Astronomy 101The Solar System

Tuesday, Thursday2:30-3:45 pmHasbrouck 20

Tom Burbinetomburbine@astro.umass.edu

Course

• Course Website:– http://blogs.umass.edu/astron101-tburbine/

• Textbook:– Pathways to Astronomy (2nd Edition) by Stephen Schneider

and Thomas Arny.• You also will need a calculator.

Office Hours

• Mine• Tuesday, Thursday - 1:15-2:15pm• Lederle Graduate Research Tower C 632

• Neil• Tuesday, Thursday - 11 am-noon • Lederle Graduate Research Tower B 619-O

Homework

• We will use Spark• https://spark.oit.umass.edu/webct/logonDisplay.d

owebct• Homework will be due approximately twice a

week

Astronomy Information• Astronomy Help Desk• Mon-Thurs 7-9pm• Hasbrouck 205

•The Observatory should be open on clear Thursdays

• Students should check the observatory website at: http://www.astro.umass.edu/~orchardhill for updated information

• There's a map to the observatory on the website.

Final

• Monday - 12/14 • 4:00 pm• Hasbrouck 20

HW #12 and #13

• Due today

HW #14

• Due Tuesday at 2:30 pm

Exam #3

• Next Thursday• Covers material from October 15th – November 5th

• FormulasDensity = mass/volumeVolume = 4/3πr3

• Luna 2 - impact on the surface of the Moon (1959) (USSR)• Luna 3 - first photos of the far side of the Moon (1959)

(USSR)• Apollo - Six manned landings on the Moon with sample

return 1969-72. – (The seventh landing, Apollo 18, was canceled for

political reasons)• Luna 16 - automated sample return from the Moon (1970)

(USSR) • Clementine - a joint mission of the Ballistic Missile Defense

Organization and NASA (1994)• Lunar Prospector - the first NASA mission to the Moon in

almost 30 years (1998-1999)• SMART-1 - The European Space Agency’s (ESA) spacecraft

orbited the Moon and then crashed into the Moon in (September, 2006)

Currently• Japanese SELENE mission (also known as Kaguya) orbited the

Moon• Goal was "to obtain scientific data of the lunar origin and evolution

and to develop the technology for the future lunar exploration"

http://www.selene.jaxa.jp/en/about/image/img_equipment_001_e.jpg

Pythagoras Crater from SMART-1

http://www.space.com/imageoftheday/image_of_day_060626.htmlhttp://cdn2.libsyn.com/astronomy/moon_show20.gif?nvb=20081110153501&nva=20081111153501&t=0b619a8f8100c5f7820f5

Pythagoras Crater from Selene

http://wms.selene.jaxa.jp/data/en/hdtv/006/hdtv_006_3/hdtv_006_3_l.jpg

Diameter 130 km, Depth 5.0 km

• http://space.jaxa.jp/movie/20080411_kaguya_movie01_e.html

• India's national space agency launched Chandrayaan-1, an unmanned lunar orbiter, on October 22, 2008.

• Estimated cost is $80 million • The probe revolved around the Moon for ~1 years (no

longer working)• Its scientific objectives were to prepare a three-

dimensional atlas of the near and far side of the moon and to conduct a chemical and mineralogical mapping of the lunar surface.

http://upload.wikimedia.org/wikipedia/en/8/89/Chandrayaan1_Spacecraft_Discovery_Moon_Water.jpg

Chandrayaan-1

http://en.wikipedia.org/wiki/Image:Chandrayaan_1.jpg

• A total of 382 kg of rock samples were returned to the Earth by the Apollo and Luna programs.

