Gravity Telescope Could Capture Clear Picture of Alien Worlds

Christmas Eve, 1968 - Apollo 8 astronaut Bill Anders takes a photo that soon changed humanity's view of the universe. It was a picture of the Earth. 

When you look at this photo, a crisp planet is visible, just above the lunar horizon like a turquoise sunrise. This picture of Anders was given the name "Earthrise". 

Ever since Anders photographed from a spacecraft orbiting the Moon, scientists have captured absolutely adorable photos of Saturn's rocky rings, Neptune's blue hue and even Jupiter's orange marble stripes. 

But these pictures could not explore the planets of our solar system much. 

Thousands more alien worlds exist apart from our solar system, but they remain hidden from us because they are located at a distance of many light-years from us. 

Our telescopes are still too far to capture their beauty. However, soon the focus may be on these obscure exoplanets. 

In The Astrophysical Journal Tuesday, a team of Stanford researchers outlined a futuristic telescope concept. 

That could theoretically photograph alien-potential exoplanets as clearly as Anders' iconic "Earthrise" photo. This is called a gravitational telescope.

Study co-author Bruce Mackintosh says that with the help of this technique, we hope to take a picture of a planet 100 light-years away, which will be similar in clarity to the Earthrise of Apollo 8.

Mackintosh is a professor of physics at Stanford University and also deputy director of the Kavli Institute for Particle Astrophysics and Cosmology. 

Researchers say that the gravity telescope will work with the help of gravitational lensing.

What is Gravitational Lensing?

Gravitational lensing refers to the fact that light emitted from stars or other space objects is distorted when passing through a supermassive, gravitationally dense cosmic body.
This is due to general relativity, a well-established theory of gravity first proposed by Albert Einstein in the early 1900s. 

As for gravitational lensing, all you need to know is that general relativity regards space and time as intertwined like giant pieces of moldable fabric. 

This fabric can bend and twist just like your clothes, and that's basically what happens when there's an object in it.

Galaxy clusters warp it like no other, black holes warp it a lot, the Earth deforms it only somewhat, the Moon deforms it less than Earth, and even We even give it a tiny little taunt. 

Everything distorts it, but the bigger the object, the more combat you get. 

Importantly for gravitational lensing, a sort of magnifying glass effect is created when light passes through one of these warps. 

Typically, astronomers use this effect around the most distorted regions - usually galaxy clusters - to "magnify" distant objects. 

Gravitational lensing gives them a better picture of what they are seeing. The gravitational telescope concept works with the same idea, but with a few changes.

Gravity Binocular Glasses

The first difference is that the researchers suggest using our Sun as the warp-source of the gravitational telescope, rather than the general galaxy cluster. 

Second, gravity binoculars require an additional step that is similar to a Sherlock Holmes-style deduction.

According to the research paper, the device will first capture the Sun-distorted exoplanet's light (the standard gravitational lensing stuff). 

But then, the telescope's so-called solar gravitational lens will use that light data to work backward and what the exoplanet actually looks like, will rebuild it.

To demonstrate how this would work, the researchers used images of existing Earth taken by the satellite Dscovr. 

This spacecraft sits between our planet and the Sun, so it is well suited for theoretical gravity telescope testing.

The team operated images of our planet through a computer model to see what Earth would look like through the Sun's gravitational lensing effects. 

Then, they developed and used an algorithm to "unbend" or unbend, the light, and begin the reconstruction process.

"By uncovering the light that is bent by the Sun, an image can be formed much more than an ordinary telescope" says Alexander Madurovich, A student at the Kavli Institute for Particle Astrophysics and Cosmology.

"The scientific potential remains an untapped mystery because it is opening up this new observational capability that does not yet exist," he said. 

Taking a super clear picture of any exoplanets would traditionally require a telescope that is four times as wide as Earth.

But using gravitational lensing, a Hubble-sized telescope will also be able to do this work easily.

Practical Challenges

For any of this to work, the gravitational telescope would need to be at least 14 times farther from the Sun than Pluto. 

Extreme patience will be needed with conventional and existing rocket technology, "with travel times of about 100 years" or advances in propulsion to achieve greater departure velocities, such as solar sails, write the study authors.

In other words, it will take almost a century to get the gravitational telescope to where we need it. 

Solar sails, in this way, could potentially reduce travel times to 20 or 40 years, but solar sails are far from routine use.
Still, the researchers say they are inspired by the dire consequences of one day taking spectacular exoplanet photos. 

For example, this could greatly benefit the quest to find evidence of extraterrestrial life.

"It's one of the final steps in finding out whether there is life on other planets," Mackintosh said. 

"By taking a picture of another planet, you can look at it and possibly see samples of green that are forests and blue spots that are oceans - with that, it would be hard to argue that it doesn't have life."
And, as far as my fellow amateur planetary fans, I think seeing a picture of an exoplanet will adjust our view of existence - the way Earthrise once did for humanity.
Even now, looking at Earthrise undoubtedly strikes a strange feeling in us; 

There is a sense of disbelief that we are traveling through the universe which is basically a huge, round ship. 

What will we feel when we catch a glimpse of all the other giant, round ships in the universe?