Scientists discover first Earth-sized planet that could support life

[Makanyaga]

[h=1]Scientists discover first Earth-sized planet that could support life[/h] By by Miriam Kramer, Staff Writer 11 hours ago

.'Earth's Cousin': Scientists Find Alien Planet That's Most Like Home




For the first time, scientists have discovered an Earth-sized alien planet in the habitable zone of its host star, an "Earth cousin" that just might have liquid water and the right conditions for life.
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The newfound planet, called Kepler-186f, was first spotted by NASA's Kepler space telescope and circles a dim red dwarf star about 490 light-years from Earth. While the host star is dimmer than Earth's sun and the planet is slightly bigger than Earth, the positioning of the alien world coupled with its size suggests that Kepler-186f could have water on its surface, scientists say. You can learn more about the amazing alien planet find in a video produced by Space.com.
"One of the things we've been looking for is maybe an Earth twin, which is an Earth-sized planet in the habitable zone of a sunlike star," Tom Barclay, Kepler scientist and co-author of the new exoplanet research, told Space.com. "This [Kepler-186f] is an Earth-sized planet in the habitable zone of a cooler star. So, while it's not an Earth twin, it is perhaps an Earth cousin. It has similar characteristics, but a different parent." [9 Exoplanets That Could Host Alien Life]
Potentially habitable planet
Scientists think that Kepler-186f — the outermost of five planets found to be orbiting the star Kepler-186 — orbits at a distance of 32.5 million miles (52.4 million kilometers), theoretically within the habitable zone for a red dwarf.
Earth orbits the sun from an average distance of about 93 million miles (150 million km), but the sun is larger and brighter than the Kepler-186 star, meaning that the sun's habitable zone begins farther out from the star by comparison to Kepler-186.
View gallery

This artist illustration shows what it might be like to stand on the surface of the planet Kepler-18 …

"This is the first definitive Earth-sized planet found in the habitable zone around another star," Elisa Quintana, of the SETI Institute and NASA's Ames Research Center and the lead author of a new study detailing the findings, said in a statement.
Other planets of various sizes have been found in the habitable zones of their stars. However, Kepler-186f is the first alien planet this close to Earth in size found orbiting in that potentially life-supporting area of an extrasolar system, according to exoplanet scientists.
'An historic discovery'
"This is an historic discovery of the first truly Earth-sized planet found in the habitable zone around its star," Geoff Marcy, an astronomer at the University of California, Berkeley, who is unaffiliated with the research, told Space.com via email. "This is the best case for a habitable planet yet found. The results are absolutely rock-solid. The planet itself may not be, but I'd bet my house on it. In any case, it's a gem."
The newly discovered planet measures about 1.1 Earth radii, making it slightly larger than Earth, but researchers still think the alien world may be rocky like Earth. Researchers still aren't sure what Kepler-186f's atmosphere is made of, a key element that could help scientists understand if the planet is hospitable to life. [Kepler-186f: Earth-Size World Could Support Oceans, Maybe Life (Infographic)]
View gallery

This diagram shows the position of Kepler-186f in relation to Earth.

"What we've learned, just over the past few years, is that there is a definite transition which occurs around about 1.5 Earth radii," Quintana said in a statement. "What happens there is that for radii between 1.5 and 2 Earth radii, the planet becomes massive enough that it starts to accumulate a very thick hydrogen and helium atmosphere, so it starts to resemble the gas giants of our solar system rather than anything else that we see as terrestrial."
The edge of habitability
Kepler-186f actually lies at the edge of the Kepler-186 star's habitable zone, meaning that liquid water on the planet's surface could freeze, according to study co-author Stephen Kane of San Francisco State University.
Because of its position in the outer part of the habitable zone, the planet's larger size could actually help keep its water liquid, Kane said in a statement. Since it is slightly bigger than Earth, Kepler-186f could have a thicker atmosphere, which would insulate the planet and potentially keep its water in liquid form, Kane added.
"It [Kepler-186f] goes around its star over 130 days, but because its star is a lower mass than our sun, the planet orbits slightly inner of where Mercury orbits in our own solar system," Barclay said. "It's on the cooler edge of the habitable zone. It's still well within it, but it receives less energy than Earth receives. So, if you're on this planet [Kepler-186f], the star would appear dimmer."

