Planet/Bulan yang berpotensi sebagai habitat manusia

dauswq

Ade bbpr planet & bulan yg berpotensi sbg habitat manusia:

aku amik bbrp artikel dr wikipedia & berdasarkn pengetahuan aku mase di kelas astronomi dulu

1. Mars



The current understanding of planetary habitability—the ability of a world to develop and sustain life—favors planets that have liquid water on their surface. This most often requires that the orbit of a planet lie within the habitable zone, which for the Sun currently extends from just beyond Venus to about the semi-major axis of Mars.
During perihelion Mars dips inside this region, but the planet's thin (low-pressure) atmosphere prevents liquid water from existing over large regions for extended periods. The past flow of liquid water, however, demonstrates the planet's potential for habitability. Recent evidence has suggested that any water on the Martian surface would have been too salty and acidic to support terrestrial life. Tests conducted by the Phoenix Mars lander have shown that the soil has a very alkaline pH and it contains magnesium, sodium, potassium and chloride.
The soil nutrients may be able to support life, but life would still have to be shielded from the intense ultraviolet light.

Small quantities of methane and formaldehyde recently detected by Mars orbiters are both claimed to be hints for life, as these chemical compounds would quickly break down in the Martian atmosphere. It is possible that these compounds may instead be replenished by volcanic or geological means such as serpentinization.

Info: http://en.wikipedia.org/wiki/Life_on_Mars

2. Titan - Saturn's moon




It has also been suggested that life could exist in the lakes of liquid methane on Titan, just as organisms on Earth live in water.
Such creatures would inhale H2 in place of O2, react it with acetylene instead of glucose, and exhale methane instead of carbon dioxide.
In 2005, astrobiologist Chris McKay predicted that if methanogenic life is consuming atmospheric hydrogen in sufficient volume, it will have a measurable effect on the mixing ratio in the troposphere.


  


Evidence for this form of life was identified in 2010 by Darrell Strobel of Johns Hopkins University; an over-abundance of molecular hydrogen in the upper atmospheric layers, which leads to a downward flow at a rate of roughly 1025 molecules per second. Near the surface the hydrogen apparently disappears, which may imply its consumption by methanogenic life forms.
Another paper released the same month showed little evidence of acetylene on Titan's surface, where scientists had expected the compound to accumulate; according Strobel, this is consistent with the hypothesis that acetylene is being consumed by methanogens. Chris McKay, while agreeing that presence of life is a possible explanation for the findings about hydrogen and acetylene, has cautioned that other explanations are currently more likely: namely the possibility that the results are due to human error, or to the presence of some as-yet unknown catalyst in the soil.
He noted that such a catalyst, effective at 95 degrees K, would in itself be a startling discovery.



  

There is debate about the effectiveness of methane as a medium for life compared to water or ammonia;
while water is a far better solvent than methane, enabling easier transport of substances in a cell,

methane's lesser chemical reactivity allows for the easier formation of large structures akin to proteins.

Info:http://en.wikipedia.org/wiki/Colonization_of_Titan



3. Europa - Jupiter's moon




Europa's unlit interior is now considered to be the most likely location for extant extraterrestrial life in the Solar System.
Life could exist in its under-ice ocean, perhaps subsisting in an environment similar to Earth's deep-ocean hydrothermal vents or the Antarctic Lake Vostok  Life in such an ocean could possibly be similar to microbial life on Earth in the deep ocean.
So far, there is no evidence that life exists on Europa, but the likely presence of liquid water has spurred calls to send a probe there.



  

Until the 1970s, life, at least as the concept is generally understood, was believed to be entirely dependent on energy from the Sun. Plants on Earth's surface capture energy from sunlight to photosynthesize sugars from carbon dioxide and water, releasing oxygen in the process, and are then eaten by oxygen-respiring animals, passing their energy up the food chain. Even life in the deep ocean far below the photic zone was believed to obtain its nourishment either from the organic detritus raining down from the surface, or by eating animals that in turn depend on that stream of nutrients.
A world's ability to support life was thus thought to depend on its access to sunlight.

In 1977, during an exploratory dive to the Galapagos Rift in the deep-sea exploration submersible Alvin, scientists discovered colonies of giant tube worms, clams, crustaceans, mussels, and other assorted creatures clustered around undersea volcanic features known as black smokers.
These creatures thrive despite having no access to sunlight, and it was soon discovered that they comprise an entirely independent food chain. Instead of plants, the basis for this food chain was a form of bacterium that derived its energy from oxidization of reactive chemicals, such as hydrogen or hydrogen sulfide, that bubbled up from the Earth's interior. This chemosynthesis revolutionized the study of biology by revealing that life need not be sun-dependent; it only requires water and an energy gradient in order to exist. It opened up a new avenue in astrobiology by massively expanding the number of possible extraterrestrial habitats.

