We may have found 20 habitable worlds hiding in plain sight

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By John Wenz

There could be more habitable planets out there than we thought. An analysis of data from the Kepler space telescope has revealed 20 promising worlds that might be able to host life.

The list of potential worlds includes several planets that orbit stars like our sun. Some take a relatively long time to complete a single orbit, with the longest taking 395 Earth days and others taking Earth weeks or months. The fastest orbit is 18 Earth days. This is very different to the very short “years” we see around smaller stars with habitable planets like Proxima Centauri.

The exoplanet with a 395-day year is one of the most promising worlds for life on the list, says Jeff Coughlin, a Kepler team lead who helped find the potential planets. Called KOI-7923.01, it is 97 per cent the size of Earth, but a little colder.

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3 COMMENTS

  1. @OP – We may have found 20 habitable worlds hiding in plain sight

    “May have”, is a long way from “confirmed”!

    Earth sized planets are NOT Earth type planets! (Check out Venus)

    These are discoveries which merit further investigation, but there are good reasons to believe many Earth size planets are NOT habitable by humans, and may well be not habitable by other Earth life forms either over the extended periods of time which are required for life to evolve!

  2. I see HARPS has found another POSSIBLE candidate for a planet with life or capable of supporting life!

    http://www.bbc.co.uk/news/science-environment-41995572

    Astronomers have found a cool, Earth-sized planet that’s relatively close to our Solar System.

    The properties of this newly discovered planet – called Ross 128 b – make it a prime target in the search for life elsewhere in the cosmos.

    At just 11 light-years away, it’s the second closest exoplanet of its kind to Earth.

    The closest one, known as Proxima b, looks to be less hospitable for life.

    Found in 2016, it orbits the star Proxima Centauri, which is known to be a rather active “red dwarf” star. This means that powerful eruptions of charged particles periodically batter Proxima b with harmful radiation.

    The new planet, Ross 128 b, orbits a star that’s not dissimilar to Proxima Centauri (it’s also a red dwarf), but is significantly less active.

    “But we still need to know what the atmosphere of Ross 128 b is like. Depending on its composition and the reflectivity of its clouds, the exoplanet may be life friendly with liquid water as the Earth, or sterile like Venus.”

    The new world was discovered by a team using the High Accuracy Radial velocity Planet Searcher (Harps) instrument at the La Silla Observatory in Chile. The work will be published in the journal Astronomy & Astrophysics.

    Dr Astudillo-Defru said the find was the result of more than a decade of “intensive monitoring” using the Harps instrument.

    Ross 128 b orbits 20 times closer to its star than the Earth orbits the Sun. But because its parent star is much smaller and dimmer than our yellow sun, it receives only a little more solar radiation than Earth.

    Consequently, it is expected to have a surface temperature close to that on our own planet.

    In the search for habitable worlds beyond our Solar System, astronomers generally look for low-mass, rocky and temperate planets like our own.

    At “just” 4.2 light-years away, Proxima b is the closest exoplanet with a mild temperature. But it receives about 30 times more extreme ultraviolet radiation than Earth. Ross 128 b, on the other hand, is the “quietest” nearby star to host a temperate exoplanet.

    There’s still uncertainty about whether Ross 128 b is within its star’s habitable zone, but scientists say that with temperatures of between -60 and +20°C, it can be considered temperate.

    Next, astronomers want to study the atmospheric composition and chemistry of suitable, nearby worlds like Ross 128 b. The detection of gases such as oxygen could potentially point to biological processes on planets orbiting other stars.

    Several gases have already been detected in the atmospheres of exoplanets, but this line of enquiry is expected to be boosted immeasurably when observatories such as the European Southern Observatory’s Extremely Large Telescope (E-ELT) and Nasa’s James Webb Space Telescope (JWST) come online in the next few years.

    Although currently 11 light-years from Earth, the new planet’s parent star Ross 128 is moving towards us and is expected to overtake Proxima Centauri as our nearest stellar neighbour in just 79,000 years – a heartbeat on cosmic timescales.

  3. Meanwhile, as we contemplate other planetary systems, it seems part of one of them is visiting us, but looks like it is only passing through the Solar System on a “fly-by”!
    Perhaps we should be thankful that it is an asteroid and not a planet – with all the disruptive potential to orbits which a planet would bring!

    http://www.bbc.co.uk/news/science-environment-42019778

    The first known asteroid to visit our Solar System from interstellar space has been given a name.

    Scientists who have studied its speed and trajectory believe it originated in a planetary system around another star.

    The interstellar interloper will now be referred to as ‘Oumuamua, which means “a messenger from afar arriving first” in Hawaiian.

    The name reflects the object’s discovery by a Hawaii-based astronomer using an observatory on Maui.

    It was discovered on 19 October this year by Rob Weryk, a postdoctoral researcher at the University of Hawaii Institute for Astronomy.

    Weryk and fellow Institute for Astronomy researcher Marco Micheli realised it was going extremely fast (with enough speed to avoid being captured by the Sun’s gravitational pull) and was on a very eccentric trajectory taking it out of our Solar System.

    Scientists who have made observations of ‘Oumuamua, say that despite its exotic origins, the asteroid is familiar in appearance.

    In a paper submitted to Astrophysical Journal Letters , they argue that its size, rotation, and reddish colour are similar to those of asteroids in our Solar System.

    Measuring about 180m by 30m, it resembles a chunky cigar.

    “The most remarkable thing about [‘Oumuamua] is that, except for its shape, how familiar and physically unremarkable it is,” said co-author Jayadev Rajagopal from the US National Optical Astronomy Observatory (NOAO).

    If planets form around other stars the same way they did in the Solar System, many objects the size of ‘Oumuamua are predicted to be slung out in the process.

    “U1 may provide the first direct evidence that planetary systems around other stars ejected objects as they formed,” said Dr Rajagopal.

    The object has also been given the more formal designation of 1I/2017 U1 by the International Astronomical Union (IAU), which is responsible for naming celestial bodies.

    The “I” in this formal name stands for “interstellar” object, similar to the “C” and “A” in the designations for comets and asteroids, respectively.

    ‘Oumuamua is the first object to carry the “I” in front of its name.

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