Exoplanet hunting in the future
Kepler-186f could be too dim for follow-up studies that would probe the planet's atmosphere. NASA's James Webb Space Telescope — Hubble's successor, expected to launch to space in 2018 — is designed to image planets around relatively nearby stars; however, the Kepler-186 system might be too far off for the powerful telescope to investigate, Barclay said.
Scientists using the Kepler telescope discovered Kepler-186f using the transit method: When the planet moved across the face of its star from the telescope's perspective, Kepler recorded a slight dip in the star's brightness, allowing researchers to learn more about the planet itself. Kepler suffered a major malfunction last year and is no longer working in the same fashion, but scientists are still going through the spacecraft's trove of data searching for new alien worlds.
"I find it simply awesome that we live in a time when finding potentially habitable planets is common, and the method to find them is standardized," MIT exoplanet hunter and astrophysicist Sara Seager, who is unaffiliated with the research, told Space.com via email.
The new research was published online today (April 17) in the journal Science.
Follow Miriam Kramer @mirikramer and Google+. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

• Gallery: The Smallest Alien Planets
• The Strangest Alien Planets (Gallery)
• Alien Planet Quiz: Are You an Exoplanet Expert?
• New Earth-Size Planet Could Have Water | Video

Copyright 2014 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Source: Scientists discover first Earth-sized planet that could support life

 

[rushanju]

Hii iko 500 light year. Je ina msaaa gani kwetu.

 

[dagii]

Huko mpaka tukifa ndo tutafika

 

[Makanyaga]

Hii iko 500 light year. Je ina msaaa gani kwetu.

Sayari hii iko umbali wa 490 light-years. Tuseme kwa mfano, mwanga huu unaotuwezesha kuona huwa una mwendo kasi wa kilometa laki tatu kwa sekunde moja (300,000km per second). Hii inamaanisha kuwa mwanga unaweza kusafiri kutoka hapa kwetu kwenda kwenye sayari hiyo, ukaifikia baada ya miaka 490, au kwa maana nyingine wataalamu wakifanikiwa kutengeneza chombo kinachoweza kusafiri kwa kasi ya mwanga, basi wakiamua wakitume kiende kwenye sayari hiyo kitachukua muda wa miaka 490. Umbali wa kutoka hapa tulipo kwenda mwezini ni kilometa 300,000, ndiyo maana huwa ukiangalia angani kama kuna mbalamwezi, huwa inakuchukua sekunde moja tu kuuona mwezi plae ulipo. Tuseme kama mwezi ungekuwa uko umbali wa kilometa laki tisa, ingekuwa inakuchukua sekunde tatu kuuona pale ulipo, au ungekuwa umbali wa kilometa laki moja na nusu, basi vilevile ingekuwa inakuchukua nusu sekunde kuuona pale ulipo.

 

[SuperImpressor]

Mwone wanasayansi walivyo waongo. Je, chombo walichotumia kuona kimetumia miaka mia ngapi ili kuiona hiyo sayari. Mengine tutakuwa tunakubali na mengine tutakataa.

 

[kabanga]

ah...490 yrs?

 

[Makanyaga]

Mwone wanasayansi walivyo waongo. Je, chombo walichotumia kuona kimetumia miaka mia ngapi ili kuiona hiyo sayari. Mengine tutakuwa tunakubali na mengine tutakataa.

How do we measure the distances to things in space?

It is not an easy thing to measure the distances to objects in the universe since these objects are usually very far away. We can't just run out there with a ruler! To measure distances in the universe, we will need to construct what is commonly referred to as a "cosmic distance ladder". In other words, astronomers use different methods to determine the distances to objects; the specific method which is used depends on how far away the object is. But all of the methods are wonderful combinations of science and mathematics!

