Why Do the Brightest Minds of Our Generation Invest in the Search for Extraterrestrial Life?
Why do billionaires like Paul Allen and Yuri Milner, scientists like Stephen Hawking, and universities including Harvard, Princeton, Cambridge, and Caltech pursue the quest for extraterrestrial life?
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Did you know that we have probes and radio signals currently en route to stars such as Sirius, Polaris, Gliese 445, and Aldebaran, as well as to the constellation of Aquila, the cluster Messier 13, and many others?
Did you know that the scientific community is currently exploring the real possibilities of life existing on Mars, Venus, Europa (moon of Jupiter), Enceladus (moon of Saturn), Titan (moon of Saturn), and Ganymede (moon of Jupiter)?
Our team at Space Ambition is highly enthralled by Liu Cixin's The Three-Body Problem. The novel paints a fictional narrative spanning the past, present, and future, where Earth engages with an alien civilization from a nearby star system featuring three sun-like stars in orbit around each other. We highly recommend it if you haven't read it yet. While the encounter with the alien civilization propels Earth's own civilization forward in the story, such an event might seem far-fetched in our reality. Or is it? Join us as we dive into our analysis of the current programs dedicated to the search for extraterrestrial life. We'll explore their objectives, who's backing them, and the discoveries they've unearthed so far.
The Optical Illusion That Fueled Life on Mars Speculation and Inspired Legendary Sci-Fi Tales
In the late 19th and early 20th centuries, astronomers mistakenly believed that there were 'canals' on Mars, a series of long straight lines observed in the equatorial regions of the planet. These canals were initially seen through early telescopes, leading to misinterpretations of the Martian surface. They were first described by the Italian astronomer Giovanni Schiaparelli during the 1877 opposition and confirmed by later observers. Schiaparelli called them canali ('channels'), which has been incorrectly translated into English as 'canals'. Later, Percival Lowell promoted the theory that these canals were constructed by intelligent entities for the purpose of irrigation. His scientific books about canals on Mars circulated widely around the world, cementing the idea of inhabited Mars in people's minds.
Scientists believed in artificial canals on Mars, and therefore in life on Mars, and the controversy lasted until the mid-20th century (Mariner 4's flyby in 1965). Improved astronomical observations revealed the 'canals' to be an optical illusion, and modern high-resolution mapping of the Martian surface by spacecraft shows no such thing as a canal on Mars’s surface.
But the idea that there might be life on Mars contributed greatly to human culture and art, inspiring the creation of several fantastic works like War of the Worlds by H. Wells and The Martian Chronicle by R. Bradbury, etc.
Venus: From Earth's Twin Fantasies to the Fiery Reality
In the mid-20th century, human knowledge of the surface conditions of Venus was largely speculative due to its complete cloud cover. It was widely believed that Venus could potentially support life, as its surface environment was thought to be similar to Earth. In fact, British astronomer Richard A. Proctor stated in 1870 that life on Venus would be impossible near the equator, but possible near the poles. This speculative nature of Venus allowed science fiction writers to freely imagine what the planet might be like until the 1960s. Some of the speculations included a jungle-like environment or oceans of either petroleum or carbonated water. They reasoned that there are clouds on Venus, so it rains there, and where there is water, there is life. However, as space probe technology has advanced, scientists have gained a better understanding of Venus and its inhospitable conditions.
In 1962, Mariner 2, the first successful mission to Venus, measured the planet's temperature for the first time and found it to be about 930 degrees Fahrenheit (500 degrees Celsius), which made it uninhabitable.
It is important to note, the search for extraterrestrial life is divided into different areas. Search for extraterrestrial intelligent life that can leave its "traces" in space and send signals, as well as a search for living microorganisms. We will briefly cover both directions in this article.
Signaling the Cosmos: Human Efforts in Establishing Extraterrestrial Contact
There are two major approaches to the process of Searching for Extraterrestrial Intelligence (SETI):
Search for signals from alien civilizations, assuming extraterrestrial life to be intelligent and also seeking contact. The main problems with this approach are threefold: what to look for, how to look for it, and where to look for it.
Sending what is called a METI (Messaging to Extra-Terrestrial Intelligence) and trusting that someone will be looking for this signal. The main issues with this approach are actually similar to those of approach one but with fewer technical problems.
There are two types of METI: material messages (I.e. sending an artificial object to space) and radio messages. The speed of transmission of material messages is relatively low, so the nearest star can be reached in hundreds or thousands of years. Therefore, it is obvious that our civilization can count on "communication" with extraterrestrial civilizations only with the help of radio messages or under the condition of the physical introduction of the extraterrestrial civilization on own initiative.
Here are some examples of material interstellar messages:
Pioneer plaque - two identical anodized aluminum plates aboard Pioneer 10 (launched 2 March 1972) and Pioneer 11 (launched 5 April 1973) The plates depict a man, woman, and the Pioneer ship to the same scale. To their left is the Sun, with rays showing the location and distances to the 14 nearest pulsars and the center of the Galaxy. The authors are Carl Sagan of Cornell University and Frank Donald. Pioneer 10 is heading towards the star Aldebaran in the Taurus constellation and will take more than two million years to reach it. Pioneer 11 is headed toward the constellation of Aquila (The Eagle) and is expected to pass nearby in about 4 million years.
