Ask Ethan: Would An Alien Civilization Classify Earth As An ‘Interesting’ Planet?
“I was thinking about the projection of light through space. My curtain was open and I saw the stars and something from a book popped into my head. It had said that the stars we see are basically reruns. The light is from so long ago, we don’t even know if the star still exists or not.
[…] Whatever signals we send out, or changes in our planet that might be observable to prove intelligent life lives here, would take billions of years to reach anything alive and capable of responding! What do you think?”
The cosmic distances separating the stars and galaxies are absolutely tremendous, and even though the speed of light is the fastest speed there is, it still takes an awfully long time to traverse the astronomical abyss of space. Humanity has only been a technologically advanced civilization for a few hundred years, and we’ve only entered the space age a few decades ago. Yet that doesn’t mean we’re off-limits to advanced aliens who might be looking for us at all. Even if they couldn’t discover our technosignatures, they could still tell, even from billions of light-years away, that Earth was an interesting, inhabited planet, using nothing more than more advanced versions of the technologies we’re using today and in the near-future to look for life on exoplanets in our cosmic backyard.
Happy 230th Birthday, Enceladus, Our Solar System’s Greatest Hope For Life Beyond Earth
“It is still a complete unknown whether Earth is the only world in the Solar System to house any form of life: past or present. Venus and Mars may have been Earth-like for a billion years or more, and life could have arisen there early on. Frozen worlds with subsurface oceans, like Enceladus, Europa, Triton or Pluto, are completely different from Earth’s present environment, but have the same raw ingredients that could potentially lead to life as well.
Are water, energy, and the right molecules all we need for life to arise? Finding even the most basic organisms (or even the precursor components of organisms) anyplace else in the Universe would lead to a scientific revolution. A single discovered cell in the geysers of Enceladus would be the most momentous discovery of the 21st century. With the recent demise of Cassini, on the 230th anniversary of Enceladus’ discovery, the possibility of finding the incredible compels us to go back. May we be bold enough to make it so.”
On this date in 1789, William Herschel, armed with the most powerful telescope known to humanity at the time (you can get a lot of grant money when you discover the planet Uranus and name it after the King), discovered a relatively small moon of Saturn just 500 kilometers across: Enceladus. For some 200 years, Enceladus was never seen as more than a single pixel across, until the Voyager probes flew by it. What they revealed was a remarkable, unique world in all the Solar System. Now that the Cassini mission is complete, we can look back at all we know about this world, and all the signs point to a remarkable story: there’s a subsurface ocean, possibly suitable as a home for undersea life.