Transcript Scales in the UniverseApollo

How BIG is the
Universe?
A Photographic Tour
Apollo 17 Lunar Rover
(scale: a few metres)
Space Shuttle, Columbia
(scale: 100 metres)
Barringer Crater, Arizona
(1.2 km diam, 200 m deep - 50 m diam asteroid at 11 km/s)
Earth
(diam 12,756 km)
Cloud covered Venus
(0.95 Earth diameters)
Mercury
(0.38 Earth diameters)
The Moon
(0.27 Earth diameters)
The Sun
(diam 1 392 000 km or 109 Earth diameters,
distance 150 000 000 km or 1 astronomical unit - 1 AU)
Eclipse of the Sun by the Moon as seen from Antarctica
(both subtend almost exactly the same angle
of half a degree at the Earth)
Mars - the Red Planet
(0.53 Earth diam)
Surface of Mars
Phobos and Deimos
(max lengths 28 and 16 km)
Orbits of the planets
to scale
Asteroid Gaspra
(20 km long)
Jupiter and its Great Red Spot
(11.2 Earth diam,
distance 5.2 AU)
Jupiter’s cloud belts as seen by
the Cassini spacecraft
Jupiter with (top to bottom)
Io, Europa, Ganymede and
Callisto
Io and its sulphur volcanoes
(0.28 Earth diam, 1.04
Moon diam)
Ganymede,
largest moon
in the Solar System
(0.41 Earth diam,
1.51 Moon diam)
Not all Jupiter’s moons are large:
Thebe (100 km), Amalthea (270 km max) and Metis (40 km)
Saturn and its beautiful rings
(9.4 Earth diam at 9.6 AU)
Orbits of the planets
to scale
Uranus, the tilted planet
(4.0 Earth diam
at 19.2 AU)
Neptune
(3.9 Earth diam
at 30.1 AU)
Pluto and Charon - double planet
(0.18 and 0.09 Earth diam
1.54 Earth diam apart
at 29.7 to 49.4 AU from Sun)
Comet Hale-Bopp in March 1997
A comet tail can be over 1 AU long,
but its nucleus measures only a few km across
Comet Halley and the Milky Way
Southern Pinwheel Galaxy
15 million light years away
and similar to the Milky Way
How the Milky Way might look seen edge-on
Sun
160 million light years
Size of the Milky Way Galaxy
Sombrero Galaxy
Whirlpool Galaxy
Andromeda Galaxy
(2.5 million light years away most distant naked eye object)
Giant Elliptical Galaxy M87
in Virgo Cluster
50 million light years away
Virgo Cluster of Galaxies
1500 galaxies
9 million light years across
50 million light years away
Coma
Cluster
Hubble Deep Field showing galaxies over 10 billion
light years away (looking back in time to near the
beginning of the universe)
How the Milky Way might look seen edge-on
Sun
160 million light years
The Milky Way as seen from Australia
(Notice the pink nebulae where new stars are forming)
Milky Way with Faulkes Telescope in Australia in
foreground
The constellation of Orion
and the Milky Way
(The bright stars we see here are no more than
a few hundred light years away)
Betelgeuse
Rigel
Orion
Nebula
Orion Nebula
a small star forming region about 1 light year across
New solar systems forming
in Orion
New stars forming in pillars
of molecular hydrogen and
dust that are light years in
length (in Eagle Nebula)
Pleiades and Hyades
star clusters
(with Jupiter and Saturn)
Betelgeuse - a Red Supergiant star
(big enough to reach the orbit of Jupiter)
The Life Cycles of Stars in Outline
Cloud of dust and gas
Life Cycles
of Stars in Outline
Contracts under gravity and
heats up until eventually
thermonuclear reactions start
Main Sequence star
(Most of a star's life)
Low mass star
< 4 solar masses
Expands
Red giant
Loses outer layers
White dwarf
and
planetary nebula
< 1.4 solar masses
High mass star
Very high mass star
4 to 25(?) solar masses > 25 (?) solar masses
Expands
Red supergiant
Explodes as a
supernova
Neutron star
and
supernova
remnant
Expands
Red supergiant
Explodes as a
supernova
Black hole
and
supernova
remnant
> 3 to 5 (?) solar masses
Helix Planetary Nebula (1.5 light years across)
Planetary nebula
(remains of
outer layers of star)
White dwarf star
(remains of core
of star and about
size of the Earth)
Cat’s Eye Planetary Nebula and white dwarf
(A solar mass white dwarf would be only as big as the Earth)
Cocoon Planetary Nebula
Ring Planetary Nebula
Abell Planetary Nebula
Crab Nebula
a supernova remnant - remains of a star that exploded
10 light years across
neutron star about 10 km
across is at centre (not visible)
Vela or Gum
Nebula
A Black Hole
(“Radius” of a 10 solar mass black hole
would be only 30 km)
A black hole a few million times the mass of the Sun lurks at
the centre of our galaxy and causes nearby stars to orbit very
rapidly
How Orion would look if you were near a
black hole (computer simulation)
Gravitational lensing by a galaxy
cluster 2 billion light years away
bends light from a galaxy so far away
that its light has been travelling for
95% of the age of the Universe
The End