How aliens would see us if they looked through a telescope

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Mar 26, 2021, 12:00 AM EDT (Updated)

We’re always wondering what aliens and their distant planets look like as we peer through our telescopes from Earth, but what about the (hypothetical) aliens?

Astronomers have recently observed over 2,500 previously undiscovered exoplanets by catching them in transit of their stars, according to NBC Mach, but the question remains whether (again, hypothetical) alien scientists are eyeing us just like that from millions if not billions of light-years away.

This has been swirling through the mind of math and physics doctoral student Robert Wells for years. After obsessing over astronomical catalogs, Wells, who studies at Queen’s University in Ireland, identified nine exoplanets from which aliens would have a proverbial front-row seat to view our planet passing in front of the sun. Except these planets are gargantuan gas monsters hot enough to incinerate anything alive.  

But wait. What if they can see us, but we can’t see them?

An exoplanet and its star have to be aligned with Earth and the sun if our telescopes want any chance of observing them. That wasn’t enough for Wells, who was insistent that there had to be more than just great balls of fire out there. Whatever other planets from which Earth is visible may have optimal alignment for extraterrestrials to see us, our own planet being positioned at the wrong angle could leave us in the dark about their very existence.  

Venus in transit.

Then you have to think that if there are actually intelligent life forms out there, they could be mind-blowingly more technologically advanced than us. They could have built instruments and spacecraft that defy this obstacle somehow while we’re still in the comparative Dark Ages. Or way ahead. It’s just as possible that aliens have no idea what a telescope even is as it is that they’ve already built one so superpowered that it hasn’t even been dreamed up in a sci-fi novel yet.

If you’re thinking SETI is all over this, you’re right.

“If the aliens have really huge optical telescopes, it’s conceivable they might see structures such as the highway systems or cities,” SETI’s Seth Shostak, who has always believed the truth is out there, told Mach.

Aliens may not even need to depend on watching for transits to detect new planets. They may be able to figure out this is a planet with a technological civilization from industrial chemicals or radio broadcasts or artificial lights, and alien brains may have conceived other methods of detecting these signs other than a telescope. Meanwhile, back on Earth, we’re still trying to figure out a viable way to zero in on exoplanets without waiting for transists. Enter HabEx.

The Habitable Exoplanet Imaging Mission, aka HabEx, is the proposed next level after Hubble. Astronomers concepting this telescope are thinking in terms of a 32-foot mirror and unprecedented technology that can detect exoplanets by just their glow in the darkness of space and even zoom in to search for signs of biosignatures, and yes, aliens.

We may just find them—if they actually want to be found. 

(via NBC Mach)