- 4633
- WEBB DISCOVERIES - The James Webb Space Telescope since coming
online in mid-2022, the most powerful telescope ever built has both blown our
minds with its stunning images and swept away many of our preconceptions about
the early universe.
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------------------------------------------ 4633
- WEBB DISCOVERIES
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- The oldest ever black holes, a preview of
our solar system's gory demise, and a measurement of distant starlight that
threatens to bring the standard of cosmology crashing down, here are the JWST's
wildest discoveries of 2023.
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- Not long after coming online, the JWST
immediately discovered six enormous "universe breaker" galaxies,
containing what seemed to be almost as many stars as the Milky Way, dating to
just 500 million years after the Big Bang.
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- The strange discovery pointed to a deepening
mystery around how large galaxies first bloomed in our universe. After running
simulations, other astronomers suggested that the galaxies might not contain as
many stars as first seemed, and could instead just be glowing unusually
brightly.
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- The universe is expanding, but depending on
where cosmologists look, it's doing so at different rates. In the past, the two
best experiments to measure the expansion rate were the European Space Agency's
Planck satellite (which gave a most likely expansion rate of 67 kilometers per
second per megaparsec) and the Hubble Space telescope, which studied pulsating
stars called Cepheids and found a higher value of 73 km/s/Mpc.
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- Cosmologists thought this tension might be
down to uncertainty caused by Hubble not distinguishing between Cepheids and
background stars, but the JWST snuffed out that hope with a result of 74
km/s/Mpc.
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- There weren't just inexplicably large
ancient galaxies on the JWST's list of discoveries this year, but whopping
black holes too. The first, CEERS 1019, had a mass 10 million times that of our
sun and was found by the JWST just 570 million years after the Big Bang, making
it the oldest black hole ever spotted at the time of its discovery in April
2023.
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- The telescope later discovered an even
older massive black hole 440 million years after the universe began. How these gigantic space-time ruptures
swelled to such staggering scales so early on is an ongoing mystery.
Astrophysicists are currently exploring options that include the black holes
being formed from the rapid collapse of giant gas clouds.
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- The telescope's ultrapowerful eye has also
revealed glimpses of completely new, unexplainable objects. After being trained
on the Orion Nebula, the JWST found 42 pairs of Jupiter-mass binary objects, or
"JuMBOs", Jupiter-sized planets drifting through space in pairs, some
as far apart from each other as 390 times the distance between Earth and the
sun.
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- The JuMBOs are too small to be stars, but
as they bafflingly exist in pairs, they are unlikely to be rogue planets
ejected from solar systems. Their discovery has alerted astronomers to a
brand-new formation mechanism for planets or even for failed stars.
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- Another feature of the JWST is its ability
to measure a spectrum of the atmospheres of distant exoplanets, a toolkit which
enabled it to spot the potential signs of life in "alien farts" on a
Goldilocks water world 120 light-years away.
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- The exoplanet it found, “K2-18 b”, is a
sub-Neptune planet (weighing in somewhere between the mass of Earth and
Neptune) orbiting the habitable zone of a red dwarf star. After taking an
atmospheric spectrum, the JWST found it rich with hydrogen, methane and carbon
dioxide, all chemical markers of a hydrogen-rich hycean world that is a prime
contender for extraterrestrial life.
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- More tantalizing still was the detection of
dimethyl sulfide (DMS), a cabbage-smelling compound only known to be produced
by microscopic algae in Earth's oceans.
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- Stars and galaxies aren't evenly spread
throughout our universe. Instead, they're connected by an enormous cosmic web,
a gigantic network of crisscrossing celestial superhighways paved with hydrogen
gas and dark matter.
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- Taking shape in the chaotic aftermath of the
Big Bang, the web's tendrils formed as clumps from the roiling broth of the
young universe; where multiple strands of the web intersected, galaxies
eventually formed.
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- Insights into the structure of this web not
only give us a glimpse of the chaotic particle interactions that led to a
universe existing in the first place, so astronomers using the JWST were
stunned when they spotted the earliest strand of this web ever seen a gassy
tendril made of of 10 closely packed galaxies spanning more than 3 million
light-years in length.
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- The filament formed when the universe was
just 830 million years old, and is partially wrapped around a bright black
hole. In the field of one of JWST's
largest-area surveys, COSMOS-Web, an Einstein ring was discovered around a
compact, distant galaxy. It is the most distant gravitational lens ever
discovered by a few billion light-years.
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- Besides making for a very pretty picture,
distantly-lensed light shows like this could help astronomers to understand the
puzzling nature of dark matter: the unseen substance believed to make up 70% of
the universe's matter.
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- The donut-shaped Ring Nebula, also known as
Messier 57 (M57), is a 2,200 light-years distant corpse of an exploded star,
harboring at its center a tiny pinprick of a white dwarf that is the last
remaining piece of the star's core.
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- As it reached the end of its life, the star
exploded outwards, hurling its innards far and wide to form what looks like a
gigantic eye. The explosion likely obliterated or ejected any unfortunate
planets in its way, a fate that will similarly befall our own solar system in 5
billion years time.
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December 4, 2024 WEBB DISCOVERIES 4633
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--------------------- --- Saturday, December 7,
2024
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