GS Paper III

News Excerpt:

Search for Extraterrestrial Intelligence (SETI) is as fascinating for the casual observer as they are for an engaged specialist.

Radio Signals vis-a-vis Neutrino Signals:

• Researchers use electromagnetic-wave signals to identify ourselves and others across the cosmos, ranging from narrow-frequency radio signals to wideband signals.
• However, differentiating naturally occurring waves (like radio noise from the magnetosphere of Jupiter or the environs of stars) from those transmitted from more interesting sources is challenging.
• As space waves are distorted during their journey to Earth, and the information they carry may not survive the journey intact.
• Scientists are exploring the possibility of extraterrestrial intelligence communicating with us through neutrinos, which are the most abundant particles in the universe after photons.
• Neutrinos interact weakly with matter and can move relatively untouched through the same media as electromagnetic waves.

Messaging Extraterrestrial Intelligence (METI):

• It is a scheme to communicate with intelligent alien life in outer space. It began in 1960 and has evolved over the years.
• NASA launched Pioneer 10 and 11 spacecraft in 1972 and 1973 to study the outer Solar System.
• Each spacecraft carried a plaque depicting human bodies, hydrogen atom properties, cosmic landmarks, and an image of the spacecraft.
• In 1974, scientists like Frank Drake and Carl Sagan encoded a graphical message into radio waves and broadcasted it to the M13 globular cluster.
• METI has gained momentum in recent decades with satellites and astronomy programs aiming to find exoplanets orbiting other stars.

Recent developments and collaborative efforts:

• Scientists are studying instances of radioactive decay that involve neutrinos. A 2017 experiment at Purdue University found that the decay rate of radioactive manganese declined sharply due to small changes in the ambient flow of neutrinos.
• The scientists proposed setting up decay experiments at different sites around the world and analyzing the collected data for signs of a non-uniform neutrino flux, which could be associated with events in outer space.
• They called their proposal NU-SETI, and premised that this is an experimental fact that advanced extraterrestrial civilizations could understand and use to communicate with us.
• Some METI efforts suggest physical structures or artefacts built by aliens, such as light from the star KIC 8462852, which exhibited a periodic dimming pattern.
• One hypothesis is that an alien structure is obstructing our view of the star.
• SETI and METI programs have collaborated on scientific initiatives to increase technical understanding and literacy of human longevity and sustenance on multigenerational timescales. 

Challenges:

• Performing SETI or METI activities is a challenging task due to our limited indirect methods to traverse space, and one has no clear expectations of what one should find.
• SETI and METI practitioners are likely to be intercepted or received in specific parts of space or on specific worlds, requiring attention to language, content, and medium properties.

Way forward:

• SETI and METI practitioners have also had to consider interstellar aspirations, such as Elon Musk's aspiration to colonize Mars and a new space race to establish bases on the moon.
• These efforts demand scholars working as a global community to understand life, its existence, forms, and identification.
• They need to pay attention to the language and the content while also considering the properties of the medium of transmission.
• Efforts should be expanded to include radio signals, optical telescopes, laser light, and neutrinos. The ultimate goal is to understand the universe and its potential intelligence.