While the tube worms and other multicellular eukaryotic organisms around these hydrothermal vents respire oxygen and thus are indirectly dependent on photosynthesis, anaerobic chemosynthetic bacteria and archaea that inhabit these ecosystems provide a possible model for life in Europa's ocean. The energy provided by tidal flexing drives active geological processes within Europa's interior, just as they do to a far more obvious degree on its sister moon Io. While Europa, like the Earth, may possess an internal energy source from radioactive decay, the energy generated by tidal flexing would be several orders of magnitude greater than any radiological source.
However, such an energy source could never support an ecosystem as large and diverse as the photosynthesis-based ecosystem on Earth's surface.
Life on Europa could exist clustered around hydrothermal vents on the ocean floor, or below the ocean floor, where endoliths are known to inhabit on Earth. Alternatively, it could exist clinging to the lower surface of the moon's ice layer, much like algae and bacteria in Earth's polar regions, or float freely in Europa's ocean.However, if Europa's ocean were too cold, biological processes similar to those known on Earth could not take place. Similarly, if it were too salty, only extreme halophiles could survive in its environment.



  

In September 2009, planetary scientist Richard Greenberg calculated that cosmic rays impacting on Europa's surface convert the ice into oxidizers, which could then be absorbed into the ocean below as water wells up to fill cracks. Via this process, Greenberg estimates that Europa's ocean could eventually achieve an oxygen concentration greater than that of Earth's oceans within just a few million years. This would enable Europa to support not merely anaerobic microbial life but potentially larger, aerobic organisms such as fish.

INFO:http://en.wikipedia.org/wiki/Colonization_of_Europa





  

4. Calisto - Jupiter's moon




As with Europa and Ganymede, the idea has been raised that extraterrestrial microbial life may exist in a salty ocean under the Callistoan surface.[18] However, the conditions for life appear to be less favourable on Callisto than on Europa. The principal reasons are the lack of contact with rocky material and the lower heat flux from the interior of Callisto.[18] Scientist Torrence Johnson said the following about comparing the odds of life on Callisto with the odds on other Galilean moons:



  The basic ingredients for life—what we call 'pre-biotic chemistry'—are abundant in many solar system objects, such as comets, asteroids and icy moons. Biologists believe liquid water and energy are then needed to actually support life, so it's exciting to find another place where we might have liquid water. But, energy is another matter, and currently, Callisto's ocean is only being heated by radioactive elements, whereas Europa has tidal energy as well, from its greater proximity to Jupiter.

  

Based on the considerations mentioned above and on other scientific observations, it is thought that of all of Jupiter's Galilean moons, Europa has the greatest chance of supporting microbial life.


5. Enceladus -Saturn's moon





In late 2008, scientists observed water vapor spewing from Enceladus's surface. This could indicate the presence of liquid water, which might also make it possible for Enceladus to support life.
Candice Hansen,
a scientist with NASA's Jet Propulsion Lab in California headed up a research team on the plumes after they were found to be moving at ~2,189 kilometers per hour (1,360 miles per hour). Since that speed is unusual and is usually attained when water is involved, they decided to investigate the compositions of the plumes.




Evidence from the Cassini probe points to a possible global liquid ocean beneath the frozen surface. Particles of ice analyzed by Cassini revealed that the ice was of salt water which could, it is surmised, only occur in a large liquid body of water; as such Enceladus is a candidate for the harboring of extraterrestrial life.
An alternative interpretation of the results is of large water filled caverns.

On August 13, 2009 scientists announced that analysis of the vapor spewing from Enceladus' south pole contain unusually high levels of salt in the ice grains. Additionally, Cassini found traces of organic compounds such as carbonates and dust grains. All these together strengthen evidence that an ocean does exist under the moon's surface. The dust particles may be able to provide details that would normally require drilling to obtain.

The presence of liquid water under the crust means there has to be an internal heat source. Scientists now believe it is a combination of radioactive decay and tidal heating,
as tidal heating alone is not enough to explain the heat. Mimas, another of Saturn's moons, is closer to the planet and has a much more eccentric orbit, meaning the moon should be exposed to far greater tidal forces than Enceladus, and yet the object seems to be geologically dead judging from the old and scarred surface.

  
6. Ceres - dwarf planet






There are indications that Ceres may have a weak atmosphere and water frost on the surface.
Surface water ice is not stable at distances less than 5 AU from the Sun, so it is expected to sublime if it is exposed directly to solar radiation. Water ice can migrate from the deep layers of Ceres to the surface, but will escape in a very short time. As a result, it is difficult to detect water vaporization. Water escaping from Ceres's polar regions was possibly observed in the early 1990s but this has not been unambiguously proven. It may be possible to detect escaping water from the surroundings of a fresh impact crater or from cracks in the sub-surface layers of Ceres.
Ultraviolet observations by IUE spacecraft detected statistically significant amounts of the hydroxide ion near the Cererean north pole, which is a product of water vapour dissociation by the solar ultraviolet radiation.



Today, Ceres appears to be a geologically inactive body, with a surface sculpted only by impacts. The presence of significant amounts of water ice in its composition
raises the possibility that Ceres has or had a layer of liquid water in its interior.
This hypothetical layer is often called an ocean. If such a layer of liquid water exists, it is believed to be located between the rocky core and ice mantle like that of the theorized ocean on Europa.
The existence of an ocean is more likely if dissolved solutes (i.e. salts), ammonia, sulfuric acid or other antifreeze compounds are dissolved in the water.

