# Kepler, Exoplanets and the Drake Equation

Is there an intelligent life in the universe? An old age question. Apparently, scientists have come up with several theories and equations that might help compute for the probability of alien life.

One of which is the Drake Equation that summarizes the factors and likelihood that there is active and communicative life outside Earth, particularly, in the Milky Way.

Developed in 1961 by Frank Drake, the equation allows astronomers to compute for the probability of alien planet existence by multiplying several factors. The Search for Extraterrestrial Intelligence (SETI) institute, explains Drake equation:

N = R* • fp • ne • fl • fi • fc • L

N = The number of civilizations in the Milky Way galaxy whose electromagnetic emissions are detectable.
R* =The rate of formation of stars suitable for the development of intelligent life.
fp = The fraction of those stars with planetary systems.
ne = The number of planets, per solar system, with an environment suitable for life.
fl = The fraction of suitable planets on which life actually appears.
fi = The fraction of life bearing planets on which intelligent life emerges.
fc = The fraction of civilizations that develop a technology that releases detectable signs of their existence into space.
L = The length of time such civilizations release detectable signals into space.

However, this formula is being criticized for not having a specific measurement as any number can be used for it. Hence, the error related to the derived value is very large that astronomers cannot derive firm conclusions.

Kepler’s Exoplanet Discoveries

Even if experts claim that the equation is widespread in spite of questions on the accuracy of the results, it is highly regarded for it triggers curiosity and focus on the factors that should be considered if we want to pursue search for extraterrestrial life.

Inciting more research, the first exoplanet, that is a planet outside our solar system, was discovered in 1995 called 51 Pegasi b.

While it is nearly difficult to estimate how many potential life forms are out there, astronomers theorize that there are about 1.6 planets per star. Considering the number, there could potentially be about 1.6 billion planets in the Milky Way alone.

The existence of potential planets can be observed or proven in two ways: first, the gravitational wobble they create as they orbit their stars and second, by the shadow they create as they do this — which can be picked up by the Kepler Space Telescope.

Since the discovery of 51 Pegasi b, hundreds of exoplanets have been found afterwards.

The Drake Equation in a Nutshell

So, what is the importance of Drake equation in this exploration? Since our technology is very limited, science needs to prove the possibility of exoplanet existence via equation with results that our technology can cover. This is why Drake equation focuses on communicative extraterrestrial life. This is an alien existence with technology that can be caught within our frequency.

Simply put, the Drake Equation is limited to seeking only exoplanet civilizations that can transmit radio signals. This equation also encapsulates the factors that might explain how these lives are created and how long they last in broadcasting frequencies.

The Fusion of Drake Equation and Kepler Discoveries

Nevertheless, the equation is outdated that it does not include the recent discoveries captured by Kepler. Thus, astronomers began modifying it.

Currently, scientists realized that planets are quite common in the galaxy. Around 140,000 had already been discovered and about 8 were newly found that is of the size of the Earth. And the Kepler is only looking at a minuscule portion of the universe.

What is more interesting is that these 8 planets orbit in an area where temperature allows the harboring of liquid water that is essential in harnessing life. But scientists are still convinced that only about 1% among what we have uncovered could be habitable.

These discoveries make some of the factors in the Drake equation very useful in the roadmap to finding more life-nurturing planets aside from Earth. It is also a great instrument in plotting more studies on space exploration.

However, the Drake Equation could only harbor limited results: it can help give an estimate to the number of exoplanets in the galaxy, but it cannot give deep scientific explanation as to how alien civilizations might be formed and how long they possibly exist.