Download Sun and Planets

Sun and Planets
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Sun and planets formed
around 4.55 billion years
ago
Planets are by-products of
star formation
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Lots of them initially
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Mercury, Mars may be
a single formation
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Venus and Earth are
numerous collisions
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One of those collisions
(with Theia) formed the
Moon
Images: NASA
The Terrestrial Planets
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Mercury
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About the size of the
Moon (~4800 km
diameter compared to
~3500 km diameter)
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Craters like the Moon,
but...
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Dipolar magnetic field
suggests iron core
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Iron core that is actually
about the size of the
Moon (which the Moon
does not have)
The Terrestrial Planets
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Mercury
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Known to exist since at
least 3000 BCE
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In the epic of
Gilgamesh
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Does not have a
significant tilt,
therefore poles are not
exposed to sun...hence
cold (and ice?)
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Density like the Earth
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Mariner 10 in 1974
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Messenger just arrived
March, 2011...
The Terrestrial Planets
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Messenger (Mercury Surface Space Environment, Geochemistry, and Ranging) at
Mercury
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Messenger is at Mercury now!
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New images everyday, check it out!
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http://www.nasa.gov/mission_pages/messenger/main/index.html
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http://messenger.jhuapl.edu
From APL
The Terrestrial Planets
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Venus
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~12000 km diameter (similar to
Earth)
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Hotter than Mercury because of
greenhouse effect (mean
surface temperature 480 °C)
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Retrograde rotation
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Atmosphere
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Carbon Dioxide 96%
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Nitrogen ~3%
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Venera (16 official missions,
many more duds) missions from
the USSR most important
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Pioneer and Magellan from the
US added some additional
knowledge
The Terrestrial Planets
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Venus
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ESA's Venus Express at Venus now
gather new data
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Water boiled away – Earth's future?
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ESA and Russia contributed to this
experiment
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Venus Express is a twin of the Mars
Express
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ASPERA (Analyser of Space Plasma
and Energetic Atoms)
MAG (Venus Express Magnetometer)
PFS (Planetary Fourier
Spectrometer)
SPICAV/SOIR (Ultraviolet and
Infrared Atmospheric Spectrometer)
VeRa (Venus Radio Science
Experiment)
VIRTIS (Visible and Infrared Thermal
Imaging Spectrometer)
VMC (Venus Monitoring Camera)
The Terrestrial Planets
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Earth
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Largest terrestrial
planet
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About the size of Venus
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Larger than Mars
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Mean surface
temperature ~15°C
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Atmosphere
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Nitrogen ~78%
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Oxygen ~21%
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Argon ~1%
http://www.geo.umass.edu/courses/climat/radbal.html
The Terrestrial Planets
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Earth
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The Moon is fifth largest
moon behind Ganymede
(Jupiter), Callisto (Jupiter),
Titan (Saturn), and Io
(Jupiter)
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The Moon (r~1735 km) is
larger then Pluto (r~1195
km)
Image from http://www.astroobservers.com
The Terrestrial Planets
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Mars
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~-140 °C to 20 °C with a
mean surface temperature
of -63 °C
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Has polar caps
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South (Carbon Dioxide)
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North (Water)
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Moons: Phobos and Deimos
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Atmosphere (thin)
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Carbon Dioxide 95%
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Nitrogen ~3%
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Argon ~2%
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Oxygen ~0.1%
The Terrestrial Planets
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Mars is on google!
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http://www.google.com/mars
The Asteroids
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The Minor Planets
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Main belt between Mars and
Jupiter
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Destroyed or failed planet?
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Some asteroids have moons
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Planets downgraded
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Ceres
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Has atmosphere?
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Dwarf planet (so planet again)
Vesta
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Had volcanic activity
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Piece of it fell to Earth
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Protoplanet?
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Pallas, Juno, Eros, Kleopatra
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Present Mission: Dawn
Vesta: Asteroids
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Large asteroids Vesta
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525 km diameter
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Minor planet “4 Vesta”
Ceres: Dwarf Planet
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Ceres
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932 km diameter
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Thin atmosphere
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Water vapor recently detected
in atmosphere
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Originally classified as an
asteroid, then a planet, than an
asteroid, now a dwarf planet
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Dwarf planet in the asteroid
belt
The Asteroids
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Types
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C-Type
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Carbon
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75% of asteroids
S-type (Stony or Silicate type)
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Nickel-iron
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Some iron and magnesium silicates
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17% of asteroids
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Many sub-types under this type
M-type (Metallic type)
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Nickel-iron
The Jovian Planets (Gas)
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Jupiter
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Diameter: 142984 km
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Atmosphere (similar to Sun)
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Hydrogen 90%
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Helium 10%
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Mean cloud temperature -121 °C
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67 known moons (53 confirmed and
named, 14 pending confirmation)
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Very thin rings
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Differential rotation
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Galilean satellites are the largest
moons of Jupiter: Io, Europa,
Ganymede, and Callisto
The observatory satellite Juno
reached Jupiter in July 2016
Jupiter's Moons
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Ganymede (largest moon)
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Diameter: 5262 km
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Small atmosphere
Europa
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Brightest object
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Smooth surface
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Crust over water, very active
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670,900 km from Jupiter (compared
to 150,000,000 km for the Earth
from the Sun)
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Heated by gravitational stresses
(tidal forces) and radioactive decay
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May harbor life!