The Voyager Golden Record (launched in 1977) is a gold-plated information record of sound and video signals, packaged in an aluminum case. The recordings contain greetings in 55 world languages, as well as music from many cultures. Voyager 1 is headed towards the star Gliese 445, located in the constellation of Camelopardalis, and will take about 40,000 years to reach its vicinity. Voyager 2 is on a trajectory toward the star Sirius in the constellation of Canis Major, and it will also take about 40,000 years to approach it.
Here are some examples of radio messages:
The Morse Message was a series of brief radio messages in Morse code that were transmitted from the Evpatoria Planetary Radar complex and directed to the planet Venus in 1962. The message was the first radio broadcast intended for extraterrestrial civilizations in the history of mankind.
The Arecibo Message was sent in 1974 from Arecibo Telescope in Puerto Rico. This interstellar radio message encapsulated basic information about humanity and our home planet and was beamed towards the globular cluster Messier 13 (M13). The target, M13, was chosen due to its relative proximity and the significant size of its star collection, even though it lies about 25,000 light-years away from Earth.
One of the most recent events (10 October 2016) - A Simple Response to an Elemental Message (ASREM) was an Interstellar Radio Message (IRM) consisting primarily of 3775 recorded worldwide responses to the question: "How will our present, environmental interactions shape the future?". The message was transmitted toward Polaris, the North Star, 434 light years away.
How are scientists searching for extraterrestrial civilizations now?
Of course, space exploration is a task for humanity as a whole. The search for extraterrestrial civilizations is a task that has brought together scientists from all over the world. The best known of these is the SETI (Search for Extraterrestrial Intelligence) Institute, a private, non-profit research organization in Silicon Valley. Founded in 1984, its sponsors and specific functions have changed over time, but its researchers have always been focused on finding signs of extraterrestrial intelligence. Other SETI research groups at other institutions and universities around the world share the same basic goal.
Any advanced extraterrestrial civilization is believed to leave traces of its activity in space. The SETI program serves to detect such traces. It is designed to search for extraterrestrial civilizations by means of radio listening to the space. Examples of such activities include centimeter-band radio waves emitted by radars, radio transmitters, and space communications systems. These waves are weakly absorbed by interstellar matter and can travel gigantic galactic distances, retaining invaluable information about their origin. The named properties of radio waves formed the basis of the SETI program. It began in the sixties of the last century and continues now on the largest radio telescopes equipped with sensitive receivers to receive waves at different frequencies.
Most SETI projects follow the fictional character Dr. Eleanor Arroway’s (by actress Jodie Foster) strategy in the movie Contact, where she used the National Radio Astronomy Observatory’s Very Large Array (VLA), sprawled across the deserts of New Mexico, to look for artificial radio emissions.
Many ongoing projects of SETI mostly use existing radio telescope projects but have their own huge search facilities and devices. Here are some of them:
The AllenTelescope Array (ATA), formerly known as the One HectareTelescope (1hT), is a radio telescope array dedicated to astronomical observations and a simultaneous search for extraterrestrial intelligence. The project was originally developed as a joint effort between the SETI Institute and the Radio Astronomy Laboratory (RAL) at the University of California, with total donations to the project - $25 million by billionaire Paul Allen.
The Breakthrough Listen project was supported by Prof. Stephen Hawking and the Royal Society in London. Investor Yury Milner invested $100m in this initiative. The project is observing for thousands of hours every year on two major radio telescopes, the Green Bank Observatory in West Virginia, and the Parkes Observatory in Australia. Previously, only about 24 to 36 hours of telescope per year were used in the search for alien life.
Galileo Project envisages the creation of a global network of medium-sized telescopes, cameras, and computers to investigate unidentified aerial phenomena (UAP), and has so far been funded with $1.75 million from private donors. The project includes researchers from Harvard, Princeton, Cambridge, Caltech and the University of Stockholm.
SETI@home - the project launched on 17 May 1999, it was the third significant use of volunteer computing for research over the Internet, achieving a total number of volunteers of 1,803,163. The project analyses radio signals from telescopes in an attempt to find signs of extraterrestrial intelligence. Until March 2020, it operated as an open online volunteer computing project. Anyone could join the network, and the calculations were done on everyone's computer. It is one of several initiatives under the global SETI program run by the Space Science Laboratory at the University of California, Berkeley.
What are Some Indications of Extraterrestrial Life in Our Solar System?
Even while there is an astounding diversity of worlds, the hunt for extraterrestrial life in our solar system has not yet produced any conclusive evidence. However, a separate area - the search for microorganisms on other planets - is relatively successful. We will not go into the details and techniques of the search, but we are very encouraged that scientists already have several observations that may indicate the presence of life on several planets.
