Awaiting discovery

Way back in the 1960s—most likely 1964—my father brought home two slim softcover books for me, part of the Life Nature Library series. One was The Sea and the other, The Universe. Looking back now, those two books probably did more to shape my interests than anything else I read in childhood. At first, it was the colour pages that drew me in; pages of colour and information. For a boy growing up at No. 10 Seang Tek Road, where everything felt familiar and enclosed, these pages opened windows to unimaginable worlds—deep beneath the oceans and high into the stars. I still remember leafing through The Universe, wide-eyed, barely able to pronounce "nebula" or "quasar", but completely captivated all the same.

Once I began reading them properly, page by page, I realised what a treasure they held. The Universe in particular fascinated me. It gave names to things I could only dream of: galaxies, moons, planets and stars—some so far away their light had travelled millions of years to reach us. I dreamt of one day owning a telescope, of pointing it to the skies and tracing Saturn’s rings with my own eyes. And though I never did get that telescope, my fascination with the night sky never left me. The photos I take of the moon these days say as much, even if I don't always put it into words.

That childhood interest has stayed with me. Over the years, I've kept up with the big stories in space exploration. I followed Hubble’s incredible images, celebrated the James Webb’s first light, marvelled at China’s moon landings, the Mars rovers, Cassini probes and the two Voyager spacecraft billions of miles from us, Most recently, found myself once again pulled into the mystery of our own solar system—specifically, the search for the elusive Planet Nine. Does such a planet even exist?

It all started with Pluto. Discovered in 1930 by Clyde Tombaugh, Pluto reigned for decades as the ninth planet until it was quietly demoted to a “dwarf planet” in 2006. It didn’t make sense to call it a planet anymore, not when so many other icy worlds had been found nearby in what we now call the Kuiper Belt.

But then astronomers noticed something odd. Certain distant objects in the Kuiper Belt weren’t behaving as expected. Their orbits were strangely aligned—as though something massive, something unseen, was tugging at them. In 2016, Caltech astronomers Mike Brown and Konstantin Batygin proposed a new theory: perhaps there was a giant planet hiding far beyond Neptune. A real ninth planet. Not a Pluto-sized rock, but something 10 times the mass of Earth, orbiting so far out that it would take up to 20,000 years to complete just one trip around the sun.

They called it Planet Nine. And now, for the first time, we may have actually seen it.

A team of astronomers led by Terry Long Phan at National Tsing Hua University in Taiwan went digging through old infrared survey data—specifically from IRAS in 1983 and AKARI in 2006. They found something. A faint object that appeared in both sets of data, separated by 23 years, and had moved just enough to suggest it was orbiting our sun from an estimated distance of 700 AU. For reference, Neptune sits at 30 AU. This thing—if it is what they think—is more than 65 billion miles from the sun.

Most previous Planet Nine candidates vanished just as quickly as they were spotted. This one stands out because it appears in two different surveys, taken more than two decades apart. That consistency matters in astronomy.

Some experts remain cautious. Even Mike Brown, the same Brown who helped demote Pluto and proposed Planet Nine, says the object’s path might not quite match his model. But the new team is urging follow-up observations with large-field telescopes like the Dark Energy Camera in Chile or the upcoming Vera C. Rubin Observatory. If confirmed, this planet would not only be real, but possibly more massive than Neptune.

And the big question remains: how did it get there? Was it a fifth gas giant thrown out by Jupiter billions of years ago? Or a rogue planet, captured from another star system in the sun’s youth? Either way, it could change our understanding of how the solar system formed—and how common such distant giants might be in the rest of the galaxy.

So here I am, 60 years after those first books sparked my curiosity, still looking at the sky, still following the stories. Still waiting for someone to find the ninth planet. It might be out there. And we might be just days—or decades—away from finally confirming it.