There currently isn't any evidence of life on other planets. (Representative pic)
The possibility of extraterrestrial life has always fascinated humans and we've been searching for alien life for some time now. However, despite decades of peering at and listening to planets around other stars, we still don't have a concrete answer to the question of whether we are alone in the universe. But the lack of evidence of life beyond our planet doesn't mean it doesn't exist. The more we learn about the Cosmos - from the planets and moons in our Solar System to the great expanse beyond - the more confident people have become that alien life must be out there. Now, here's what scientists say about the biggest questions people might have about what kind of life is most likely to actually be out there.
How likely is it that alien life exists?
There currently isn't any evidence of life on other planets, but the universe is a big place, and it seems unlikely that out of the trillions of planets that are presumed to exist in our 13.8 billion-year-old universe, only Earth has ever hosted life. Thus, the search for extraterrestrial life is a serious business.
The first efforts in the search for extraterrestrial life started well before humans had the capacity to get off our own planet. According to the BBC, early attempts to search for extraterrestrial intelligence, called Seti, began in the mid-20th Century, with astronomers looking in vain for radio signals on other planets.
In recent times, military pilots in the US have seen things that look otherworldly. The Pentagon has established an office to look into the sightings. US Congress has heard hearings. Moreover, UFOs were rebranded. Unidentified flying objects are now, per the US government edict, unidentified anomalous phenomena (UAPs).
Only a small fraction of our galaxy has been studied and the question of whether aliens exist is something scientists have been trying to understand, explore and figure out for a long time. All possibilities remain in play. Including the possibility that we are alone.
Where we might find aliens?
It is possible that there is alien life within our solar system. Over the years, everything we've learnt about Mars suggests that its formation and evolution are comparable to Earth and that the planet was once quite capable of hosting ecosystems. NASA believes that exploration of Mars could uncover evidence of life and answer one of the fundamental mysteries of the cosmos: Does life exist beyond Earth?
Moreover, according to the Planetary Society, the moons of Jupiter and Saturn also have the potential of hosting alien life, since many of them have liquid water under their icy crusts.
The growing field of exoplanet research is yielding new possibilities for life beyond our Solar System. We now know of more than 5,500 planets around other stars, known as exoplanets, and more continue to trickle in every day. With the immense power of new telescopes, most notably the James Webb Space Telescope (JWST), astronomers are now beginning to probe some of these planets in exquisite detail.
So, as we discover planets in other star systems, we can also look at the atmosphere for biosignatures, and maybe even listen for signs of alien life.
What are UFOs or UAPs?
Unidentified flying objects (UFOs), now more commonly known as unidentified aerial phenomena (UAPs), have captured people's imaginations for generations. They are catch-all terms to describe objects detected in the air, sea and space that defy easy explanations. Many believe that aliens are responsible for UFO and UAP sightings, but there is no concrete evidence to support it.
By definition, UFOs and UAPs are just things that aren't identifiable. There is a widespread belief that aliens regularly visit our planet. Hundreds of military and commercial pilots have reported UAP encounters. The Pentagon has released several videos in recent years showing some of the objects.
However, while many end up having innocent explanations, others remain shrouded in mystery and none of the investigations have turned up any evidence of alien visitors. But experts continue to collect improved data about the objects, in the hopes of gaining a better understanding of what they may be.
The search for alien life continues
Although there's no evidence yet that aliens are out there, scientists continue to look for them. With every mission to explore another world, every space telescope peering at a distant star system, and every radio telescope listening for signals from another civilization, experts are learning more about the Cosmos. The hunt is a long shot, but scientists are optimistic that new methods will reveal that we're not alone in the universe. But for now, the only life we know of is right here at home.