XI - Expansion of the Universe

1.- The Supermassive Black Hole at the center of our Milky Way:

www.astro.umd.edu/~rhc/bh_mw.mpg
Source: http://www.eso.org/public/usa/videos/eso0226a/

2.- Multiwavelength view of our Milky Way:

X - Galaxies

After a looong time exploring the solar system, we are finally going to study galaxies :)

1.- Hubble Deep Field:

Watch video here: http://www.astro.umd.edu/~rhc/hdf_video.mov

Source: http://hubblesite.org/newscenter/archive/releases/2004/07/

The Hubble Deep Field (HDF) covers an area 2.5 arcminutes across, about one 24-millionth of the whole sky, which is equivalent in angular size to a 65 mm tennis ball at a distance of 100 metres.

2.- Galaxies in interaction: Simulation vs Observations:

3.- Discussion Summary:

IX - HR Diagram and Nebulae

1. The Fate of Stars

Source: http://chandra.harvard.edu/edu/formal/stellar_ev/

2.- Nebulae Classification


3.- Hertzsprung - Russell Diagram

4.- The Milky Way Project

http://www.milkywayproject.org/

VIII - Radiation

0.- Comment on last week's lab - Hydrogen Spectrum:

1.- Super Planet Crash - Can you feel the gravity?

http://www.stefanom.org/spc/

2.- Hertzsprung-Russel Diagram:

3.- Star Size Comparison:

VII - More on Coments and the Nature of Light

1.- "The Comet of the Century": Comet ISON

2.- Solar Sunspots:

Butterfly Diagram

Maunder Minimum

Named after the solar astronomers Annie and Walter Maunder (1851–1928) who studied how sunspot latitudes changed with time. The period the husband and wife team examined included the second half of the 17th century. The Maunder Minimum coincided with the middle part of the Little Ice Age, during which Europe and North America were subjected to very cold winters.

Solar Activity Predictions for 2014

3.- The Nature of Light

Solar Spectrum

VII - Comets and Orbits

1.- Halley's Comet

Image taken in 1986. Next perihelion predicted: July 2061

(source: space.com)

2.- Deep Impact Mission 

Deep Impact was a NASA space probe launched on January 12, 2005. It was designed to study the interior composition of the comet Tempel, by releasing an impactor into the comet. On July 4, 2005, the impactor successfully collided with the comet's nucleus. The impact excavated debris from the interior of the nucleus, allowing photographs of the impact crater. The photographs showed the comet to be more dusty and less icy than had been expected. The impact generated a large and bright dust cloud, which unexpectedly obscured the view of the impact crater (source: http://goo.gl/ORqmou)

Principal Investigator: Prof. Michael A'Hearn (UMD)

Comet Tempel 1 taken by Deep Impact Probe:

Deep Impact Ejecta Plume:

3.- Comet Shoemaker Levy 9

4.- Prof. Meg Urry on: "A meteor and asteroid: 1 in 100 million odds"

I encourage you to read the following opinion column by Prof. Meg Urry (Yale):

http://www.cnn.com/2013/02/16/opinion/urry-meteor-asteroid/

Asteroid 2012 DA14 passed closest on February 15, 2013. As the image above shows, it passed much closer than the orbit of the moon - closer even that orbiting geosynchronous satellites (22,000 miles). Image Credit: NASA, Source: http://goo.gl/OpGNsq

Chance of an asteroid like DA14 to pass close to Earth: once every decade or two.

Meteor (~50 feet across) fell, on the same day, near Chelyabinsk, Russia.

Chance of impact of a meteorite like this: once every 100 years.

Therefore, the chance of both events happening on any one day are indeed very small: 1 in 3,650 days times 1 in 36,500 days, or about 1 in 100 million!!!

Discussion VI - Surface of the Planets and Moons

1.- You can now explore the surface of the Moon, Mars, Venus, Mercury and more thanks to Google Maps Gallery!

For example, here is the map of Mars:



this is the map of the Moon:



and this is the map of Io, moon of Jupiter:



you can find more maps here: http://maps.google.com/gallery/search?cat=space&hl=en

2.- Some Mars surface features that I would like to highlight:

1) I found a crater/smiley face on Mars!

2) Valles Marineris: a system of canyons that is 4,000 km long

3) Olympus Mons, the largest volcano in the solar system (3 times higher than Mount Everest!)

4) Craters

3.- The lunar maria and the formation of Mare Humorum

Image taken from the book: The Essential Cosmic Perspective.

4.- Bonus:

Cosmos Trailer

You can watch the full episodes here: http://www.cosmosontv.com/

Lunar Eclipse

You can observe the curved shadow of the Earth on the Moon

Scales and Angular Measurement

Source: http://chandra.harvard.edu/photo/scale.html

Moon and Mercury Comparison

source: http://earthandsolarsystem.wordpress.com/2013/05/13/looking-forward-to-the-bepicolumbo-mission-to-mercury/

This is me on June 6, 2012 observing clouds
(and behind those clouds...the transit of Venus!)

Now, I just need to wait until December 2125!

Discussion V - Review for Exam

1.- A summary of what we covered today in discussion section:

Discussion IV - Astrology & Weight and Mass in the Universe

1.- The "dark constellations" of the Inkas: Lluthu, a partridge in the Coalsack Nebula2

Source: http://journals.cambridge.org/download.php?file=%2FIAU%2FIAU5_S260%2FS1743921311002183a.pdf&code=b458365823d951167005a5003ed21b36

3.- Annular Eclipse

Remember that: "The Sun's distance from Earth is about 400 times the Moon's distance, and the Sun's diameter  is about 400 times the Moon's diameter. Because these ratios are approximately the same, the Sun and the Moon as seen from Earth appear to be approximately the same size: about 0.5 degree of arc in angular measure"

and that the orbit of moon is elliptical and inclined to the ecliptic at an angle of 5 degrees. 

2.- A little bit of humor...and physics :)

3.- Your weight on other worlds calculator:

http://www.exploratorium.edu/ronh/weight/

4. What would happen to your weight if: (1) Earth's mass increased by a factor of 5? (2) Earth's size doubled?

5.- Ancient astronomers that you need to remember

Discussion III - Celestial Coordinates & Astrology

1.- Did you know that according to a very recent survey, 1 In 4 Americans thinks the sun goes around the Earth?

Here you can read more: http://www.npr.org/blogs/thetwo-way/2014/02/14/277058739/1-in-4-americans-think-the-sun-goes-around-the-earth-survey-says

and that ~55% of Americans in the 18 to 24 age range think astrology is "very" or "sort of scientific"?

Caveat: some people confuse astrology with astronomy

Read more here: http://neoacademic.com/2014/02/14/nsf-report-flawed-americans-do-not-believe-astrology-is-scientific/#.Uv-gmEJdXLZ

2.- Wild Wild West and the Full Moon:

We will watch this part of the movie and discuss about this 'special' full moon at discussion section.

Link to video: http://www.astro.umd.edu/~rhc/www.mov

Curious about more examples of bad astronomy in movies? 
Check this website: http://www.badastronomy.com/bad/movies/index.html#list

I highly recommend to read the comments on the movie Armageddon ;)

3.- Celestial Coordinates:

Discussion II - Seasons & Moon Phases

1.- Remember the first class when we asked you: "List 3 things that you would like to learn in this astronomy class". Well, here are the results for sections 105 and 106:

As you can see, solar system related topics were the most voted!

2.- Why are there seasons on Earth? Let's ask Harvard Graduates ;)

3.- Useful links:

Sun Motions Overview 
Meridional Altitude

4.- Summary of what we discussed on Wednesday: