The search for technosignatures has taken a back seat in the search for alien life forms. Methane in an exoplanet's atmosphere is one of the biosignatures. While we are looking for signs of biology, signs of technology may be hidden. According to a new report from the members of the TechnoClimes conference, humanity could possibly find signs of technology by simply using data that will already be collected for other purposes. They came up with a list of possible technosignatures and cross-referenced them with a list of observatories that could potentially find them. There is a framework of how to find technosignatures and a lot of references for those looking for them.
The conference took place in August 2020. The workshop was supposed to develop a research agenda for non-Radio technosignatures. One of the objectives of the workshop is to encourage a broader range of astronomy to consider the relevance of technosignatures to their research by serving as a resource that describes the detectability of various non-radio technosignatures.
The second objective was to develop mission concepts that could specifically look for technosignatures. A framework to evaluate non-canonical astrophysical phenomena is the third objective. Broadening international participation in technosignature searches is one of the final objectives.
The field needs all the help it can get with the amount of data it has. As more capable observatories come online, that amount of data will only increase. The framework of the TechnoClimes participants broke the observatories down into three different categories.
There are currently and recently completed missions in the first observatory category. The Roman Space Telescope and PLATO are expected to be launched in the next five years. Future missions that are five or more years away are largely still concept studies. There are also LUVOIR and HabEx.
There are three main areas for techno categories. The authors point out that radio-based technosignatures have already received attention in the form of SETI and other efforts to detect them over the past few decades.
The category is called optical beacon. These can be thought of as lasers, which can be used for communication or as a light sail. The exhausts of fusion drives can be seen hundreds of light-years away. A wide array of telescopes, ranging from already existing ground telescopes up through LUVOIR, would be able to detect powerful optical beacon.
The planetary technologies are next on the list. This is broken down into two sub- categories. The first sub-category is Atmospheric Technosignature, and it is divided into UV, visible light, and near-infrared categories. Industrial or non-biological processes can release gases into the atmosphere.
Humans produce a lot of these gases. Nitrogen dioxide could be seen in visible light. The amount of gas produced by them is small compared to the amount produced by industrial processes It should be seen around planets that are similar to the Sun.
The credit is NASA/ GSFC.
The mid-infrared wavelength is more likely to be captured by other gases. One of the TRAPPIST planets may have atmospheric technosignatures similar to Earth's. There are a lot of atmospheric observations that could be used to search for technosignatures.
Artificial surface modifications are a sub- category of planetary technologies. Seeing the city lights of an exoplanet is the most obvious of these. During the night, parts of the Earth are brightly lit, and even lights that are only slightly brighter can be seen. The Roman Space Telescope might be able to see them.
It is possible to see vast swathes of solar panels, which could be seen from far away, and their effect on the reflected light of an exoplanet could be noticed. The effect of a heat island could be seen in the mid-infrared range.
The last category of potential technosignatures is called system megastructures. These are engineered objects that can be large enough to have their own transit of their host star that would be visible to the naked eye. It is possible to find them by looking for the waste heat they would inevitably produce. Every currently launched and future mission should be able to see the transits of such a structure. The waste heat would be visible by the two aging observatory.
No one has come up with a viable search criterion for them in the data, so there is no evidence that they don't exist. Even if you don't find any technosignatures, it's still a very valuable scientific endeavor because you can put statistical constraints on the likelihood of the existence of those technosignatures elsewhere.
Most of the bright stars are likely to have planets. It is possible that no technosignatures are found on any of them. There is more data to be fed into a statistical model of the likelihood of intelligent life in other parts of the universe. If a technosignature is found, that could change our understanding of life. It seems like it is worth the investment.
You can learn more.
Haqq-Misra and her team are looking for technosignatures in exoplanetary systems.
Next generation telescopes could be used to search for intelligent civilization.
NASA's technosignatures report is no longer available. There are many ways to find evidence of an intelligent civilization.
NASA is looking for new ways to detect other civilization in space. Wait until you're sure. A technosignature is what it is.
All Rights Reserved © 2024
