The Universe: A place of infinite gases, solids, and liquids, surrounded by a vast majority of emptiness.
For every one cluster, there's billions of galaxies, and for every galaxy, there's billions of stars and planets.
It's hard to imagine how big the universe really is and no one fully understands what's out there. But with the advancements in technology, space experiments are becoming more and more efficient. Thanks to this, researchers and astronomers can now study and understand the universe better than ever before.
Over the course of several years with the use of the HARPS spectrograph (High Accuracy Radial Velocity Planet Searcher), thousands of Earth-like planets have been discovered at an unbelievable rate; faster than anyone's expectations. These planets are in the habitable zone of their solar systems, which means it's a possibility they can sustain life if the given conditions are right (Atmosphere, size, etc.). Although there is still much debate about the limits of how life can exist, in order for life to occur, liquid water is required. These planet discoveries are major breakthroughs, as humans need to grow and maybe eventually one day become a universal species. Without further ado, on the journey to find another 'Goldilocks planet' like ours, here are the top 10 Earth-like planets:
10 Planet Gliese 163c
All the way from the Dorado constellation 50 light-years away, fully circulating its star every 26 days, weighing in about seven times the size of Earth, introducing planet Gliese 163c! Researchers don't know whether this planet is rocky, all ocean, or just one big cloud of gas. It can be difficult to estimate the temperature of an alien planet because scientists don't know what these planets' atmospheres fully consist of.
A suggested theory stated that there may be a possibility the surface and the atmosphere of planet Gliese 163c are too hot and thick to sustain almost every type of life. If anything, scientists hope to find some sort of microbial life.
9 Planet Gliese 832c
Discovered in 2014, planet Gliese 832c was spotted by luck from a small shake in its parent star's motion. It's located 16 light-years away in the constellation of Grus, making it the second closest known exoplanet to ours.
There are two possible outcomes for this planet. The first possibility is that this planet could be a super-Earth, with a rich atmosphere like ours, stronger seasons but still able to hold life. Or, because of its massive size (5.4 times larger than Earth), this planet could be a super-Venus with the same chance as planet Gliese 163c (#10).
8 Planets Tau Ceti e & Tau Ceti f
In December 2012, five planets were found orbiting the Tau Ceti star, but only two of these planets (Tau Ceti e and f) were considered potentially habitable. Best part about it was that they're only 12 light-years away; right in our backyard!
But new studies this year have shown that astronomers can't seem to find any sort of life in the planets' atmospheres. Whether it's too early for detectable "biosignatures" or not, one thing is for certain; both planets are in the habitable zone of their star. Planets Tau Ceti e and Tau Ceti f are both larger than Earth. (Planet Tau Ceti e is 4.3 times larger while Tau Ceti f is 6.6 times larger.) The Tau Ceti star system has also become a very well-known place for science-fiction fans and writers alike, helping to create very imaginative ideas.
7 Planet Gliese 581g
This planet caused a bit of a controversy when it was first spotted. In 2010, the astronomer team from the UCO/Lick Observatory at the University of California claimed the planet existed. Meanwhile, the Geneva Observatory team astronomers from Switzerland carried out a few studies of their own and their results turned up empty-handed. After 2 years the issue was finally resolved when another paper published by the UCO Team defended their results, proving the planet was real.
Planet Gliese 581g's size is nearly three to four times bigger than Earth, and it's very close to us at a distance of only 20 light-years away! This isn't the only planet in its area, as there are another five potentially habitable planets in that same star system. Sounds like a great place for an intergalactic neighborhood.
6 Planet Gliese 667Cc
Planet Gliese 667Cc was discovered 22 light-years away in the constellation Scorpius; a star system that the astronomers have been studying for years. This planet is "tidally locked", meaning it always shows the same face while orbiting its sun. Tidal locking can be a problem because one hemisphere of the planet is stuck in darkness while the other half isn't, which can strongly influence the planet's global climate.
This planet is 80% larger than Earth and it fully orbits its star every 28 days. So your birthday comes around every 4 weeks. What more could you ask for?
5 Planet HD 85512 b
Located only 35 light-years away from Earth in the southern constellation of Vela, this habitable alien planet is one of the better exoplanets found outside our solar system. Although we do not have the capabilities of flying the speed of light (yet), the short distance between Earth and HD 8551 b had astronomers excited when first discovered.
This super-Earth planet is estimated to be about 3.6 times larger than Earth. It was found orbiting on the perfect edge of its star's habitable zone, which means water is a high possibility and life could also exist (if the given conditions are correct).
4 Planet Kepler 69c
When astronomers at NASA discovered planet Kepler 69c in 2013, it was considered to be the most "Earth-like" planet. It was the first habitable-zone super-Earth ever found, and it is about 50% larger than Earth. Located at a staggering 2,700 light-years away, this planet has a 242-day orbit and it circles around a star smaller but very similar to our sun.
This discovery was made public on January 2013, at the 221st American Astronomical Society meeting.
3 Planet Kepler 22b
An interesting fact, this planet was a very early and lucky discovery. As soon as the Kepler space telescope was ready for observations, in the mission's first three days, Kepler 22b was spotted while transiting.
Scientists and astronomers have estimated that the planet's temperatures are roughly the same as Earth. If the greenhouse effect is also similar, then the estimated surface temperature is about 20-22 degrees Celsius. With a 290-day orbit and a magnitude 2.4 times larger than Earth, the only real problem is the fact that it's 600 light-years away. Bummer...
2 Planet Kepler 62f
According to a modeling study, as long as there are enough clouds to warm the surface, there is a high possibility that planet Kepler 62f is completely covered in water. If you take a good look at our ocean, you can find millions of different life species, most of which we know nothing about. Even scientists are now saying that all life on Earth might have started from there!
A day on Kepler 62f could be very different as the gravity is more gentle. But it would be challenging to breathe in the mushy air, therefore needing special equipment. This alien world is almost the same size as Earth, about 1.4 times larger. Unfortunately, it's roughly 1,200 light-years away. So only the imagination can take you here...unless you have a secret Millennium Falcon hidden somewhere.
1 Planet Kepler 186f
Regarded as the first ever confirmed Earth-size planet found in another habitable zone, this groundbreaking discovery was a big step into finding planets the same size as ours. While every other planet on this list was at least 40% (or more) bigger than Earth, Kepler 186f is relatively the same size. Although scientists don't know what the temperature is like on this planet, there are many similar properties between this planet and Earth.
Scientists don't consider this planet as Earth's twin, but more like Earth's distant cousin. It fully orbits its star every 130 Earth-days, and because of the distance (Kepler 186f being on the outer edge of the habitable zone), the brightness of the star is much dimmer on the surface of the planet. Oh yeah, one more thing I forgot to mention..it is located 500 light-years away...