When we look up into the night sky and lose ourselves in the dark mystery of endless space, our mind naturally begins to wander. For those lovers of all things astronomical, we know that there are hundreds of billions of stars in the Milky Way alone, not to mention hundreds of billions of other galaxies with just as many secrets and stars as ours!
Space truly seems like an infinite expanse that we’ll never fully understand, but that doesn’t stop us from trying. When we do look up at those stars overhead, our thoughts often drift to the idea of living on other worlds. There has been plenty of talk lately about colonizing Mars, or some of the moons orbiting other planets in our solar system, but is that the extent of our search?
We’ve been staring into the deep recesses of space for decades, but have we found any other planets that resemble our pale blue dot? More importantly, are we getting any closer to finding them?
What Have We Found So Far?
Although we haven’t found definite evidence of life out there, we actually have found plenty of planets. Planets outside of our solar system are known as exoplanets, and the first one was discovered back in 1988. Since then, we have identified hundreds of other exoplanets, ranging from icy worlds to steaming gas giants. Essentially, we have found that while Earth is in a “sweet spot” for life to exist, there are plenty of other planets circling other stars.
In 2014, for example, over 800 exoplanets were discovered, whereas no more than 200 had ever been found in a single year before. As we continue to increase our technological abilities and skills at spotting exoplanets in the vast reaches of space, these numbers will likely continue to rise. After all, we’ve only found a few thousand, out of hundreds of billions of stars.
We have a number of detection methods, including the transit method (spotting a change in light output from a star because a planet is passing in front of it), radial velocity (shifting in light output as a planet and star gravitationally interact and move each other), gravitational lensing (when a closer star magnifies the light from a more distant star behind it), and even the rare “direct imaging” approach.
With so many different ways of detecting exoplanets, we assume that it is only a matter of time before we find an Earth-like planet. In fact, we have already located some planets that are similar in size to Earth, and are located in the “habitable zone” of their star, meaning that it is not too far away that water would freeze, nor too close that it would evaporate. The most Earth-like exoplanet that we’ve discovered is called Kepler-452b, located roughly 1,400 light-years from Earth.
The Kepler Space Telescope has identified more than 1,000 exoplanets, but unfortunately, it can only provide limited amounts of information about the planets it spots. The good news is that humans tirelessly pursue better technology – and futuristic space telescopes are no exception!
The Next Generation of Space Telescopes
You might not believe this, but with the naked eye, human beings can only see about 10,000 stars – even in a completely dark cornfield far away from the nearest city! To see deeper into the darkness, and collect crucial data from those points of distant light, we need to use telescopes – powerful ones! While some of the massive telescope lenses on the surface of Earth can see deep into the distance of space, a telescope outside of our atmosphere can see even further.
Kepler has done an incredible job over the past 6 years, but even more exciting things are “on the horizon”. The Wide-Field Infrared Survey Telescope (WFIRST) project combines a space telescope and a starshade flying in tandem. A starshade is a device that can block a source of light to allow for observation of a fainter object. The telescope would also contain a coronograph, which will allow it to directly image exoplanets throughout the galaxy.
While this new project is still months (or even years) away, the possibility of directly observing these exoplanets would give us the necessary clues to determine if we’ve found “Earth 2.0”. Currently, we can only guess if an exoplanet is rocky or icy, particularly from such incredible distances. The WFIRST project represents a very exciting step towards finding a new home, if we ever need it!
The James Webb Space Telescope
For the past 20 years, specialists from 17 different countries have been working on the James Webb Space Telescope (JWST), which will be the next space telescope in an impressive tradition, which includes the legendary Hubble and Spitzer Space Telescopes. The JWST will feature a 21-foot diameter primary mirror, and will be able to provide observations and data about some of the greatest mysteries in our universe.
It will be able to see further into deep space than any telescope yet conceived, but it will also be able to directly image exoplanets thousands of light-years away. It will focus primarily on infrared light detection, unlike Hubble, which also observes visible and ultraviolet light. There is an $8 billion project cap on the JWST, and it is set to launch in 2018.
While we probably won’t be able to travel to any of these exoplanets anytime soon, due to the massive amount of time that it would take to make the journey, identifying exoplanets and possibly discovering life out in the universe is well worth the investment. Who knows…in the next few years, we may finally have an answer to the ultimate question…
Are We Alone in the Universe?
- Exoplanet – Wikipedia
- WFIRST Infrared Telescope – NASA
- 20 Intriguing Exoplanets – NASA
- James Webb Space Telescope (JWST) NASA