This article was first published by The Conversation. Space.com's Expert voices: Op-Ed and Insights was contributed by the publication.
Tim Thompson, Teesside University's Dean of Health & Life Sciences and Professor of Applied Biological Anthropology
Space travel is becoming an increasingly real possibility. We may soon be able to travel to other planets to enjoy our holidays or even live. Blue Origin, a commercial space company, has begun sending customers to sub-orbital flight. Elon Musk also hopes to establish a base on Mars through SpaceX.
This is why we should start to think about how it would be to live in space, and what happens if someone dies there.
The human body goes through several stages of decomposition after death. These stages were first described in Song Cis The washing away of wrongs (1247), which was essentially the first forensic science manual.
The blood stops flowing, and then it pools due to gravity. This is called livor mortis. The body then cools to algor moris and the muscles become stiffened due to an uncontrolled buildup of calcium within the muscle fibers. This is called rigor mortis. Next, enzymes, which are proteins that speed up chemical reactions and break down cell walls, release their contents.
The bacteria from our gut can also escape and spread throughout the body. Putrefaction is when they eat the soft tissues. The gases they emit cause swelling. Rigor mortis can be broken when the muscles are destroyed, strong odors are emitted, and the soft tissues are degraded.
These are the intrinsic decomposition factors. However, there are external factors that can influence the process such as temperature, insect activity and presence of water or fire.
Mummification is the drying or desiccation of the body in dry conditions that can be either hot or cold.
Adipocere can form in damp environments that lack oxygen. This is where water can cause fats to be hydrolysed and become waxy. To protect and preserve the skin, this waxy coating acts as a barrier.
In most cases, however, the soft tissues will eventually disappear to expose the skeleton. These tissues are more durable and can last for many years.
Halting decomposition
What about death at the last frontier?
The gravity of other planets will definitely impact the livor moris stage. Also, blood wouldn't pool if there was no gravity.
Rigo mortis could still be present in a spacesuit because it is caused by the cessation or impairment of bodily functions. The soft tissues would be eaten by bacteria in the gut. These bacteria require oxygen for proper functioning, so a limited supply of air would slow down the process.
The soil microbes also aid in decomposition. Therefore, any environment that hinders microbial activity, such as extreme dryness or extreme heat, increases the chance of soft tissue preservation.
External factors can make decomposition more difficult, as the Earth's environment is different. Bone is a living material that contains both organic materials such as blood vessels and collagen and inorganic substances in a crystal structure.
The organic part will naturally decompose and museums have skeletons that are mostly made up of inorganic remains. However, in extremely acidic soils (which may be found on other planets), the reverse can occur and the inorganic can disappear, leaving only the soft tissue.
The Earth's decomposition of human remains is part of a healthy ecosystem in which nutrients are recycled by living organisms such as microbes, insects, and plants. Different environments will not have evolved in the same way to use our bodies. Our system does not contain any insects or scavenging creatures.
However, Mars' dry desert conditions could mean that soft tissues are not able to function properly. The windblown sediment might erode the skeleton and cause it to be more damaged than what we see on Earth.
Mars's desert environment. (Image credit: https://pixabay.com/users/wikiimages-1897, CC BY-NC)
Decomposition is also affected by temperature. Temperatures can vary from 250 to –270 degrees Fahrenheit (120 degrees to -170 Celsius) on the moon. Therefore, heat-induced changes or freezing damage could be seen in the bodies.
It is possible that the remains of human beings would remain intact, as the process of decomposition we see on Earth wouldn't take place. Our bodies would become "aliens" in space. We might need to develop a new type of funerary practice that doesn't require the use of high-energy cremation or digging graves in an inhospitable environment.
Read more: William Shatner is the oldest astronaut at age 90. Here's how space tourism might affect older people
This article was republished by The Conversation under Creative Commons. You can read the original article.
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