- 4560 -
ASTRONOMY DISCOVERIES? -
The discovery 25 years ago, on April 15, 1999, astronomers found the first planetary system
outside our own. In the past 25 years,
astronomers also discovered hundreds of free-floating worlds that challenge the
definition of a planet, the long-sought "God particle,"
"ripples" in the fabric of spacetime, the sun's missing neutrinos,
the first real clue about the nature of dark energy, and a lot more.
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--------------- 4560
- ASTRONOMY DISCOVERIES?
-
------------------------ 1999: Planetary system
------------------------ 2001: 1st free-floating planet
------------------------ 2001: First exo-asteroid belt
------------------------ 2001: Sun's missing neutrinos
------------------------ 2001: 1st exoplanet with atmosphere
------------------------ 2007: Fast radio bursts
------------------------ 2012: Higgs boson
------------------------ 2016: Gravitational waves
------------------------ 2017: 1st interstellar visitor
------------------------ 2019: Supermassive black hole photo
------------------------ 2020: Milky Way map
------------------------ 2024: "Empty" galaxies
------------------------ 2024: Dark energy
------------------------ 2024: JWST reveals early universe
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- 1999: ASTRONOMERS DISCOVER A PLANETARY
SYSTEM OUTSIDE OUR OWN,
three planets orbit a star in
space. Astronomers found a trio of
Jupiter-size planets circling the sun-like, yellow-white star Upsilon
Andromedae A, located roughly 44 light-years from Earth. This was the first extraplanetary system ever
to be discovered.
-
- The discovery disproved the notion that our
solar system was a singular phenomenon in the universe and offered compelling
evidence that the discovery of other planetary systems was only a matter of
time and technology.
-
- In 2010, astronomers also found that unlike
the planets in our solar system, the Jupiter-size planets in this extrasolar
system do not orbit in the same plane. Rather, two are inclined by 30 degrees
with respect to each other, which helps astronomers refine theories of
planetary formation and evolution. As of
April 2024, astronomers have found close to 900 stars that host two or more
planets.
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- 2001: FIRST FREE-FLOATING PLANET DETECTED
IN THE MILKY WAY CHALLENGES THE TRADITIONAL DEFINITION OF A PLANET. Astronomers detected the first free-floating
planet hovering by itself in the nearby Trapezium Cluster, a stellar nursery
near the heart of the Orion Nebula.
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- In our galaxy alone, there may be as many as
a quadrillion of these "rogue planets," which are kicked out of the
star-circling disks of gas and dust in which they are born. Only a handful have
been found cruising through our galaxy, however; because they are ultra faint,
they are difficult to spot. The orphaned planets are the lightest products of a
star's birth and important carriers of information about the environments where
they formed.
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- 2001: FIRST EXO-ASTEROID BELT FOUND AROUND
A NEARBY, SUNLIKE STAR.
NASA's Spitzer Space Telescope found evidence
of the first asteroid belt outside the solar system around the nearby, sunlike
star HD 69830, located roughly 40 light-years away, in the constellation
Puppis.
-
- The belt is estimated to be 25 times more
massive than the main asteroid belt between the orbits of Mars and Jupiter. In
2005, astronomers discovered three Neptune-like planets orbiting this star,
with the outermost planet possibly within the star's habitable zone.
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- Astronomers are interested in the size and
location of asteroid belts in multiplanetary systems, as the rocky shards
influence the coalescence of planets and even the emergence of life. In our own
pocket of the cosmos, a leading theory is that asteroids delivered water and
organic compounds to early Earth, which is supported by recent detections of
water molecules in asteroid samples returned to Earth as well as a couple in
space.
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- 2001: MYSTERY OF SUN'S MISSING NEUTRINOS
SOLVED AFTER 30 YEARS. Physicists
announced that they had found the sun's missing neutrinos, subatomic particles
that have no charge and practically no mass. The detection ended a
three-decade-long search for the tiny packets of energy but implied they must
have a bit of mass.
-
- Nuclear reactions at the sun's heart — the
same process by which the sun shines — produce billions of neutrinos, half of
which were estimated to make the 93-million-mile journey to Earth. Yet
experiments during the late 1960s detected too few of the ghostly particles, a
discrepancy that came to be known as the solar neutrino problem.
