EXOPLANETSAND E.T. LIFE

OUTLINE•Introduction: The Solar System•Exoplanets•Exoplanet Detection•Planetary Habitability•A Glimpse on the Drake Equation

Intro: The Solar System•the Sun•Planets•Dwarf Planets•Asteroids•Meteoroids

•Comets•Dust•Gas

Intro: The Solar System

Exoplanets•from Ancient Greek exo—”outer, external” + planet•planets outside the solar system that orbit around a star•a.k.a. extrasolar/exosolar planets

Exoplanets •Mercurian•Subterran•Terran•Superterran•Neptunian•Jovian

Exoplanets•51 Pegasi b is the first planet found orbiting around another Sun-like star. (1995)• There are 1894 confirmed exoplanets as of March 2015.

Exoplanets: Detection•Ground-based telescopes

Hobby-Eberly Telescope

Exoplanets: Detection• Space telescopes

Hubble Space TelescopeKepler Space Telescope

Exoplanets: Detection•Method 1: Transit Method

--detecting a drop in a star’s brightness as a planet transitsacross its disk.

Exoplanets: Detection•Method 2: Wobble Method

--detecting a slight change in a star’sposition while a planet orbits around it.

Exoplanets: Detection•Method 3: Direct Imaging

--taking a direct picture of an exoplanet.

Can life existon exoplanets?

Criteria for life: a ChecklistAdequate Star Size

Criteria for life: a ChecklistAdequate Star Size

• the Life Zone

Criteria for life: a ChecklistRight planetary characteristics

• Terrestrial type

• Massive

Criteria for life: a ChecklistPresence of essential elements• SPONCH CaFe S- Sulfur

P- PhosphorusO- OxygenN- NitrogenC- CarbonH- Hydrogen

Ca- CalciumFe- Iron

Criteria for life: a ChecklistPresence of water

Potentially Habitable Exoplanets

•The current number of confirmed potentially habitable exoplanets as of Mar. 2, 2015 is 29. (Planetary Habitability Laboratory)

• 10 are Earth-sized and 19 are Super-Earths.

Potentially Habitable Exoplanets

Potentially Habitable Exoplanets

Kepler-22 b

Potentially Habitable Exoplanets

Kapteyn b

Potentially Habitable Exoplanets

tau Ceti e

Is there intelligent life elsewhere in our Universe?

The Drake equation• The Drake equation was

made by Dr. Frank Drake of the Search for Extraterrestrial Intelligence (SETI) Institute.• it estimates the number of

probable intelligent and active civilizations throughout our home galaxy

The Drake equation

The Drake equationPessimist

R* 5 per yearfp 0.05fl 0.5ne 1fi 0.01fc 0.01L 1,000 years

OptimistR* 10 per yearfp 0.2fl 1ne 2fi 0.1fc 0.1L 10,000 years

N = 0.0125 N = 400

Final thoughts“ Our Sun is one of 100 billion stars in our galaxy. Our galaxy is one of billions of galaxies populating the universe. It would be the height of presumption to think that we are the only living things in that enormous immensity.”

--Wehner von Braun

Final thoughts“Really, it’s okay to reserve judgment until the evidence is in.”

--Carl Sagan

Thank you, Earthlings!