According to recent research, there may be hope for life on Mars, Venus, and the moons of gas giants like Enceladus and Europa, which might have enormous subterranean oceans. There are intriguing possibilities for finding life in our solar system on these moons.
Life on Mars: Deep Biosphere, Extremophiles, and Brine Channels?
We talked with ALFA Mars - a group of scientists, engineers, science communicators, and volunteers aiming to determine whether indigenous life is present today on Mars before humans walk on its surface. We wondered - What's the likelihood and what indications suggest there might be life on Mars? That’s what Jan Špaček from ALFA Mars had to say:
“We have solid evidence that rivers, lakes, and perhaps oceans, existed on Mars in the past. Martian life would thrive during the Martian wet period. If life did not originate on Mars separately, it was likely delivered there via impact ejecta from Earth by a process called lithopanspermia.
Analogically to Earth’s deep biosphere, where microbes live down to 10 km underground, lithotrophic microbiota likely exist in the deep Martian subsurface, oblivious to the fact that Mars lost most of its atmosphere billions of years ago.
Many astrobiologists however agree that there is a realistic possibility that Mars hosts indigenous microbial life not just in the deep underground, but also close to its surface. This conclusion is based on a study of extremophiles. Several other different ways for life to survive on Mars were proposed, one of which is in brine channels between crystals of subsurface ice.”
Life on Venus: Microorganisms Producing Phosphine?
In September 2020, a team of scientists led by Prof. Jane Greaves of Cardiff University in Wales reported the detection of phosphine, a possible indicator of life, in the clouds of Venus. The announcement sparked a heated debate and a surge of follow-up studies, which have generally failed to spot the intriguing molecule in the Venusian atmosphere.
Phosphine is generated by microorganisms living in a very low-oxygen environment. Phosphine is generally not produced in other ways on our planet, as Earth lacks an abundance of "loose" hydrogen. This suggests that phosphine, detected in other worlds, is a potential biosignature.
Now there's a new twist. Speaking at the Royal Astronomical Society's National Astronomy Meeting 2023 in Cardiff, Greaves revealed the discovery of phosphine deeper in the atmosphere of Venus than it had been spotted before.
But, the real question is, what does phosphine mean? Could it be evidence of life on Venus?
Life on Europa: Carbon Dioxide is a BioSignature?
Europa, one of Jupiter’s moons, has long been considered a prime candidate for extraterrestrial life due to its deep saltwater ocean. However, the moon’s icy shell, potentially miles thick, has posed challenges for exploring its potential habitability. Recent evidence suggests that this icy shell may be more dynamic than previously thought, potentially making it a site for habitability.
Recently NASA found a possible sign of life on Jupiter's moon. Two independent teams of astronomers (NASA’s Goddard Space Flight Center and Cornell University) used the James Webb Space Telescope to observe the frozen surface of Europa, and each analysis of the space observatory's detections revealed a notable presence of carbon dioxide (CO2) in a particular region of the icy terrain. While carbon dioxide alone isn't a definitive biomarker of life, its detection, especially when analyzed alongside other potential biosignatures, could provide insights into the moon's geochemical processes or its potential habitability.
Two future missions will be able to take a closer look at Europa in the future, including the European Space Agency’s Jupiter Icy Moons Explorer (JUICE) was launched in April 2023, and NASA’s Europa Clipper, expected to lift off in October 2024.
Life on Enceladus: Phosphorus and Ingredients for Amino Acids?
Enceladus is a moon of Saturn. Phosphorus residue has been found on it. Phosphorus, a key chemical element for many biological processes, has been found in icy grains emitted by the small moon and is likely abundant in its subsurface ocean.
Using data collected by NASA’s Cassini mission, an international team of scientists has discovered phosphorus – an essential chemical element for life – locked inside salt-rich ice grains ejected into space from Enceladus.
The small moon is known to possess a subsurface ocean, and water from that ocean erupts through cracks in Enceladus’ icy crust as geysers at its south pole, creating a plume. The plume then feeds Saturn’s E ring (a faint ring outside of the brighter main rings) with icy particles.
During its mission at the gas giant from 2004 to 2017, Cassini flew through the plume and E ring numerous times. Scientists found that Enceladus’ ice grains contain a rich array of minerals and organic compounds – including the ingredients for amino acids – associated with life as we know it.
There are also research projects proposing life on Titan and Ganymede.
In addition to searching for life in our solar system, scientists are looking for life outside of it. 5,000+ exoplanets have been discovered already, where life conditions may be similar to those on Earth, and dozens of them could be habitable. But we’ll dive into that in future articles.
However, when humans look for life, they look for Earth-like life. Even the aliens we imagine are bipedal, as shown in films and books. But what if there are completely different life forms that we can't even imagine and comprehend? Hopefully, our generation will be the ones to find life on another planet.
What do you think, is there life on other planets and what does it look like? How will the meeting with other civilizations go? Write your answers to us at hello@spaceambition.org!
A very comprehensive and interesting article, I enjoyed reading it!
That was an excellent article offering a neat insight on SETI, I'll now follow your newsletter with great interest