Space is now the final frontier of forensic science

Forensic astronomy is the use of astronomy, the scientific study of celestial objects, to determine the appearance of the sky at specific times in the past. This has been used, if relatively rarely, in forensic science (that is, for solving problems of relevance to the legal system) and for resolving historical problems more generally, notably issues in art history.

As a forensic science in the strict sense of the term, astronomical knowledge can help resolve certain legal questions. In one reported instance, an astronomer testified in court as an expert witness as to whether a newly built house would cast a shadow on another house. More generally, questions about the Sun's or Moon's placement in the sky at certain times of day or night may be legally relevant, such as for determining the date on which a photograph was made(1). It has for instance been reported that Abraham Lincoln once successfully defended a legal case by describing the location of the Moon on the night of the offense (2).

For research in art history, in particular, methods of astronomy are sometimes useful for determining the place and time of creation of a particular work of art, or of the event that inspired it. Such methods have for instance been used to date Vincent van Gogh's painting Evening Landscape with Rising Moon (to 9:08 pm, 13 July 1889), and to identify the meteors described in Walt Whitman's poem Year of Meteors (1859-60) – in conjunction with Frederic Edwin Church's painting of the same event  – as the meteor procession of 1860.[3]

Frederic Edwin Church, The Meteor of 1860

Claude Monet created almost 2,000 paintings during his career, including his painting of the sunset on a winter afternoon in 1883. The painting is of a cliff that faces the English Channel called Falaise d’Amont where the north-east half of the cliff is called the Porte d’ Amont, which means “upstream portal”, and the southwest half is called “Porte d’Aval”, which means “downstream portal”. The pyramid-shaped rock is called the Aiguille, which means “needle”. When people look farther southwest, there is another bay and beach which can only be accessed when the tide is low called the Manneporte, which means “great portal”. When looking back toward the northeast a completely new view of the Porte d’Amont and Needle can be seen. When people walked along the curve of the beach Etretat, the sun overlaps the Needle In a farther distance. In the southwest part of Etretat Beach, the Needle completely disappears because it is behind the cliff. Once people have walked northeast, The Needle loses the end of the Aval arch. At certain points to the person's eye, the Needle forms a perfect pyramid in the sun's horizon. By taking into consideration all of Monet's paintings of the Etretat beach and the shadows of the Porte d’ Aval and Needle, Monet's easel's exact placement can be determined due to this forensic astronomy (5).

By extension, the adjective "forensic" has come to be used for any detailed analysis of past events, whether related to legal questions or not, and so the determination of past celestial constellations more generally is now increasingly referred to as "forensic astronomy" (4).

How forensic astronomy was used to understand the tragedy of Titanic

On April 10, 1912, a ship sailed from Southampton, England called the RMS Titanic The Titanic stopped in France and Ireland, and then to sailed for New York City but never made it. On April 14, at 11:40 pm, the ship struck an iceberg, and by April 15 the Titanic had sunk completely by 2:20 am. Many were saved, but at least 1500 or more people drowned in the shipwreck.

When survivors were asked to recall this night and what may have happened, they could all say there was “no moon”. Many also said the night was silent and motionless. The night that the Titanic sank was so serene. It was peaceful while disturbing. The night was beautiful even with all the horror and sadness that just occurred. Lawerence Beesley, who was a passenger described the sky as a “setting made [only] for them in which to display their wonder” which showed how close and beautiful the sky was when meeting the waterline. 

Forensic astronomy comes into play when Beesley realizes they are being rescued and noticed the sky in the east is brightened at the end of his lifeboat saying, “First a beautiful, quiet shimmer away in the east, then a soft golden glow that crept up stealthily from behind the sky-line...And next the stars died, slowly,– save one which remained long after the others just above the horizon. The star that Beesley is speaking of is believed to be Venus. Because of Beesley's descriptive view of what he saw during his rescue, allows forensic astronomy to be used to show the possibility to know where the iceberg was lying during the time of the Titanic ship wreckage. The iceberg hit the ship and caused the plates to cripple, and create rivets for water to then seep into the gaps. The original theory of how the Titanic sank was that the iceberg ripped the boat open "300 ft on the starboard of the ship" causing it to sink, but with the evidence and using forensic astronomy, researchers have been able to piece together the most accurate reason for the Titanic shipwreck.

Now Astro-forensics is entering into a new phase.  Extraterrestrial environments, space ships, and in understanding critical accidents onboard a space station or shuttle.

