Wednesday, February 1, 2023

3855 - EXO-PLANETS - and gravitational waves

 

            -  3855 -   EXO-PLANETS  -  and gravitational waves.  -    Exoplanet astronomers are searching for planets around other stars that host conditions in which life can likely thrive, and simultaneously figuring out how to recognize whether an extrasolar planet can or does support life.

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            ----------------------  3855  -   EXO-PLANETS  -  and gravitational waves

           


            -     A whole new era of telescopes in space and on the ground is set to revolutionize astronomy in the next two decades.   From black holes to the search for life and beyond, all of astronomy's greatest mysteries are on the table, and, astronomers are already planning how to solve them, using tools that range from the biggest space telescopes to arrays of tiny radio telescopes scattered across a desert on Earth.

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            -    Recognizing life and understanding a planet's conditions are really complicated tasks. Not only do we need to look for the actual signs of life, known as biosignatures, but we also need to understand the context in which we spot those signs, the planet's environment, even including the behavior of the star it orbits. 

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            -    Looking ahead, the major Habitable Worlds Observatory (HWO), planned for the 2030s, will be able to peer deeper into these planets' atmospheres and give us an even better shot of finding life. Whereas JWST mainly uses transits, a planet crossing in front of its star, to observe Earth-size exoplanets, the Habitable Worlds Observatory will take a more direct approach, imaging the planets themselves, even down to Earth-like sizes.

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            -    Behemoth observatories here on Earth also promise new insights into the search for life. A new class of observatories known as "Extremely Large Telescopes" or ELTs are under construction in Hawaii and Chile. These mammoth projects will have mirrors around 98 feet in diameter, almost three times larger than any other optical telescope in existence.

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            -    The coming decades also promise new ways of “seeing” and hearing the universe, including the ability to detect more types of gravitational waves, or ripples in the fabric of space-time.

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            -    LIGO [the Laser Interferometer Gravitational Wave Observatory] is currently the only gravitational wave detector to have made a direct observation of gravitational waves,  However, LIGO is only looking at a small fraction of the whole spectrum of gravitational waves, there are plenty of signals it's not able to observe.

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            -    For these other gravitational waves, distinguished by their lower frequencies and longer-lasting signals, astronomers will need to wait for the space-based detector known as LISA, the Laser Interferometer Space Antenna. Like a massive LIGO detector, LISA will keep three satellites in a huge and perfect triangle as they all orbit the Earth together.

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            -    Astronomers will need another technique known as “pulsar timing”. Pulsars are spinning dead cores of large stars that each shoot two beams of light into space like a cosmic lighthouse. Pulsars are often used to time events in the cosmos because they're so predictable that their time-keeping would only be off by 100 nanoseconds over an entire decade.

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            -    As gravitational waves pass through pulsars, astronomers can spot the tiny changes in the pulsar's regular rhythm. This method promises to reveal colliding pairs of black holes in which each partner is around a billion times the mass of our sun; the technique can also begin watching a black hole up to 25 million years before the objects merge.

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            -    Tens of radio telescopes across the globe, from the Deep Synoptic Array in California to the MeerKAT telescope in South Africa, are undergoing upgrades and working together to gather the data needed for pulsar timing to reveal the impact of gravitational waves from supermassive black holes.

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            -     Scientists hope they will help answer our most fundamental questions: where did we come from, and are we alone? It's a historic time for astronomy, and for humankind as a whole.

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            January 28, 2022     EXO-PLANETS  -  and gravitational waves?           3855                                                                                                                           

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            --------------------- ---  Wednesday, February 1, 2023  ---------------------------

             

             

             

             

                     

             

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