bodies, as well as their geological associations, provide important information about surface processes. We analyzed all available images of the surface of Mercury that have sufficient resolution and quality to detect boulders, and we mapped all the boulders observed. The lower size limit of...

Pipe fouling is a challenging problem in many industrial applications. Current cleaning techniques require halting the production during the cleaning phase and the existing methods are unable to do targeted cleaning, even though fouling is often localized to certain areas inside the pipeline. To address this issue, we use FEM-simulated, time-revers...

The Finnish Fireball Network (FFN) was established in 2004 due to growing interest to continuous meteor and fireball monitoring. In the current state, the network consists of the 24 active stations with permanent instrumental setup and monitors a surface over Finland and neighbouring areas of about 400.000 km2. Most of the active stations are run...

Boulders on the surfaces of planets, satellites and small bodies, as well as their geological associations, provide important information about surface processes. We analyzed all available images of the surface of Mercury that have sufficient resolution and quality to detect boulders, and we mapped all the boulders observed. The lower size limit of...

The primary goal of this study is to localize a defect (cavity) in a curved geometry. Curved topologies exhibit multiple resonances and the presence of hotspots for acoustic waves. Launching acoustic waves along a specific direction e.g. by means of an extended laser source reduces the complexity of the scattering problem. We performed experiments...

The Earth’s spherical albedo describes the ratio of light reflected from the Earth to that incident from the Sun, an important input variable for the Earth’s radiation balance. The spherical albedo has been previously estimated from satellites in low-Earth orbits, and from light reflected from the Moon. However, neither of these methods can produce...

The paper is concerned with a decoding of the Extended Prediction Orbit data format file for an assisted-GPS web-service via cypher-text only attack. We consider mandatory data content of the file and reveal the changes of this content at different moments of time. The frequency of changes hints on the location of records for current GPS date and s...

Tsunamis are unpredictable and infrequent but potentially large impact natural disasters. To prepare, mitigate and prevent losses from tsunamis, probabilistic hazard and risk analysis methods have been developed and have proved useful. However, large gaps and uncertainties still exist and many steps in the assessment methods lack information, theor...

The disruption of asteroids and comets produces cm-sized meteoroids that end up impacting the Earth’s atmosphere and producing bright fireballs that might have associated shock waves or, in geometrically-favorable occasions excavate craters that put them into unexpected hazardous scenarios. The astrometric reduction of meteors and fireballs to infe...

In this study, we investigate the ablation properties of bolides capable of producing meteorites. The casual dashcam recordings from many locations of the Chelyabinsk superbolide associated with the atmospheric entry of an 18 m in diameter near-Earth object (NEO) have provided an excellent opportunity to reconstruct its atmospheric trajectory, dece...

The disruption of asteroids and comets produces cm-sized meteoroids that end up impacting the Earth's atmosphere and producing bright fireballs that might have associated shock waves or, in geometrically-favorable occasions excavate craters that put them into unexpected hazardous scenarios. The astrometric reduction of meteors and fireballs to infe...

The presence of meters-thick polar deposits exposed directly on the surface of Mercury provides unique science opportunities that should be prioritized in the next decade of planetary exploration. The poles of Mercury provide a natural laboratory for understanding the chemical, physical, and thermal processes that have governed the supply, retentio...

We discuss scientific mysteries in the planetary systems of Uranus and Neptune and argue that magnetosphere-related measurements are key to resolve them. Uranus and Neptune represent a distinct class of planets that remains the least-investigated in the solar system and marks the frontier for a wide range of scientific areas. Several reviews have p...

Since realising the idea that a man-made object can be intentionally placed into the Earth’s orbit, almost 10,000 satellites have been launched for multiple scientific, commercial and military purposes. These activities produce a huge amount of junk comprised not only of defunct artificial objects that no longer serve a useful purpose, but various...

Bjurböle L/LL4 ordinary chondrite was studied using scanning electron microscopy with energy dispersive spectroscopy, Raman spectroscopy, X-ray diffraction, magnetization measurements and Mössbauer spectroscopy. The phase composition and the relative iron fractions in the iron-bearing phases were determined. The unit cell parameters for olivine, or...

When an object enters the atmosphere it may be detected as a meteor. A bright meteor, called a fireball, may be a sign of a meteorite fall. Instrumentally observed meteorite falls provide unique opportunities to recover and analyse unweathered planetary samples supplemented with the knowledge on the Solar System orbit they had. To recover a meteori...

We formulate major scientific questions about the properties of the solar nebula, and about the formation and early evolution of the first planetesimals, that should be addressed in the 2023-2032 decade. We provide recommendations on small Solar System body spacecraft missions that would address these questions most efficiently.

We prepared a preliminary comparative analysis of the asteroid absolute magnitudes between the Kharkiv dataset and the MPC, Pan-STARRS, and PTF datasets. The analysis has shown that the absolute magnitude dataset obtained from the Pan-STARRS survey project is closest to our dataset and can be the most suitable for the determination of diameters or...

