The Editorial team

782 views

0 likes

You will need to sign in before you can comment or like.        

Every one of our readers must have wondered how our alien brothers will look like. Apart from movie and comic illustrations, we will now explore the conditions feasible for earth like alien life to thrive as proposed by scientists.

The right object
On what you are searching for life matters most, one won't find alien wildlife on a red supergiant star or on Halley's Comet. Rocky planets and satellites (moons) are best.

The right parent
Imagine the condition of a planet between a binary star system in which a red giant and a white dwarf orbit each other, the white dwarf acting as a vacuum cleaner sucking material from the red giant by its enormous gravity. Sun like main sequence yellow dwarfs and red dwarfs are good parents.

Suitable neighborhood
The best planet location is said to be in the Habitable Zone. The Habitable Zone refers to intersection of the two locations of the planet, one planetary (such as within our Solar System), and the other galactic. The planet in this location is (scientifically) called the ‘Goldilocks planet’. The catch is that some planets have the possibility to sustain life in microenvironments. However gas giants such as Jupiter can also be in the goldilocks zone, which do not support life.

High Metallicity of parent star
Metallicity of an object in cosmology is basically the proportion of matter consisting of elements other than Hydrogen and Helium. Astronomers collectively used the term ‘metal’ to describe all the other elements. Thus a star with low metal would reduce the chance of planet formation around that particular star.

Less luminosity alteration in star
Although fluctuation luminosity is common to all stars, some stars termed as variable stars experience sudden and intense fluctuations lasting from minutes to years. Changes in luminosity would also be accompanied by high doses of Gamma and X-Ray radiation. Temperature fluctuations, as we know, are not suitable.

Mass
Objects with low mass, would have less gravity, and would not be able to retain the life supporting atmosphere. Smaller planets and satellites also tend to lose the energy left after their formation, becoming dead of the geological activity such as volcanic eruptions and tectonic shift which provide the surface with life sustaining biomass. This would also result in continent creation, improving biodiversity.

Bodyguard
A huge gas giant bodyguard neighbor like our Jupiter would be in fact, good for our candidate in many ways. They have circular orbits, far enough from the habitable zone, to stabilize the orbits and therefore the temperature of the inner terrestrial planets and protect the candidate from comets and meteors. The gas Giant's protector role was visualized in 1994 when Comet Shoemaker Levy 9 struck Jupiter. If not for its gravity . . . , oh . . . . . . just forget that.

Magnetosphere
The endogenic forces taking place in the molten magma beneath the earth crust work like an enormous heat engine, which keeps the magnetosphere active. The magnetic shield protects life from highly ionized charged alpha particles along with high amounts of Gamma and X ray radiation.


Less eccentricity in orbit
Eccentricity is basically the amount of orbit deviation from a perfect circle. The greater the eccentricity, greater will be the temperature fluctuations. Orbital eccentricity is the difference between the farthest and closest approaches of a planet's towards its parent star divided by the sum of the said distances.
Even with life's adaptive properties, the freezing and boiling points of the candidate's primary solvent mostly overlap. Our earth's orbit is almost circular with less than 0.02 eccentricity.

Tilt in Axis
We all know our planet is a bit tilted (23.5 degrees).The advantage of this is that it brings the dynamism and diversity our life holds. And with a significant tilt, the intensity of radiation will be focused only within the equatorial areas, the warmth wouldn't move poleward and the entire planet would be dominated by colder climates.

Biomass
If we are to find life similar to ours, then we expect it to be based on the same biochemistry as ours, Carbon, Hydrogen, Oxygen and Nitrogen being the most common. The elements in fact, comprise over 96% of Earth's all biomass. Biogenic compounds, such as amino acids (simple proteins) have been found in meteorites and interstellar mediums. Carbon is the main basis for earth life, which can bond itself to form complex structures, Hydrogen and Oxygen combine to form the solvent of earth life i.e. water. The energy released by oxidation of organic compounds and formation of strong covalent bonds between Carbon and Oxygen, is the fuel of all living creatures of earth.
It is widely argued that carbon and the other elements are not necessarily required as the building blocks of life. Sulphur, which comes just below carbon in the periodic table, is said to be a substitute for carbon, with ammonia being the solvent instead of water.

Time
Life, being an extremely sophisticated race, takes its time to develop. Humans, as we know them (read ‘ourselves’), came to this stage after a 3.5 billion years of development of life. We also picture the future after 10 or 20 years. Can we even think the rate of development of life?

Intelligent Life?
Till now we only discussed about simple life survival conditions. Let's now extend this idea further. Suppose we find a planet or satellite which is fulfilling all the requirements. So what will be our next step? After all, life and intelligent life are very distinct. If life on a planet has reached the stage of what would be some 2050 on earth? We would positively consider them to be more intelligent, right?
Other than time, a few factors if included would produce the most complex and intelligent species ever imagined by us.

Super Earths

A planet which would host such intelligent life would-
- Orbit a red dwarf star (which has greatest life among all other stars without any significant size or luminosity fluctuation) and be in between the arms of a galaxy quite far from the centre. (the safest galactic location)
- Be terrestrial, ranging in size from 2 to 5 times larger than our Earth.
Because it would have greater gravity (due to its size), leading to greater atmospheric retention and stronger magnetosphere.
- It would lack significant tilt and eccentricity.
- Life would have existed for more than 4.5 billion years.

Comments