These experts publish their research results in the journal Astrobiology, and they propose two different indices, namely the Earth Similarity Index (ESI) and Habitabilitas Planet Index (PHI).
"The first question is whether Earth-like conditions can be found on other worlds. Because, we know empirically, the Earth could hold life, "said lead author Dr Dirk Schulze-Makuch of Washington State University, United States (U.S.).
The second question, whether the conditions in the exoplanet suggests the possibility of other life forms known whether human or not, he added.
As the name suggests, ESI planets and moons rank based on how similar they are to the Earth and to consider factors such as the size, density and distance from the parent star.
PHI looks at a series of different factors, including whether the world has a rocky or frozen surface, whether it has the atmosphere or magnetic field. The system also considers the energy available for each organism.
Whether through starlight parent or through a process called tidal flexing in which gravitational interactions with another object can heat a planet or moon internally.
Finally, PHI will take into account the levels of chemicals such as organic compounds on the planet, and whether liquid solvents available on the planet for important chemical reactions.
The maximum value for the Earth Similarity Index was 1.00 and for the Earth, it is not surprising. Top marks owned outside our solar system where the existence of Gliese 581g doubt some astronomers and planetary scored 0.89.
Last is exoplanet orbiting the same star, Gliese 581d, with a value of 0.74 ESI. Gliese 581 system has been well studied by astronomers and comprises four or five planets orbiting a red dwarf star.
Neptune-sized exoplanet, HD 69 830 d, orbits the star in the constellation of Puppis different also gets high marks, namely 0.60. The planet itself is allegedly located in the Goldilocks Zone where the place around the parent star that its surface temperature is not too hot or too cold for life.
The world with high value of our solar system is Mars, which is the value of 0.70, and Mercury, with 0.60. Habitabilitas Planet Index yield different results. Completion of the list is Saturn's moon Titan, which scored 0.64.
After months of Saturn, there is Mars (0.59) and the Jupiter moon Europa (0.47) who allegedly has a subsurface water ocean heated tidal stretch. Exoplanet with the highest score obtained again Gliese 581g (0.49) and Gliese 581d (0.43).
In recent years, the search for planets that could potentially be dwelling in the outer solar system have progressed. NASA's Kepler space telescope was launched into orbit in 2009, has found more than a thousand candidate planets so far.
Future telescopes may even be able to detect so-called biomarkers in the light emitted by distant planets, such as the presence of chlorophyll, a key pigment plant.
Hopefully Helpful ... :)
Tidak ada komentar:
Posting Komentar