Several centuries ago, scientists began to consider the astonishing thought that Earth was not the center of the universe and that the stars in the night sky may be suns orbited by their own worlds.
That hypothesis existed until the 1990s. By then, telescopes could see a star approximately 50 light-years away wobbling, indicating a small world was pushing on it. It was an exoplanet.
Astronomers have found more than 5,300 exoplanets and are examining their atmospheres to see whether their clouds may support life.
They even found an exoplanet engulfed by its fading star. Telescopes are great now. The fact that the cosmos is packed of exoplanets is now well known, even if most people can’t name one.
Planets, asteroids, auroras, and more cosmic wonders exist outside our solar system.
Exo- goes beyond planets. Astronomers have detected exoauroras, exoasteroid belts, and exorings like Saturn’s. Astronomers think exomoons outnumber exoplanets. Recently, the quest for such celestial objects and structures has increased. Astronomers discovered an exoradiation belt, a magnetic field-held cocoon of charged particles, this week. Exothings rule today.
Exothings provide scientific promise and comfort. Earth is a little island amid a vast ocean. We’re cosmically alone. It’s pleasant to stare out across that dark, mysterious sea and occasionally see other islands and familiar coastlines.
“Oh, you’ve got one of those too?” is how exothing research communicates with the universe. Exothings may answer our most existential question: Are we alone?
UC Santa Cruz astronomer Melodie Kao looked for exothings 20 light-years away on a brown dwarf, a strange object with a mass between stars and planets. Kao earlier researched this brown dwarf and discovered that its powerful radio emissions created auroras like our northern lights.
She found inspiration in our solar system, where planets with auroras have radiation bands. No one had located one outside the solar system. When Kao searched around her brown dwarf, she found a radiation belt, undetectable to the naked eye but billowing in radio frequencies.
Infrared exoasteroid belts are spectacular. The James Webb Space Telescope saw a 25-light-year-away star with an asteroid belt. Three material rings astonished them. Planetary motions in the concentric rings likely shaped the dusty area.
Exoradiation band “almost 10 million times more intense” than Earth’s
“It’s sort of comforting that the same processes likely play out, to some extent, very similarly,” said University of Arizona astronomer Andras Gaspar, who led the observations. “Maybe we’re not the only ones deciphering how our universe works,” he said.
Although the cosmos repeats, each iteration has its own idiosyncrasies. Kao stated his exoradiation belt is “almost 10 million times more intense” than Earth’s. Our main asteroid belt between Mars and Jupiter and the Kuiper Belt beyond Neptune, an area of frozen particles and dust, are simpler than the exoasteroid belt. The only known exorings are 200 times bigger than Saturn’s—possibly because it orbits a young sunlike star rather than a planet.
Astronomers would wager the cosmos that some exothings exist, but they have eluded them. Exomoons: Our solar system has many moons, thus others must too. They’re unproven. In 2018, two astronomers discovered the first exomoon circling a planet near a star 8,000 light-years away. Other teams analyzing the same data had varied results. Searching continues.
It continues for that most elusive exothing: a lovely, stony Earthlike planet with a chemically rich atmosphere and temperatures that would allow water to lap on the surface. Caltech astronomy professor Mansi Kasliwal, who discovered the sad exoplanet devoured by its star, told me she often wonders about exohomes.
Not another planet where humans might live (though she hopes future generations will try before our sun kills our globe in a few billion years), but another speck where life emerged and thrived. “It doesn’t even have to be Earth-like,” she remarked. It merely has to be livable and welcoming.
Our exothing collection grows every year. Jackie Villadsen, a Bucknell University physics and astronomy professor who collaborated with Kao, says she had exoplanet envy until recently. Exoradiation belts are possible now. Radiation belts appear dull compared to exoplanets with lava seas and glass rains.
However, exothings encourage daydreaming. Gaspar’s exoasteroid belt. Its central star is 440 million years old, significantly younger than our 4.6-billion-year-old sun. Earth was dead when our sun was that old. Gaspar stated, “It’s very doubtful that any life could have emerged, let alone sophisticated, intelligent life forms.
However, a cosmic spark may occur. A group of humans on a planet in that system may send tiny robots to adjacent planets and moons. They’ll leave footprints from their comfy atmosphere to their asteroid belt and beyond. It occurred here.