The links below will take you to descriptions of various common methods.

• Radar - measuring distances in our solar system
• Parallax - measuring distances to nearby stars
• Cepheids - measuring distances in our Galaxy and to nearby galaxies
• Supernovae - measuring distances to other galaxies
• Redshift and Hubble's Law - measuring distances to objects far, far away

1. Radar

This modern method of measuring distances is based on the fact that light (whether in the form of radio waves, microwaves, visible light, or X-rays) travels with a speed of 300,000 km/sec. Therefore, based on the fact that distance traveled equals to the speed at which you travel times the length of time you travel at that speed, we can determine distances in our solar system.

Specifically,
d = v x t where d is distance, v is velocity, and t is time. As mentioned above, when we use any form of light, v is equal to 300,000 km./sec. So if we measure how long it takes for light to go to an object, we can calculate the distance.
This method has been used in one form or another to determine the distances to all of the planets in our solar system (except Pluto, which we have not visited). It is also routinely used to measure the distance from the Earth to the Moon. Mirrors left by Apollo astronauts reflect a laser beam shot from Earth and allow scientists to keep close track on the lunar orbit. The image below shows how the technique works.

>


2. Parallax

Astronomers derive distances to the nearest stars (closer than about 100 light-years) by a method called stellar parallax. This method that relies on no assumptions other than the geometry of the Earth's orbit around the Sun. You are probably familiar with the phenomenon known as parallax. Try this. Hold out your thumb at arm's length, close one of your eyes, and examine the relative position of your thumb against other distant (background) objects, such as a window, wall, or tree. Now look at your thumb with your other eye. What do you notice? Move your thumb closer to your face and repeat the experiment. What was different this time? This is a demonstration of the parallax effect: the apparent shift in position of a relatively nearby object against more distant ones when viewed from different vantage points.
Now consider that the Earth moves in its orbit around the Sun, allowing us to look at nearby stars from slightly different locations - just like your two eyes are at slightly different locations. This is shown in the image below.

From the image above, you can see that by knowing the size of Earth's orbit and measuring the angles of the light from the star at two points in the orbit, the distance to the star can be derived. The farther the star is, the smaller the angles. For stars more than about 100 light-years from Earth, we cannot measure any shift and the method fails.
The mathematical formula of a parallax distance is:

​

3. Cepheids

​

Cepheids, also called Cepheid Variables, are stars which brigthen and dim periodically. This behavior allows them to be used as cosmic yardsticks out to distances of a few tens of millions of light-years.

In 1912, Henrietta Swan Leavitt noted that 25 stars, called Cepheid stars, in the Magellanic cloud would brighten and dim periodically. Leavitt was able to measure the period of each star by measuring the timing of its ups and downs in brightness. What she determined was that the brighter the Cepheid, the longer its period. In fact, Cepheids are very special variable stars because their period (the time they take to brighten, dim and brighten again) is

• regular (that is, does not change with time), and
• a uniform function of their brightness. That is, there is relation between the period and brightness such that once the period is known, the brightness can be inferred.

Cepheids are reasonably abundant and very bright. Astronomers can identify them not only in our Galaxy, but in other nearby galaxies as well. If one requires the distance to a given galaxy one first locates the Cepheid variables in this galaxy. From these observations one determines the period of each of these stars. Leavitt's data states that a given period has a unique brightness associated to it. So from the period and Leavitt's plot we get the brightness at the distance of one light-year (see the image above). We can also measure the brightness on Earth. The brightness at the distance of one light-year will be larger than the observed brightness due to the fact that brightness drops like the square of the distance. From these numbers one can extract the distance to the stars. This method works up to 13 million light-years when Earth-bound telescopes are used; for larger distances these stars become too dim to be observed. Recently, space-based telescopes such as the Hubble Telescope, have used these stars to much farther distances. Looking at a galaxy in the Virgo cluster called M100, astronomers used the Cepheid variables observed there to determine its distance - 56 million light-years.


