,summary life in the universe 5th edition 2022 bennett 9780691241784
, summary life in the universe 5th edition 2022 bennett 9780691241784
Chapter 1 - The Possibility of Life Beyond Earth
What are we searching for?
Not just looking for intelligent life, but anything we can find
Difficult to define life; ie. What makes us think people,
mushrooms, bacteria are alive as opposed to crystals, clouds, and
fire?
b/c life so difficult to define, presume a search on Earth-like life because
it’s all we know
Is it reasonable to imagine life beyond Earth?
Life once speculated on Venus (because of clouds) and Mars
(canals which =/= exist)
Unlikely to find multicellular life, but rather simple life (tiny microbes)
Potential life on planets that surround the universe of stars
New technology gives for more possibility than years
past The Scientific Context of the Search 1.2
How does astronomy help us understand the possibilities for aliens?
Once though earth was center of universe – geocentric
Now know Earth just a tiny part of the universe
Physical laws in universe also apply to Earth
How does planetary science help us understand the possibilities for aliens?
Planetary science – study of planets, moons orbiting, other objects that
may form in association with planets (asteroids/comets); sets the
context for search for life in 2 main ways
1. Learn how planets form >> understand how common we might expect planets
to be
2. Learn how planets work; ie. Why Venus so hot even though only lil closer to Sun
1995: strong evidence found for existence of extrasolar planets – planet
1 and 2 (above) help understand what to look for as we search
habitable worlds – worlds containing basic necessities for life
habitable =/= always mean plants/animals; could be microscopic shit
planet doesn’t HAVE to harbour life, but possibility
How does biology help us understand the possibilities for aliens?
Physics and bio are universal, so is bio as well?
Complex molecules found in meteorites means can withstand harsh
conditions of space >> form readily and may be common in other
worlds
Early origin of life on earth makes it reasonable that life could emerge
on other planets with similar conditions
Understand conditions needed for life; ie. Some bacteria live in ^ temps
No reason to think life is
rare Places to Search 1.3
Where should we search for life in the universe?
1st = search for life on earth to learn diff places/conditions life exists
then the rest of our solar system
b/c looking for life somewhat earth-like, would assume they need
water or something similar
, summary life in the universe 5th edition 2022 bennett 9780691241784
ie. Mars once had flowing water so could assume life may have arisen
moons are also a
possibility Could aliens be searching
for us?
SETI (search for extraterrestrial
intelligence) The New Science of Astrobiology 1.4
Astrobiology: study of universe coupled with study of
life How do we study the possibility of life beyond
Earth?
NASA astrobiology institute look for the following:
1. Study conditions conductive to the origin and ongoing existence of life
2. Look for such conditions on other planets in solar system
3. Look for actual occurrence of life elsewhere
Astrobio meant to connect life and places it resides
, summary life in the universe 5th edition 2022 bennett 9780691241784
Chapter 1 - The Possibility of Life Beyond Earth
What are we searching for?
Not just looking for intelligent life, but anything we can find
Difficult to define life; ie. What makes us think people,
mushrooms, bacteria are alive as opposed to crystals, clouds, and
fire?
b/c life so difficult to define, presume a search on Earth-like life because
it’s all we know
Is it reasonable to imagine life beyond Earth?
Life once speculated on Venus (because of clouds) and Mars
(canals which =/= exist)
Unlikely to find multicellular life, but rather simple life (tiny microbes)
Potential life on planets that surround the universe of stars
New technology gives for more possibility than years
past The Scientific Context of the Search 1.2
How does astronomy help us understand the possibilities for aliens?
Once though earth was center of universe – geocentric
Now know Earth just a tiny part of the universe
Physical laws in universe also apply to Earth
How does planetary science help us understand the possibilities for aliens?
Planetary science – study of planets, moons orbiting, other objects that
may form in association with planets (asteroids/comets); sets the
context for search for life in 2 main ways
1. Learn how planets form >> understand how common we might expect planets
to be
2. Learn how planets work; ie. Why Venus so hot even though only lil closer to Sun
1995: strong evidence found for existence of extrasolar planets – planet
1 and 2 (above) help understand what to look for as we search
habitable worlds – worlds containing basic necessities for life
habitable =/= always mean plants/animals; could be microscopic shit
planet doesn’t HAVE to harbour life, but possibility
How does biology help us understand the possibilities for aliens?
Physics and bio are universal, so is bio as well?
Complex molecules found in meteorites means can withstand harsh
conditions of space >> form readily and may be common in other
worlds
Early origin of life on earth makes it reasonable that life could emerge
on other planets with similar conditions
Understand conditions needed for life; ie. Some bacteria live in ^ temps
No reason to think life is
rare Places to Search 1.3
Where should we search for life in the universe?
1st = search for life on earth to learn diff places/conditions life exists
then the rest of our solar system
b/c looking for life somewhat earth-like, would assume they need
water or something similar
, summary life in the universe 5th edition 2022 bennett 9780691241784
ie. Mars once had flowing water so could assume life may have arisen
moons are also a
possibility Could aliens be searching
for us?
SETI (search for extraterrestrial
intelligence) The New Science of Astrobiology 1.4
Astrobiology: study of universe coupled with study of
life How do we study the possibility of life beyond
Earth?
NASA astrobiology institute look for the following:
1. Study conditions conductive to the origin and ongoing existence of life
2. Look for such conditions on other planets in solar system
3. Look for actual occurrence of life elsewhere
Astrobio meant to connect life and places it resides
