The artist’s impression depicts the surface of the planet Proxima b as it orbits the red dwarf star Proxima Centauri, the closest star to our solar system. The binary star system Alpha Centauri AB is also visible in the upper right part of the image. ESO/M. Kornmesser
Over the last two decades, astronomers have made remarkable discoveries, locating hundreds of planets scattered throughout our galaxy. Among them is Kepler-452b, a planet bearing striking similarities to our own Earth in terms of size and location within its star’s habitable zone.
However, the vast majority of these distant planets lie beyond our reach, with Kepler-452b, for instance, requiring 1,400 years for light, the universe’s fastest entity, to traverse the distance. This inaccessibility makes today’s announcement from the European Southern Observatory and the Pale Red Dot project all the more exhilarating: Astronomers have detected a potentially habitable planet orbiting Proxima Centauri, our nearest stellar neighbor.
Proxima b, as it’s known, likely represents the closest exoplanet to Earth’s solar system that we’ll ever discover. What’s even more intriguing is that it resides within a potentially temperate region, making it suitable for liquid water and possibly life.
Described as a rocky world slightly more massive than Earth, Proxima b orbits its star, Proxima Centauri, at a mere eight times the distance between Mercury and the Sun. This close proximity keeps it warm within an otherwise frigid solar system.
Proxima b is approximately 1.3 times more massive than Earth, and it’s thought to be tidally locked, meaning it only exposes one side to its star’s light, similar to the moon’s relationship with Earth. A year on Proxima b lasts about 11.2 Earth days, and its surface would be bathed in red light from the star, potentially giving any plant life a crimson hue to maximize light absorption.
This discovery is the culmination of years of observations by scientists collaborating under the Pale Red Dot initiative, aimed at detecting the influence of a planet on the quality of light emitted by Proxima Centauri.
While Proxima b appears to be in a habitable zone in terms of distance and temperature, it may still face other challenges that could make life unsustainable. Its close orbit to the star exposes it to potentially deadly levels of radiation from ultraviolet and X-ray flares. Scientists suggest that life on Proxima b might have to exist underground or underwater, or develop means to shield itself from the intense radiation.
Regarding the possibility of human travel to Proxima b, it remains a daunting endeavor. At a distance of 4.2 light-years, it would take over 130,000 years to reach the planet with current technology. However, there’s a glimmer of hope in the form of the Breakthrough Starshot initiative proposed by Russian billionaire Yuri Milner and renowned physicist Stephen Hawking.
This initiative aims to send tiny spacecraft, capable of traveling at 20 percent of the speed of light, to nearby stars like Alpha Centauri and Proxima Centauri. While this concept is still in its early stages and faces numerous challenges, it offers the tantalizing prospect of human exploration of this distant world, showcasing the power of human ingenuity and imagination.