Astroforensics could possibly be one of many coolest new jobs of the longer term

NASA's Artemis program aims to return astronauts to the moon and establish a permanent orbiting laboratory by the end of the decade.

Meanwhile, private companies are taking significant steps to bring paying customers further into space. As humanity's footprint expands beyond the familiar reaches of Earth to the moon and possibly beyond, a fascinating new field is emerging at the final frontier: astroforensics.

Still in its infancy, this discipline is driven by the inevitability of human nature. Space provides a unique and harsh environment for forensic investigations. Environments with altered gravity, cosmic rays, extreme temperatures, and the need for oxygen-supplying climate systems are some examples of the unearthly variables that future explorers will face.

Unlike on Earth, where gravity, a constant force, shapes many aspects of our reality, the significant reduction in gravity in space presents new challenges for understanding the behavior of evidence. This shift is critical to forensic sciences such as Analysis of bloodstain patterns, relying heavily on gravitational effects to determine the circumstances under which bloodstains form.

The thought of gravity in space immediately conjures up images of astronauts floating hauntingly in the emptiness of space or levitating gymnastics exercises in the International Space Station (ISS).

However, true weightlessness exists far from all celestial bodies. Gravitational influence occurs near a body such as a moon or a planet, even if it is in orbit around a planet such as Earth.

Therefore, most space environments experience low or microgravity rather than weightlessness. Given that gravity is omnipresent and largely constant, we pay little attention to it and usually automatically include it as a constant in calculations without thinking about it.

Altered gravity

But for a forensic discipline like bloodstain pattern analysis, it's gravity
plays a critical role in how liquid blood in the air interacts with a surface and creates stain patterns. Bloodstain pattern analysis uses fluid dynamics, physics and mathematics to understand the flight and origins of blood and interpret how it is deposited on a surface during criminal investigations.

In a recently published study, we and our colleagues sought to understand the basic principles of how the changing gravity environment of space will impact future forensic science disciplines.

For this study, published in Forensic Science International: Reports, we used a parabolic research aircraft that induces short periods of microgravity due to its up-and-down trajectory. This type of flight is also known colloquially as a “vomit comet”.

During this period of weightlessness in free fall, a series of blood drops were projected onto a sheet of paper and the resulting blood spot was then analyzed using routine Earth-based protocols. Although the concept sounds simple, the challenge was to create a safe and controllable area to conduct experiments in a plane that essentially fell to Earth for 20 seconds.

Therefore, the test environment had to be connected to the cabin
Research level and the generation and documentation of all blood stains can be easily controlled. The experiments were conducted in a repurposed children's incubation chamber called a glove box. This chamber is used in space medicine research to study bleeding control.

Due to biohazard concerns, a synthetic analogue of blood was used in the cabin of the aircraft instead of real blood. This analogue replacement mimicked the physical properties of blood viscosity and surface tension. To start the experiment, the analog blood was loaded into a syringe, and once microgravity was induced in free fall, the syringe was manually depressed to project the blood over 20 cm onto a white sheet of paper.

Although this bears little resemblance to real crime scenarios, what is of interest to the forensic investigator is the interaction between the blood and the surface – rather than the actual mechanism of projection. The bloodstained papers were then photographed and analyzed according to standard procedures.

We found that microgravity actually changes the behavior of blood drops and the stains they create. On Earth, blood tends to fall parabolically, with gravity pulling it downward until it hits a surface. But in this case the blood continued to move in a straight line until it reached the surface.

This straight-line trajectory is a fluid example of inertia in action. However, at a distance of only 20 cm, this had minimal impact on the later pattern.

This difference would be more apparent over longer distances, but due to the operational limitations of the parabolic research aircraft, it would be difficult to replicate effectively. The second important observation was the spreading effect of the blood upon hitting the surface.

In Earth's typical gravity environment, liquid drops of blood go through a series of phases in the process of staining. This causes the droplet to collapse, creating a small ripple and spreading out into a final spot shape.

However, when gravity is eliminated in this action, the spreading effect is inhibited by the dominant force of surface tension and cohesion, resulting in the spot being smaller in shape and size than its terrestrial counterpart.

We are at the beginning of a new era of research, exploring the influence of the extraterrestrial environment on the behavior of forensic evidence. However, the implications of this research are not limited only to the forensic sciences, but also to more traditional natural sciences, such as fluid dynamics in spacecraft design and the analysis of errors in space forensic engineering following a spacecraft malfunction.

Expanding research in this new forensic discipline will require larger microgravity environments, and the authors would be more than happy to operate the galaxy's first extraterrestrial forensic science laboratory.The conversation

Graham Williams, Professor of Forensics, University of Hull and Zack Kowalske, PhD candidate, Staffordshire University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Comments are closed.