A Telescope to Boggle Your Mind #astronomy #physics

Telescopes use mirrors and lenses. I have an 8 inch reflector with several eyepieces that I can pick up and carry outside. The focal length (the major determining factor of a telescope’s magnifying power) is roughly four feet.

Now, can you imagine a telescope with a focal length of 650 AU?

AU. That’s Astronautical Units – the distance from the Sun to Earth. It averages about 93 million miles. So 650 AU would put your eyepiece over 60 billion miles away. If you sent a message telling an eyepiece at the focal point to move a squinch farther out, it would take your instructions almost four days to reach the target.

This sounds like science fiction, but the concept is already a tool in astronomy: Gravitational lensing. This occurs because the Sun’s mass creates ripples and dents in the fabric of spacetime. Light has to follow along those lines, and that can create a magnifying effect. For example, the James Webb Space Telescope detects how light bends around massive galaxy clusters in space to reveal fainter, farther away galaxies behind them.

Wait, you say. The James Webb is a mere one million miles away. You’re right, but scientists are looking into the future.

In a new paper, Slava Turyshev computes all the detailed math needed to show that it is actually possible to harness our sun’s gravity in this way [to] help us beam light messages into the stars for interstellar communication or investigate the surfaces of distant exoplanets. Plans are underway at NASA’s Jet Propulsion Laboratory. Popular Science

A laser positioned at the sun’s gravitational focus could send messages to other stars! Way better than radio! Unfortunately, that pesky limit to the speed of light applies to the entire project. Using the effect for communications to distant worlds means a message sent to a star four light-years away would take four years to get there, and another four for the reply to reach us. Assuming anyone responds.

But exoplanets could be within our grasp.

Turyshev’s mission would be the next big step towards confirming life on other worlds, hopefully launching around 2035. [The] telescope will then actually map the surface of an exoplanet in detail. Turyshev claims it would be able to see a planet blown up to 700 by 700 pixels—a huge improvement on direct imaging’s current 2 or 3 pixels. “If there is a swamp on that exoplanet, emitting methane, we’ll know that’s what is positioned on this continent on this island, for example,” he explains. Popular Science

Hopeful launch dates seldom hold, but this is a breathtaking idea. I hope I live long enough to spy on alien worlds. Today, I can only imagine what exoplanets hold, and share my world with you. Click here for Chronicle of an Alien World.