June 2013 : Kepler Mission updated its estimates. Here are these latest numbers right from the horses-mouth (Professor Ravi Kopparapu). As at 20 June 2013, Dr. Kopparapu, expert with the Kepler Mission estimates :
- Stars in the Galaxy : 400 billion
- The number of habitable earth-like exoplanets in our Milky Way Galaxy : 144 billion (> 1011).
- The OORT Cloud around our Sun (it is also hypothesized by some astronomers that most suns have OORT clouds) is estimated :
- to contain : several trillion individual asteroids (objects) larger than 1 km (0.62 mi).
- to reach 1 ly towards the next closest star just 4 ly away – Proxima Centauri.
Comets have a wide range of orbital periods, ranging from a few years to hundreds of thousands of years. Short-period comets originate in the Kuiper belt (eg Halley’s Comet – orbit 75 years). Longer-period comets are thought to originate in the Oort cloud (Orbit – thousands of years). The latest theory is that they are mostly water, with a frozen, dust-encrusted shell. This would explain why objects like the Chelyabinsk, in February 2013, often leave few meteorites (rock fragments).
This year (In 2013), ALMA (Atacama Large Millimeter/submillimeter Array (ALMA)) – which CANADA is part of – managed from Herzberg Institute in Victoria, BC) has confirmed that researchers have discovered an important pair of prebiotic molecules in the icy particles in interstellar space (ISM). ISM is the empty part of the spiral arms.
The chemicals, found in a giant cloud of gas about 25,000 light-years (half way to centre of the galaxy) from Earth in ISM, may be a precursor to a key component of DNA and the other may have a role in the formation of an important amino acid.
Researchers found a molecule called cyanomethanimine, which produces adenine, one of the four nucleobases that form the “rungs” in the ladder-like structure of DNA. The other molecule, called ethanamine, is thought to play a role in forming alanine, one of the twenty amino acids in the genetic code.
Previously, scientists thought such processes took place in the very tenuous gas between the stars. The new discoveries, however, suggest that the chemical formation sequences for these molecules occurred not in gas, but on the surfaces of ice grains in interstellar space.
In February 2013, NASA ALMA spokesman announced : “Finding these molecules in an interstellar gas cloud means that important building blocks for DNA and amino acids can ‘seed’ newly-formed planets with the chemical precursors for life.”
See Video Interview and Animations with Dr. Anthony Remijan of the National Radio Astronomy Observatory.
“…..Microbiology may be said to have had its beginnings in the nineteen-forties. A new world of the most astonishing complexity began then to be revealed. In retrospect I find it remarkable that microbiologists did not at once recognise that the world into which they had penetrated had of necessity to be of cosmic order. I suspect that the cosmic quality of microbiology will seem as obvious to future generations as the Sun being the centre of the solar system seems obvious to the present generation…..”
Mwaka 2013: Kepler ilibadilisha takwimu zake. Hapa ni idadi hizi za hivi karibuni moja kwa moja kutoka mdomo wa farasi (Professor Ravi Kopparapu). "Kama ilivyo kwa Juni 20, 2013, Dk Kopparapu, mtaalamu wa Kepler Mission, inakadiria: ""Nyota katika Galaxy: 400 bilioni - Idadi ya exoplanets habitable dunia-kama katika Galaxy yetu Milky Way: 144 bilioni.""" Oort Cloud ni kundi la nyota za dunia ambazo zinaonekana kuwa na mawingu ya Oort, na zinaonekana kuwa na idadi kubwa ya asteroids kubwa kuliko 1 km. - kufikia 1 ly kuelekea nyota ya karibu zaidi ya pili tu 4 ly mbali <unk> Proxima Centauri. Kometi zina vipindi vingi vya kuzunguka angani, kuanzia miaka michache hadi mamia ya maelfu ya miaka. Kometi za kipindi kifupi zinatokana na ukanda wa Kuiper (kwa mfano Halley's Comet <unk> orbit 75 years). Inadhaniwa kwamba kometi zenye kipindi kirefu hutoka katika wingu la Oort (Orbit <unk> maelfu ya miaka). Nadharia ya karibuni zaidi ni kwamba wao ni maji hasa, wakiwa na ganda lililohifadhiwa, lililofunikwa na vumbi. "Hii ndiyo sababu ya ""Chelyabinsk"" ya Februari 2013 na ""Meteorite"" ya Oktoba 2013 kuwa na athari kubwa kwa dunia." Mwaka huu, ALMA (Atacama Large Millimeter Submillimeter Array) imethibitisha kuwa watafiti wamegundua jozi muhimu ya molekuli za prebiotic katika chembechembe za barafu katika nafasi ya kati ya nyota. Mfumo wa ISM ni sehemu tupu ya mikono ya mviringo. "Kemikali hiyo, iliyopatikana katika wingu kubwa la gesi, karibu miaka 25,000 ya mwanga (karibu nusu ya njia ya katikati ya galaksi) kutoka duniani, inaweza kuwa kiambishi cha sehemu muhimu ya DNA na nyingine inaweza kuwa na jukumu katika kuunda amino asidi muhimu.""" "Mchanganyiko wa cyanomethanine na adenine ni moja ya ""vitu vya msingi vya nyuklia"" vinavyofanyiza ""vitu vya msingi"" katika muundo wa DNA." Molekuli nyingine, iitwayo ethanamine, huonwa kuwa na fungu katika kutokeza alanini, mojawapo ya asidi za amino ishirini katika kanuni ya urithi. Hapo awali, wanasayansi walidhani kwamba michakato hiyo ilitukia katika gesi nyembamba sana iliyokuwa kati ya nyota. Hata hivyo, uvumbuzi huu mpya unaonyesha kwamba utaratibu wa kemikali ya molekuli hizo haukufanyika katika gesi, bali kwenye nyuso za chembe za barafu katika anga ya kati ya nyota. "Mwaka 2013 msemaji wa NASA ALMA alitangaza: ""Kupata molekuli hizi katika wingu la gesi ya kati ya nyota inamaanisha kuwa vitalu muhimu vya DNA na asidi za amino vinaweza ""kuza"" sayari zilizofanyizwa hivi karibuni na vichwa vya kemikali vya maisha." .....Microbiology inaweza kusemwa kuwa na mwanzo wake katika miaka ya kumi na tisa arobaini. Ulimwengu mpya wenye utata wenye kushangaza zaidi ulianza kufunuliwa wakati huo. Kwa kutazama nyuma, mimi kupata ni ajabu kwamba microbiologists si mara moja kutambua kwamba dunia ambayo walikuwa kupenya alikuwa lazima kuwa na utaratibu cosmic. Mimi tuhuma kwamba ubora cosmic ya microbiology itaonekana kama dhahiri kwa vizazi vijavyo kama Jua kuwa kituo cha mfumo wa jua inaonekana dhahiri kwa kizazi cha sasa..... <unk>