We introduce a new atmospheric refraction correction method which allows to retrieve fireball position with high accuracy without the need to consider at which distance from the observer or height above the Earth's surface the fireball is situated. Traditional refraction correction is valid for objects positioned at infinite distance and it overcom...

Many natural land surfaces, such as sand or snow, consist of densely packed grains, often covered by dust, water droplets, contaminated with other materials such as possible oil leaks, hoar frost, and can also be internally cracked, porous, and heterogeneous. Most scattering models ignore these complications, but here a more detailed approach is ta...

The spectral bidirectional reflectance distribution function (BRDF) maps incident radiation of a surface to its outgoing counterpart at different wavelengths. This function plays a fundamental role in characterizing the various type of Earth surfaces. Due to its high dimensionality, the measurements, analysis, and simulation of spectral BRDF are ch...

Omnidirectional microscopy (OM) is an emerging technology capable of enhancing the three-dimensional (3D) microscopy widely applied in life sciences. In OM, the precise position and orientation control of the sample are required. However, current OM technology relies on destructive mechanical methods to hold the samples, such as embedding samples i...

Meteoroids impacting the Earth atmosphere are commonly classified using the PE criterion. This criterion was introduced to support the identification of the fireball type by empirically linking its orbital origin and composition characteristics. Additionally, it is used as an indicator of the meteoroid tensile strength and its ability to penetrate...

Meteoroids impacting the Earth atmosphere are commonly classified using the PE criterion. This criterion was introduced to support the identification of the fireball type by empirically linking its orbital origin and composition characteristics. Additionally, it is used as an indicator of the meteoroid tensile strength and its ability to penetrate...

Meteor science contributes greatly to the study of the Solar System and the Earth’s atmosphere. However, despite its importance and very long history, meteor science still has a lot to explore in the domain of meteor plasma microphysics and the meteor–ionosphere interaction. Meteors are actually a difficult target for high-resolution observations,...

Meteoroids impacting the Earth atmosphere are commonly classified using the PE criterion. This criterion was introduced to support the identification of the fireball type by empirically linking its orbital origin and composition characteristics. Additionally, it is used as an indicator of the meteoroid tensile strength and its ability to penetrate...

In order to extend remote sensing techniques to reveal further important properties of land surfaces, such as pollution, we have measured and modelled the bidirectional reflectance factor and degree of linear polarization from several particulate surfaces with different materials and different amount of oil contamination. Typically, polarization si...

We studied the interior and the fusion crust of the recently recovered Ozerki L6 meteorite using optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy, X‐ray diffraction (XRD), magnetization measurements, and Mössbauer spectroscopy. The phase composition of the interior and of the fusion crust was determined by...

The desire to know how our Solar System came to be is a fundamental driving force for humanity's exploration of space. "Building new worlds-understanding Solar System beginnings" is a major cross-cutting theme in the 2010 Planetary Science Decadal Survey. Drastically improving our understanding of Solar System formation also has synergy effects. It...

Ultrasonic NDT is a commonly used modality for ensuring structural integrity. When the geometry of the structure in question is complex, challenges arise, especially for structures that curve upon themselves, such as pipes and spheres. One challenging case is the hemisphere, where edge reflections (such as occurring in plates) and multiple propagat...

Acoustic levitation permits non-contact particle manipulation. The position and orientation of the levitated particle can be controlled by altering the acoustic field. Existing acoustic levitators have employed a single frequency which limits the types of acoustic traps that can be created. The use of multiple frequencies makes it possible to contr...

There is a need for contactless health evaluation of curved propellers ranging from servicing drones to wind power plants. Structures that close upon themselves feature multiple paths for acoustic waves to travel which causes interference and reduces contrast. In addition, blade curvature makes it challenging to scan the structure in a contactless...

Acoustic levitation permits non-contact handling of mm-scale samples. To improve its applicability, we did a simulation study to optimize orientation control of a sample residing in a phased array levitator. The acoustic forces and torques on asymmetric samples in asymmetric traps were determined by solving the acoustic scattering problem with the...

Time reversal (TR) is a technique based on the reciprocity principle of the wave equation that can be used to focus waves. In an enclosed system, comprising homogenous medium that includes no reflecting targets, it normally is impossible to use time reversal to focus ultrasound into the medium. Our proposed solution to this problem is to use simula...

Meteor science contributes greatly to the study of the Solar System and the Earth's atmosphere. However, despite its importance and very long history, meteor science still has a lot to explore in the domain of meteor plasma microphysics and the meteor-ionosphere interaction. Meteors are actually a difficult target for high-resolution observations,...

As fireball networks grow, the number of events observed becomes unfeasible to manage by manual efforts. Reducing and analysing big data requires automated data pipelines. Triangulation of a fireball trajectory can swiftly provide information on positions and, with timing information, velocities. However, extending this pipeline to determine the te...