Wright DJ et al. Three planets orbiting Wolf 1061. Astrophysical Journal Letters, December 2015.

Astronomers from Australia have discovered the closest potentially habitable planet outside our solar system. They named it Wolf 1061c. It is four times the mass of Earth and only 14 light years away (126 trillion kilometers). The closest exoplanet discovered so far was Gliese 667c, which is 22 light years from earth. Wolf 1061c is located in the constellation Ophiucus and is one of three planets that orbit around a red dwarf star, Wolf 1061. Scientists find this discovery particularly exciting, because all three planets have low enough mass to have potentially solid rocky surfaces, unlike gaseous planets, such as Neptune. The one orbiting closest to Wolf 1061 would be too hot and the furthest one would be too cold. But the one in the middle, Wolf 1061c, is potentially optimum for generating temperatures just right for the formation of liquid water and, ultimately, life. Red dwarfs are known to be very active with X-ray bursts and super flares, which doom the possibility of any life. However, Wolf 1061 seems to be a quiet star, and very similar to our sun. The next challenge for scientists is to develop a method to study the atmosphere of Wolf 1061c to conclusively say whether it is conducive to life.

Most cancers are found to be avoidable

Wu S. et al. Substantial contribution of extrinsic risk factors to cancer development. Nature, December 2015.

It has been long recognized that cancer is caused by a mix of factors, including genes, lifestyle, and environment. However, the relative contributions of each factors have never been settled. A recent study found that the risk of developing most cancers is more correlated to lifestyle and environmental factors than genes and DNA mutations. The biggest risk factors are diet, sun exposure, UV radiation, tobacco, alcohol, the human papilloma virus, and hepatitis B and C. They make up between 70% and 90% of several types of cancer, including lung, colorectal, skin, and cervical. Researchers particularly focused on people who move from a low-risk cancer area to a high-risk cancer area, and found that migrated people soon developed diseases at significant rates consistent with new risky environments. They also analyzed a comprehensive set of specific mutations associated with certain cancers. Ultraviolet light, for example, creates a signature of mutations in DNA. When cross-compared, spontaneous mutations during cell division rarely reaches the frequencies of producing cancer mutations, even in tissues with high rates of cell division. In almost all cases, the research team found that some exposure to environmental factors would be needed to trigger the disease. So if you smoke or are overweight or tan for hours under the sun, you dramatically increase your odds getting cancer. You can do a lot to reduce your cancer risk; you can’t just blame “bad genes” for getting sick.

Mutant mosquitos to stop malaria

Gantz VM et al. Highly efficient Cas9-mediated gene drive for population modification of the malaria vector mosquito Anopheles stephensi. PNAS, December 2015.

The tiny mosquito is one of the deadliest weapons in human history. Malaria is thought to be the oldest and deadliest disease. Despite intense efforts at treatment and eradication, it still is a reason for the death of approximately half a million people per year. So researchers have changed their tactics and tried to treat mosquitos instead of humans. Researchers used the revolutionary gene-editing technique CRISPR-Cas9 and generated a new breed of malaria with two genetic modifications. The first modified gene released antibodies against the malarial parasite and rendered its host immune to the parasite. The second modified gene, called “the gene drive,” would copy and paste the malaria-resistant genes into another mosquito, when mated. This two-gene system has the potential to spread malaria resistance across a wild population in just 10 generations – in other words, a single summer. Experts think that further research is needed before conducting a field trial. One potential problem would be to create a “hole” in the eco-system by changing the balance of malaria-carrying mosquito species. However, since the approach does not kill mosquitos rather make them resistant to the parasites, only a small amount of ecological damages are expected.

A planet that revolves around another star outside our solar system is called an Exoplanet or Extra solar planet. Ongoing studies involving this field are carried out via simultaneous ground and space based missions and observations. Scientists are searching a small portion of the Milky Way galaxy, approximately 3000 light years away, by using ground and space telescopes, along with various other astronomic methods (1). Despite all this technology, the observation area is too big when compared to the size of the object of interest.

It has been calculated that the Milky Way, a disc shaped galaxy, consists of 200 billion stars spread over a diameter of nearly 100,000 light years and a thickness of 1000 light years. When we consider the amount of stars in a single galaxy, and the fact that there are between a hundred billion and one trillion galaxies in the universe, the number of possible exoplanets is likely much larger than those we currently know of.

Classification of exoplanets

Exoplanets are classified according to their physical, chemical, and other characteristics, along with their diameter and mass: Jupiter like; greater than Jupiter; Earth like; greater than Earth

Classifications according to surface and atmospheric temperatures are as follows: Hotter than Jupiter; colder than Neptune; colder than Jupiter; small blue dots or twin Earths.

The presences of free-floating planets which have lost their parent stars because of different formation processes or other factors have also been discovered.

One of the common features of the exoplanets currently discovered is their short distance to the star they revolve around, which is usually less than half the distance between the Earth and the Sun. The known exoplanets are also defined by their faster revolutions in much shorter periods. Therefore, larger planets that are closer to their stars can be observed easily. When these planets are passing in front of their stars, a decrease in the brightness of the star is detected via spectrometers (Figure 1).

