NASA announces discovery of a second Earth

[Medium of the Damned]

NASA announces discovery of a second Earth
Posted on Thursday, 23 July, 2015



Have we finally found another planet like our own - an Earth 2.0 ? Image Credit: NASA

Astronomers using the Kepler Telescope have found the most Earth-like extrasolar planet ever discovered.
Kepler-452b is thought to be a rocky terrestrial world with an orbit very similar to our own around a star that is also very similar to our own. Out of more than 1,000 extrasolar planets identified to date this particular world is being hailed as the most significant and Earth-like of them all.

"Kepler-452 has similar characteristics to our sun, which makes finding a planet with an orbital period similar to Earth in this system very exciting," said Daniel Huber of the University of Sydney.

"It is the first time we have found such a planet."

The discovery was outlined at a NASA press conference earlier today with scientists indicating that standing on its surface could potentially feel "a lot like home".

That is not to say that Kepler-452b is exactly like the Earth however - it is approximately 60 percent larger than our own planet and one year there would be 385 days long.

It is also a very long way away at a distance of 1400 light years in the constellation Cygnus.

Nonetheless its remarkably Earth-like orbital distance places it right in its star's habitable zone and scientists believe that it has been there for six billion years - enough time for life to have developed.

It is currently unknown whether or not the planet has an atmosphere or if there really is life there but it is likely to be a prime target for future observation once telescopes become powerful enough.



http://www.smh.com.au/technology/sci-tech/astronomy/sunlike-star-found-to-have-an-earthlike-planet-in-its-goldilocks-zone-20150723-gij5yd.html

[Medium of the Damned]

Sun-like star found to have an Earth-like planet in its Goldilocks zone

Date
    July 24, 2015

    6 reading now

Marcus Strom

    Tweet
    Pin It
    submit to reddit
    Email article
    Print
    Reprints & permissions

NASA discovers new Earth-like planet

Scientists using NASA's powerful Kepler telescope have found a planet beyond the solar system that is similar to Earth.

    Autoplay OnOff
    Video feedback
    Video settings

For the first time a near-Earth-sized planet has been found orbiting a star that is very much like our own sun. NASA on Friday announced the discovery of Kepler-452b, which is 1400 light years from Earth in the constellation Cygnus.

The international team of astronomers working on NASA's Kepler mission that identified the planet includes Daniel Huber of the University of Sydney.

Dr Huber told Fairfax Media that, although more than 1000 exoplanets - those outside our solar system - have been identified, Kepler-452b was special because of the star it orbits and the planet's long orbital period.
An artist's impression of a comparison between the Earth, left, and the planet Kepler-452b.

An artist's impression of a comparison between the Earth, left, and the planet Kepler-452b. Photo: NASA/Ames/JPL-Caltech/T. Pyle via AP

"Kepler-452b has similar characteristics to our sun, which makes finding a planet with an orbital period similar to Earth in this system very exciting," Dr Huber said. "It is the first time we have found such a planet."

A year on Kepler-452b is 385 days, just 20 days longer than on Earth. The planet is 60 per cent larger than Earth, but its mass is unknown. It may or may not have an atmosphere.

Kepler-452b orbits at 1.05 astronomical units – that means its orbit is only 5 per cent more distant from its star than Earth is from the sun.
An artist's impression of one possible appearance of the planet Kepler-452b, the first near-Earth-size world to be found in the habitable zone of a star that is similar to our sun

An artist's impression of one possible appearance of the planet Kepler-452b, the first near-Earth-size world to be found in the habitable zone of a star that is similar to our sun Photo: Reuters

"The system is too distant to determine whether it has an atmosphere, so we don't know if it has the right conditions to harbour life," Dr Huber said.

But, based on its radius, the team estimates a better than even chance the planet has a rocky composition rather than being a gaseous planet.

Dr Huber said that most other exoplanets have been found orbiting the more prevalent M-type dwarf red stars. These stars are much cooler than the sun, which is a G2-type star. Kepler-452b is also orbiting a G2-type star.
Artist's impression of an earlier discovered exoplanet, Kepler-186f. Unlike Kepler-452b, this planet orbits a cooler red dwarf.

Artist's impression of an earlier discovered exoplanet, Kepler-186f. Unlike Kepler-452b, this planet orbits a cooler red dwarf. Photo: NASA

Because M-type stars are much cooler, their habitable or "Goldilocks" zones are much closer to the stars, meaning that planets in these orbits have much shorter orbital periods.

G2-type stars such as the sun are much hotter, so the habitable zones are further out. This means that planets in these zones have longer orbital periods, just like Earth ... and now Kepler-452b. Habitable zones are defined as those where planets could have liquid on the surface.

But does it matter? Dr Huber emphatically says yes.
Daniel Huber, from the University of Sydney, is part of an international team of astronomers working on NASA's Kepler mission.

