One of our Solar System’s spectacular interlopers was on everybody’s tongues 20 years ago—Comet Hale-Bopp.
Yes, it was two decades ago that the world was abuzz with the hype and strange events surrounding appearance of this icy body just a couple miles in size as it spewed gas and cosmic debris into space as it rounded the Sun for its first only time.
Comet Hale-Bopp appearance in 1997 had a lot of fanfare as it was the first seen easily since the famous Halley’s Comet encounter in 1986.
That is for dwellers of our Northern Hemisphere of Earth. There have been several spectacular comets since Hale-Bopp, but all were only visible from the Southern Hemisphere and obscured in our daylight skies.
So it very likely if you’ve seen a comet with your naked eye, it was Hale-Bopp when it was closest to Earth 20 years ago.
Not that we haven’t had a bunch of hopefuls out of the fickle world of comets. It seem every other year or so astronomers predict a comet seen at the outskirts of our Solar System is headed for a spectacular loop around the Sun that will mesmerize humans on Earth.
Well, those predictions haven’t materialized. And it’s not the fault of astronomers. It’s the unpredictable personality of these chunks of ice and rock that are believed to be the leftovers of our creation around 5 billion years ago.
Comet Hale-Bopp came on the heels of another beautiful, naked eye comet the year before, Comet Hyakutake in 1996. This cosmic interloper had a long, thin tail, in contrast to the stubby appearance of brighter Hale-Bopp.
Comets are named after their discoverer, which was once a prestigious exercise in observing by a handful of amateur astronomers. But today’s modern telescope technology has many comets being discovered by automatically operated telescopes designed for that purpose, thus Pan-Stars, klj and other names of the observing system are used.
Comets are one of the greatest wonders of the night sky every seen by humans. Their appearance was seen an omen of great importance to ancient civilizations all over the world.
Taken from the Greek word for “hairy star,” a comet would create a lot of attention to peoples of antiquity, the astrologers predicting cataclysmic events or a change in kingly leadership.
Even in the 20th Century after science proved comets to be nothing more than icy rocks pulled into the Sun by gravity, there still exists a mind-set among extremists that comets have an effect on humans on Earth.
Remember the Heaven’s Gate sect and the suicide of jlj, members wanting a ride on Comet Hale-Bopp? Sadly led by a delusional, false prophet, these desperate followers took their lives by poison after preparing for the journey to Hale-Bopp, decked in purple and gold sweat suits and Nike shoeslkljk.
Yes, comets have a long history of affecting the mind of man. Today, in the 21st Century, we know some of the facts about comets, but they are still a large mystery.
NASA and the European Space Agency have now flown spacecraft to rendezvous, orbit and even land on comets.
The best mission so far has been the now defunct Rosetta, which caught up to Comet Churyumov-Gerasimenko and orbited it for a year before and after its closest encounter with the Sun. The Rosetta spacecraft even released a small lander that failed to grapple the surface and instead hopped for an hour in the extremely low surface gravity before landing in a crevasse.
What we learned up close is much what scientists expected: comets are like dirty snowballs with plenty of water and amino acids critical to the building blocks of life.
And they come from an immense reservoir of billions upon billions of comets that circle the Solar System in a halo called the Oort Cloud. Astronomers still have a lot to learn about this unseen area maybe 15 billion miles away. The Oort Cloud is believed to be a storehouse of what is presumed to be leftover matter that didn’t coalesce into planets, dwarf planets or moons.
The power of gravity is what propels everything in the Universe. And in the Sun’s system, the gentle tug from one of our four giant worlds—Jupiter, Saturn, Uranus and Neptune—can influence a comet’s orbit and send it inward.
This gravitational influence on the Oort Cloud might come from a passing star, or even one or more unseen worlds that some astronomers predict lurk way beyond dwarf planet Pluto, 4 billion miles away, in another region called the Kuiper Belt. This belt is inside the Oort Cloud and contains possibly thousands of super cold, worlds ranging from 10 to 1,000 miles wide.
The close-up images of Pluto astonished astronomers by showing a very active world with icy mountains floating on slushy, nitrogen seas. So the exact nature of Kuiper Belt objects remains an exciting mystery to be solved later.
What we understand today is something can dislodge a 1-10 mile wide comet that is 10 billion miles away and send it on a gravity path straight for the Sun. As it gets closer and heats up, solids become liquids and liquids become gas, just like water that that can be ice, liquid and steam.
The solar wind rips the material off the comet, forming two tails—one of gas and one of tiny bits of rocky debris. As the tails grow with proximity to the Sun, the comet body becomes a nucleus enveloped in a “coma” of out gassing debris. And if close enough to Earth, we see this comet coma and tail slowly move across our sky—a spectacular sight, indeed.
Most comets loop around the Sun in an orbit that will never bring them back as they rejoin the Oort Cloud for millions of years, like Comets Hale-Bopp and Hyakutake. And many become kamikaze comets that are simply devoured by the Sun. But a handful, called periodic comets, are in stable orbits around the Sun and make predictable return trips through our Solar System.
And none is more famous than Halley’s Comet, named after the British astronomer Sir Edmond Halley, who figured out the 76-year orbit of the cosmic interloper. This comet had been recorded for centuries in all kinds of ancient scientific and religious recordings. Once Halley figured out they were all the same object, he proved it mathematically. The great astronomers never lived to see the kjlj appearance that proved him correct, but he lives on as the most famous, Comet Halley.
After seeing Comet Hale-Bopp 20 years ago, are we overdue for a good comet gracing our dark nights? Of course I say yes! Anytime is a great time to see a comet. The problem is, we never know when a new one will appear, or just how to predict its brightness.
It’ll happen one day, again. But be forewarned—it’ll be spectacular!