The Planets Where We Are Headed in the Next Few Lectures

The Planets Where we are headed in the next few lectures

Nuclear energy Layers of the Sun

Sun’s energy Light producon and transport

Other planets

Helioseismology 2 Missions to other planets - Mercury

Mariner 10 (US, 1973), MESSENGER (US, 2004), BepiColumbo (ESA/JAXA, 2015) Missions to other planets - Venus

Venera 1-16 (USSR, 1961-1983), Pioneer Venus 1-2 (1978), Magellan (US, 1989) Venus Express (ESA, 2005) Missions to other planets - Mars

Mariner 3-9 (USA, 1964-1971), Viking 1-2 (USA, 1975), Mars Express (ESA,2003) Missions to other planets - Jupiter

Pioneer 10-11 (USA, 1972-1973), Voyager 1-2 (USA, 1977), Galileo (USA, 1989) Missions to other planets - Saturn

Pioneer 11 (USA, 1973), Voyager 1-2 (USA, 1977), Cassini (USA, 1997) Missions to other planets - Uranus

Voyager 2 (USA, 1977) Missions to other planets - Neptune

Voyager 2 (USA, 1977) Missions to other planets - Pluto

New Horizons (USA, 2015) Mars Mars in a nutshell

• Orbital distance = 1.5 AU • One Maran day = 24.6 hours • One Maran year = 687 days • Mass = 0.11 x Earth’s Mass • Radius = 0.53 x Earth’s Radius • Temperature: Min = -87o C, Max = 20o C • No global magnec ﬁeld Mars Topography Atmospheric Composion

Venus Earth Mars

• 96.5% CO 2, • 77% N, • 95.3% CO 2, 3.5% N, 21% O, 2.7% N, traces of SO2, traces of Ar , 1.6% Ar, Ar, H2O CO2 traces of O, H2O

What was the past atmospheric composion like? Water on Mars ? Current Maran Atmosphere

Earth surface pressure ~ 1 bar Dust Storms! Side Note – Dust is also a BIG problem at the Moon Maran Landers Mars Exploraon Rovers (MER) – Spirit and Opportunity

Launched June 10 and July 7, 2003 Landed January 3 and January 25, 2004 Dust Devils at Mars…

MER cleaning crew

Maran Landers Mars Exploraon Rovers (MER) – Spirit

A 3 month mission turned into a 7 year adventure… Mars Exploraon Rovers (MER) – Opportunity

A 3 month mission turned into a 7 year (and counng) adventure… Mars Science Lab – Curiosity

Launched November 26, 2011; Landed August 5, 2012 Gale Crater Water on Mars ? Current ‘seepage channels’

MGS: NASA/JPL/Malin Space Science Systems Water on Mars ?

Water prevalent up to late Noachian (~ 3.5 Gya)

Episodic events during the Hesperian (> 2.0-2.5 Gya)

Arid during the Amazonian with some break-out events (< 2.0 Gya)

Manning et al., 2006; and references therein Former Ice ﬂows? Atmospheric Composion

Past liquid water: 150 mb of CO2 Current : 7-8 mb of CO2 Old Convensional Wisdom: More CO2 → greenhouse eﬀect → carbonate rock (not seen, originally)

Then Opportunity landed! Blueberries = concreons

Form in aquious ﬂuids In every layer looked at in Eagle crater

Surrounding rock is Jarosite : requires a pH < 5 to form on Earth typically forms for pH 1-3

VERY acidic water – can’t form carbonate rock in CO2 atmosphere

(e.g Fairen et al., Nature, 2004) But then Phoenix landed… But then Phoenix landed…

Water ice found pH ~ 8-9 • good for bacteria • good for asparagus

And Spirit Broke a Wheel…. and found salt, lots of salt. Plus evidence of past geologic hot springs. Maran Polar Caps

North Pole

South Pole Water on Mars

Esmated from thermal and epithermal neutrons What about magnec ﬁeld?

Acuna et al., Connerney et al. 1999

Maran Aurora Solar Wind Interacon with Mars

Solar wind density

Vsw High Resoluon Simulaons

Solar Wind Hydrogen Oxygen Density Density Density

Vsw