Today, I am set to embark upon a rather solitary journey. Solitary, because it is all too likely that many readers, upon realising that the subject I wish to address is not one of widespread popularity, will choose to disembark prematurely, leaving this vessel to sail with but a scant number of passengers aboard. The topic at hand is space — that vast, enigmatic expanse that has fascinated humankind for centuries.
I have ventured into the realm of space several times before in this column. I recall a fervent reader once expressing his discontent, remarking that he did not care for “these issues about Mars.” His sentiment was, of course, clear to me. Many Malawians tend to immerse themselves wholeheartedly in politics, sport, and the like, to the near exclusion of other subjects, particularly the realms of science and technology. Ever since receiving that pointed critique, I endeavoured to behave more prudently, steering clear of space-themed discourse, lest I lose my readership.
Yet today, I must beseech the forgiveness of those with scant interest in the cosmos, for I shall once again indulge in the fascinating complexities of outer space, embracing all its grandeur and mystery.
In the late summer months of 1977, the National Aeronautics and Space Administration (NASA) of the United States launched a pair of remarkable sister spacecraft, Voyager 2 and Voyager 1, to explore the distant outer edges of our solar system and the beyond — the beguiling region known as interstellar space.
Voyager 1, arriving at the majestic planet Saturn in November 1980, conducted an intimate rendezvous, meticulously studying the planet’s splendid rings and gliding past its enigmatic moon, Titan. This encounter proved pivotal, altering Voyager 1’s trajectory from its original course and propelling it towards the very fringe of the solar system. On the 18th of December 2004, it crossed a remarkable boundary known as the termination shock — the invisible frontier where the solar wind’s stream of charged particles slows almost to a halt as it encounters the interstellar medium permeating outer space. This moment marked the probe’s entry into the heliosheath, a turbulent and chaotic outer sheath enveloping our solar system. Then, on the 25th of August 2012, it breached the heliopause, the final threshold where the Sun’s influence relinquishes its hold and the vast realm of interstellar space begins. In so doing, Voyager 1 etched its name in history as the very first artificial object forged by human hands to escape the confines of our solar system.
Voyager 2, launched a mere three weeks before its sister craft, ventured onwards to explore the distant domains of Uranus and Neptune, conducting invaluable in-situ observations before finally departing the solar system itself on the 5th of November 2018. To date, these two intrepid explorers remain the only spacecraft known to have ventured into interstellar space.
Currently, it takes approximately 23 hours and 9 minutes for a signal to traverse the void from Earth to Voyager 1. Consequently, a round-trip communication with mission control consumes some 46 hours and 18 minutes. On the 15th of November 2026, Voyager 1 is set to reach a remarkable milestone: the distance of one light day from Earth. To put this in perspective, it means that a signal transmitted from Earth will take a full day to reach this distant traveller.
Voyager 1 heads steadfastly in the direction of AC +79 3888, a star system situated some 17.6 light-years away. (A light year, for the uninitiated, is the distance light travels in a single year—approximately 9.4607 trillion kilometres.) In compliance with Newton’s First Law of Motion, taught in school but often regarded as abstract theoretical knowledge, the spacecraft continues its journey along an unwavering path, carried solely by its own momentum without propulsion, and will do so indefinitely unless perturbed by an unbalanced force. It would take nearly 300,000 years to reach this star.
Had the mission instead been aimed at Proxima Centauri, the star nearest to our Sun at a distance of 4.24 light-years, the journey would take approximately 73,000 years. These distances are colossal, as are the periods required to traverse them; travel on such scales defies easy comprehension. Consider the notion of intergenerational travel, where one generation departs Earth, only to perish before the destination is reached, and their far-removed descendants eventually arrive. If the Biblical patriarch Abraham had embarked on such a voyage some 4,000 years ago, his descendants would still be en route to Proxima Centauri today, with roughly 69,000 years yet remaining.
The vast cosmos invites us to wonder and to dream, even as it humbles us with its immensity. For now, the stars seem out of reach.