Extra-terrestrial life: Is there anybody out there?

Extra-terrestrial life:Extra-terrestrial life:Is there anybody out there?Is there anybody out there?

Dr Martin HendryUniversity of Glasgow

Reach for the Stars

Is there Anybody Out There?

Extra-Solar Planets

Life in the Solar System?

Searching for Life

Life in the Solar System

Runaway Greenhouse Effect

Formation of the Moon: Impact from Mars-sized planetesimal during first aeon.

Impact energy = 1 million million megatons

5 billion cubic miles of the crust sprayed into space

Atmosphere ejected into space

Ring of ejecta coalesces into Moon

Is there life on Mars?…Is there life on Mars?…

Is there life on Mars?…Is there life on Mars?…

Mars 2004:Mars 2004: Mars Express ( + Beagle 2)

Spirit + Opportunity

Jan 23rd 2004:

Mars Express Orbiter detects water ice at the South Pole of Mars.

Jan 23rd 2004:

Mars Express Orbiter detects water ice at the South Pole of Mars.

Jan 23rd 2004:

Mars Express Orbiter detects water ice at the South Pole of Mars.

H2O CO2 Visible light

Water on Mars

Images suggest flowing water on Mars in the past

Mars Earth

2mm

The moons of The moons of JupiterJupiter

Isaac Newton:1642 – 1727 AD

The Principia: 1684 - 1686

The tidal pull of the Moon on the Earth

Galileo’s Moons

Inside Europa

Could there be life?…..

The stars are VERY far away. The nearest star (after the Sun) is about 40 million million km from the Earth. It takes light more than 4 years to travel this distance..

If the distance from the Earth to the Sun were the width of this screen, the nearest star would be in Paris !!!!

EXTRA-SOLAR PLANETSEXTRA-SOLAR PLANETS

Wobbling stars: the key to finding extra-solar planets

Planets and stars orbit their common centre of mass

Planets are too faint to see directly

- so stars wobble

but

The Sun’s “wobble”, due to Jupiter, seen from 30 light years away = width of a 5p piece in Baghdad

The ElectromagneticSpectrum

Doppler Shift Doppler Shift

Star

Laboratory

The origin of spectral lines

Absorption

e -

e -

Emission

e - e -

Star

Laboratory

51 Peg – the first new planet

What have we learned about exoplanets?Highly active, and rapidly changing, field

Aug 2000: 29 exoplanets

What have we learned about exoplanets?Highly active, and rapidly changing, field

Aug 2000: 29 exoplanets

2004: ~120 exoplanets

What have we learned about exoplanets?Highly active, and rapidly changing, field

Aug 2000: 29 exoplanets

Up-to-date summary at

http://www.exoplanets.org

Now finding planets at larger orbital semimajor axis 2004: ~120 exoplanets

1. The Doppler wobble technique will not be sensitive enough to

detect Earth-type planets (i.e. Earth mass at 1 A.U.), but will

continue to detect more massive planets

Looking to the Future

1. The Doppler wobble technique will not be sensitive enough to

detect Earth-type planets (i.e. Earth mass at 1 A.U.), but will

continue to detect more massive planets

2. The ‘position wobble’ (astrometric) technique will detect Earth-type planets – Space Interferometry Mission in 2009

(already done with HST in Dec 2002 for a 2 x Jupiter-mass planet)

Looking to the Future

Looking to the Future

1. The Doppler wobble technique will not be sensitive enough to

detect Earth-type planets (i.e. Earth mass at 1 A.U.), but will

continue to detect more massive planets

2. The ‘position wobble’ (astrometric) technique will detect Earth-type planets – Space Interferometry Mission in 2009

(already done with HST in Dec 2002 for a 2 x Jupiter-mass planet)

3. The Kepler mission (launch 2007?) will detect transits of Earth-type planets, by observing the brightness dip of

stars

(already done in 2000 with Keck for a 0.5 x Jupiter-mass planet)

1. The Doppler wobble technique will not be sensitive enough to

detect Earth-type planets (i.e. Earth mass at 1 A.U.), but will

continue to detect more massive planets

2. The ‘position wobble’ (astrometric) technique will detect Earth-type planets – Space Interferometry Mission in 2009

(already done with HST in Dec 2002 for a 2 x Jupiter-mass planet)

3. The Kepler mission (launch 2007?) will detect transits of Earth-type planets, by observing the brightness dip of

stars

(already done in 2000 with Keck for a 0.5 x Jupiter-mass planet)

Looking to the Future

There was a (rare) transit of Mercury on May 7th 2003, and a (very rare) transit of Venus on June 8th 2004

4. NASA: Terrestrial Planet Finder ESA: Darwin

Looking to the Future

}~ 2015 launch

These missions plan to use nulling interferometry to ‘blot out’ the light of the parent star, revealing Earth-mass planets

4. NASA: Terrestrial Planet Finder ESA: Darwin

Looking to the Future

}~ 2015 launch

These missions plan to use nulling interferometry to ‘blot out’ the light of the parent star, revealing Earth-mass planets

Follow-up spectroscopy will search for signatures of life:-Spectral lines of oxygen, watercarbon dioxide in atmosphere

Simulated ‘Earth’ from 30 light years

ESP

What will TPF look for?….

Earth from 30 lyrs

Is there anybody out there?….Is there anybody out there?….

…….if there isn’t, it seems.if there isn’t, it seems a terrible waste of space !!!!a terrible waste of space !!!!