INFO:http://en.wikipedia.org/wiki/Colonization_of_Ceres


  
7. Mercury




INFO: http://en.wikipedia.org/wiki/Colonization_of_Mercury


8. Earth's moon




INFO: http://en.wikipedia.org/wiki/Colonization_of_the_Moon




9. Venus



INFO: http://en.wikipedia.org/wiki/Colonization_of_Venus



  

iris_love

wuuu seram jer...bumi gak best

aurorae

Saintis minta manusia hidup di planet lain


STEPHEN HAWKING

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LONDON - Pakar astrofizik, Stephen Hawking, 68, memberi amaran bahawa bangsa manusia perlu membuka penempatan baru di angkasa lepas dalam tempoh dua kurun lagi atau berdepan risiko pupus, lapor sebuah akhbar semalam.

Pakar astrofizik terkenal itu berkata, satu-satunya peluang untuk mengekalkan kesinambungan manusia adalah dengan membuka penempatan baru di planet-planet asing.

"Saya melihat bahaya menunggu umat manusia. Sebelum ini, sudah beberapa kali kita diancam kepupusan. Sebagai contoh, krisis peluru berpandu nuklear Cuba pada 1963," kata Hawking.

"Populasi manusia meningkat dan sumber asli di bumi terhad. Kita pula mengubah alam sekitar yang mendatangkan risiko manusia itu sendiri," tambahnya.

Menurut Hawking, adalah sukar bagi umat manusia mengelak bencana dalam masa 100 tahun akan datang, inikan pula untuk tempoh 1,000 tahun atau sejuta tahun.

"Satu-satunya peluang untuk selamat adalah untuk tidak kekal di bumi, tetapi memulakan kehidupan di angkasa lepas," jelasnya. - Agensi

dauswq

wuuu seram jer...bumi gak best
iris_love Post at 10-8-2010 21:06

semestinya...

dlm senarai di atas

ada tiga je planet/bulan yg berpotensi besar dijadikan tapak pengkalan manusia

Mars
Europa
Enceladus


Ceres..belum dipastikan lagi
sbb kedudukan planet itu di antara Mars ngan Jupiter
jd info agak limited

Ceres - sbnrnye asteroid yg besar

din_atos

Aku rasa belum sempat nak ada teknologi bina pangkalan angkasa lepas da kiamat pun...

alphawolf

Mercury? Dekat sangat ngan mentari kot?

hyie

pluto anyone?

salimrock

aku rasa planet ni tak buleh duduk..busuk..Uranus..( bunyi nye u're anus )

he.he..anus tu salur ta.ik kan?

dauswq

pluto anyone?
hyie Post at 12-8-2010 09:33

Pluto terlalu jauh...kepekatan cahaya matahari kurang
& tiada tanda2 life kt situ

Pluto's atmosphere consists of a thin envelope of nitrogen, methane, and carbon monoxide gases, which are derived from the ices of these substances on its surface

gmbrn Pluto

dauswq

Mercury? Dekat sangat ngan mentari kot?
alphawolf Post at 12-8-2010 09:27

ah..yup

dekat ngan matahari...keberangkalian tuk idup susah
sbb tu least chance

dulu..sblm Europa ngan Enceladus dijumpai
rmi berpendapat Mercury, Mars & Venus adalah tmpt menarik
ttp keadaan planet itu, terutamanya Mercury dan Venus tidak menjamin sbg penempatan 'life'

Venus - aktiviti volcanic yg kerap + awan sulphuric acid yg bnyk menyebabkn kandungan C02 terlalu tinggi..so tak selamat even planet ni dekat je ngan bumi berbanding ngan Mercury

dauswq

aku rasa planet ni tak buleh duduk..busuk..Uranus..( bunyi nye u're anus )

he.he..anus tu salur t ...
salimrock Post at 12-8-2010 09:56

gituh plak

2tigapuluh2

nnti raya tahun 3000

"ko dah beli tiket balik bumi? baik beli cepat2 karang terlepas kapal"

Freer

WA.....kalau manusia di takdirkan berpindah ke plenet lain mesti best kan...dah kurang perkataan balik kampung...mesti ko balik planet ko tak tahun ni???
wakakaka!!

fly_in_d_sky

dok planet lain?
cm ner nak cari kiblat?
cam ner nak tgk anak bulan??

salimrock

WA.....kalau manusia di takdirkan berpindah ke plenet lain mesti best kan...dah kurang perkataan bal ...
Freer Post at 12-8-2010 13:48

    nanti ujud la conversation cam ni..


wa :Freer ko dah beli ke tiket balik kg ke Marikh...

freer: tak la..raya ni aku balik kg bini aku..ke planet Zuhal..

wa:wa balik planet sagitarius la....nanti kirim ek beli jersey team zuhal...( masa tu team bola sepak zuhal kira setaraf Man U )hehe...