Daniel Huber, from the University of Sydney, is part of an international team of astronomers working on NASA's Kepler mission. Photo: Supplied

"We have a curiosity to find out whether we are alone. What is our place in the galaxy and the universe?

"Finding out more about exoplanets is Kepler's key mission. We want to find out how abundant Earth-like planets are."

The research that found Kepler-452b was led by Jon Jenkins from NASA's Ames Research Centre. The findings will be published in The Astronomical Journal on Friday.

Dr Huber said that exoplanets are identified using the transit method. The planets themselves are not directly observed but their impact on the brightness of the stars they orbit is closely measured. As the planet passes in front of the star, the brightness dims. The timing and regularity of these transits provides a rigorous method for identifying exoplanets.

Dr Huber, originally from Austria, did his PhD in astrophysics at the University of Sydney. He worked at the Kepler mission in the US from 2011 to 2014 before returning to live and work in Sydney.

"Kepler has shown us that exoplanets are abundant," Dr Huber said. "Now we just need to find if any are supporting life."

This week, Professor Stephen Hawking launched the Breakthrough Initiative, a $US100 million, 10-year mission to find out if we are alone in the universe.

Where the Kepler mission searches for planets in the optical electromagnetic wavelength, Breakthrough will use radio telescopes such as the dish at Parkes to search for tell-tale blips from aliens.

[Medium of the Damned]

[Medium of the Damned]

An artist's impression of one possible appearance of the planet Kepler-452b, the first near-Earth-size world to be found in the habitable zone of a star that is similar to our sun Photo: Reuters

[Medium of the Damned]

Artist's impression of an earlier discovered exoplanet, Kepler-186f. Unlike Kepler-452b, this planet orbits a cooler red dwarf. Photo: NASA

[Medium of the Damned]

Daniel Huber, from the University of Sydney, is part of an international team of astronomers working on NASA's Kepler mission. Photo: Supplied

[Xomon]

Of course "earth-like" only means a rocky planet in the goldilocks zone. It could be more like Mars or Venus than like Earth.

[Zalmoxis]

Absolutely and it is a little unfortunate that that is the term we have adopted to describe these types of planets IMHO. Earth-zone maybe?

[Astra]

Except that Venus and Mars both orbit outside the Sun's goldilocks zone.

[the Joker]

Isn't the estimated gravity on that planet 2 times our own? Wouldn't that make for funky look lifeforms? Or not really?

[The Creeper]

How did you arrive at that conclusion? Estimates for the habitable zone within the Solar System range from 0.725 to 3.0 astronomical units, though arriving at these estimates has been challenging for a variety of reasons. Numerous planetary mass objects orbit within, or close to, this range and as such receive sufficient sunlight to raise temperatures above the freezing point of water. However their atmospheric conditions vary substantially. The aphelion of Venus, for example, touches the inner edge of the zone and while atmospheric pressure at the surface is sufficient for liquid water.

[Back to Earth]

No, they make an announcement and then it goes on the news with a close up shot of a 'planet' with clouds continents and oceans ... 'everyone' goes "Oooooo ! " ... and funding is justified.

[Annihilus]

As many of you may know, yesterday was announced the existence of the most Earth-like planet ever discovered.

Of course this can give us some material to discuss what types of life forms may or may not be living in Kepler 452b. To do that, let's take a look at the facts:

    Kepler 452-b is spinning in an orbit around a star 10% brighter and 20% larger than our sun, at an orbital radius just 5% larger than that of the Earth.






    A year on 452-b is 385 Earth-days long.






    The planet is about 60 percent larger than the Earth, and its weight could be about 5 Earth masses, giving it a surface gravity of roughly 2g.





That being said, let the speculation begin: What kind of lifeforms may have been living in Kepler 452-b? and How the higher gravity of this planet could influence the evolution of potential life forms?

[Annihilus]

So on 2G we could expect that any land based creature would have thicker bones and more massive musculature.  Also, the planet is larger and so is the star so temperatures would be higher across the planet and especially at the equator.  Would this extra heat cook off the water?  Also, it is hypothesized that in a billion years the Sun will have grown enough to make the earth uninhabitable for humans and 452b's star is now that large so will they have been destroyed or did they get of the planet in time?

[Annihilus]

I would expect any animal life forms to be similar to horseshoe crabs - low to the ground, small(ish) and living mostly in water (if any)... What I would not expect at 2g's is an intelligent (sapient) lifeform... I would
think that 1.5g's would be the max for sapience to develop -no scientific reasoning for this - just a hunch based on a sapient species needing to be able to manipulate its environment (Pick things up, make items etc)
and 2g's I think would be too much to ever develop that...

Plant life would most likely be mosses, lichens and perhaps short thick trees/grasses...

To my mind this planet is most likely a Hot Venus type world - unsuited to life forms as we know them...