Dwarf planets

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Transcript Dwarf planets

Bell work
What do you think the major
differences are between a planet
and a dwarf planet?
Our Moon
Dwarf planets
Eris
Ceres
Pluto and
Cheron
Objectives
Describe the differences between a
planet and dwarf planet.
Identify unique characteristics of each
dwarf planet.
What is a Dwarf Planet?
 According to the International Astronomical Union, which sets
definitions for planetary science, a dwarf planet is a celestial
body that:
 Orbits the sun.
 Has enough mass to assume a nearly round shape.
 Has not cleared the neighborhood around its orbit.
 Is not a moon.
 The main distinction between a dwarf planet and a planet is
that planets have cleared the path around the sun while dwarf
planets tend to orbit in zones of similar objects that can cross
their path around the sun, such as the asteroid and Kuiper
Belts. Dwarf planets also are generally smaller than the planet
Mercury.
 There are currently five officially recognized dwarf planets. The
IAU estimates there may be dozens or even more than 100
dwarf planets awaiting discovery.
 The IAU recognized Pluto's special place in our solar system
by designating dwarf planets that orbit the sun beyond
Neptune as plutoids. Eris, which orbits far beyond Neptune, is
a plutoid while Ceres, which orbits in the main asteroid belt
between Mars and Jupiter is a dwarf planet.
Pluto
Distance from sun-5.4 light-hours
Period of rotation-6 days, 10 h (R)
Period of revolution-*248 years, 4
days
Diameter-2,390 km
Density-1.75 g/cm3
Surface temperature- −225°C
Surface gravity- 6% of Earth's
Pluto
In 2006 Pluto was reclassified as a
Dwarf planet.
Pluto is smaller than Mercury.
Pluto
A Small World
Scientists think that Pluto is covered by
frozen nitrogen and has a thin atmosphere
of methane. Pluto's moon, Charon (KER
uhn), is covered by frozen water and is
more than half Pluto's size! In fact, Charon
is the largest satellite relative to its planet in
the solar system.
Discovered in 1930, Pluto was long
considered our solar system's ninth planet.
But after the discovery of similar intriguing
worlds deeper in the distant Kuiper Belt, icy
Pluto was reclassified as a dwarf planet.
Ceres
www.solarsyatem.nasa.gov
• Ceres is a dwarf planet located in
the inner solar system. It was
discovered in Jan. 1801.
Distance from the Sun
The average distance of Ceres
from the sun is 257,143,648
miles. Ceres has an eccentric
orbit, so its actual distance from
the sun will vary.
Periods of Rotation and Revolution
The period of revolution: 4 years and
219 days
The period of rotation: 9 hours, 4.5
minutes
Jared110.wordpress.com
Diameter
The diameter of Ceres is 950 km,
or 590 miles.
en.wikipedia.org
Surface Temperature
For its distance, the Cererian surface
is warm. It is -53 degrees Celsius.
en.wikipedia.org
Ceres’ Atmosphere

No one knows yet if Ceres has an
atmosphere or not. Scientists believe Ceres may
have a weak atmosphere with frost made of water
on the surface.
Ceres only has 4% of Earth’s gravity, so its hard
to keep a strong atmosphere. However, water
vapor on Ceres may have formed a small
protective layer like an atmosphere.
Ceres also gets some solar radiation on the
surface. That results in significant amounts of
hydroxide in the poles.
Surface

Its surface brightness is the same as our
moon’s. Scientists believe Ceres has a
surface like our moon’s. With many craters
and a rocky surface.
 However, Ceres is relatively warm, our moon
is cold. Since Ceres is a dwarf planet AND an
asteroid, Ceres is made of iron, nickel, and
metals like most asteroids.
 Scientists also believe that a layer of icewater lay beneath the surface.
What makes Ceres unique?

Ceres is named after the Roman
goddess of agriculture, grain crops, and
motherly love. It is the only dwarf planet in
the inner solar system.
Ceres was discovered in 1801 before Pluto
and Neptune. It was a considered a planet
for 50 years, then reclassified as an
asteroid, and then in 2006 as a dwarf planet.
Oddly, Ceres only the size of Texas.
Objectives
Describe the differences between a
planet and dwarf planet.
Identify unique characteristics of each
dwarf planet.
Eris is 2400 kilometers wide
1 year on the planet Eris is equal to 557 years
or 203,600 days on Earth
Temperature on Eris averages -217°C to 243°C
The planet Eris is about 4.5 billion years old
Eris
Eris was first spotted in 2003. The discovery was confirmed
in January 2005. When people first found this planet they
called it UB313. But people then did not want to call it
UB313 they decided to call it the tenth planet. People didn’t
want to have to remember those letters and numbers. Then
when people were finding a different name for it they
nicknamed it Xena. Xena was a warrior princess on TV show
in that time. When they changed the name they called Eris
after the Greek goddess of discord. It was the first object in
the Kuiper Belt found to be bigger than Pluto
DYSNOMIA The moon of eris
The planet Eris has one moon that is called
Dysnomia. It was discovered in 2005 by Mike
Brown and his team of scientists. He named it
after Eris’ daughter and D was the first letter of
his wife’s middle name. Eris is 60x brighter than
it’s moon Dysnomia. The moon is about 175
kilometers in diameter. Many scientists believe
that the moon is made of frozen water.
Eris is one of the farthest planets from the
sun. Right now it is about at its farthest
distance that it will be from the sun. Eris is a
Kuiper belt object and it passes through the
belt all of the time. The only exception is
when it is way past the edge. Eris is my
favorite planet because it is the biggest dwarf
planet. Everybody likes Pluto but Eris is more
massive, bigger, and it has it’s own moon.
Makemake
 After Eris and Pluto, Makemake is the third largest known
dwarf planet. Along with fellow dwarf planets Pluto and
Haumea, Makemake is located in the Kuiper Belt. Pluto and
Makemake are the two brightest objects that have so far
been discovered in the Kuiper Belt.
 It takes 310 Earth years for this dwarf planet to make one
orbit around the Sun.
 Makemake was first observed in 2005 by Michael Brown. It
was officially recognized as a dwarf planet by the
International Astronomical Union in 2008.
 Observations have found evidence of frozen nitrogen on
Makemake's surface. Frozen ethane and methane have
also been detected on the surface.
Haumea
4.4 light-years away
Period of rotation-3
h, 55 min
Period of revolution285 years
Temperature= 241°C
Gravity-0.024% of
Earth’s
Moons-Hi’iaka and
Namaka
Haumea
• Haumea is spinning so quickly that it has turned
into the shape of an ellipsoid.
• In Hawaiian mythology, Haumea is the goddess
of fertility and childbirth.
• Haumea might not have an atmosphere.
• Haumea has a dark spot that reflects more red
light than blue light, which means it has a reddish
tint that is in the visible spectrum. Scientists thing
that a reddish object hit haumea, therefore
creating a dark, reddish spot.
Objectives
Describe the differences between a
planet and dwarf planet.
Identify unique characteristics of each
dwarf planet.