There cannot be an astronaut who has ever gone into space who hasn’t thought about life on their home planet. Perhaps just as many space travelers have wondered whether there might not be a glimmer of life somewhere in the infinity to which they were heading. The exploration of space is much like a tireless search for a small piece of Earth in space, a place where something moves, whether or not it has a consciousness like ours. The existence of life in extraterrestrial environments is one of the most intriguing scientific questions. And it was just as intriguing 30 years ago when Dirk Frimout became the first Belgian to leave the atmosphere. Researchers from the VUB Research Group Structural Biology Brussels are working with the VUB-UGent Alliance Research Group NanoMicrobiology, and VUB-EPFL (Switzerland) International Joint Research Group BioNanotechnology & NanoMedicine to develop methods for determining extra-terrestrial life in a simple but well-founded way.
There are various methods for detecting extraterrestrial life. But almost all of them come up against a fundamental question. What we call life: is it similar elsewhere in space to what we know here? The answer is simple: we don’t know. Life may have taken a very different form on another planet or in another galaxy. It may be based on the carbon chemistry found on our planet, but other candidate chemical compounds may carry life in conditions too extreme for our terrestrial life. So, we don’t know what we’re looking for.
Vibrations as a universal signature for life
“Since the chemical composition of these organisms is unknown, a chemistry-independent life detector would be a suitable device to equip interplanetary missionaries in their search for extraterrestrial life,” says VUB professor Ronnie Willaert.
“A few years ago, we showed that all living organisms oscillate or vibrate on the nanometre scale, vibrations that almost completely disappear once the organism is dead.” - professor Ronnie Willaert
The small-scale vibrations seem to be a universal signature of life. Every living cell, whether a yeast cell or a bacterium, the cell of a tree or a human body cell, vibrates throughout its life at a frequency somewhere between 5 and 10 hertz. The vibrations stop, or almost stop, as soon as the cell dies. Willaert: “The vibrations were discovered at l’Ecole Polytechnique Fédérale de Lausanne (EPFL) , one of the world’s leading universities and a partner of VUB in this research. To demonstrate the vibrations, cells were attached to a flexible cantilever, after which it could be shown with a laser that the cells vibrated at a more or less fixed frequency and that this stopped when they died.”
Home-made optical microscope
Since January, Vjera Radonicic, a VUB researcher, has been working on this fact with an FWO Frank De Winne Ph.D. grant. However, she wants to detect the vibrations more simply. For this purpose, she is working on developing an optical microscope, with which the oscillations can be filmed.
“The aim is to design a microscope, use open-source models for it and make it ourselves with a 3D printer in the VUB laboratory in Brussels."
For the lenses, we will look for the right ones on the commercial market. The instrument will be a prototype on which a spacecraft instrument will be based. It must be able to detect the cellular nano-movements and record them on film.”
The detector also needs to be optimised to perform antimicrobial susceptibility testing in microgravity to be taken into space. The device could be used to check the extent to which human activity in space causes microbial contamination so that disinfection methods can be developed to control microbial contamination in space habitats.
The device will be based on optical microscopy, and for sample collection and examination the researchers will use microfluidics – filtration and cell trapping – and existing image processing algorithms.
"The VUB microscope will also be used to examine samples that come to Earth from space. This can then be done in the laboratory."
An offshoot of the VUB research focuses on samples taken by Ghent University in the ice in Antarctica. There is a chance that there are considerable water reserves in the form of ice on other bodies (“icy planets” such as Europa) and that life forms or remnants of earlier life are hidden in them that are unknown to us. Willaert: “We want to try to trace and capture the bacteria trapped in the Antarctic ice with our method.”
On the occasion of the 30th anniversary of Dirk Frimout's space journey (March 1992) and the 20th anniversary of Frank De Winne's space journey (October 2002), VUB and ULB welcome an international space delegation in October 2022. In collaboration with Belgian Space Week, we invite students from the third grade of secondary school to an inspiring programme about space.