new worlds and old © 2010 john sheff consulting services

SOLAR SYSTEM DISCOVERIESNew Worlds and Old

© 2010 John Sheff Consulting Services

John Sheff

Solar System Ambassador Program, Jet Propulsion Laboratory

[email protected]

http://www2.jpl.nasa.gov/ambassador/

http://ww.jsheff.com

http://www.bostonastronomy.net

Solar System Ambassador Program


http://www.bostonastronomy.net/

http://www.bostonastronomy.net/

Solar System Discoveries

At first, all we knew about the planets was that they were "wanderers" against the background stars. Four hundred years ago, Galileo first turned the telescope to the sky, and the planets became "worlds." A half century ago, the first unmanned space probes started their explorations and the planets became "landscapes." What have we learned since about the planets of our Solar System and others? Is our Solar System unique? Are we close to finding another Earth? And -- most importantly of all -- what ever happened to Pluto?


Typical Ancient Astronomy

7 Planets (including the Sun and Moon, but not Earth):

Mercury Venus Mars Jupiter Saturn


Greek Astronomy

Nicolaus Copernicus (1473 – 1543)

Giordano Bruno (1548 – 1600)


Tycho Brahe (1546 – 1601)

Galileo Galilei (1564 – 1642)

Galileo’s Discoveries

Lunar features Stars in Milky Way

Galileo’s Discoveries

Moons of Jupiter Phases of Venus

Johannes Kepler (1571 – 1630)

Isaac Newton (1643 – 1727)

William Herschel (1738 – 1822)

Discovery of Uranus - 1781


Uranus

Titius-Bode Law


1 0 4 0.4 0.39 Mercury

2 3 7 0.7 0.72 Venus

3 6 10 1.0 1.00 Earth

4 12 16 1.6 1.52 Mars

5 24 28 2.8 2.77 ?

6 48 52 5.2 5.20 Jupiter

7 96 100 10.0 9.54 Saturn

8 192 196 19.6 19.2 Uranus

9 384 388 38.8 30.6 ?

10 768 772 7.72 39.44 ?

Ceres


Pallas, Juno, Vesta

Pallas Vesta


Vermin of the Skies


Irregularities of Motion - Uranus


Discovery of Neptune - 1846Urbain Jean-Joseph Le Verrier John Couch Adams


Neptune

Irregularities of Motion - Mercury


Irregularities of Motion - Neptune


Lowell Observatory


Pluto – found at last!


1992 QB1


Eris (2003 UB₃₁₃)


The IAU Meeting: Prague 2006


An Inventory of the Solar System

8 (or 9, 0r 13, or ?) Planets 169+ Moons 2 “Asteroid” Belts, with 100,000+

bodies ea 1012 Comets 1 G2 Star Interplanetary Medium


The Inner Solar System


The Asteroid Belt


The Outer Solar System


The Kuiper Belt


The New Solar System

Dwarf Planets and Some Contenders

Solar System Roadmap

• Flagship Missions (> 650 M$)• Cassini• Galileo

• New Frontiers (425 M$ - 650 M$)• New Horizons• Juno

• Discovery (< 425 M$)• NEAR• Messenger• Dawn


Coming Up:

Venus Climate Orbiter/PLANET-C launch (5/2010)

Hayabusa return to Earth ? (6/2010)

Rosetta asteroid Lutetia flyby (7/10/2010)

Deep Impact Comet 103P/ Hartley 2 flyby (10/11/2010)

Venus Climate Orbiter/PLANET-C arrival (12/2010)

Stardust Comet Tempel 1 flyby (2/14/2011)

MESSENGER Mercury orbit (3/18/2011 – 3/18/2012)

Dawn Vesta orbiter (7/2011 – 7/2012)

Juno launch (8/5/2011)

MSL launch (10/2011) Phobos Grunt launch (10/2011) BepiColombo launch (8/2013) Maven launch (11/18/2013 –

12/7/2013) Maven Mars orbit (9/16/2014) Dawn Ceres orbiter (2/2015 –

7/2015) New Horizons Pluto flyby

(7/2015) ExoMars launch (4/2018 ) Juno Jupiter polar orbit (8/2016

– 10/2018) BepiColombo Mercury orbit

(8/2019 – 8/2020)

Mercury

Why is Mercury so dense?

What is the geologic history of Mercury?