-
- In 2001, experiments from the Sudbury
Neutrino Observatory in Canada revealed that the "missing" neutrinos
had, in fact, merely transformed into two other types of neutrinos on their way
to Earth and escaped detection. This transformation demands that the ubiquitous
neutrinos possess some mass, now estimated to be hundreds of thousands of times
less than the mass of the next-lightest particle, the electron.
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- 2001: FIRST EXOPLANET BLANKETED BY AN
ATMOSPHERE WIDENS EXOPLANET SCIENCE.
Astronomers entered a new phase of exoplanetary science when data from
the Hubble Space Telescope revealed for the first time the presence of an
atmosphere blanketing an alien world. The exoplanet, “HD 209458b”, is located
150 light-years away, in the constellation Pegasus. It was the first of many
exoplanets now known to host atmospheres ranging from vanishingly thin to very
dense, like Jupiter's.
-
- The discovery sparked a new era in
exoplanet exploration, as astronomers could begin to compare exoplanets'
atmospheres, including the abundances of atmospheric gases known to emerge from
life on Earth.
-
- 2007: FAST RADIO BURSTS REVEAL THE
UNIVERSE'S MISSING MASS. Astronomers
using the Parkes Observatory in Australia discovered a fast radio burst (FRB) —
a bright, incredibly short burst of radio waves — from a galaxy billions of
light-years from Earth. In just milliseconds, the intensely bright pulse, named
“Lorimer Burst FRB 010724”, blasted into space as much energy as the sun does
in 80 years.
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- Since then, hundreds of such intensely
bright pulses have been detected from faraway galaxies scattered across the
universe, including a few that seem to erupt repeatedly and irregularly. Astronomers have used the intense pulses to
find some of the universe's missing matter, which lurks in spaces between
galaxies and was detected by studying the dispersion of radio waves from FRBs
as they traveled through interstellar gas.
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- 2012: DISCOVERY OF THE HIGGS BOSON, THE
"GOD PARTICLE". The field of
particle physics captured the global spotlight with the discovery of the Higgs
boson, a long-sought subatomic particle that pervades the universe as a field
that gives other elementary particles their masses.
-
- The existence of the Higgs boson was first
predicted independently by physicists Peter Ware Higgs and François Englert in
1964, close to half a century before it was found by two experiments at the
Large Hadron Collider in Switzerland, which detected the "God
particle" within just two years of beginning operations.
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- 2016: DETECTION OF GRAVITATIONAL WAVES
CONFIRMS EINSTEIN'S THEORY, OPENS A NEW WAY TO VIEW THE UNIVERSE. Scientists using the Laser Interferometer
Gravitational-Wave Observatory announced that, in September 2015, they had
detected gravitational waves — faint ripples in space-time predicted by
Einstein a century ago — for the first time when those that emerged from
colliding black holes washed over Earth.
-
- Because these waves traveled unscathed
through sizzling matter of the early universe, their detection heralded a new
way of studying the universe that was never possible with electromagnetic
waves.
-
- Another new era in gravitational wave
astronomy began in June 2023, when scientists with the “North American
Nanohertz Observatory for Gravitational Waves” (NANOGrav) revealed compelling
evidence for the presence of a faint-but-persistent hum of gravitational waves
pervading the universe. They strongly suspect the hum, which, at one-billionth
of 1 hertz, was a few hundred times fainter than the gravitational waves
detected in 2015, represents a collective echo of supermassive black hole pairs
circling each other in orbits that shrink across millions of years.
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- 2017: FIRST INTERSTELLAR VISITOR SPOTTED IN
OUR SOLAR SYSTEM.
Astronomers spotted a strange
object zipping through our solar system — the first known interstellar visitor.
The identity of the object, dubbed 'Oumuamua, was shrouded in mystery because
its brightness varied more than what would be expected from an asteroid and it
didn't act like a comet.
-
- First considered an asteroid, “'Oumuamua”
was recast as a comet in 2023, with one group of astronomers suggesting it was
likely ejected from an extrasolar planetary system and accelerated by tiny
amounts of hydrogen gas emerging from the object's icy heart.