4. Supernovae

At large distances (up to about 1 billion light-years), astronomers can no longer use methods such as parallax or Cepheid variables. At such large distances, the parallax shift becomes too small and we can no longer even see individual stars in galaxies. Astronomers then turn to a series of methods that use "standard candles", that is, objects whose absolute magnitude is thought to be very well known. Then, by comparing the relative intensity of light observed from the object with that expected based on its assumed absolute magnitude, the inverse square law for light intensity can be used to infer the distance. The unique characteristics and enormous brightness of a certain type of supernova, the explosion which can occur at the end of the main sequence life of a massive star, can be used to determine distances beyond the reach of the previous methods.
There have been many measurements of the manner in which a supernova, whose distance to Earth is known (using one of the previous methods), increases its brightness and then dims into oblivion. There is one type (called type Ia) for which this brightening and dimming is very regular: when the maximum brightness at a distance of 1 light-year is calculated (using the known distance and the 1/distance[SUP]2[/SUP] rule), it is found to be about the same for all stars. Such Type Ia supernovae are then our standard candles.
If the distance to a far away galaxy is required, one must first locate a type Ia supernova in it (which do occur regularly) and then measure its observed brightness. Comparing this result with the known maximum brightness achieved by all such supernovae one can determine the distance to the galaxy in question (again using the 1/distance[SUP]2[/SUP] rule). Since supernovae are extremely bright, this method is useful to very large distances, up to one billion light-years.


5. Redshift and Hubble's Law

For very far objects (beyond about 1 billion light-years) none of the above methods work. Scientists must move from direct observation to using observations in conjunction with a theory. The theory used to determine these very great distances in the universe is based on the discovery by Edwin Hubble that the universe is expanding.

[TD="align: center"]

[/TD]
[TD="align: center"]

[/TD]

In 1929, Edwin Hubble announced that almost all galaxies appeared to be moving away from us. In fact, he found that the universe was expanding - with all of the galaxies moving away from each other. This phenomenon was observed as a redshift of a galaxy's spectrum. This redshift appeared to be larger for faint, presumably further, galaxies. Hence, the farther a galaxy, the faster it is receding from Earth. You can see this trend in Hubble's data shown in the images above. The velocity of a galaxy could be expressed mathematically as
v = H x d where v is the galaxy's radial outward velocity, d is the galaxy's distance from Earth, and H is the constant of proportionality called the Hubble constant.
The exact value of the Hubble constant is still somewhat uncertain, but is generally believed to be around 65 kilometers per second for every megaparsec in distance. (A megaparsec is given by 1 Mpc = 3 x 10[SUP]6[/SUP] light-years). This means that a galaxy 1 megaparsec away will be moving away from us at a speed of 65 km/sec, while another galaxy 100 megaparsecs away will be receding at 100 times this speed. So essentially, the Hubble constant reflects the rate at which the universe is expanding.
So to determine an object's distance, we only need to know its velocity. Velocity is measurable thanks to the Doppler shift. By taking the spectrum of a distant object, such as a galaxy, astronomers can see a shift in the lines of its spectrum and from this shift determine its velocity. Putting this velocity into the Hubble equation, they determine the distance. Note that this method of determining distances is based on observation (the shift in the spectrum) and on a theory (Hubble's Law). If the theory is not correct, the distances determined in this way are all nonsense. Most astronomers believe that Hubble's Law does, however, hold true for a large range of distances in the universe.
It should be noted that, on very large scales, Einstein's theory predicts departures from a strictly linear Hubble law. The amount of departure, and the type, depends on the value of the total mass of the universe. In this way a plot of recession velocity (or redshift) vs. distance, which is a straight line at small distances, can tell us about the total amount of matter in the universe and may provide crucial information about the mysterious dark matter.