• Apollo - 381.69 kg • Luna – 300 g

http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1970-072A

Luna 16

http://en.wikipedia.org/wiki/Image:Apollo_16_LM.jpg

Apollo 16

http://en.wikipedia.org/wiki/Image:Apollo_15_Genesis_Rock.jpg

Apollo 15 sample“Genesis Rock”Very ancient sample4 billion years old

Rocks and More Moon

• Mineral – A naturally occurring, homogeneous inorganic solid substance having a definite chemical composition and characteristic crystal structure

• Rock - naturally occurring aggregate of minerals

Forming Different Mineralogies

• Can be on a planet-scale• Or a few meters to kilometers

http://www.gly.fsu.edu/~salters/GLY1000/8Igneous_rocks/Slide16.jpg

Some minerals formbefore other minerals

What minerals form?

• Depends on the composition of the magma• Depends how quickly the magma cools

Types of Rocks

• Igneous – rock that solidified from molten or partially molten material

• Metamorphic - rock that has changed in composition, mineral content, texture, or structure by the application of heat or pressure

• Sedimentary – rock formed from material that was deposited as sediment by water, wind, or ice and then compressed and cemented

Igneous Rock

http://en.wikipedia.org/wiki/Image:Magma.jpg

Metamorphism

http://en.wikipedia.org/wiki/Image:Quartzite.jpg

Quartzite

Sedimentary• Examples of two types of sedimentary rock: limey

shale overlaid by limestone

http://en.wikipedia.org/wiki/Image:Limestoneshale7342.jpg

• Rock formed from sediments covers 75-80% of the Earth's land area

Lunar Meteorites• ~60 are known• only 1 in 1200 meteorites are lunar• Lunar meteorites are expensive• http://www.meteorites.tv/298-buy-a-lunar-

meteorite• By comparison, the price of 24-carat gold is about

$20 per gram and gem-quality diamonds start at $1000-2000/gram.

http://epsc.wustl.edu/admin/resources/moon_meteorites.html

Mare

http://epsc.wustl.edu/admin/resources/moon/howdoweknow.htmlhttp://en.wikipedia.org/wiki/Image:Lunar_Ferroan_Anorthosite_60025.jpg

Lunar Highlands

• Highlands – contain Al-rich material– Plagioclase feldspar - CaAl2Si2O8

• Mare – contain Fe-rich material – basaltic eruptions– Olivine - (Mg, Fe)2SiO4

– Pyroxene – (Mg,Fe)SiO3

– Ilmenite - FeTiO3

http://epsc.wustl.edu/admin/resources/moon_meteorites.html

Fe-rich

Al-rich

Magma Ocean

How do you form the Moon?

Definitions

• Volatile – evaporates easily• Refractory – does not evaporate easily

Need to account for these things

• The Moon's low density (3.3 g/cc) shows that it does not have a substantial iron core like the Earth does.

• Moon rocks contain few volatile substances (e.g. water), which implies extra baking of the lunar surface relative to that of Earth.

• The relative abundance of oxygen isotopes on Earth and on the Moon are identical, which suggests that the Earth and Moon formed at the same distance from the Sun.

Oxygen Isotopes• There are three stable isotopes of oxygen• They have masses of 16, 17, and 18 atomic mass units

%

• 16O ~99.762• 17O ~0.038 • 18O ~0.200• The oxygen isotopic ratios (17O/16O and 18O/16O of

silicate rocks from the Earth and Moon are the same and are different from most meteorites and Mars

http://www4.nau.edu/meteorite/Meteorite/Images/MeteoriteOxygen9.jpg

Giant impact Hypothesis• Formation of the Moon as a result of a collision between

the young Earth and a Mars-sized body• Evidence

– oxygen isotope ratios of Moon identical to those of Earth.– A large portion of the Moon appears to have been once

molten, and a giant impact scenario could easily have supplied the energy needed to form such a magma ocean.

– The Earth has a large iron core, but the moon does not. This may be because Earth's iron had already drained into the core by the time the giant impact happened. Therefore, the debris blown out of both Earth and the impactor came from their iron-depleted, rocky mantles.

Atmosphere

• Not much of an atmosphere since the Moon’s gravity is so small

Did We Land on the Moon

• http://www.youtube.com/watch?v=Y5MVVtFYTSo

Any Questions?