Remember growing up and learning about the nine planets in our solar system?
Yes, that included Pluto, which was discovered in 1930 but later downgraded in 2006 to a “dwarf planet” – then unofficially brought back into the full planetary fold by popular non-astronomer demand.
Nine planets circling the sun – our local star – to memorize for those pesky science tests.
The human race had no idea how many planets were actually in our solar system until Italian astronomer Galileo and his primitive telescope came along in 1610 to discover Venus, Jupiter and Saturn – and then Mercury in 1631.
Later came Uranus, Neptune and Mars -- and finally Pluto.
But with the advent of ever larger and more precise telescopes – including the brand-new James Webb Space Telescope launched a million miles into space in December – astronomers have dramatically increased the number of known planets out there in the cosmos.
Today, there are now more than 5,000 known planets (glad kids in school today don't have to memorize their names!). They’re called “exoplanets,” meaning they are spinning around outside of our tiny little solar-based community.
NASA says there are likely hundreds of billions of such exoplanets, with the first discovery dating back to 1992. Since then, NASA's Exoplanet Archive continuously updates its Exoplanet Encyclopedia – including detailed data on all known exoplanets.
"It's not just a number," said Jessie Christiansen, research scientist with the NASA Exoplanet Science Institute, of the ever-growing number of planets being discovered. "Each one of them is a new world, a brand-new planet. I get excited about every one because we don't know anything about them."
Not yet, but more resources are being devoted to researching and identifying exoplanets, with NASA expected to launch the Nancy Grace Roman Space Telescope in 2027 to make new exoplanet discoveries.
But will "life" be found on any of them?
"To my thinking, it is inevitable that we'll find some kind of life somewhere -- most likely of some primitive kind," said Alexander Wolszczan, astronomy and astrophysics professor at Pennsylvania State University.
What we DO know about the solar system is that only one planet – Earth – has Life existing in an identifiable way upon it. Some planets – like Mars – may have had living organisms in the distant past.
Pluto
But none show any sign of life as of now.
Most of these billions of exoplanets are likely either gaseous or rocky worlds too hot or too cold to sustain living creatures that we are familiar with.
But what we can now look forward to is the telescopic exploration of these exoplanets to see if ANY of them might be able to support Life.
Or are we truly alone in the universe?
Only Time will tell.
Comments