Embed Size (px)
DESCRIPTION
The EPOXI View of Earth. Nick Cowan (University of Washington) KITP (May 18, 2010). “Habitable” Planets. Looking for Water. }. Daily Variability. Water in atmosphere? H 2 O vapor Variable cloud cover Water on surface? Color of oceans Glint of oceans Polarization from oceans. - PowerPoint PPT Presentation
Citation preview
The EPOXI View of Earth
Nick Cowan (University of Washington) KITP (May 18, 2010)
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
May 18, 2010 Nick Cowan's Talk at ESMSSP 2
“Habitable” Planets
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
May 18, 2010 Nick Cowan's Talk at ESMSSP 3
Looking for Water
• Water in atmosphere?– H2O vapor
– Variable cloud cover
• Water on surface?– Color of oceans– Glint of oceans– Polarization from oceans
Long-ExposureSpectroscopy
DailyVariability}}
YearlyVariability
May 18, 2010 Nick Cowan's Talk at ESMSSP 4
NWO, THEIA, TPF/Darwin, etc.(n+1 decades from now)
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
(Simulated image from Oakley & Cash 2009)
A. Long-Exposure SpectroscopyB.Time-Resolved Photometry
May 18, 2010 Nick Cowan's Talk at ESMSSP 5
Oak
ley
& C
ash
(200
9)
Orbital & Rotational Variability
time
flux
• Will not know A0 (degenerate with Rp)
• Will measure A(t)/A0 and A()/A0
May 18, 2010 Nick Cowan's Talk at ESMSSP 6
EPOXI (PI: A'Hearn) ~Deep Impact Part II
EPOCh (PI: Deming)1. Observe known
exoplanets
2. Observe Earth as an exoplanet
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
May 18, 2010 Nick Cowan's Talk at ESMSSP 7
EPOXI Light Curves
QuickTime™ and aMPEG-4 Video decompressor
are needed to see this picture.
May 18, 2010 Nick Cowan's Talk at ESMSSP 8
EPOXI Light Curves
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Cow
an e
t al
. (2
009)
May 18, 2010 Nick Cowan's Talk at ESMSSP 9
Backward Modeling v.s. Forward Modeling
Data
Simple Model
Sophisticated Simulation
Assumptions
Parameters
Data Starved
Data Rich
May 18, 2010 Nick Cowan's Talk at ESMSSP 10
Forward (Predictive) Modeling
March 19th, 2008(Robinson et al. 2010)
Data
Model
time
RMSE = 1.9%
RMSE = 1.6%RMSE = 2.0%
RMSE = 2.3%
March 19th, 2008
time
RMSE = 1.9% RMSE = 2.3%
RMSE = 2.0% RMSE = 1.6%
Data
Model
June 5th, 2008(Robinson et al. 2010)
time
RMSE = 3.7%
RMSE = 3.7%
RMSE = 2.8% RMSE = 3.5%Data
Model
June 5th, 2008
time
RMSE = 2.8% RMSE = 3.5%
RMSE = 3.7%
RMSE = 3.7%
Data
Model
May 18, 2010 Nick Cowan's Talk at ESMSSP 15
Backward (Interpretive) Modeling
May 18, 2010 Nick Cowan's Talk at ESMSSP 16
Time-Averaged Spectrum
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Cow
an e
t al
. (2
009)1) Clouds are plentiful and bright
2) Can we learn about planetary surface despite them?
May 18, 2010 Nick Cowan's Talk at ESMSSP 17
Principal Component Analysis
Fa
Fb
C1
C2
<C>
May 18, 2010 Nick Cowan's Talk at ESMSSP 18
Eigencolors
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Cow
an e
t al
. (2
009)
May 18, 2010 Nick Cowan's Talk at ESMSSP 19
Earth from Above
Cow
an e
t al
. (in
pre
p)
May 18, 2010 Nick Cowan's Talk at ESMSSP 20
Northern Eigencolors
Cow
an e
t al
. (in
pre
p)
May 18, 2010 Nick Cowan's Talk at ESMSSP 21
Earth from Below
Cow
an e
t al
. (in
pre
p)
May 18, 2010 Nick Cowan's Talk at ESMSSP 22
Southern Eigencolors
Cow
an e
t al
. (in
pre
p)
May 18, 2010 Nick Cowan's Talk at ESMSSP 23
Reflected Light
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Diffuse (Lambert) Reflection
Specular (Shiny) Reflection
May 18, 2010 Nick Cowan's Talk at ESMSSP 24
Specular Reflection (it’s small)
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Williams & Gaidos (2008)
May 18, 2010 Nick Cowan's Talk at ESMSSP 25
Equatorial Map
Cow
an e
t al
. (2
009)
May 18, 2010 Nick Cowan's Talk at ESMSSP 26
A Different Kind of Map
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
1) Simulated white light curve of Earth with real cloud cover
2) Can’t recover major landforms
Oakley & Cash (2009)
May 18, 2010 Nick Cowan's Talk at ESMSSP 27
Conclusion
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Fro
m V
PL
Time-Resolved, Multi-Band PhotometryComplements Time-Averaged Spectroscopy
