It is unlikely that any other device is capable of taking away the laurels of the "discoverer of the planets" from the Kepler space observatory. Since its launch more than 10 years ago, the giant space telescope has discovered more than 4,000 planets.
And although the creators of Kepler did not intend their brainchild to search for life in space directly, the observatory managed to find about fifty planets on which life could potentially originate. And we will tell you about the most likely candidates according to NASA and the University of Puerto Rico.
10. Wolf 1061 c
Opens a list of 10 potentially habitable "super-earth" planets. This is how scientists call the planets that are very similar to the Earth, only more. The radius of Wolf 1061 c is one and a half times that of the Earth, and the mass is 4.3 of the Earth's.
This planet is located at a distance of only 14 light years from Earth, and its density, diameter and temperature are the very things for the emergence of life. The organization METI International is so confident in the existence of life on the "super-earth" that every February, when this star system is visible through a telescope, carefully studies the sky in search of signs given by aliens.
9.GJ 273 b
The star system, which houses another potentially inhabited planet, was discovered about 80 years ago. However, the existence of the GJ 273 b became known much later - in 2013.
It is a big planet; its size is 2.5 times larger than that of the earth. It is located exactly in the habitable zone and is presumably built of hard rocks. And the red dwarf, around which it revolves, is distinguished by a quiet disposition and is not prone to violent outbreaks of radiation destroying all living things.
True, given the current state of science, it is impossible to know for sure whether there is life on GJ 273 b. But uncertainty did not stop the enthusiasts from launching a message into space addressed to this star system. Packaged in radio waves "parcel" includes mathematical formulas and excerpts from musical works.
8. Kepler-442 b
This planet is located in the constellation Lyra, 1200 light years distant from Earth. Scientists are 97% confident that Kepler-442 b is in the "habitable zone." It revolves around a red dwarf, a small and dim star.
The year on Kepler-442 b lasts 112 days, and the axis tilt angle is too small for the planet to have seasons similar to the Earth. The planet belongs to the category of "super-earth" - its mass is more than the Earth by about a third.
There is a high probability that the planet's surface is solid and composed of rock; it may even contain liquid water.
7. Proxima Cen b
Surprisingly, life can exist on the surface of one of the planets closest to us. Beta Proxima Centauri, which orbits a small red dwarf, is 4.2 light years away. However, despite such a small distance, little is known about her. It weighs a little more than the Earth, and makes a complete revolution around its star in just 11 days.
This proximity to the star has its drawbacks - most likely, the planet is always facing Proxima Centauri with only one side. So life, if it is there, exists on a narrow strip between eternal day and eternal night.Also, optimism is not added by violent radiation flares, which from time to time an aging, but still active star sometimes bombards the planet's surface.
6.GJ 667 C f
In sixth place in the list of planets that are theoretically habitable is the sixth planet of the smallest star in the Gliese system of three suns. She is perhaps one of the largest planets rating - from its mass you can "blind" three Earths!
And although GJ 667 C f receives 60% less starlight than Earth, it compensates for this by an increased influx of infrared rays. How favorable this is for the development of life is an open question.
5. Trappist-1 e
A lone red dwarf in the constellation of Aquarius turned out to be surprisingly generous to the planets. At the moment, scientists have discovered as many as 7 planets, which are strikingly similar in size to our Earth. And three of them are even potentially located in the "residential" zone!
By the way, these planets were discovered not by Kepler's telescope, but by his older brother, the Spitzer infrared telescope.
Scientists believe that on the planet E Trappist-1, the chances are very high that not only water, but even an entire ocean will appear. In general, this planet is strikingly similar to Earth: in mass, radius, density, gravity and surface temperature. And it is located not so far away - about 40 light years from Earth.
However, according to the latest research, the chances for the birth of life on Trappist-1 version E are too exaggerated. She is in a danger zone - there is too much carbon monoxide in the atmosphere for the existence of terrestrial life.
And other scientists, on the contrary, believe that the presence of traces of carbon monoxide in the atmosphere is an indicator of the presence of this very life. So you won't understand who to believe.
4. Trappist-1 d
It is a small planet whose mass barely reaches two-thirds of that of the earth. It is the smallest in the Trappist-1 planetary system, but despite its size, about 5% of its mass is unstable. This means that it can be the atmosphere, oceans and even ice caps. True, according to recent studies, the atmosphere of version D may be more similar to that of Venus - dense and very hot.
3.GJ 3323 b
GJ 3323 b is located in the constellation Eridanus, at a distance of 17.5 light years from Earth. It was discovered only two years ago, and very little is known about it, except that it is located in the habitable zone and is a "super-earth". Its mass is twice as large as our planet.
2. K2-72 e
This Earth-like rocky planet is located in the constellation Goldilocks. Like many other planets on this list, it orbits an unnamed, aging red star. This is not surprising, since most of the stars in our universe are red dwarfs; they are the most durable of all.
The star K2-72 e will shine for many years after our Sun goes out. Although the planet is located in the habitable zone, it is most likely that it always faces its star with only one side (like our Moon to Earth). Therefore, life on it, if it exists, developed on a small island between light and darkness.
1. Teegarden b
Probably the most habitable planet Teegarden b was discovered as recently as early 2019. Around the star Tigarden in the constellation Aries, two planets revolve at once, the conditions on which resemble those of the earth. And it is located just 12 light years from the Sun.
Like other terrestrial planets, on which life can potentially exist, it is in the "habitable zone" - not too far, not too close to its star. And it seems that of all 10 planets in our ranking, it is Teegarden b that is most similar to our Earth, both in mass and density and even possible surface temperature.
Only the violent and violent radiation flares emitted from time to time by red dwarfs inspire fear. Powerful streams of radioactive particles can destroy any life in its path.
How scientists determine if there can be life on the planet or not
Our knowledge of the Universe is limited by the experience accumulated by humanity in the process of evolution. So scientists, determining whether life is possible on a particular planet, are primarily guided by the well-known planet Earth.In their opinion, life is capable of originating on a planet if it meets the following criteria.
- Comfort zone.
A planet should not be very close or very far from its star. And, roughly speaking, it should not be very hot and not too cold. - Fulcrum.
The planet must have a solid surface. It is assumed that a giant gas soup like Jupiter or Uranus is a bad habitat for living things. - Size matters.
The planet must be large enough to form a hot core. It is the core that creates the magnetic field around the planet, which protects its surface from harmful solar radiation. - Dense layer of the atmosphere.
Its thickness should be just such as to protect fragile living organisms from both radiation and foreign objects, and also give them something to breathe. - Tiny residents.
It is worth adding that the possible life is likely to be microbial. Judging by the fact that the first microorganisms appeared on our planet about 4.25 billion years ago (and the planet itself arose about 4.54 billion years ago), the chances of populating the Universe with "living dust" are quite high. But whether it is capable of turning into something more is a completely different question.