- 4517
- WEBB TELESCOPE
- new discoveries in
astronomy? - On Christmas morning two years ago was the
launch of the James Webb Space Telescope (JWST), the world's biggest, most
daring endeavor to probe the earliest stars and galaxies in the universe.
-
------------------------------ 4517
- WEBB TELESCOPE
- new discoveries in astronomy?
-
---- 1. The JWST takes a fresh look at our solar
system
---- 2. Nearby exoplanet has abundant
life-supporting molecules
---- 3. The JWST discovers its smallest object yet
---- 4. The JWST finds massive, mysterious
galaxies in the infant universe
---- 5. An intensifying debate over the universe's
expansion rate
---- 6. Shining a spotlight on the first
supermassive black holes
---- 7. Complex organic molecules in a primordial
galaxy
---- 8. Maisie's galaxy is among the earliest ever
spotted
---- 9. The most distant supermassive black hole
ever seen
---- 10. The JWST rediscovers an ancient ghostly
galaxy
---- 11. The JWST spots 3 possible fabled
"dark stars"
---- 12. The earliest galaxies looked surprisingly
similar to our Milky Way
-
------------------ 1. THE JWST TAKES A FRESH LOOK AT OUR SOLAR
SYSTEM
-
- Although the JWST's purpose is to see some
of the first stars and galaxies in the universe, its fresh look at our own
solar system has been nothing short of breathtaking. The JWST identified carbon dioxide in the
salty liquid oceans of Jupiter's icy moon Europa for the first time.
-
- The space observatory also offered a new
look at Saturn captures the gas giant's delicate ring system and three of its
146 known moons. The gas giant is eerily dark when seen through the JWST's
infrared eyes, because in this wavelength, methane gas absorbs almost all of
the sunlight falling on the atmosphere.
-
------------------ 2.
EXOPLANET HAS ABUNDANT LIFE-SUPPORTING MOLECULES
-
- JWST discovered methane and carbon dioxide
in the atmosphere of a fairly nearby exoplanet named “K2-18 b”, which circles a
cool star 120 light-years from Earth and is larger than our planet but smaller
than the giant planets in our solar system.
-
- Previous observations with the Hubble Space
Telescope had indicated that K2-18 b may be
a "Hycean world," an exoplanet that hosts thick, hydrogen-rich
atmospheres with oceans of liquid water underneath. Recent observations with
the JWST support that hypothesis, as the new data shows evidence for abundant
methane and carbon dioxide but little ammonia.
-
------------------ 3. THE JWST DISCOVERS ITS SMALLEST OBJECT YET
-
- JWST's unexpected discovery of a small
asteroid embedded in the main asteroid belt between Mars and Jupiter. Like most
residents of that region, the space rock, which is about as tall as the
Washington Monument, is thought to be a remnant of the formation of the solar
system and thus contains tantalizing history about its evolution.
-
- Asteroids less than a mile long are
difficult to spot with other telescopes, so the find underscored the
telescope's usefulness closer to home.
-
------------------ 4.
JWST FINDS MASSIVE GALAXIES IN THE INFANT UNIVERSE
-
- The discovery of galaxies as massive as the
Milky Way sprinkled across the JWST's images of the universe just 500 million
to 700 million years after the Big Bang. From what existing theories and models
tell us, the galaxies the JWST found are too big, and the mature red stars in
them too old, that the study authors said the find "creates problems for
science."
-
- It calls the whole picture of early galaxy
formation into question.
-
------------------ 5. INTENSIFYING DEBATE OVER UNIVERSE'S
EXPANSION RATE
-
- A large galaxy takes up the entirety of the
image. The galaxy has a bright white core, and several large spiral arms
extending out from that core, rotating clockwise. The arms are light blue with
many pink speckles and clumps littering the arms. The background is also filled
with a smattering of white and pink dots.
-
- Combined observations from NASA’s NIRCam
(Near-Infrared Camera) and Hubble’s WFC3 (Wide Field Camera 3) show spiral
galaxy NGC 5584, which resides 72 million light-years away from Earth.
-
- We know that the universe is expanding at
an ever-increasing rate, but we don't know precisely how fast. The issue has
become a debate centered on resolving the correct value of the “Hubble
constant”, an important number for estimating the universe's expansion rate.
Right now, model estimates for the Hubble constant don't agree with values
based on telescope observations.
-
- JWST observed a class of stars known as
Cepheid variables, which are usually humongous stars some 100,000 times
brighter than the sun and the most reliable source to measure cosmic distances
(and thus to tease out the universe's expansion rate). But instead of resolving
the debate, the JWST's data only deepened the ongoing debate over the Hubble
constant.
