The Search for Extra-Terrestrial unIntelligence

Jonathan Tennyson

Department of Physics and Astronomy

University College London

"The two most common things in the universe are hydrogen and stupidity."

Harlan Ellison

Is there anybody out there?

Sagittarius Star Cloud / Hubble Space Telescope

At least 100 thousand million (1011 or 1012) stars in the milky wayAt least 100 thousand million (1011 or 1012) galaxies in the universe

How to find aliens

1. Hope that they visit us

2. Listen for their signals

3. Look for them

Search for

extraterrestrial

intelligence

(SETI)

The Arecebo

telescope

SETI: >500,000,000 screensaver downloads and counting ……What has been found?

Nothing

Extra solar planets

Kepler (the mission)Kepler (the mission)

Earth-size planet transiting Sun-type star ~ 0.01 %

Kepler (NASA)launch 2009

10

More than 1200 planetary candidates discovered by

Kepler!

Exoplanets are common…

Jupiter—Sun: 15 m/s

Present sensitivity: 1 m/s

Earth—Sun: 0.09 m/s

You are here!

Characterizing extrasolar planets

Habitable zone for different stars

“Goldilocks zone”

Earth and moon fromthe Galileo spacecraft

Can one detectthe signature of

life on Earth?

NASA’s Galileo SatelliteLaunch 1989Arrived at Jupiter 1995

“Flatulent ruminoids”Segan et al, Nature (1995)

100 million+

years ago –

Plenty of

methane

emissions?

Time (Gy)

Oxy

gen

1

0.1

0.01

0.001

0.0001

0.000014.5 4 3.5 3 2.5 2 1.5 1 0.5 0

Multicell-

Humans

Invertebrates

Rye and Holland, 1998

Oxygen!!!

Eukaryotes

Prokaryotes

Methane ?

How far is it to the nearest star?A long way!

“ We will never know how to study by any means the chemical composition (of stars), or their mineralogical structure ”

Auguste Comte (1835)

Fraunhofer’s map of the solar spectrum

High resolution optical spectrum of the Sun

EmissionAbsorption

Level 3

Level 2

Level 1

photon

photon

Ene

rgy

Jumping between energy levels in an atom or molecule

Methane in the Earth’s atmosphere

Beforephotosynthesis

Afterphotosynthesis

A pale blue dot, at 6 billion km away…

() C. Sagan

Direct observationDirect observation

109 photons in the VIS -> Coronagraph

106 photons in the IR -> Nulling interferometry

Direct observation of star GQ Lupiand its planet GQ Lupi b

Transit of Venus June 8th 2004.

NextJune 5th 2012.

Radial velocity / Occultation

Period = 3.524738 daysPeriod = 3.524738 days

Mass = 0.69 ±0.05 MMass = 0.69 ±0.05 MJupiterJupiter

Radius = 1.35 ±0.04 RRadius = 1.35 ±0.04 RJupiter Jupiter

Density = 0.35 ±0.05 g/cmDensity = 0.35 ±0.05 g/cm33

HD 209458bHD 209458b

NASA’s Spitzer space telescope

Beaulieu et al., 2007

Knutson et al., 2007

Primary transit + IR + SpitzerPrimary transit + IR + Spitzer

Water, T-P at the terminator

Water line list: BT2

Barber et al., 2006

Tinetti et al., Nature, 444, 169 (2007)

Methane, plusConfirmation of

water and hazes!

Beaulieu et al., 2007

Knutson et al., 2007

Swain et al., 2007

Pont et al., 2007

Giovanna Tinetti, UCL

So far discovered:Water H2OMethane CH4 Carbon dioxide CO2

Carbon monoxide COHydrogen cyanide HCN

On HD189733bwith more to come

HD1897733b too hot for life

Transit huntersTransit hunters

Transits of objects down to Earth-size

COROT (CNES/ESA)launch Dec. 2006 (mission extended)25 transiting planets foundincluding 1 super-earth

Kepler (NASA)launch 6 March 2009. 3.5 year mission: 22 confirmed planets so far + >1200 candidates

NWO is a large-class Exoplanet mission that employs two spacecrafts: a “starshade” to suppress starlight

before it enters the telescope and a conventional telescope to detect and characterize exo-planets.

Cash, Nature, 2006

The New World Observer

Exoplanet Characterisation Observatory

Telescope Baffle

V-groove side sunshield

GaAs Solar Cells

Detectors

Service Module

1.5m silicon carbide mirror

Exoplanet Characterisation Observatory

• 1.2 to 1.5m dedicated telescope

• L2 halo orbit, direction anti-Sun

• Broadband spectral coverage from VIS to IR ( 0.4 to 16 µm )

• Maximum spectral resolution R=300

• 5 year mission

PI Giovanna Tinetti (UCL)

launch 2022?

A year in the life ofJuly 10 Talk WCGS Science Conference

July 10 European Space Agency (ESA) formal call for M3 missions

Oct 10 European Research Council (ERC) awards me 2.5 MEuros for ExoMol: Molecular line lists for exoplanet & other atmospheres

Nov 10 59 Expressions interest to ESA

Dec 10 43 Formal bids to ESA

Jan 11 13 bids selected (including EChO)

Feb 11 8 bids selected (including EChO)

March 11 4 bids selected for further study:

EChO, LOFT, MarcoPolo-R, STEQUEST

May 11 ExoMol project starts

June 11 UK Space Agency + PPARC select EChO as top priority

Future timelines (approximate)

2011-13 Specification and testing

2014 “Down selection”

2015-19 Instrument and satellite build

2019-21 Assembly and testing

2022 Launch ?

H3+ Liesl Neale (H2D+ Taha Sochi)

H2O Bob Barber (HDO Boris Voronin)HCN/HNC (H13CN/ H13CN) Greg Harris

HeH+ Elodie Engel NH3 Bob Barber and Sergei Yurchenko (Dresden)

HCCH Andrea Urru

C3 Santina La Delfa and Taha Sochi

Linelists completed or under construction @ UCL by

The ExoMol project