Figure 1. Passing of a planet in front of a star and a spectrum of this event.

Radial velocity, one of the methods used to discover exoplanets, relies on the observations of a star’s kinetic fluctuations. The proximity and size of a revolving planet leads to slight changes in location and velocity of a host star. As a result of this, the star gets closer to earth and then becomes more distant, which is observed as the Doppler shift of spectral line color waves. 75 % of all known planets have been discovered using this method (Figure 2).

Figure 2. Doppler shift – radial velocity

Earth-like planets or habitable places

In an official NASA report in December 2011, the discovery of an Earth-like planet was announced for the first time. This planet, named Kepler 22b, is 600 light years away and remains the most similar one to Earth among the known heavenly bodies. The distance of Kepler 22b to its star shows a high possibility for the presence of a habitable zone.

So what does this mean?

Earth is such a special home for us humans that everything here has been assigned to serve us with delicate calculations. Factors such as the Earth’s mass, gravity, distance to the Sun, rotational and revolution velocity, chemistry, thickness of the atmosphere, magnetic shield, hydrosphere/land ratio, ecological balances, and average temperature are all perfect for biological life.

Earth revolves in such a region and position that a majority of the planetary water is in a liquid state and is not ice or vapor.Thedistance of the habitable zone to our Sun is between 135,000,000 – 225,000,000 km. Earth revolves at a 150,000,000 km distance to the Sun. The value of a habitable zone for each planet depends on the diameter, mass, heat and radiation strength of the host star. In other words, aside from the similarity of an exoplanet to Earth, a classification of its host star with in terms of size and age is also important.

Kepler 22b owns the title as the first planet to match the criteria above with its following features:

• Has a radius 2.4 times bigger than Earth
• Revolution time is 290 days (365 for Earth)
• 15% closer to its star compared to the Earth-Sun distance
• The size and surface temperature of Kepler 22b’s host star is very similar to that of the Sun’s
• The surface temperature of the planet is 22 C
• The size of the habitable zone for Kepler 22bis 133,500,000 – 240,000,000 km (Figure 3).

Figure 3. Comparison of the solar systems of Kepler 22b and Earth.

Aside from these similarities, it is noteworthy to report the problems that scientists encountered regarding Kepler 22b:

• The unknown presence of water on the surface
• No information on the gaseous contents of the atmosphere.
• The gravitational force is 2.5 times greater than on Earth.
• Rocks constitute the surface instead of soil.

The hardest part is that Kepler 22bremains 600 light years away from us. This means it would take us 11 billions years to get there with today’s fastest spacecrafts. Who knows when we will be able to decrease this time with the advent of superior technology.

What do religious scholar say about life in outer space?

Among His manifest signs is the creation of the heavens and the earth, and that He has dispersed in both of them living creatures. And He has full power to gather them together when He wills. (Ash-Shura 42:29)

While interpreting the Qur’anic verse above, Fethullah Gülen notes the following:

“Since the earliest times, this verse has been taken as a proof for the view that there are living creatures, whether resembling human beings or not, in the places other than the earth. This view may be true. The second part of the verse, ‘He has full power to gather them together when He wills,’ has been understood that these creatures and human beings will possibly come together either in this world or in that of the other creatures. … there may be earth-like globes in the heaven where creatures resembling earthly ones live.” (Gülen 2012, 272-273)

“Perhaps people will not be able to reach those places individually or as a whole generation, but this can be achieved by mankind as a species. In other words, when the Divine Will manifests itself in that direction, humans here can encounter those other life forms.” (Gülen 2007, 232)

This commentary reflects what Bediuzzaman Said Nursi had said decades ago:

“The earth, although much smaller than other heavenly bodies, is so densely inhabited by living creatures that even its grossest and most rotten parts are full of living things, such as micro-organisms. This shows that those infinite firmaments, with their numerous stars and constellations, are inhabited by conscious, living beings …” (Nursi 2010, 530-531) 29th Word, First Aim, First Fundamental)

Nebiyev is a professor of physics in Azerbaijan.

References

• http://kepler.nasa.gov/
• http://planetquest.jpl.nasa.gov/
• http://en.wikipedia.org/wiki/Habitable_zone
• Gülen, M. Fethullah. 2007. Kendi iklimimiz, Istanbul, Nil Yayinlari.
• Gülen. M. Fethullah. 2012. Reflections on the Qur’an: Commentaries on Selected Verses, NJ: Tughra Books.
• Nursi, Bediuzzaman Said. 2010. The Words, (29th Word) NJ: The Light, Inc.
• Chris Kitchin Exoplanets: Finding, Exploring, and Understanding Alien Worlds- (www.springer.com/series/6960)-2012
• Mercy, G., P. Butler et al. 2005. “Observed Properties of Exoplanets: Masses, Orbits, and Metallicitie”.. Progress of Theoretical Physics Supplement, Vol. 158, No. 24-42.