Extraterrestrial summary

Imagine you’re a detective. For your next assignment, you’re tasked with discovering all you can about a certain mysterious object. But there’s a catch. You can’t examine the object. Not only is there no clear picture to look at, but the item itself has left the solar system forever.

This is the challenge facing astronomers studying ‘Oumuamua. When scientists first spotted it, ‘Oumuamua was already speeding away. The scientific community had only 11 days to collect data about the ever-distant enigma. Even so, the collected data raised more questions than answers.

It’s 17 months before ‘Oumuamua graced our solar system, and astrophysicist Avi Loeb is hard at work on a goat farm in rural Israel. However, Loeb isn’t tending to the livestock. He’s putting the finishing touches to a bold proposal. 

It’s called the Starshot Initiative. This plan outlines a realistic way for humanity to send a probe to Alpha Centauri, a star system some four light-years away. The probe would be powered by a lightsail, a theoretical technology that harnesses the power of light just as a ship’s sail captures the wind here on Earth.

By now, it’s clear that ‘Oumuamua is an exceptionally strange object. Yet, if we consider ‘Oumuamua’s velocity-position, it becomes even stranger.

Every object in the galaxy is moving. An object’s velocity-position is its movement as compared to all other objects. Some velocity-positions are faster, others are slower, and amazingly, ‘Oumuamua’s was nearly exactly average. It occupied something called the local standard of rest, meaning that on a galactic scale, it was essential standing still.

Gaze up at the sky on a clear night. Above you, thousands of stars twinkle through the Earth’s atmosphere. Amazingly, this shimmering array is only a small fraction of our galaxy, which is home to billions of stars. Beyond that, other galaxies contain billions more.

The universe is expansive in size, but it’s deep in time, too. Recent estimates place it at more than 13 billion years old. Given these dimensions, it’s inconceivable that other life hasn’t arisen out there, somewhere, at some time. 

It’s three to four billion years ago. Here on Earth, a swirling stew of proteins and carbohydrates begin to mix and assemble into complex structures. Over time, these biomolecules develop metabolisms and start to replicate. Voilà, life! 

Now, when we search for extraterrestrial life, we take this familiar story as a starting point. We look for planets with similar conditions to Earth. That is, planets with similar size, temperature, or similar stars to orbit. It’s not a bad idea. After all, we understand life on Earth and can apply that knowledge to seek life elsewhere. 

OK, it’s finally happened. At last, humanity has detected definitive, unambiguous evidence of intelligent extraterrestrial life. Maybe it’s a radio communication picked up by SETI. Or, perhaps, it’s another interstellar object drifting through the solar system. Either way, it’s all over the news.

In this scenario, are we ready to respond appropriately? Maybe; maybe not.