|Is Earth's core as hot as the surface of the sun?
|Question Date: 2014-09-14|
The temperature of the Earth's core is not known
as well as the temperature of the Sun's surface
(photosphere)! Is that not amazing? The
distance from Goleta to the center of the Earth is
6300 kilometers; the distance to the Sun is 93
million miles!! Yet we know that the Sun's
surface is 5800 degrees Kelvin. For the
Earth's core we can only estimate that its
temperature is about 6000- 7000 Kelvin;
actually it could be a little higher or lower, we
do not know its value so well.
So, as a decent guess we can say that the
temperature of Earth's core is ABOUT the same as
the temperature of the Sun's photosphere, of 5800
degrees Kelvin .
Discoveries in the last 2 years do actually show
that the Earth's core is a similar temperature to
the surface of the sun (which is about 5778
Kelvin=5505 Celsius). Scientists don't have a good
way right now to directly measure the Earth's core
temperature, but they can do experiments above
ground to get good estimates.
The French scientists who made the most recent
estimations knew that the Earth's core is made of
iron, so they made very careful measurements of
the melting point of small bits of iron in very
high pressure chambers above ground to simulate
what it's like at the core. They found that the
Earth's core is about 6000 C.
The temperature of the sun's surface is actually
much easier to measure. The sun's temperature is
measured by "spectroscopy" which refers to
the analysis of light and color. The color of the
light emitted from hot objects (also called
"black bodies" in science) corresponds to
certain temperatures. Astronomers can use
spectroscopy to know the temperature of just about
any clearly visible star.
Yes. Scientists recently measured the melting
temperature of iron at very high pressures to
determine that the temperature at the boundary
between Earth's solid inner core and liquid outer
core is 6000 degrees Celsius. (If you are
interested in learning more about how they did
this, here is a link to an article about it:
here to read).
Meanwhile, the surface of the Sun is only about
5500 degrees Celsius. Keep in mind however, that
the surface of the Sun is the coolest layer of the
Sun; the corona, the outermost layer of the Sun's
atmosphere, is about 2 million degrees Celsius and
the core of the Sun is about 15 million degrees
The core of the Earth is around 6000 degrees
Celsius, or 10,800 degrees Farenheit. The surface
of the Sun is about 5500 degrees Celsius, or 9900
degrees Farenheit. So, the core of the Earth is
hotter than the surface of the sun. However, the
core of the sun is 15,000,000 degrees Celsius or
27,000,000 degrees Farenheit. Wow!
Great question! First, the Earth's core is made of
a mixture of iron and nickel. It also has two
parts: an outer liquid core and an inner solid
The edge of the outer core is about 4000
degrees Kelvin (7000 degrees Fahrenheit). The
inner core is about 6000 degrees Kelvin (10 000
degrees Fahrenheit) and that IS as hot as the
surface of the Sun!
The inside of the sun is much hotter of course
(~20 000 000 degrees Fahrenheit!), because of the
nuclear reactions that release heat from the
center of the sun.
If you want to know why the Earth's core is so
hot ask us next week!
The Earth's core is about 8,000 degrees Celsius
or Kelvin grades (C and K aren't that different at
that temperature). The surface of the sun is
between 5,000 and 6,000. Thus, the Earth's core is
hotter. Of course, the sun's core is hotter yet,
at about 14,000,000 Kelvin.
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