As human beings are now again visiting the moon, and as space presents a unique and tough environment for forensic investigations, we have to think differently now.  Settings that present altered gravity, cosmic radiation, extremes in temperature, and the need for oxygen-providing climate systems provide a few examples of the unearthly variables that are faced by future explorers and also forensic scientists. The the reduction of gravity in space introduces novel challenges in understanding how evidence behaves. This shift is crucial for forensic sciences like bloodstain pattern analysis, which relies heavily on gravitational effects to determine the circumstances under which blood stains are formed.

Astro-forensics : How blood behaves in microgravity

Analyzing bloodstain patterns in microgravity

As more people seek to go where no man has gone before, researchers are exploring how forensic science can be adapted to extraterrestrial environments.

A new study  highlights the behaviour of blood in microgravity and the unique challenges of bloodstain pattern analysis aboard spacecraft.

Studying bloodstain patterns can provide valuable reconstructive information about a crime or accident. However, little is known about how liquid blood behaves in an altered gravity environment. This is an area of study that, while novel, has implications for forensic investigations in space. Forensic science is more than just trying to solve crimes; it additionally has a role in accident reconstruction or failure analysis. With this concept, consider how various forensic disciplines could be utilized in a critical accident onboard a space station or shuttle.

Understanding how air-borne liquid blood interacts with a surface and creates stain patterns is crucial. Blood stain pattern analysis is the use of fluid dynamics, physics, and mathematics to understand the flight and origin of blood and interpret how it was deposited on a surface in criminal investigations (6).

Experiments were conducted aboard a Zero Gravity Corporation modified Boeing 727 parabolic aircraft. A mixture of 40% glycerin and 60% red food coloring was used, simulating the relative density and viscosity of human blood. Blood droplets were propelled from a hydraulic syringe toward a target during periods of reduced gravity between 0.00 and 0.05 g.

From these blood stains, the researchers reconstructed the angle of impact. With the lack of gravitational influence, surface tension and cohesion of blood droplets are amplified. What this means is that blood in space has a higher tendency to stick to surfaces until a greater force causes detachment. Within the application of bloodstain formation, it means that blood drops exhibit a slower spread rate and, therefore, have shapes and sizes that would not be reflective on Earth.

On Earth, gravity and air drag have a noticeable influence on skewing the calculated angle. The initial hypothesis was that because of the absence of gravity, certain mathematical calculations would be more accurate. However, the amplified effect of surface tension became a predominant factor that caused the calculation to have greater variance, even in the absence of gravity.

This is the first study relating to the behavior of blood in free flight. With the rate of technological evolution in space exploration, the authors say that the need for reliable forensic science techniques will become increasingly important.

Astroforensics is a novel subdiscipline that is in its infancy. Broadening the understanding of all forensic sciences in non-terrestrial environments is critical as we expand into a space-faring species. Research is needed, research that spans across all disciplines.

The paper is  published in the journal Forensic Science International: Reports (6).

6. Zack Kowalske et al, Bloodstain pattern dynamics in microgravity: Observations of a pilot study in the next frontier of forensic science, Forensic Science International: Reports (2024). DOI: 10.1016/j.fsir.2024.100358

Bloodstain pattern experiments were conducted in reduced gravity aboard a parabolic aircraft. Credit: Zack Kowalske

Footnotes:

1.  Marché, Jordan D. (2005). Theaters of time and space: American planetaria, 1930-1970. Rutgers University Press. p. 177. ISBN 978-0-8135-3576-0.
2.  Pistalu, Mary Ellen (2006). "Astronomy Takes the Stand: Using the Heavens to Solve Crimes". Mercury Magazine. Astronomical Society of the Pacific. 35 (January/February 2006): 28. Bibcode:2006Mercu..35a..28P.
3. Falk, Dan (1 June 2010). "Forensic astronomer solves Walt Whitman mystery". New Scientist CultureLab. Archived from the original on 4 February 2017. Retrieved 2 June 2010.
4. Gunn, Alan (2009). Essential Forensic Biology. John Wiley and Sons. p. 1. ISBN 978-0-470-75803-8.
5. Olson, Donald W. (2014). Celestial Sleuth: Using Astronomy to Solve Mysteries in Art, History and Literature. Springer Praxis Books. p. 240. ISBN 978-1-4614-8402-8.
6. https://theconversation.com/were-working-out-how-to-solve-crimes-in...