no evidence for life beyond Earth yet'

1

• no evidence for life beyond Earth yet.
• multitude of good reasons to believe life is
  widespread.
• life may exist elsewhere in our solar system,
  not intelligent life
• the possibilities, i.e. number of places, where
  life may be are innumerable
• we are star stuff Gods kitchen (the
  universe) builds all the ingredients for life
• thus, ASTROBIOLOGY, studying the development
  of life on Earth and in the universe!

2
5. Galaxy Cluster
3. Galaxy (stellar system)
4. Galaxy Group (several galaxies)
2. Planetary System (with star)
1. Planet (ecosphere)
3
Distance measured in light time speed of light
300,000 km/s 186,000 miles/sec Sun-Earth
distance.......... 8
light minutes Solar System diameter.
22 light hours Nearest Star
4 light years
(lys) Galaxy diameter........
100,000 lys Local Group diameter
1,000,000 lys Galaxy Cluster diameter...
100,000,000 lys Size of Universe.
12,000,000,000 lys
4
Anatomy of a Galaxy 250,000,000 yr rotation 20
Sun orbits
5
(No Transcript)
6
Solar System Formation
Gravity dominates then angular momentum and
pressure from heat.
7
Solar System Formation
8
Solar System Formation

• star born in center
• planets form in disk
• metal/rock seeds in inner disk
• ice seeds in outer disk
• gas survives in outer disk forms gas giants
  with ice cores
• star lights up blows remaining gas away
• Terrestrial Planets inner systems
• Jovian Planets outer system

9
The Solar System
Relative Sizes
Scale
10
A Star a balance between gravity and pressure
core
Gravity tends to crush the star, which causes the
temperature and the density to increase toward
the center.
The very center is called the core. In the core
the density is 150 times that of water and the
temperature is 15 million degrees Kelvin
11
Planetary Nebulae
White Dwarf
The Suns Fate
12
Supernovae Remnants in Our Galaxy
Young
Old
Fate of very Massive Stars
Supernova in a distant galaxy.
13
Atoms are comprised of a nucleus and electrons
(in orbits -gt would appear as a swarm or cloud)
protons positive charge neutrons no
charge electrons negative charge
14
The nucleus is extremely tiny atoms are empty
space!
4.5 football fields 450 yards 1350 feet ¼
mile
This atom is blown up a trillion times 1012
1,000,000,000,000
15
Atoms are defined by atomic number number of
protons hydrogen 1 helium 2 carbon
6 The number of electrons is equal to the number
of protons.
A given atom does not always have the same number
of neutrons (or mass). These different
flavors of a given atoms are called isotopes.
16
How elements are built and energy is released
Fusion small atoms bind together to form large
atoms Fission break up large atoms to form small
atoms Shown is the energy released per
fusion/fission event this is called the binding
energy. Note that a large amount of energy is
released binding hydrogen into helium. Still, it
takes 1038 reactions per second to support the
sun! That is the conversion of 5 millions tons of
mass into energy every second. Thus mass is lost
from the sun forever.
Note the special location of iron.
17
The Energy Source of Life (and the chemical
source!)
Step 1 of the Proton-Proton Chain
e
2H e n
1H 1H
Two hydrogen ions (1H) collide. They stick
together, or fuse, into deuterium (2H), an
isotope of hydrogen- it has one proton and one
neutron. This is called fusion. Also, in the
process, a positron (e, antimatter of electron)
and a neutrino (n) are produced. In the process
the positron (anti-matter version of electron)
finds a free electron in the suns core plasma
and when they collide they annihilate and release
energy (photons).
18
The Energy Source of Life (and the chemical
source!)
e
Step 2 of the Proton-Proton Chain
3He g
2H 1H
The deuterium from step 1 collides with a
hydrogen, forming tritium, an isotope of helium,
with only one neutron instead of the typical
two. In the process, a photon (g) is produced.
This photon carries away energy.
19
The Energy Source of Life (and the chemical
source!)
e
Step 3 of the Proton-Proton Chain
4He 1H 1H
3He 3He
3
1
2
Two tritium from two different step 2s collide
and form helium. In the process two hydrogen
(1H) are produced.
e
20
Massive stars undergo multi-layered shell burning.
The time duration that each shell burns becomes
shorter and shorter as the star becomes desperate
to battle against the merciless crushing force of
its own gravity.
Hydrogen . 7 million yrs
Oxygen . ½ yr Helium .. 500 thousand yrs
Silicon .. 1 day Carbon . 600 yrs
Iron collapse 0.1 second
21
BOOM!
Carbon, nitrogen, oxygen are blasted into
interstellar space!
22
Interstellar Gas Clouds Have Chemistry
Carbon is the most versatile chemical element
(atom) It can make 1,2, 3, or 4 strong bonds
Compounds are molecules with more than one type
of element
23
These chemical elements form the next generation
of planets!
Which of these are good sites for biology?
24
On Earth, biology/life persists even in very hot
and/or dark environments!
Hot Spring
Black Smoker
25
On Earth, biology/life persists even in very
cold/frozen environments!
Antarctica
Frozen rocks are the habitat of microbes. They
hibernate in a frozen state, and then drink up
when the sun warms the ice to water
26
Is Mars much different than Antarctica? Is the
warm upper atmosphere of Jupiter teaming with
microbes?
Mars is covered in a permafrost- are the rocks
any different than those in Antiarctica?
Room temperature about 300 km down
27
Jupiters Moon Europa
Covered with Water Ice- The cracks change with
time, revealing a dynamic geology Dynamic
geology means energy input into planet!
A theoretical cutaway of Europa we think the
moon has a water ocean under the surface ice
28
Saturns Moon Titan
Thick Methane atmosphere Laboratory experiments
to create a gas to match the measured
properties of Titans atmosphere suggest a
hydrocarbon gas rich with organic molecules!
The Huygens Probe, supplied by the European Space
Agency, has six complex instruments aboard. The
data from these instruments will be received by
the Cassini spacecraft and relayed to Earth after
the probe descends into Titan's mysterious
atmosphere in early 2005.
29
(No Transcript)
30
ASTROBIOLOGY
astro study of the universe biology study
of life astrobiology study of life in the
universe

• NASAs 3 main questions
• How does life begin and develop?
• Does life exist elsewhere in the universe?
• What is lifes future on Earth and beyond?