Extra-terrestrial life: Is there anybody out there?
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Extra-terrestrial Extra-terrestrial life: life: Is there anybody out Is there anybody out there? there? Dr Martin Hendry University of Glasgow Reach for the Stars
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Extra-terrestrial life: Is there anybody out there?. Reach for the Stars. Dr Martin Hendry University of Glasgow. Is there Anybody Out There?. Life in the Solar System?. Extra-Solar Planets. Searching for Life. Life in the Solar System. Runaway Greenhouse Effect. - PowerPoint PPT Presentation
Transcript of 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 !!!!
