- 4259 -
PARKER SUN PROBE
- The Parker Solar Probe on
September 27th, 2023, made its 17th
close approach and skimmed just 4.51 million miles above the sun’s “surface”
layer (called the photosphere). That’s
just the latest achievement by the probe, which also became the first-ever
spacecraft to fly through a “coronal mass ejection”.
-------------------------- 4259 - PARKER SUN PROBE
- The spacecraft’s most recent accomplishment was set up by a gravity-assist flyby of Venus in late August. During the closest approach, the Parker Solar Probe was moving at 394,735 miles per hour.
- Both the close
approach and the CME encounter are just two of many highlights of a mission
that’s planned to continue its studies of the Sun and solar environment through
mid-2025.
-
- The spacecraft is
in pretty good shape, considering what it’s experiencing during the mission.
Parker does all this while experiencing temperatures up to 1400 C. Its main
instruments are protected by shielding, which allows them to operate in a
near-normal room-temperature environment.
-
- Solar scientists
sent Parker to help them understand some of the most puzzling aspects of our
star’s activities. Its main target is the solar corona. They want to figure out
what heats the corona by tracing the flow of energy that heats this uppermost
part of the solar atmosphere. They want to understand how and why the solar
wind gets accelerated as it leaves the Sun.
-
-
- Since the Sun is
largely plasma, they want to understand its structure and the magnetic fields
that exist and influence the flow of plasma from the Sun through the solar
wind. The mission is equipped to study energetic particles flowing from the Sun
and determine their transport mechanism.
-
- We on Earth
experience coronal mass ejections as they pass from the Sun on their way
through the Solar System. These powerful events hurl huge masses of plasma
through space, moving at speeds of 100 to 3,000 kilometers per second.
-
- Many CMEs do not
encounter our planet, but when they do, they twist and stretch our planet’s
magnetic field. The results can range from beautiful displays of aurora
borealis to disruption of communications and electrical grids.
-
- Solar physicists
would like to be able to forecast these awesome solar storms. They’ve long
wanted to measure the forces that drive CMEs. In particular, they want to know
what accelerates the charged particles in the explosions to high speeds. They
hope that Parker can give them data on just what’s happening on the Sun as one
builds up.
-
- On On September 5, 2022, Parker was cruising the
far side of the Sun. It flew just about 6 billion kilometers above the surface.
That’s when it detected the CME as it built up. Later on, the spacecraft passed
through the structure of the ejection, experienced its leading edge, and then
exited the material.
-
- It was a pretty
extreme CME and allowed Parker to pick up data about the shock wave’s speed and
density. Luckily, this one didn’t hit Earth. However, if it had, the event
would have severely damaged communications systems and probably caused
widespread power blackouts.
-
- This is the
closest to the Sun we’ve ever observed a CME.
We’ve never seen an event of this magnitude at this distance. To get the scientific information to
understand the corona and CMEs, scientists needed a spacecraft that could
essentially fly through the Sun, or at least its corona. A heat shield, onboard radiators, and a
thermal protection system protect it from CMEs and the solar wind. During the
CME, the only effect it suffered was a little “torque”, a small turning action
that it compensated for immediately.
-
- For the rest of
this year and into 2024, Parker will be following close orbits around the Sun.
In late 2024, it will make its final Venus flyby, which will set the last three
perihelion passages into 2025. In all, scientists plan for 24 perihelion
passages before the mission ends. The data it is providing should open new
windows of understanding about the solar wind and the processes that launch it
through the Solar System.
-
- The fierce
eruptions of the CME's can expel magnetic fields and sometimes billions of tons
of plasma at speeds ranging from 60 to 1,900 miles per second. When directed
toward Earth, these ejections can bend and mold our planet’s magnetic field,
generating spectacular auroral shows.
