Here on the little space rock we call Earth , we humans often wonder whether or not we are alone in this universe. Although that question was not answered in 2020, many discoveries seemed to raise the possibility that extraterrestrial entities exist. Findings on the planet closest to us, in the outer solar system and beyond seemed to point to the possibility that other worlds could host organisms ranging from bacteria to technological beings. Perhaps next year’s new results will finally reveal who else might be out there.
Is ET calling us from Proxima Centauri?
The answer to strange signals happening in the universe is never aliens, until maybe it is. Earlier this month, researchers announced that they had captured a very mysterious beam of energy in the radio part of the electromagnetic spectrum at 980 megahertz, coming from the star closest to our own. Proxima Centauri, which is just 4.2 light-years away, is home to a gas giant and a rocky world 17% larger than Earth that lies in its star’s habitable zone, meaning liquid water could exist. over there. The unexplained signal reportedly shifted slightly while being observed, in a way that resembled the shift caused by the movement of a planet. The researchers are excited but cautious, explaining that they will need to find out whether more mundane sources, such as a comet, a hydrogen cloud, or even human technology, could be mimicking an extraterrestrial signal, and that it will likely be time before they know a way. or another if ET is calling us.
Alien bacteria could live in the clouds of Venus
Astrobiologists chirped with anticipation and skepticism in September when news emerged of possible evidence of life in the upper clouds of Venus. The announcement noted the presence of phosphine, a rare and often poisonous gas that, at least on Earth , is almost always associated with living organisms. With its hellish surface temperature, extravagant pressure, and sulfuric acid clouds, Venus has long played second fiddle to the seemingly more potentially habitable Mars.
But one team targeted Venus with the James Clerk Maxwell Telescope in Hawaii and the Atacama Large Millimetre/submillimetre Array in Chile and detected the phosphine signature in a Venusian cloud layer with temperatures and pressures downright similar to those on Earth. Terrestrial bacteria are known to thrive in some pretty harsh conditions, making the biological explanation not far-fetched. The research team doesn’t claim it’s irrefutable evidence of space errors, and many in the community aren’t entirely convinced , but it will at least mean more funding for the search for life in unlikely places .
Read more: Possible sign of life found in the clouds of Venus
‘Oumuamua could still be an alien artifact
Two years ago, scientists detected a cigar-shaped object hurtling through the solar system. Nicknamed ‘Oumuamua, the entity is considered by most to be an interstellar comet launched around another star. But close observations showed that ‘Oumuamua was accelerating, as if something was propelling it, and scientists still aren’t sure why. Avi Loeb, an astrophysicist at Harvard University, has proposed that, instead of a comet, the interstellar visitor could have been an extraterrestrial probe powered by a luminous sail: a wide piece of material a millimeter thick that accelerates as it is pushed by solar radiation. Other scientists have thrown cold water on Loeb’s idea, noting that hydrogen ice could have melted from the object in a manner similar to a rocket engine or other propulsion method. But in August, Loeb struck back, writing in a study that claimed that hydrogen ice heats up very easily, even in the cold depths of interstellar space, and should have sublimated before ‘Oumuamua reached our system. It seems like the debate could last at least a little longer.
A good number of Earthlings don’t care about the ambiguous evidence that scientists present to prove that there are extraterrestrials out there. They are convinced that we have been visited many times by technological beings, pointing out stories about UFOs and encounters with extraterrestrials (practically all of them denied). True believers got a boost in April when the US Navy released footage captured by pilots showing strange wingless aircraft traveling at hypersonic speed , looking all like strange alien machinery. Despite the existence of these types of videos, people should continue to be cautious, argued independent journalist Sarah Scoles in her book “ They Are Already Here: UFO Culture and Why We See Saucers ” (Pegasus Books, 2020). After deciding to investigate the Navy evidence, Scoles was unable to determine whether it actually showed extraterrestrial aircraft. But he found a much more human story by talking to leaders of contemporary UFO culture and discussing our basic need to believe in something beyond ourselves.