-
- We want to understand why our best tools —
our gold standard tools — are not agreeing with each other. James Webb Space Telescope deepens major
debate over universe's expansion rate
-
------------------ 6. A
SPOTLIGHT ON THE FIRST SUPERMASSIVE BLACK HOLES
-
- The JWST helped astronomers see starlight
from two early galaxies where they think one of the first supermassive black
holes emerged. The JWST observed the galaxies as they were when the universe
was younger than 1 billion years, showing how, over time, black holes gain
unfathomable masses — often millions or billions of times that of the sun.
-
------------------ 7. COMPLEX ORGANIC MOLECULES IN A PRIMORDIAL
GALAXY
-
- Astronomers using the James Webb Space
Telescope discovered evidence of complex organic molecules similar to smoke or
smog in the distant galaxy shown here. The galaxy, more than 12 billion light
years away, happens to line up almost perfectly with a second galaxy only 3
billion light years away from our perspective on Earth.
-
- Astronomers using the James Webb Space
Telescope discovered evidence of complex organic molecules similar to smoke or
smog in the distant galaxy shown here.
JWST had detected intriguing carbon-based molecules, similar to the ones
found in oil and coal deposits on Earth, from over 12 billion years ago, when
the universe was just 10% of its current age. In space, these molecules link to
minuscule dust grains.
-
------------------ 8.
MAISIE'S GALAXY IS AMONG THE EARLIEST EVER SPOTTED
-
- The blurry orange blob, imaged by the JWST
in summer 2022, is known as Maisie's galaxy, and in August 2023, astronomers
announced that it's one of the earliest galaxies ever discovered. The galaxy
seems to have existed when the universe was only 390 million years old, making
it one of the four earliest galaxies ever seen.
-
- This was the undiscovered frontier where we
really didn't know how the galaxies formed or what they looked like until we
went and looked for them with the JWST.
-
------------------ 9. THE MOST DISTANT SUPERMASSIVE BLACK HOLE
EVER SEEN
in a deep view of space
showing thousands of galaxies
-
- JWST had detected the most distant active
supermassive black hole ever seen, whose host galaxy formed just 570 million
years after the Big Bang. However, this ancient black hole has puzzlingly low
mass, just 9 million times that of the sun. For comparison, most of these
cosmic beasts weigh over 1 billion solar masses. It is still difficult to explain how it
formed so soon after the universe began.
-
------------------ 10. THE JWST REDISCOVERS AN ANCIENT GHOSTLY
GALAXY
a blurry, pixelated red and
green splotch dissipates outward to black.
-
- The JWST's sighting of a fuzzy galaxy
embedded deep inside a dust cloud has been of recent interest to astronomers,
in part because it is seen as it appeared just 900 million years after the Big
Bang, when the very first stars were appearing. But astronomers are also
interested in the science lessons this galaxy is waiting to reveal,
"potentially telling us there's a whole population of galaxies that have
been hiding from us.
-
------------------ 11. THE JWST SPOTS 3 POSSIBLE FABLED
"DARK STARS"
-
- JWST had found three bright objects that
could possibly be "dark stars," a reference to the Grateful Dead song
"Dark Star." The "stars" were originally tagged as galaxies
by the JWST in 2022.
-
- When we look at the James Webb data, there
are two competing possibilities for these objects. One is that they are galaxies containing
millions of ordinary, population-III stars. The other is that they are dark
stars. One dark star has enough light
to compete with an entire galaxy of stars.
-
- Astronomers think these types of stars are
powered by dark matter, the elusive substance that makes up 85% of the matter
in our universe but is invisible to telescopes. If dark stars really do exist,
their presence would help solve the puzzling observations of how a very young
universe grew to host so many large galaxies as observed by the JWST.
-
------------------ 12.
EARLIEST GALAXIES LOOKED SIMILAR
TO OUR MILKY WAY
-
- Galaxy evolution theories have predicted
that the earliest galaxies in our universe were too young to flaunt any
noticeable features, like spiral arms, bars or rings; astronomers have thought
these more complex structures began appearing about 6 billion years after the
Big Bang. But this year, the JWST found that galaxies with such delicate shapes
could have existed as early as 3.7 billion years after the Big Bang.
-
- Astronomers must rethink our understanding
of the formation of the first galaxies and how galaxy evolution occurred over
the past 10 billion years.
-
-
July 1, 2024 WEBB
TELESCOPE - new discoveries in astronomy? 4517
------------------------------------------------------------------------------------------
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------ “Jim Detrick” -----------
--------------------- --- Tuesday, July 2, 2024
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