Transcript Extraterrestrial Life - Virtual Planetary Laboratory

Extraterrestrial
Life
Antígona Segura Peralta
Penn State University, College of Earth and Mineral Sciences
Penn State Astrobiology Research Center
They do exist!
Astrobiology
Astrobiology is the science that studies the origin,
evolution and distribution of life in the Universe
The origin of life on Earth
4 billion years ago
What does life need?
Raw materials: hydrogen, carbon,
oxygen, nitrogen and minerals like iron
and sulfur.
Energy: Sun, volcanoes
A liquid: Water
Planets, the perfect place
They contain raw materials
Energy sources
They can have liquid water
Our Solar System
Jupiter
Saturn
Uranus
Pluto
Neptune
Mercury
Venus
Earth
Mars
The terrestrial planets
Mercury
Very hot because its
atmosphere
Mars
Very near the Sun
Venus
No atmosphere, cold
but…
Mars today
Mars, an interesting past
Ancient volcanoes
Ancient rivers?
Mars might be like this
Little martian?
The giant planets
Jupiter
Saturn
Uranus
Neptune
Europa, Jupiter’s moon
Europa
Europa
Milky Way
100 billion of stars!
Where the stars are born
Molecular cloud
Formation of stars and planets
Beta Pictoris, a newborn star
Formation of stars and planets
Beta Pictoris disk (artist conception)
Extrasolar planets
The life of the stars
Red Giant
Panetary nebula
and white dwarf
Yellow dwarf
10 billion years
The life of the stars
Blue giants 100 million years
Supernova remmanent
and neutron star
Supernova
A habitable world
Characteristics:
Distance from its star, not too far, not
too close
Size, not too big, not too small
Atmosphere to keep the planet warm
and water liquid
Water
Biomarkers
Those features whose presence or
abundance can be attributed to life
Signatures of life?
Small things can make big changes
Cyanobacteria
How to find a planet?
Problem:
The stars emit light (a lot!) and planets doesn’t, they just
reflect the light from their parent star.
How to solve it?
Cover the star!!!!
Measure the effects of the planets on the stars:
Stars wobble because of the planets
Stars dim when a planet crosses in fron of them
Looking for habitable worlds
Kepler:
Look for terrestrial planets around 100,000 stars.
Launch on 2006.
Looking for habitable worlds
Terrestrial Planet Finder (TPF):
Look for terrestrial planets around 100 nearby stars.
Analyze the planets to detect those that may be
habitable
Launching on 2012-2015
Looking for habitable worlds
Eddington:
Looking for planets bigger than Mars around
500,000 stars.
Launching on 2008.
Looking for habitable worlds
Darwin:
Look for terrestrial planets around 1,000.
Launching after 2014.
Intelligent life?
Arecibo Antenna,
Puerto Rico
Globular Cluster M13
The Pioneer mesage
Voyager
SETI: Search for extraterrestrial life
Allen array
Project Phoenix
A habitable world