- 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.
-
- 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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