Source: http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question39.html

 

[Sendoro Mbazi]

Mwone wanasayansi walivyo waongo. Je, chombo walichotumia kuona kimetumia miaka mia ngapi ili kuiona hiyo sayari. Mengine tutakuwa tunakubali na mengine tutakataa.

wanauona mwanga uliotoka kwenye sayari hiyo.Hii inamaana wameona mwanga uliotoka huko miaka 490 iliyopita

 

[JZHOELO]

wanauona mwanga uliotoka kwenye sayari hiyo.Hii inamaana wameona mwanga uliotoka huko miaka 490 iliyopita

yap.. it seems you are not into terestrial stuffs.. ni kweli the light from the planet inachukua hiyo miaka kufika,, na je unajua mwanga wa jua unachukua dakika NANE (8) kufika duniani mkuu. kwahiyo incase (not possible) jua likipotea ghafla au kuzima hatutajua mpaka dakika nane zikiisha... kwa theory hiyohiyo nyota unayoiona leo inawezekana kwa asili mia 100 ikawa imeshalipuka zaidi ya miaka milioni mia ila sisi tunaiona ipo because mwanga wake tayari ulishaanza kusafiri na umbali wa nyota hiyo ndio unachangia. kwahiyo unavyoona nyota inang'ara huwa haingári as such. ni mwanga unafika kwa muda tofauti katika macho yako mkuuu..
ninachoweza kusema ni impossible kwa chombo kusafiri kwenda kwenye system nyingine au galaxy nyingine kwa sababu zifuatazo;

• chombo kitakachofikia speed ya mwanga kitadesentegrate kuwa vumbi maana kitafikia level ya attomic desentergration
• hatutoweza kufikia kwasababu mpakachombo kinafika waliokituma watakua wamekwishakufa(itakua haina maana)
• hatuwezi jua kama sayari hiyo badop ipo as to the late light arrival.
• labda tukitumia dark energy ambayo nayo ni 1bilion times the biggest attomic bomb lililotengenezwa na soviets TZAR BOMBA (GOOGLE KUJUA ZAIDI KUHUSU HILI BOMU)ambalo hilo bomu lenyewe lilikuwa mara 50 ya lile lililolipuka hiroshimA

KWAHIYO TS ALMPST IMPOSIBLE ila science have an amazing way to transform... lets wait and see maybe kitukuu chakitukuu cha kitukuu change wanaweza kufikia anothe galaxy.
pia angalieni hii link ya huyu mshkaji na mkisubscribe mtajua zaidi about galaxies... https://www.youtube.com/channel/UC6nSFpj9HTCZ5t-N3Rm3-HA
nawakaribisha Mwl.RCT, njunwa wamavoko, CYBERTEQ, h120,JOAQUEM, waltham, MziziMkavu kama wanalakuongeza

 

[SuperImpressor]

Kwa hiyo kumbe siyo kwamba labda wameboresha vyombo vyao ndipo wakaiona hiyo kitu ila wameshtukia tu mwanga umefika baada ya kusafiri kwa siku nyingi. Hiki kitendawili Kukitegua si mchezo.

 

[Makanyaga]

Kwa hiyo kumbe siyo kwamba labda wameboresha vyombo vyao ndipo wakaiona hiyo kitu ila wameshtukia tu mwanga umefika baada ya kusafiri kwa siku nyingi. Hiki kitendawili Kukitegua si mchezo.

Vyombo vya ku-predict umbali vipo siku nyingi, wala teknolojia yake siyo big deal kwao, issue inayogomba ni kuweza ku-comeupp with something which can travel at the speed of light, hiyo ndiyo itakuwa puzzle kwa vizazi na vizazi, tuipe labda minimum hata ya miaka si chini ya 500 mbele. Pia ni kama alivyovchambua mtaalamu hapo juu, kwamba hata ukifanikiwa kutrengeneza chombo chenye mwendokasi huo na ukakituma, bado kuna matatizo mawili makubwa
1. kuna uwezekano mkubwa kwamba hiyo nyota hakitaikuta
2. Itabidi hata kikiikuta, wtakaokuwepo ni vitukuu wenu watakaokutwa wako hai anagalau miaka 400 baada ya wale waliokituma hicho chombo, kuwa wamefariki!

