Ray Systems in Granular Cratering.
Tapan Sabuwala1, Christian Butcher2, Gustavo Gioia1
1Continuum Physics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa 904-0495, Japan.
Physical Review Letters
|July 14, 2018
Summary
Surface undulations transform ejecta blankets into ray systems during granular cratering. The number of rays correlates with impactor size and surface wavelength, offering insights into planetary cratering.
Area of Science:
- Planetary Science
- Geophysics
- Fluid Dynamics
Background:
- Classical granular cratering experiments yield uniform ejecta blankets.
- The influence of surface topography on ejecta patterns has been largely unaddressed.
Purpose of the Study:
- To investigate how surface undulations affect ejecta patterns in granular cratering.
- To understand the formation mechanism of rayed crater systems.
Main Methods:
- Conducted numerous granular cratering experiments.
- Performed computational simulations of the cratering process.
- Analyzed the relationship between impactor size, surface wavelength, and ray system characteristics.
Main Results:
- Surface undulations transform uniform ejecta blankets into ray systems.
- The number of rays in a ray system is directly proportional to the impactor diameter (D) and inversely proportional to the surface undulation wavelength (λ).
- Ejecta forming ray systems originate from a narrow annular region around the impact site.
Conclusions:
- Surface topography is a critical factor in determining ejecta patterns.
- The findings provide a physical model for the formation of rayed craters observed on planetary bodies.
- This research may help explain enigmatic ray systems on the Moon and other celestial bodies.
Related Concept Videos
02:18X-ray Crystallography
26.2K
The size of the unit cell and the arrangement of atoms in a crystal may be determined from measurements of the diffraction of X-rays by the crystal, termed X-ray crystallography.
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
26.2K
01:24X-ray Imaging
10.5K
German physicist Wilhelm Röntgen (1845–1923) was experimenting with electrical current when he discovered that a mysterious and invisible "ray" would pass through his flesh but leave an outline of his bones on a screen coated with a metal compound. In 1895, Röntgen made the first durable record of the internal parts of a living human: an "X-ray" image (as it came to be called) of his wife’s hand. Scientists worldwide quickly began their own experiments with...
10.5K
01:18Second Order systems II
411
In an underdamped second-order system, where the damping ratio ζ is between 0 and 1, a unit-step input results in a transfer function that, when transformed using the inverse Laplace method, reveals the output response. The output exhibits a damped sinusoidal oscillation, and the difference between the input and output is termed the error signal. This error signal also demonstrates damped oscillatory behavior. Eventually, as the system reaches a steady state, the error diminishes to zero.
411
01:21First Order Systems
433
First-order systems, such as RC circuits, are foundational in understanding dynamic systems due to their straightforward input-output relationship. Analyzing their responses to different input functions under zero initial conditions reveals significant insights into system behavior.
When a first-order system is subjected to a unit-step input, its response is characterized by its transfer function. By applying the Laplace transform of the unit-step input to the transfer function, expanding the...
When a first-order system is subjected to a unit-step input, its response is characterized by its transfer function. By applying the Laplace transform of the unit-step input to the transfer function, expanding the...
433
01:20Second Order systems I
603
A servo system exemplifies a second-order system, featuring a proportional controller and load elements that ensure the output position aligns with the input position. The relationship between these components is described by a second-order differential equation. Applying the Laplace transform under zero initial conditions yields the transfer function, showing how inputs are converted to outputs in the system.
By reinterpreting the system, one can derive the closed-loop transfer function, which...
By reinterpreting the system, one can derive the closed-loop transfer function, which...
603
01:06Thermodynamic Systems
8.2K
A thermodynamic system is a set of objects whose thermodynamic properties are of interest. The system is considered to be embedded in its surroundings or the environment. The system and its environment can exchange heat and do work on each other through a boundary that separates them. However, the immediate surroundings of the system interact with it directly and therefore have a much stronger influence on its behavior and properties.
Consider an example of tea boiling in a kettle. The...
Consider an example of tea boiling in a kettle. The...
8.2K