-
- In 2019, astronomers found the second
interstellar visitor, “Borisov”, which was soon confirmed to be a comet, with a
telltale gaseous coma. The rogue object, which never passed near a star until
visiting the sun, is considered the most pristine comet ever studied.
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- 2019: ASTRONOMERS PHOTOGRAPH A SUPERMASSIVE
BLACK HOLE. The Event Horizon Telescope,
a planet-scale array of eight ground-based radio telescopes forged through
international collaboration, captured this image of the supermassive black hole
in the center of the galaxy M87 and its shadow. The telescope project imaged the contours of
the monster black hole lurking at the heart of the Messier 87 galaxy, which is
located over 50 million light-years from Earth. The image opened up a new way
to study black holes and was likened to the first illustrations of what insects
and plants look like through a microscope.
-
- In 2021, astronomers unveiled a new image
of the object that shed light on how magnetic fields behave close to black
holes. In 2023, the black hole image got an AI makeover, which turned the
"fuzzy orange doughnut" into a skinny ring. Astronomers also found
that the black hole is spinning, although the rate of spin remains unclear.
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- 2020: MILKY WAY GETS THE MOST DETAILED MAP
EVER. The most detailed map ever of the
Milky Way plotted in 3D nearly 1.8 billion stars in unprecedented detail using
data from the European Space Agency's Gaia spacecraft. As mind-boggling as the
1.8 billion stars may be, they represent just over 1 percent of our entire
galaxy's stars. Astronomers say studying the motions of these plotted stars
could reveal long-sought clues about the nature of dark matter.
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- 2024: STARLESS, "EMPTY" GALAXIES
BEGIN COMING INTO VIEW. Astronomers
announced that they had spotted a primordial galaxy that is so diffuse that it
hasn't formed stars. The discovery challenges leading theories of how galaxies
form and evolve and even the conventional definition of a galaxy. What is a galaxy without stars?
-
- A different team reported the discovery of
another almost-empty galaxy called “Nube”, which is Spanish for
"cloud." Unlike our galaxy's
central bulge, Nube is puzzlingly uniform and intriguingly isolated roughly 300
million light-years from Earth; its closest large neighbor is at least 1.4
million light-years away.
-
- Such "dark" galaxies, which were
once thought to outnumber all visible galaxies, shine hundreds of times fainter
than the Milky Way, whose light is powered by roughly 100 billion stars.
Astronomers continue to puzzle over why these "ghost" galaxies lack
stars even though they contain pristine star-forming gas.
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- 2024: DARK ENERGY MAY BE EVOLVING. Physicists have long considered dark energy —
the mysterious force driving the accelerated expansion of the universe — a
"cosmological constant," meaning it remains constant throughout the
history of the universe.
-
- However, astronomers who created the
largest 3D map of the universe suggested that dark energy may be evolving with
time. The discovery might be the first real clue about the elusive phenomenon
in the past two decades and one that would be as revolutionary as the discovery
of the accelerated expansion of the universe itself, if confirmed with future
data.
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- 2024: DWARF GALAXIES FLOODED THE EARLY
UNIVERSE WITH ITS FIRST LIGHT, JWST REVEALS.
Astronomers have long wondered just how the universe resurfaced from the
cosmic dark ages, when the cosmos was cloaked in dense fog of neutral hydrogen
gas, to make way for the first starlight.
-
- Using the James Webb Space Telescope (JWST)
astronomers revealed dwarf galaxies that existed in the first few hundred
million years packed enough punch to flood the early universe with its first
light. The discovery is a remarkable testament to the telescope's unprecedented
infrared capabilities that allow it to collect light from the faintest objects.
-
- JWST's amazing discoveries and breathtaking
views have stunned the world since the observatory began operations in 2022.
For instance, the telescope captured the "Pillars of Creation,"
revealing in stunning detail both the colorful tapestry of the dusty cloud
formation and the cosmic processes occurring in the region.
-
- JWST continues to awe astronomers and the
public alike with its detailed images of the most distant galaxies in the
universe, faraway supermassive black holes, exoplanets and more.
-
-
September 20, 2024 ASTRONOMY DISCOVERIES?
4560
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--------------------- --- Friday, September 20,
2024
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