How did NASA touch the Sun without melting?
Learning Stats
CEFR 레벨
Total Words
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난이도
자막 (76 segments)
DownloadThe Parker Solar Probe, the fastest object ever made by human hands,
surfs the solar winds at more than 630,000 kilometers per hour.
That’s more than 500 times the speed of sound on Earth.
Its mission?
To touch the Sun— and, ideally, to avoid melting in the process.
It achieved this goal in 2021,
when the probe flew by Venus and skimmed through the corona,
the Sun’s outermost atmosphere.
Since then, it's carved closer and closer paths,
revealing extraordinary details about our star in the process.
On its closest approach, it’s projected to cross within 8.8 solar radii—
that’s less than 4.5 sun lengths away from the solar surface.
And it will endure temperatures of 1,500 degrees Celsius.
But there’s a limit to just how close Parker can get.
And there are questions scientists can't answer without probing even deeper
into the solar atmosphere.
Among these mysteries is the astonishing fact that the solar surface
is actually much cooler than the outer corona.
Above the solar surface is a thin 100 kilometer layer
known as the transition zone,
where temperatures dip from a scorching 500,000°C
to a relatively cool 8,000 degrees.
While physicists have theories on how the transition zone forms,
we won't know for sure until we can make closer observations.
Further, some scientists predict that if a spacecraft
could fly within about 3 solar radii from the Sun’s surface
and fire its rockets at just the right time,
it could use the Sun’s gravity to slingshot itself
into the outer solar system.
This daring flight path, called the Oberth maneuver,
could propel a spacecraft past Pluto in just three years,
a trip that currently takes around a decade.
But probing deeper into the corona—
without melting, exploding, or falling directly into the Sun—
is a monumental engineering challenge.
The first challenge is directing the probe's path.
A probe falling directly towards the Sun would likely pick up so much speed
in its descent that it would either crash or be flung in the opposite direction.
To avoid this, the Parker Space Probe
made a series of complicated orbital maneuvers around Venus.
Using the planet’s gravity as a brake,
it could readjust its orbit and get incrementally closer.
But these current orbital tricks can only get us so far.
As for the scorching heat,
the Parker Probe used a strategy that is not unlike sitting under a beach umbrella.
Its instrumentation is packed behind a heat shield just 4.5 inches thick.
One side is made of highly reflective white ceramic
that scatters much of the incoming sunlight.
The other side consists of a carbon foam sandwiched between two layers of carbon,
further reinforced with carbon fiber.
The foam is around 97% air, so it acts as an insulator,
not allowing much heat to flow through.
The outer carbon panel is very dark and can withstand high temperatures,
so it efficiently absorbs any remaining heat and radiates it back out to space.
A sensor system constantly adjusts this shield
to ensure the craft’s instruments remain in its shadow.
But Parker’s heat shield can only get so close.
To get even closer,
one possibility would be to ditch the heat-absorbing carbon materials entirely
and double down on deflection.
Researchers at NASA’s Innovative Advanced Concepts program
have developed a novel ultra-reflective coating called Solar White
that’s predicted to reflect 99.9% of the Sun’s energy.
They plan to use Solar White to coat an outer curved umbrella-like shield.
Then, a second conical shield made from a silvered reflective material
would shunt away any remaining radiation that escapes through.
With both novel shields,
scientists believe they could surf a probe as close as 2 solar radii
from the surface.
But we won’t know for sure until these materials are further tested.
At these close distances, we might unlock the mystery of the transition zone.
We may learn how to better predict solar behaviors
like flares and geomagnetic storms,
which puts satellites and our communication systems on Earth at risk.
And we’d get an unprecedented look at our star, and perhaps one day,
with the Sun’s assistance, at our most distant neighbors.
Key Vocabulary (50)
toward
"Go to school."
belonging
"Cup of tea."
also
"You and me."
inside
"In the house."
specific
"That book."
A third-person singular pronoun used to refer to an object, animal, or situation that has already been mentioned or is clear from context. It is also frequently used as a dummy subject to talk about time, weather, or distance.
Used to show who is intended to have or use something, or to explain the purpose or reason for an action. It is also frequently used to indicate a specific duration of time.
A preposition used to indicate that something is in a position above and supported by a surface. It is also used to indicate a specific day or date, or to show that a device is functioning.
A conjunction used to compare two things that are equal in some way. It is most commonly used in the pattern 'as + adjective/adverb + as' to show similarity.
A preposition used to indicate a specific point, location, or position in space. It is also used to specify a particular point in time or a certain state or activity.
Used to identify a specific person, thing, or idea that is physically close to the speaker or has just been mentioned. It can also refer to the present time or a situation that is currently happening.
A coordinating conjunction used to connect two statements that contrast with each other. It is used to introduce an added statement that is different from what has already been mentioned.
Used to indicate the starting point, source, or origin of something. It can describe a physical location, a point in time, or the person who sent or gave an item.
The word 'we' is a first-person plural pronoun used to refer to the speaker and one or more other people collectively. It is used as the subject of a sentence or clause.
A modal verb used to talk about imagined situations or to express things that are not certain. It is also commonly used to make polite requests, offers, or to describe habits in the past.
Description
Explore the challenges of Parker Solar Probe’s mission to touch the Sun, and what we could learn about the star as we get closer. -- In 2021, the Parker Solar Probe achieved its mission...
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