Jupiter's Rings
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Very thin rings (3
main rings)
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Gossamer
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Halo
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Thebe within ring
system, but
Europa is not
Jupiter's Spot
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Great Red Spot
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In this infrared picture
you can see the spot in
the lower right hand
corner
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An asteroid (that hit
Jupiter on July 16, 2009)
breaking up can be see
in each picture in the
lower left
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First picture is from
July 20,2009
Second picture is
from August 16, 2009
IMAGE: NASA's Infrared
Telescope in Mauna
Kea, HI
Jupiter's Aurora
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The Sun extends out
to all the planets and
interacts with them
like it does the earth
Jupiter Aurora
Saturn
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Diameter: ~120000 km
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Atmosphere (similar to
Sun)
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Hydrogen 97%
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Helium 3%
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Mean cloud
temperature -125 °C
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62 known moons (53
confirmed, 9 pending
confirmation)
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No rings
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Differential rotation
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Tilt ~27 °
Saturn's Rings
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Ring Divisions (9 MAJOR rings)
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Ring A, B
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Brightest
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Separated by Cassini Division (Gap)
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Ring C - dimmer
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Other rings: D to G
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Outer Halo
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Made up of ice and rock (Wall-E is
essentially correct)
Saturn’s Rings and Major
Moons
Saturn's Ring A
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Ring A has a resonance pattern that might be explained by
density wave theory (used for spiral galaxy theory as well)
Saturn's Aurora
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Aurora has hexagon feature
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Deep into cloud layer
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Unusually strong polar
circulation
Still somewhat of a
mystery
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Red here represents 5 um
wavelength (IR)
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First discovered by
Voyager (1980s) but not
very good images
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Many images from Cassini
(as in here)
Saturn's Moons
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Titan
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Diameter: 2576 km
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Interesting similarity to Earth
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Water exists in three phases on Earth
Methane exists in three phases on Titan which
produces similar effects that water does on Earth
Uranus
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Diameter: ~51000 km
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Atmosphere (similar to Sun)
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Hydrogen 83%
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Helium 15%
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Methane 2%
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Mean cloud temperature
-193 °C
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27 known moons (named
after Shakespeare
characters and Pope
characters)
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Tilt 98°
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Rings (13 in all now)
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Retrograde rotation
Neptune
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Diameter: ~49500 km
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Atmosphere (similar to Uranus)
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Hydrogen 85%
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Helium 13%
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Methane 2%
Mean cloud
temperature -193 °C
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13 known moons (six
discovered by Voyager)
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Tilt 30°
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Rings: 9 rings, very faint
Image: HST, NASA
Neptune’s Largest Moon:
Triton
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Discovered in 1846 by William Lassel
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Financed his telescopy “hobby” with the money he
made from his brewry
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Discovered 17 days after Neptune was discovered
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Triton (as are all of Neptune’s moons) is named
after minor Greek sea gods and nymphs (since
Neptune is the god of the sea...duh!)
Triton has retrograde motion compared
to Neptune; they only moon that
exhibits this behavior
Triton’s fate is eventually to be pulled
apart by Neptune and become a ring
(maybe)...but don’t worry it will happen
a long time from now
Image: NASA
Neptune
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Why is Neptune blue?
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The clouds of Neptune
are mostly frozen
Methane which absorb
red light and reflect
blue light
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Same reason Uranus is
mostly blue (the bluegreen clouds are an
added ammonia and
water clouds)
Neptune’s Rings
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Rings
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9 rings, very faint
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Outermost ring is
named Adams with
three bright arcs
(see image Liberty, Equality,
and Fraternity)
Voyager observed first,
though there was
speculation before
especially given the
discovery of rings around
Uranus
Pluto (Not planet, tis a dwarf
planet or Plutoid)
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Diameter: ~2300 km
Frozen solid (rock mixed with
ices?)
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Icy surface ~98% Nitrogen
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Atmosphere Methane 0.3%
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5 known moons – Charon
(1978), Hydra and Nix (2005),
Kerberos (HST 2011), and Styx
(HST 2012)
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Possible rings
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Pluto Express (canceled)
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New Horizons Launched
2006!!! with a 2015 arrival date
Pluto (Not planet, not dwarf,
but Plutoid)
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Orbit actually goes inside
orbit of Neptune periodically
Tilted on it side like Uranus
Retrograde rotation like
Venus and Uranus
Charon is not the same
surface composition of Pluto
(unlike our Moon and our
Earth)
Pluto, not that big
Eris (Xena, Lila)
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Eris (2003 UB313)
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Originally named Xena as in
“Xena: Warrior Princess”
(Note: Eris was a recurring
character on the show in the
Latin name of Discordia)
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Plutoid
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Diameter: 3000 km +/- 400 km
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Moon: Dysnomia (Eris'
daughter demon goddess
mean “lawlessness”, original
name was Gabrielle, of course)
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This object caused the reclassification; however recent
observation suggest it is
smaller than Pluto
Haumea (Santa)
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Haumea (2003 EL61)
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Haumea is the Hawaiian
goddess of fertility
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Plutoid (pending)
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About the size of Pluto
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Moons: Hi'aka and Namaka
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Artist conception of Haumea
on right; kinda of an odd shape
isn't it
MakeMake (Easterbunny)
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MakeMake is an Easter
Island Fertility God
Where will it end?
Sedna
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Sedna (2003 VB 12)
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Plutoid??? Not yet
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Diameter: 11001600km
Dwarf planets/Plutoids
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Dwarf planets are inside Neptune's orbit and
Plutoids are outside of Neptune's orbit
Dwarf Planet: Ceres
Plutoids: Pluto, Eris, Makemake (pending),
Haumea (pending)
Numbers game (from NASA)
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Numbers from 2017
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Planets: 8
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Dwarf planets: 5 (with many pending)
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One Dwarf Planet
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Four Plutoids
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Moons: 178
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Asteroids: 732,315
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Comets: 3,463 (estimate: 1 billion)
To learn more about the planets go to
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http://solarsystem.nasa.gov