-
3826 - EARTH'S
- orbit changes around the
Sun? On January 4, 2023, Earth will reach its closest point to the sun
all year in an annual event called “perihelion”. The precise distance varies
from year to year, but -perihelion 2023 will see our planet orbiting 91.4
million miles from the sun, or roughly 3
million miles closer than Earth's “aphelion”, its farthest point from the sun,
which will occur on July 6, 2023.
--------------- 3826 - EARTH'S - orbit changes around the Sun?
- On January 4 and 5, 2023, a slow-moving
glob of solar particles called a “coronal mass ejection” (CME) will slam into
Earth's magnetic field. The collision is
expected to trigger a minor G1-class geomagnetic storm that could briefly frazzle
power grids, cause radio blackouts and push colorful auroras much farther south
than usual as far south as Michigan and Maine in the United States.
-
- Earth doesn't orbit the sun in a perfect
circle but rather in a wobbly ellipse. This elliptical orbit naturally means
Earth moves closer to the sun during certain parts of the year and farther away
during others. For many years now,
Earth's perihelion has occurred within a few weeks of the winter solstice, the
official beginning of winter in the Northern Hemisphere, when the North Pole is
at its farthest tilt away from the sun and the South Pole tilts closer toward
the sun.
-
- The solstice is Earth's tilt toward or away
from the sun, while perihelion is about the planet's physical distance from the
sun. The actual date of perihelion is
always shifting, changing by about two days every century due to small quirks
in our planet's orbit.
-
- In the year 1246, perihelion and the winter
solstice actually occurred on the same day. Thousands of years from now, in the
year 6430, perihelion will line up perfectly with the spring equinox on March
20.
-
- This year 2023 perihelion lines up with a
geomagnetic storm. These storms occur
when charged solar particles crash into Earth's magnetic field ( the
magnetosphere), compressing it slightly and allowing some particles to rain
down on the planet's upper atmosphere.
-
- Most geomagnetic storms are minor,
resulting in clearer auroras and occasional radio blackouts at high latitudes.
But some, such as the infamous Carrington Event of 1859, can push auroras from
both poles all the way down to the equator and cause mass electrical
disruptions around the world.
-
- Geomagnetic storms are triggered by CMEs,
giant outbursts of charged particles released from the sun when magnetic-field
lines at the sun's surface become too tangled and suddenly snap. These magnetic
tangles are often associated with sunspots, dark regions of intense magnetic
activity that periodically open and close on the sun's surface.
-
- If a sunspot is pointed toward Earth during
one of these magnetic snaps, the resulting CME will blast toward us over the
course of several days. The CME expected that hit Earth on January 4 and 5
burst out of an Earth-facing sunspot on December 30.
-
- The sun follows an “11-year cycle” of
activity, with more sunspots appearing close to the period of peak activity,
known as the solar maximum. NASA predicts that the next solar maximum will
occur in July 2025. As this point approaches, solar storms will become more
frequent and more intense.
-
- Every 200 million years, high-energy comets
may pelt our planet as it passes through our galaxy's spiral arms. Earth's journey through the Milky Way may
have had a profound impact on our planet's geology. When Earth passes through its galaxy's spiral
arms, the planet is pummeled with high-energy comets, and this bombardment may
thicken Earth's continental crust.
-
- The dense clouds of gas in the spiral arms
may interact with comets at the edge of the solar system, sending them hurtling
toward Earth. This conclusion was made by examining zircon crystals from two of
Earth's oldest continents and regions, where the planet's earliest continental
history is preserved, the North American Craton, in Greenland, and the Pilbara
Craton, in Western Australia.
-
- The decay of uranium in “zircon” crystals
in these regions has been used to create a geological timeline spanning 1
billion years, from 2.8 billion to 3.8 billion years ago, during the “Archean
eon”. This timeline could help geologists discover how Earth became the only
planet known to have continents and active plate tectonics.
-
- Isotopes of the element “hafnium” in zircon
enable scientists to spot periods in Earth's history that experienced an influx
of juvenile magma which is magma containing elements that have never reached
the surface before, a sign of crust production.
-
- Over a long timescale, patterns of crust
production corresponded with galactic years .
A galactic year is the time it takes the sun to complete an orbit
around the center of the Milky Way.
-
- These findings were further supported by
examinations of oxygen isotopes, which revealed a similar pattern. Not only does the solar system travel around
the Galactic Center, but the spiral arms that radiate from it also turn, at a
different rate.
-
- The sun orbits the Galactic Center at
around 536,000 mph, while the spiral arms turn at approximately 47,000 mph.
This means the sun and the solar system, as well as many of the Milky Way's
other stars, move in and out of the spiral arms.
-
- When the solar system moves into the spiral
arms, icy planetesimals in the Oort cloud at its outer edge ( 4.6 trillion
miles from the sun) interact with dense gas clouds of the whip-like arms,
sending icy material hurtling toward the inner solar system and our planet.
-
- These objects arrive with more energy than
the asteroids that regularly pelt Earth. Most of those space rocks come from
the main asteroid belt between Mars and Jupiter , a region that is much closer
to Earth than the Oort cloud is.
-
- The influence of impacts on rock formation
and increased crustal generation was also apparent in the team's examination of
spherule beds, which are deposits of small spheres created by ejected material
that cools, condenses and falls back to Earth after impacts.
-
- Spherule beds were also correlated with
Earth's passage into the Milky Way's dense spiral arms between around 3.3
billion and 3.5 billion years ago, when the planet was just over 1 billion
years old.
-
- Determining the ages of more deposits in
spherule beds could further support the findings and, in turn, encourage
geologists and astrophysicists to start thinking more about the influence of
Earth's wider cosmic environment on the planet's geology.
-
January 10, 2022 EARTH'S
- orbit changes around the Sun? 3826
----------------------------------------------------------------------------------------
-----
Comments appreciated and Pass it on to whomever is interested. ---
--- Some
reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email
feedback, corrections, request for copies or Index of all reviews
---
to: ------ jamesdetrick@comcast.net ------
“Jim Detrick” -----------
--------------------- --- Sunday, January 15, 2023 ---------------------------
No comments:
Post a Comment