Sep 25, 2026 · 16 min · 12 segments
A moon of Uranus may once have hidden an ocean more than one hundred miles deep. Astronomers have detected radio bursts coming directly from a planet sixty-three light-years away. And NASA is…
Our first story takes us all the way to Uranus, and specifically to one of its moons, Ariel.
Ariel is only about 1,160 kilometers across.
But scientists now think that beneath its frozen surface, it may once have contained an ocean more than 100 miles deep.
That is around 170 kilometers of water beneath the ice.
For comparison, the average depth of the Pacific Ocean here on Earth is only around 4 kilometers.
So this would not have been a puddle.
How can scientists possibly know that when nobody has drilled into Ariel? By looking at its surface, Ariel is covered in fractures, ridges and enormous valleys.
If Ariel once contained a deep ocean beneath its crust, that flexible interior could help explain the huge structures we see today.
And this is the first lesson of the week.
Sometimes the inside of a world reveals itself through scars on the outside.
Our first story takes us all the way to Uranus, and specifically to one of its moons, Ariel.
Ariel is only about 1,160 kilometers across.
But scientists now think that beneath its frozen surface, it may once have contained an ocean more than 100 miles deep.
That is around 170 kilometers of water beneath the ice.
For comparison, the average depth of the Pacific Ocean here on Earth is only around 4 kilometers.
So this would not have been a puddle.
How can scientists possibly know that when nobody has drilled into Ariel? By looking at its surface, Ariel is covered in fractures, ridges and enormous valleys.
If Ariel once contained a deep ocean beneath its crust, that flexible interior could help explain the huge structures we see today.
And this is the first lesson of the week.
Sometimes the inside of a world reveals itself through scars on the outside.
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