Read more: The Navy declassifies UFO videos
The Milky Way could be full of ocean worlds
Ocean worlds, which are classified as those that have significant amounts of water on or just below their surfaces, are surprisingly common in the solar system . Earth is obviously one of those places, but Jupiter’s moon Europa is believed to harbor vast seas beneath its icy shell and Saturn’s moon Enceladus is known to have water geysers gushing out of its exterior. In fact, momentum is building in the astronomical community to send a probe that could land on any of the satellites sometime in the 2030s and see if any living things could hide under their shells. As for ocean worlds beyond our sun, in a study published in June, researchers looked at 53 exoplanets similar in size to Earth and analyzed variables such as their size, density, orbit, surface temperature, mass and distance to them. his star. The scientists conclude that, of the 53, about a quarter could have the right conditions to be considered ocean worlds, suggesting that such places could be relatively common in the galaxy.
Read more: Ocean worlds could fill the Milky Way
Earth Insects Breathe Hydrogen, Maybe Aliens Do Too
Most Earthlings need oxygen to survive. But oxygen is not common in the cosmos and makes up about 0.1% of the ordinary mass of the universe. There is much more hydrogen (92%) and helium (7%), and many planets, including gas giants like Jupiter and Saturn, are made primarily of these light elements. In May, scientists took E. coli (a bacteria found in the intestines of many animals, including humans) and common yeast (a fungus used to bake bread and make beer) and tried to see if they could live in different environments. . It is already known that these microbes survive without oxygen and, when placed in a flask filled with pure hydrogen or pure helium , they manage to grow , although at a slower rate than usual. The findings suggest that when looking for organisms in other parts of the universe, we may want to consider places that don’t look exactly like Earth.
Read more: This bacteria can survive on pure hydrogen. Can extraterrestrial life do the same?
Life could live around a black hole 
When searching for life on other worlds, most scientists stick to what they know: looking for Earth-sized worlds orbiting stars similar to the Sun. But there could be much more exotic configurations, such as a planet circling and heated by a black hole . At first glance, such a scenario seems absurd. But contrary to popular representations, black holes do not simply absorb everything around them. Gravitationally stable orbits are possible and light from the cosmic background radiation (a relic with temperatures close to absolute zero of the early universe that permeates all of space) would be heated as it falls into the black hole. As a paper published in March showed, this could provide heat and energy to any organism that evolved in such a strange place.
Read more: Is life possible around a black hole?
1,000 places where ET could be watching us
As we search for beings beyond our planet, it is important to keep in mind that we may not be the only ones doing so. In October, researchers compiled a catalog of 1,004 nearby stars that would be in a good position to detect life on Earth . “If observers were looking [from planets orbiting these stars], they could see signs of a biosphere in the atmosphere of our Pale Blue Dot,” said the study’s lead author, Lisa Kaltenegger, an associate professor of astronomy at Cornell and director of the study. from the university’s Carl Sagan Institute, said in a statement . Using observation tools similar to the transit timing methods that human astronomers use to study exoplanets, these extraterrestrial observers could look for oxygen and water in our atmosphere and perhaps conclude that Earth is a good home for organisms.
Read more: Aliens in 1,000 nearby stars could see us, study suggests
Most of the aliens are probably dead.
Where there is life, there is also death. While we like to imagine that our galaxy is teeming with technological beings capable of contacting us, the flip side is recognizing that all cultures rise and fall, meaning that many cosmic societies probably bit the dust long ago. A model published in December put some numbers on these truths, taking into account aspects such as the prevalence of Sun-like stars that host Earth-like planets; the frequency of deadly supernovae that explode radiation; the time needed for intelligent life to evolve if conditions are right; and the possible tendency of tool-wielding beings to destroy themselves. The analysis found that the greatest likelihood of life emerging in the Milky Way probably occurred about 5.5 billion years ago , even before our planet formed, suggesting that humanity arrived relatively late to the galaxy and that many of our Potential partners from another world no longer exist. to talk to us.
Related: The Milky Way is probably full of dead civilizations
We must keep an open mind as we look for life elsewhere.
The human brain has many limitations. We are fooled by cognitive biases, optical illusions, and inattentional blindness to things we don’t expect to see. A question that has always dogged research into extraterrestrial creatures is whether or not we could recognize life that is so different from what we find here on Earth. Scholars have long urged us to expect the unexpected, trying not to let theory influence too much what we consider meaningful. Life on other planets may not leave the same biological signatures as terrestrial organisms, making them difficult to detect from our point of view. And, as Claire Webb, an anthropology and history of science student at the Massachusetts Institute of Technology, told LiveScience in January, we must train ourselves to “make the familiar strange,” looking at ourselves through a strange lens in a effort to constantly reexamine our own assumptions. That way, we could better understand ourselves through the eyes of others and perhaps meet creatures from other worlds on their own terms and not ours.
