article-imageAn Agave americana “Century Plant” in post-bloom (photograph by David Fulmer)

People tend to throw the phrase “once in a lifetime” around pretty liberally, applying it to mattress sales, kisses, and blockbuster movies. However, there are events that are truly rare enough to occur once in a lifetime, depending of course on how long one lives, and when one happens to live. Some, like Halley’s Comet, occur predictably, while other rare phenomena happen without much warning at all.

Rare Bloomers

Separate from the its tequila-giving cousin, the Agave americana, or maguey, blooms so rarely that it’s been given the nickname “Century Plant.” In truth, the plant takes at least 10 years to bloom in warm climates, but in colder climates only blooms every 80 years or so, and can often create a whimsical news event when it does. It’s lately become a popular decorative plant, though those patio gardeners in the northern climates can expect to wait quite a few decades before they see its eight-foot stalks and bright yellow flowers.

Agave americana in bloom, Porto Covo, Portugal (photograph by Alvesgaspar/Wikimedia)

Puya raimondii, a cactus-like plant native to the Andes, blooms only every 80 to 150 years, and on top of that is one of the rarest plants in the world. Known as the Queen of the Andes, it only grows wild in elevations above 12,000 feet, and is notoriously difficult to cultivate outside its native habitat. But when it does, stalks rise up to 26 feet, and produce approximately 8,000 flowers. A cultivated Puya raimondii bloomed at the UC Berkeley Botanical Gardens in June of this year, and drew thousands of visitors.

article-imagePuya raimondii post-bloom (photograph by Dtarazona/Wikimedia)

Even more spectacularly rare is the Tahina spectabilis, or Tahina Palm. The endangered tree was only discovered in 2007, previously mistaken for more common species since it only distinguishes itself when it bursts forth with hundreds of flowers. And this only happens when the tree is between 30 to 100 years old. Furthermore, it grows in parts of Madagascar so remote no one had ever recorded them. When a man and his family happened upon the mysterious tree in bloom, he took a photograph and sent it off for identification. To his and everyone else’s shock, he had discovered a new species.

Tahina spectabilis (photograph by John Dransfield)

Normally, when one of these rare bloomers shows its colors, it’s a cause for celebration. Not so with Melocanna baccifera, which thrives in parts of India and Myanmar. A form of bamboo that flowers every 44 to 48 years, the thousands of seeds it produces attract black rats. Not just a few rats either; this once-in-a-lifetime event is so unpleasant, it carries the name Mautam (Bamboo Death) because of the thousands upon thousands of black rats who arrive to feast on the flowering bamboo, and devour local grain stores, leaving the place in famine. Worse, the seeds may even promote rat fertility.

Flowering bamboo means rodent trouble is coming (photograph by Joi Ito)

Whether it happens at 30, 10, or 100 years, all the plants here bloom once in their own lifetime. They all then die.

Astronomical Events

The most famous comet, Halley’s Comet, appears in the sky every 75 years, making it possible to see it twice in a lifetime if you live to an advanced age. Mark Twain famously said he “came in” with the comet in 1835, and planned to go out when it returned. He died one day after it reappeared in the sky in 1910.

When the comet came around again, in 1986, Earth had reached the space age. In addition to many parties and celebrations (which were great for telescope sales), this was the first time spacecraft could be sent to study and photograph the comet. When it returns in 2061, one expects technology will have advanced to unlock even more secrets.

Halley’s Comet on the Bayeux Tapestry (via Myrabella/Wikimedia)

Halley’s Comet in 1986 (photograph by NASA/W. Liller)

Meanwhile, back in the 1990s, humans were able to observe the spectacular Hale-Bopp comet’s visit to earth, which lasted a spectacular 19 months. Those who were lucky enough to see the comet, which was visible with the naked eye even in big, light polluted cities, experienced a true once-in-lifetime event that involved copious media stories, plenty of parties, and a UFO cult’s mass suicide. It won’t return to earth for another 2,392 years. Meanwhile, a comet know as Siding Spring is expected to get very close to Mars in October of this year. So close, it might, in a very unlikely scenario, collide with the Red Planet and create a spectacular Martian meteor shower that could be observed from Earth with binoculars.

Comet Hale-Bopp, viewed from Death Valley (photograph by Mkfairdpm/Wikimedia)

Eclipses are actually pretty common, when you factor in partial, annular, and lunar total eclipses, but the total solar eclipse remains rare. Whether or not a person can see one depends not only on time, but geography and even local weather. As of this writing, the last big (as in viewed by millions of people) total solar eclipse occurred in 2012 and was see to people in Asia. One visible in Europe and North American will happen in 2015. However, if want to observe a super long total solar eclipse lasting seven rather than five minutes, you’re out of luck, since that won’t happen again until 2150.

A sunset eclipse seen from Huntington Beach, California, in 2012 (photograph by jimnista/Flickr user)

One in a lifetime astronomical events aren’t limited to eclipses and comets. In 2012, a rare Venus transit occurred as the planet, appearing tiny, black and disc-like, passed across the sun. The next time sky gazers can catch a Venus transit is in 2117. Meanwhile, in September of 2040, there will be a rare alignment of the moon, Mercury, Venus, Mars, Jupiter, and Saturn. 

Wild Weather Events

There are certain weather events that occur so rarely, a person would be lucky to see them once in a lifetime. The innocuous-sounding non-aquatic rainfall is a terrifying staple of apocalyptic mythology. Simply put, it rains animals, usually fish or frogs. Sometimes the animals hit the ground while alive, other times they are frozen. According to eyewitnesses, it recently rained frogs in Hungary and fish in India and the Philippines, and spine chilling spiders in Brazil. The town of Yoro, Honduras, allegedly experiences fish rain yearly, in an event known as Lluvia de Pesces. Most theorize the animal rains are caused by waterspouts or tornados picking up and dropping the unfortunate creatures.

article-imageRain of snakes, as depicted in a Renaissance illustration (via NOAA Photo Library)


While most phenomena here are naturally occurring, humans create once-in-a-lifetime events, such as coronations. In 1953, millions turned out to see the 25-year-old Queen of Great Britain and the Commonwealth Countries be crowned. Elizabeth II’s coronation was the first to be televised and various celebrations were held across the commonwealth. And she remains on the throne, but many who were not yet born when she was crowned will likely see her son the Prince of Wales take the position, presumably with much pomp and circumstance.

article-imageEmperor Hirohito in a 1929 photograph (via Nationaal Archief)

In Japan, the current Emperor was enthroned in 1990 and is part of the longest continuing hereditary line of rulers in the work, unbroken since 660 BCE. Popes, while not hereditary monarchs, are still absolute rulers for life (most of the time anyway). Many young people had only known Pope John Paul II as the pontiff when he passed away in 2005. When Pope Benedict XVI was chosen to succeed him, it was shocking when he retired from the job in 2013. Seeing a pope chosen when the other was still living was truly once in a lifetime.