(ORDO NEWS) — Planets outside of our solar system are pretty boring things. So faint that we can only see them directly by sifting out a scattering of reflected rays among the highlights of their parent star. But even so, the best we can do is determine its position.
Gathering enough light to bring out the intricate details of these distant worlds would require a lens far superior to anything we can build. Wider than Earth. Wider than Jupiter.
Fortunately, cosmic scale lenses already exist. Because mass dimples the fabric of space, heavy objects like our Sun can serve as telescopes on a cosmic scale.
It’s not just a theory. The so-called gravitational lensing was first demonstrated over a century ago and has been used ever since to expand the boundaries of the universe that we can see.
But using the rotating mass of our own star to detect subtle changes in the coloration and surface pattern of exoplanets is another story.
In 2020, a physicist at the California Institute of Technology named Slava Turyshev proposed a method by which the scanning light that circles the planet can be transformed into some kind of image.
Achieving this goal will require a spacecraft capable of covering a huge area of space, which will limit the possibilities of materials, fuels and the speed of current technologies.
Building on Turyshev’s idea, two physicists at Stanford University in the US have proposed a new method of using the sun’s space-warping mass to focus faint exoplanet light into a meaningful image.
Although their method involves sending a space observatory the size of the Hubble into the frozen expanses of our solar system, the algorithm to weave light caught in a ring around the sun into a sharp image requires only one shot of light.
To test this idea, the researchers used data from meteorological satellites about the rotating Earth, modeling it as a smeared bluing of light known as Einstein’s ring. Their algorithm successfully deciphered the distorted image, recreating the clearly recognizable (albeit rather pixelated) world we call home.
Theoretically, this process could result in images of distant objects 1,000 times more accurate than anything we can hope for with today’s technology.
“We want to take pictures of planets orbiting other stars that are as good as pictures of planets in our solar system,” says physicist Bruce McIntosh.
With this technology, we hope to take a picture of a planet 100 light-years away that will have the same impact as the Apollo 8 picture of Earth.”
Since the discovery of the first exoplanet in the early 1990s, astronomers have found signs of more than 5,000 worlds orbiting stars in the Milky Way (and possibly beyond).
However, these signs are tantamount to hearing footsteps in the dark. We can guess how big the planet is and how fast it is moving. We can even find out some details about the composition of its atmosphere and temperature.
The rest is up to our imagination, inspired by the characteristics of the planets that make up our solar system.
However, resolving features of clouds, oceans, mineral deposits, and even chasms and mountains on exoplanets can tell us much more about general geological features throughout the universe – including the possibility of alien biology.
“When you take a picture of another planet, you can look at it and maybe see green patches that are forests and blue patches that are oceans — it’s hard to say that it doesn’t have life,” McIntosh says.
The biggest hurdle to using this particular method is the travel that such an observatory has to make.
Currently, the Voyager 1 probe is the most distant human-made object ever to travel into the cold darkness of the outer solar system. Launched in 1977, it has covered an astounding 23 billion kilometers (14.5 billion miles) since then. This is 156 times greater than the distance between the Earth and the Sun.
An exoplanet telescope using the Sun as its lens is four times the record distance and would take at least a century to travel if we use all of our current know-how.
Innovative solutions for deep space travel can certainly get us there faster. This means that perhaps the space telescope for exoplanet research could still get its day on the Sun.
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