What is the nature of Mercury’s magnetic field?

What is the structure of Mercury’s core?

What are the unusual materials at Mercury’s poles?

What volatiles are important at Mercury?


Mercury Exploration

Mariner 10 (1973-74)

MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) (2004 – 2012)

Bepi-Columbo (2014-2020)


Venus


Venus Missions

Mariner 2 (1962) Mariner 5 (1967) Venera 4-16 (1967 –

1983) Pioneer Venus

(1978) Vega (1984 – 1986) Magellan (1989 –

1994) Venus Express (2005

- Planet C


Venus below the clouds

Venera 13 Venera 14


Lunar Exploration - LRO


Lunar ScienceSouth Pole / Aitken Basin Sample Return

Potential mission goals:

– Test cataclysm idea by dating SPA and superimposed basins

– Determine compositions of impacting bodies

– Decipher composition of mid- to lower crust (maybe mantle)

– Unravel basaltic history

Complicated set of goals

Complicated geologic setting


Mars

Strategy: From “Follow the Water” to “Explore Habitable Environments”

Determine if Life Ever Arose on Mars Characterize the Climate of Mars Characterize the Geology of Mars Prepare for Human Exploration of Mars


Mars – Mariner 9 (1971)

Mars – Viking 1 & 2

Viking 1 & 2 (1975-80)

Viking 1: Chryse Planitia

Viking 2: Utopia


Mars Exploration Rovers

Spirit & Opportunity

6+ Years on Mars Spirit: 4:80 miles Opportunity: 11.94

miles


Mars Science Lab – “Curiosity”


Mars Sample Return – 2020 ?


Dawn - 2007


Dawn Targets


Juno - 2011OriginsDetermine the ratio of oxygen to hydrogen, giving an idea of the abundance of water on Jupiter.

Obtain a better estimate of Jupiter's core mass, which will help distinguish among prevailing theories linking the gas giant's formation to the solar system.

InteriorPrecisely map Jupiter's gravitational and magnetic fields to assess the distribution of mass in Jupiter's interior, including properties of the planet's structure and dynamics.

AtmosphereMap the variation in atmospheric composition, temperature structure, cloud opacity and dynamics to depths far greater than 100 bars at all latitudes (In 1995, the Galileo probe reached only ~ 22 bars at a single location).

MagnetosphereCharacterize and explore the three dimensional structure of Jupiter's polar magnetosphere and its auroras.


Europa Explorer


Europa Astrobiology Lander


“Far” Future (2040 – 2050) ?


Europa Submersible

Saturn System


Iapetus Flyby Sept. 10, 2007


Enceladus Flyby, Mar 12 2008


Cassini-Huygens at Titan


Beyond the XM


Cassini XXM “Solstice” Mission


Cassini Mission Overview


Cassini EOM Option


Titan Explorer


Titan Lake Submersible


New Horizons

Launch: 2006 Jupiter Flyby

Gravity Assist: 2007

Pluto / Charon Encounter: 2015

KBO Encounters: 2016-2020


387 Detected as of November 2009 281 single planets around single normal

stars 98 multiple-system planets around single

normal stars 1 around red dwarf / white dwarf binary 1 around subdwarf B star / red dwarf binary 1 around pulsar / white dwarf binary 3 orbit single pulsars 1 orbits single subdwarf B star 1 orbits single brown dwarf

Exoplanets

Pulsar Planets

Two planets discovered in 1992 around the millisecond pulsar PSR 1257+12.

These were the first two extrasolar planets discovered, and the first multi-planet extrasolar planetary system discovered, and the first pulsar planets discovered.

(b) had period of 66 days and mass of 4.3 Earths.

(c) had period of 98 days and mass of 3.9 Earths.

Two additional planets of lower mass were later discovered by the same technique

51 Pegasi

First exoplanet around a main-sequence star (1995)

50 light-years away

Mass: > 1 Jupiter Period: 4 days “ Hot Jupiter”:

surface temperature 1000 ° C (1800 ° F)

HD 222582 b

The planet orbiting this G3 star has one of the most eccentric planet orbits known to date. The 572-day orbit takes it from 0.39 AU to 2.31 AU from its star. It is located in the constellation Aquarius, 137 light-years distant. The water on this world's satellite, if one exists, goes through seasonal periods of melting and refreezing.

