Jozi ya wanaastronomia wamefanya ugunduzi mkubwa wa 'exomoon' katika mfumo mwingine wa jua
Mwezi ni kitu cha mbinguni ambacho kina mawe au barafu na kuna jumla ya miezi 200 katika mfumo wetu wa jua. Hii ni pamoja na ya Dunia mwezi which is our sayari own permanent natural satellite. Moon njia the Earth as the sayari Ardhi njia ya nyota Sun. In our solar system only two sayari – Mercury and Venus- do not have moons. There are plenty of sayari beyond our solar system called ‘exoplanets’ which have been confirmed by researchers, though no confirmation is available on moons. For the first time a pair of astronomers Alex Teachey and David Kipping at Columbia University have found strong evidence of a moon in another solar system. Although 3,500 exoplanets are known, this is the first time an exomoon has been discovered. This moon is kuzunguka jitu kubwa sayari katika mwingine nyota system which is 8000 light years away from us. Its being called an ‘exomoon’ as it njia a sayari in another solar system. This celestial object is unique owing to its huge size – diameter being similar to that of sayari Neptune or Uranus – and it also looms over a giant Jupiter-sized planet and their pairing has been remarked as a ‘super-size pairing’. The exomoon is nine times bigger than Jupiter’s Ganymede which is the largest moon is our solar system. The Hubble Nafasi telescope and Kepler telescope from The National Aeronautics and Nafasi Utawala (NASA) have been used to make this significant discovery through investigations into distant nyota, planet and a possible moon.
Katika utafiti huu uliochapishwa katika Maendeleo ya sayansi what is being hailed as a milestone in astronomy, Teachey and Kipping examined data from 284 exoplanets which have been discovered till date by Kepler telescope which were seen in wide orbits for more than one month around their stars. The observations were able to measure brief dimming of a star’s light when the planet passed in front of the star i.e. during the transit. Exoplanets are discovered by astronomers by observing this reduction in brightness of the star which the planet orbits. This method is called the ‘transit method’. Theoretical models of planet formation are unable to make such predictions and that is why the transit method is used. This planet (or exoplanet), called Kepler 1625b was the only planet around the particular star. When analysing observations, researchers found one particular instance with interesting features and anomalies. This star is about the 70 percent larger than our Sun but is older and the planet is at the same distance from its star as Earth is to the Sun. Although the object was not visible but many evidences hinted towards its existence. Particularly, small deviations and wobbles were seen in the light curve. This was an interesting result based upon which researchers intensively studied the planet for around 40 hours using the Hubble telescope. Before and during the 19-hour transit of the planet across the star observations were recorded. The planet is thought to be revolving around its star in such way that it looks like a possible moon is pulling onto it gravitationally. When the planet moved in front of the star, the star’s light was dimmed very much hinting that there was something else present too. This dimness in stellar brightness was similar to the movement of the moon around the planet as only a moon could cause this kind of uncertain and wobbly path and this made for a strong evidence.
Uchunguzi na hitilafu sawia katika muda ungeonekana ikiwa mtu kutoka nje ya mfumo wetu wa jua (ziada ya dunia) angekuwa akitazama mwezi ukipitia sayari yetu ya Dunia. Exomoon hii ingekuwa karibu maili milioni 2 (kilomita milioni 3) kutoka kwa nyota yake na ingeonekana mara mbili ya ukubwa wa mwezi wetu duniani. Watafiti wanapanga kumtazama tena nyota huyo wakati ujao ili kufanya uthibitishaji zaidi, pengine mwaka wa 2019. Kile ambacho wameona kwenye jaribio lao la kwanza hakika kinaelekeza kwenye uamuzi huu na hivyo uwezekano mwingine umeondolewa. Pia, saizi kubwa ya exomoon na sayari yake ilisaidia watafiti kwani vitu vikubwa ni rahisi kugundua. Pia, kwa sababu mwezi unazunguka sayari mahali pake huendelea kubadilika na usafiri. Haya ni mafanikio ya ajabu kwa kuwa miezi si rahisi kuipata kutokana na ukubwa wake ikilinganishwa na sayari mwenyeji na kwa hivyo inaonyesha mawimbi dhaifu ya usafiri. Sayari mwenyeji na mwezi zote ni vyombo vinavyotoa gesi kwa hivyo watafiti hakika hawatatafuta dalili za uhai. Ingawa vyombo hivi vyote viwili viko katika eneo linaloweza kukaa la nyota mwenyeji ambapo maji ya kioevu au vitu vingine vikali vinaweza kuwepo kwa sababu ya halijoto ya wastani.
Hii ni mara ya kwanza exomoon imegunduliwa. Utafiti huu unatoa madai yasiyo ya kawaida na wanaastronomia wengi wanaamini kwamba maelezo haya yote yanahitaji kushikwa kwa wasiwasi fulani na kwa hakika yanahitaji ushahidi zaidi na uchunguzi zaidi. Utafiti huu ukifanywa kwa mafanikio zaidi unaweza kutupa ufahamu zaidi kuhusu jinsi miezi inavyoundwa na imeundwa na nini na jinsi mifumo ya sayari hukua na nini mfumo wa jua kutoka nje unafanana na zingine.
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Chanzo (s)
Teachey A na Kipping DM 2018. Ushahidi wa exomoon kubwa inayozunguka Kepler-1625b. Maendeleo ya Sayansi 03 Okt 2018: Vol. 4, hapana. 10, DOI:https://doi.org/10.1126/sciadv.aav1784
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