-
- Cruising on the far
side of the Sun just 5.7 million miles from the solar surface, 22.9 million
miles closer than Mercury ever gets to the Sun, Parker Solar Probe first
detected the CME remotely before skirting along its flank. The spacecraft later
passed into the structure, crossing the wake of its leading edge (or shock
wave), and then finally exited through the other side.
-
- In all, the
Sun-grazing spacecraft spent nearly two days observing the CME, providing
physicists an unparalleled view into these stellar events and an opportunity to
study them early in their evolution.
-
- The CME on
September 5, 2022, was an extreme one. As Parker passed behind the shock wave,
its Solar Wind Electrons, Alphas and Protons (SWEAP) instrument suite clocked
particles accelerating up to 840 miles per second. Had it been directed toward
Earth, it would have been close in
magnitude to the Carrington Event, a solar storm in 1859 that is held as the
most powerful on record to hit Earth.
-
- Physicists have
surmised that such an event today, if detected too late, could disable
communications systems and spawn continent-wide blackouts. Despite the eruption’s power, Parker seemed
unfazed. Its heat shield, radiators and thermal protection system ensured the
Probe’s temperatures never changed.
-
- Its autonomy
system even triggered mitigation plans so the avionics suite worked without
interruption. In fact, the only effect the CME had on the spacecraft was a
slight torque, a tiny turn for which it quickly compensated.
-
- Physicists have
been interested in deciphering the forces that drive these stellar explosions
and accelerate particles to such incredible clips. The only way to do that was
to fly through one at the Sun.
-
- There were three
major intervals during the event, but piecing them together was particularly
confusing. Two sections they had seen before in CMEs when they arrived at
Earth: the shock wave near the event’s front followed by CME plasma, and
another portion with magnetic and plasma characteristics typical of the Sun’s
solar wind. But the third section, a low-density-region with slow-moving
particles during the event, was new and odd.
-
- With the Sun near
the peak of its activity cycle, CMEs should happen more frequently. The Parker Solar Probe will fly through
several more ejections as it winds ever closer to the Sun.
-
- Scientists in
the United States are excited to use the October "ring of fire"
eclipse as valuable practice for a total eclipse in the Americas next
year. North America will experience an
annular "ring of fire" solar eclipse on October 14, that crosses eight U.S. states in between
Oregon and Texas.
-
- An annular eclipse
occurs when the moon is further away from Earth, causing it to be slightly
smaller than the sun in the sky. The smaller moon is unable to block the entire
disk of the sun, creating a "ring of fire" for a few minutes when the
moon passes in front of the sun.
-
- Scientists will be
able to view a very active corona, or upper atmosphere of the sun, during the
precious minutes that the sun is nearly completely blocked by the moon. The sun
is nearing its maximum of solar activity in its 11-year-cycle, unlike the last
U.S. total solar eclipse of 2017, meaning that the corona will be very active
this time around.
-
- Solar activity has
an immense impact on the ionosphere, which is a layer of Earth's atmosphere
that interacts with electromagnetic radiation from above and below its extent.
These interactions affect the propagation of radio signals.
-
- With the sun mostly
blacked out temporarily by the eclipse, NSF will be carefully watching what
happens "when you suddenly turn off that X-ray and the ultraviolet"
rays from the sun that usually filter into the ionosphere and affect its
extent. The ionosphere actually expands
and contracts depending on how much energy it is absorbing from the sun.
-
- The ham radio
community will also help with ionospheric studies during the eclipse, using
their GPS receivers to help professional scientists track changes in that layer
of the Earth's atmosphere.
-
- Scientists will be
watching local weather to see how it is affected by the lack of solar
radiation. The moon's shadow traverses
across the atmosphere at supersonic speeds, so things change pretty fast and
very quickly throughout the eclipse region.
-
- Once this
eclipse campaign is over, NSF says no other total solar eclipse will be visible
in the United States until 2044, that's 20 years after April's event.
-
-
December 7, 2023 PARKER
SUN PROBE 4259
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