HD 177830 b

HD177830 b is a 1.52 Jupiter mass planet orbiting the K0 star HD177830, located 192 light-years away in the constellation Vulpecula. This planet is likely to be within its habitable zone. A moon found here could have liquid water and look similar to our own home world.

Upsilon Andromedae

The first planetary system ever found around a normal star consists of three planets in orbit around Upsilon Andromedae.

The innermost (and first known) of the three planets, Upsilon Andromedae b, contains at least three-quarters of the mass of Jupiter and orbits only 0.06 AU from the star. It traverses a circular orbit every 4.61 days.

The middle planet contains at least twice the mass of Jupiter and it takes 242 days to orbit the star once. It resides approximately 0.83 AU from the star, similar to the orbital distance of Venus.

The outermost planet has a mass of at least four Jupiters and completes one orbit every 3.5 to 4 years, placing it 2.5 AU from the star.

55 Cancri

Five confirmed planets (most in any system)

The innermost planet (e): 2.8 day orbit, discovered in 2004. Mass: 11 Earth masses.

The next planet (a), discovered in 1996; 14.7-day orbit. Mass: .824 Jupiters.

Planet ( c ), with an orbit of 44.3 days. Mass: 56 Earth masses.

The fourth world (f) is the newest discovery, having 45 Earth masses and an orbit of 260 days. It is near the star’s “habitable zone”!

The farthest world out (d)has an orbit comparable to Jupiter's. Period: 14.6 years.

Gliese 581

At least four planets are believed to be orbiting Gliese 581.

A fourth planet, Gliese 581 e, was discovered in 2009. This planet, at an estimated minimum mass of 1.9 Earths, is currently the lowest mass exoplanet identified around a normal star. It takes 3.15 days to orbit Gliese 581- but it’s too hot!

Gliese 581 b is at least 16 times as massive as Earth (similar to Neptune's mass) and completes a full orbit of Gliese 581 in only 5.4 days.

Gliese 581 c is probably a rocky planet with a radius 1.5 times that of Earth and a mass of roughly five times Earth—or one third that of Neptune. Gliese 581 c orbits just inside of the habitable zone of its parent star. It is notable as it is the planet with lowest minimum mass yet discovered in the habitable zone of another star, making it the most earthlike exoplanet found to date.[The mean blackbody surface temperature has been estimated to lie between -3 °C (for a Venus-like albedo) and 40 °C (for an Earth-like albedo), however, the temperatures could be much higher (about 500 degrees Celsius) due to a runaway greenhouse effect akin to that of Venus. Gliese 581 c completes a full orbit in just under 13 days.

Observations of the star also revealed a third planet, Gliese 581 d, with a mass of roughly 7 Earths, or half a Uranus, and an orbit of 66.8 Earth days. It orbits just inside of the habitable zone of its star, which makes it a potential candidate for being able to support life. “Water world?”

Kepler Mission

Launched : March 6, 2009 First Light: April 16, 2009 Checkout Ended: May 13,

2009 Data Collection: 3.5 years Will monitor field of

223,000 stars Should find:

~ 30 outer-orbit giant planets ~ 135 inner-orbit giant

planets ~ 640 Super-Earths ~ 50 Earth-mass planets

A New Earth?

Within the next 5 years, we will probably find another Earth-like planet – an Earth-sized world in a stable orbit in a HZ of a Sun-like star

John Sheff

Solar System Ambassador Program, Jet Propulsion Laboratory

[email protected]


Background:

John Sheff has explored some remote parts of our planet on adventure travel journeys and mountaineering expeditions. His lifelong background as an amateur astronomer and space buff has him just as excited about the exploration of other planets. He enjoys participating in star parties, particularly inner-city ones, organized by his local club – the Amateur Telescope Makers of Boston (ATMoB). He also loves to share views of the sky through the observatory telescope he operates during Public Nights at the Harvard-Smithsonian Center for Astrophysics in Cambridge. In his day job he’s had a career as a freelance Network Admin and IT Manager, and now does consulting in web development and science education. When on Earth, he lives in Cambridge, MA.

Portions of this PowerPoint Slide Show - as well as a free installable PowerPoint Viewer - are available for download on John Sheff’s website:

http://www.jsheff.com

Solar System Ambassador Program



http://www.jsheff.com/

new worlds and old © 2010 john sheff consulting services

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