Life can be found in almost every corner of our planet Earth and one of the oldest and most tantalizing questions of science is whether a similar bounty of life exists elsewhere in the universe. Some believe we’re not alone, while others scorn the very idea, however, considering the vast size of the universe and the myriad stars it contains, the odds would seem for the answer being “yes.”
Today, scientists are more optimistic that extra-terrestrial life does exist and that more substantial proof than mere statistics can be found. This hope is buoyed by recent discoveries of worlds beyond our solar system and new revelations about the sturdiness of life here on Earth.
Scientists have discovered microbes, known as ‘extremophiles’ that have been found thriving in complete darkness, in arid deserts and miles below ground and are resilient to cold, heat, acidity, salt, and radiation that would normally kill humans. These extreme environments are thought to be the norm for other worlds, which give scientists hope that microbes could indeed survive elsewhere in the universe. Saturn’s moon Titan consists of deep lakes and meandering rivers, and the icy crust of its other moon Enceladus resembles the frigid depths of some of Earth’s polar oceans while Mars is as dry and dusty as any harsh desert.
“As we learn more about the diversity of life, particularly microbial life, we expand our definition of what life is and how life can exist in some very hostile (to humans) environments,” explains biologist Diana Northup of the University of New Mexico.
Brave New Worlds
Another heartening fact that there might be ‘life out there’ is the recent discovery of new planets outside our solar system. Since the first planet orbiting an ordinary star was discovered in 1995, more than 200 extrasolar planets, or “exoplanets,” have been revealed and there are now 20 times more planets outside our solar system than in it.
While the majority of these exoplanets are fast-spinning gas giants, known as “hot Jupiters,” that orbit extremely close to their stars and are therefore probably unsuitable for life, but some are very similar to Earth with liquid water. With the advent of new satellites and planet-finding techniques, scientists are able to probe it for life with spectral fingerprints that are carried by a planet’s reflected light.
“The discovery of life forms inhabiting the unexplored extremities of our own world, and eventually, the discovery of life on other planets, will bring into greater awareness the magnificence of a living universe,” says Margaret Turnbull, an astrobiologist at the Space Telescope Science Institute in Baltimore, Maryland.
Arguably, the discovery of a single-celled microbe on a distant planet or star would be enough to finally answer the age old question of “are we alone in the universe?” and change life as we know it forever.