For thousands of years we have stared at the stars and wondered ‘are we alone in the universe?’ As our understanding of our own Solar System has developed in the last 50 years, we know that finding life requires us to look beyond our immediate neighbours to the stars beyond.
Dr Chenoa Tremblay and her team are using Pawsey’s systems to analyse data from radio telescopes in an attempt to finally answer one of the most fundamental questions of our existence.
Dr Tremblay uses spectroscopy, the study of the interactions between light and matter, to look for molecules in the gas layers around stars. As molecules in space are bombarded with energy from nearby stars, they can absorb and re-emit that energy at specific frequencies based on their structure, with each molecule’s energy signature being unique.
She uses radio telescopes to collect signals across a range of narrow-frequency bands to build up and identify those full-spectrum energy signatures. This is a relatively new science, beginning in 2014 with her PhD work at Curtin University. With little historical perspective, Dr Tremblay needs to rely on modelling, theories, and ideas to predict the impact of her work.
Searching for technosignatures and molecules means, as part of a recent study, compiling more than 17 hours worth of information on the sky, equivalent to hundreds of terabytes of data. On a standard laptop, processing and analysing this data would take more than 25 years.
Dr Tremblay uses the Murchison Widefield Array (MWA) radio telescope, a precursor telescope to the Square Kilometre Array, to collect observations and detect astronomical signals that help her investigate the hypotheses she has set out. These volumes of data are stored on Pawsey’s systems until they’re ready to be used.
In order to be able to image and analyse the astronomical signals, Dr Tremblay needs to use different pieces of software, including Python, AIOFlagger, MWA_Tools, and CASA, among others. This is where Pawsey’s systems come in, allowing Dr Tremblay to switch between different software packages and be able to run multiple datasets simultaneously through each. Combining all of this disparate data in the last step.
As Dr Tremblay explains: “There isn’t a pre-formed software package to analyse this data, so we have to download the data, and either write our own software or use software packages written by other astronomers or software developers to complete each step of the process.”
With more than 500,000 images of the sky to analyse, there is a need to process multiple sets of data at the same time, as well as organise the imagery and make it easily discoverable for future analysis and comparison.
As Dr Tremblay sets out, now is an exciting time for her field: “With this recent dataset, there are a number of different publications completed and soon to be finalised, including the largest ever summary on technological signals.”
Together with Professor Steven Tingay from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR), Dr Tremblay recently used the MWA telescope to explore hundreds of times more broadly than any previous search for extraterrestrial life. Scanning a patch of sky with over 10 million stars, they found no technosignatures — that is, no obvious sign of intelligent life.
Dr Tremblay continues her search for signs of alien life, in particular the vital building block of Nitric Oxide, which hasn’t been detected as often as expected and as such will be a focus area for future research.
Key to the future success of the research is the ability to generate and process even more data. Dr Tremblay explains: “We’re still not hitting the sensitivity limits, and with the signals being very weak, finding new ones requires even more data”.
With the power of the Pawsey supercomputer behind her, Dr Tremblay has accelerated the outcomes of her research from years to days. In doing so, she may also accelerate the most defining discoveries of our lifetimes.