Aliens may contact Earth by 2029, according to a group of scientists at the University of California Los Angeles who have been studying a NASA probe traveling through space, currently 27 light years away. The researchers speculate that extraterrestrials might have intercepted a signal sent to the probe in 2002 and subsequently returned a signal expected to reach Earth by 2029.
In 2002, as part of a routine procedure to transmit data and establish communication, NASA sent a radio wave transmission to the Pioneer 12 probe. This signal also reached a star located approximately 27 light-years from Earth, as transmissions tend to spread out upon contacting an object.
The scientists are hopeful that this signal was intercepted by extraterrestrial lifeforms who have chosen to respond, meaning that humans will have alien contact.
“This is a famous idea from Carl Sagan, who used it as a plot theme in the movie Contact,” said study co-author Howard Isaacson, an astronomer at the University of California, Berkeley, when speaking to PopSci. The 1997 film Contact tells the story of a SETI scientist who discovers evidence of extraterrestrial life on a distant planet 26 light-years away and opts to make first contact using radio wave signals.
The team of researchers examined signals sent from Earth to the Voyager 1, Voyager 2, Pioneer 10, Pioneer 11, and New Horizons spacecraft. They created a map illustrating where the signals may have spread upon being released into the universe.
These spacecraft have been communicating with the Deep Station Network (DSN) radio antennas, downloading scientific and telemetry data. The DSN is NASA’s international network of massive radio antennas that support interplanetary spacecraft missions as well as a few Earth-orbiting satellites.
According to the study, published in the Publications of the Astronomical Society, the researchers found that transmissions sent to Voyager 2, Pioneer 10, and Pioneer 11 have already come into contact with at least one star.
Pioneer 10’s transmissions encountered a white dwarf star in 2002, and the team estimates that the earliest returned transmission, or alien contact, could arrive by 2029. By 2313, Pioneer 10’s transmissions will have encountered 222 stars, while signals sent to Voyager 1 and New Horizons are expected to make contact with their first stars in the near future.
The researchers calculated the data transmissions to stars by considering that light covers one parsec every 3.26 years. Using this measurement, they determined the time it would take for transmissions to reach each star, such as those sent to Voyager 1, which have not yet made contact with any stars.
“The earliest we can expect to receive a returned transmission from potential intelligent extraterrestrial life encountered by Voyager 1’s transmissions is 2109,” they wrote.
Voyager 2’s transmissions have made contact with two objects, both in 2007. By 2336, all 272 nearby stars will have been reached, and scientists anticipate a response from aliens by 2033. Signals sent to Pioneer reached a dwarf star in 2018, but researchers believe all 386 stars will have received a signal by 2317.
New Horizons’ transmissions have not yet encountered a star, but they are expected to contact one in 2119 and 139 stars by 2338. The earliest possible returned transmission is predicted for 2232.
“Transmissions to New Horizons will not encounter a star until 75 years after the transmissions of any other spacecraft,” the researchers explained.
Study lead author Reilly Derrick, an engineering student at UCLA, told PopSci that this research could help the Search for Extraterrestrial Intelligence (SETI) by providing a narrower group of stars for researchers to focus on. If aliens make contact, this would be an incredible moment in human history, to say the least.
The search for extraterrestrial life has been a significant part of space exploration for many decades. While there is no direct evidence of life beyond Earth, there are several signs that scientists look for when investigating the possibility of extraterrestrial life.
The presence of water, especially in liquid form, is a primary factor scientists consider when searching for signs of life. This is because water is essential for all known forms of life on Earth. For example, the discovery of water ice on Mars and the potential for liquid water beneath the surface of Jupiter’s moon Europa and Saturn’s moon Enceladus has excited astrobiologists.
Scientists also examine the composition of a planet’s atmosphere for signs of life. Certain gases, such as methane, oxygen, or nitrogen, may indicate the presence of biological activity if found in significant quantities.
These are any substances, phenomena or patterns that could have been created by life. For instance, certain complex organic molecules, like amino acids, or structures, like stromatolites (formed by microbial mats), could be considered biosignatures.
Also known as the “Goldilocks Zone,” this is the area around a star where conditions might be just right – not too hot, not too cold – for liquid water to exist on the surface of a planet. Planets within this zone are considered prime candidates for life.
The discovery of exoplanets, especially those in the habitable zone of their stars, is another potential sign of life. As of now, thousands of such planets have been discovered.
The Search for Extraterrestrial Intelligence (SETI) and Messaging Extraterrestrial Intelligence (METI) are initiatives that actively look for signals from intelligent life and attempt to send messages to possible civilizations, respectively. A confirmed extraterrestrial signal would be a clear sign of intelligent life.
It’s important to note that these signs are not definitive proof of life, but they indicate the conditions that could support life as we understand it. The search for extraterrestrial life continues to be a fascinating and complex field of research.