 

[Makanyaga]

yap.. it seems you are not into terestrial stuffs.. ni kweli the light from the planet inachukua hiyo miaka kufika,, na je unajua mwanga wa jua unachukua dakika NANE (8) kufika duniani mkuu. kwahiyo incase (not possible) jua likipotea ghafla au kuzima hatutajua mpaka dakika nane zikiisha... kwa theory hiyohiyo nyota unayoiona leo inawezekana kwa asili mia 100 ikawa imeshalipuka zaidi ya miaka milioni mia ila sisi tunaiona ipo because mwanga wake tayari ulishaanza kusafiri na umbali wa nyota hiyo ndio unachangia. kwahiyo unavyoona nyota inang'ara huwa haingári as such. ni mwanga unafika kwa muda tofauti katika macho yako mkuuu..
ninachoweza kusema ni impossible kwa chombo kusafiri kwenda kwenye system nyingine au galaxy nyingine kwa sababu zifuatazo;

• chombo kitakachofikia speed ya mwanga kitadesentegrate kuwa vumbi maana kitafikia level ya attomic desentergration
• hatutoweza kufikia kwasababu mpakachombo kinafika waliokituma watakua wamekwishakufa(itakua haina maana)
• hatuwezi jua kama sayari hiyo badop ipo as to the late light arrival.
• labda tukitumia dark energy ambayo nayo ni 1bilion times the biggest attomic bomb lililotengenezwa na soviets TZAR BOMBA (GOOGLE KUJUA ZAIDI KUHUSU HILI BOMU)ambalo hilo bomu lenyewe lilikuwa mara 50 ya lile lililolipuka hiroshimA

KWAHIYO TS ALMPST IMPOSIBLE ila science have an amazing way to transform... lets wait and see maybe kitukuu chakitukuu cha kitukuu change wanaweza kufikia anothe galaxy.
pia angalieni hii link ya huyu mshkaji na mkisubscribe mtajua zaidi about galaxies... https://www.youtube.com/channel/UC6nSFpj9HTCZ5t-N3Rm3-HA
nawakaribisha Mwl.RCT, njunwa wamavoko, CYBERTEQ, h120,JOAQUEM, waltham, MziziMkavu kama wanalakuongeza

Kwa hiyo kumbe siyo kwamba labda wameboresha vyombo vyao ndipo wakaiona hiyo kitu ila wameshtukia tu mwanga umefika baada ya kusafiri kwa siku nyingi. Hiki kitendawili Kukitegua si mchezo.

Vyombo vya ku-predict umbali vipo siku nyingi, wala teknolojia yake siyo big deal kwao, issue ambayo bado inagomba hapa ni namna ya kuweza ku-come up with something that can travel at the speed of light, hiyo ndiyo itakuwa puzzle kwa vizazi na vizazi, tuipe labda minimum hata ya miaka si chini ya 500 mbele. Pia ni kama alivyochambua mtaalamu hapo juu, kwamba hata ukifanikiwa kutengeneza chombo chenye mwendokasi huo na ukakituma, bado kuna matatizo mawili makubwa
1. kuna uwezekano mkubwa kwamba hiyo nyota hakitaikuta
2. Itabidi hata kikiikuta, wtakaokuwepo ni vitukuu wenu watakaokutwa wako hai anagalau miaka 400 baada ya wale waliokituma hicho chombo, kuwa wamefariki!

 

[Nyamgluu]

kuna somo la kupima uumbali hapo juu nafikiri mdau ingebidi alipwe! Duh! Ikanikumbusha kipinda cha Great Thinkers wa ukweli!