Archive for 2010

1. Go to: zooniverse.org and join. (Create a login)
2. Go to galaxyzoo.org and click “How To Take Part.” Do the tutorial.
3. Go back to galaxyzoo.org and click “Classify.” Go!

We discussed Kepler’s Laws.

I forgot to hand out the homework.

Powerpoint – 2009_02_11 LP09 Galaxies

Don’t forget: No class 2/15, and class meets at Pacific Science Center 2/17!

What you need to know:

Carbonates (like antacids that you dissolve in water) dissolve easily in water, and are deposited easily out of water. Sulfates (which are why Yellowstone’s fantastic mud-pots smell awful) are similar. Silica-rich deposits are more commonplace – so you need more detail to tell if they’re from water or not.

Up until now you’ve taken it for granted when you read in an article that a mineral discovered on Mars indicates the prehistoric existence of water. But how can a certain mineral in a rock tell you that there was once water? How can it tell you if that water was more recent or more ancient?

Carbonates

There are many carbonates, but calcium carbonate is probably the most familiar to you – and one of the most common carbonates. As you know from taking Tums or Alka-Seltzer – these dissolve easily in water. Many seashells are made of carbonates as well, and when those animals die, the shells are dissolved into the ocean and eventually that calcium carbonate is redeposited as limestone. Like that, all carbonates are usually formed in “hydro” and hydrothermal situations, and are also later dissolved by even a slightly acidic situation. Although this example only represents redeposition of carbonates – they are also deposited primarily (in the first place) by water as well. Finally, in order for carbonates to last a geologically long time they must be protected from water and other acids. Carbonates are either a good indication of water activity in the geologically recent past, or there hasn’t been any water near them in a long, long time.

Carbonates in ALH84001 (one of the meteorites from Mars)

Sulfates

Sulfate minerals are similar to carbonates in terms of their indication of water – they are also water-soluble, and occur in similar places to carbonates: embedded with limestones, etc. Sulfates tend to need more “thermal” in the term “hydrothermal” than carbonates – which is why you find a lot in volcanic regions like Yellowstone. That rotten-egg smell associated with hydrothermal areas on earth is due to the sulfur in sulfates. Sulfates are a great indicator for water activity paired with heat.

Spirit Unearths Sulfates on Mars

Silica

Almost every rock on Earth is silica-based. The presence of silicates in and of themselves is not an indication of water, current or prehistoric. More analysis or specificity is needed. After oxygen (yes, oxygen!) silica is the most common element in the Earth’s crust, as well as the crust of the Moon, and what we know of the surface of every other terrestrial planet.

Where’d I Get My Info?

Klein, Cornelius. The 22nd Edition of the Manual of Mineral Science.

~ A l i c e !

We took Test 1.

We discussed hoaxes, hoaxes, and more hoaxes.

• 2/10 – Meet in the Computer Lab OLY 203
• 2/15 – No Class
• 2/17 – Meet at Pacific Science Center

Important:

• Prepare for Test #1 on Monday.
• The field trip to Pacific Science Center is 2/17/2010 during class time. DO NOT BE LATE.
• Be sure you can draw and label a picture of our galaxy from the side.

We finished the powerpoint from last time.

We talked about our galaxy, and finished quiz #3. The handout was about the Distance ladder – it is one of the pages in the powerpoint. 2010_02_04 LP08 Our Galactic Home

Links to videos:

• http://www.youtube.com/watch?v=Suugn-p5C1M&feature=player_embedded
• http://www.amasci.com/amateur/traffic/traffic1.html
• http://www.youtube.com/watch?v=duh2srW8j3U
• http://www.youtube.com/watch?v=c5Us-jonCLA&feature=player_embedded

2009_02_02 LP07 Death and Black Holes

We covered deaths of stars, neutron Stars, black holes, what happens when you fall into a black hole etc. We got to page 16 in this powerpoint. We’ll pick up on Wednesday.

HR Diagram homework was due today.

Welcome Mama Joules to the astroblogger community – stop by Carnival of Space #139 hosted by her!

~ A l i c e !

Check out Carnival #138 over at Nancy Atkinson’s new blog!

HR Diagram Homework was assigned – due Monday 2/1
PowerPoint We discussed the star life cycle.

2010_01_25 LP05 Starlight Starbright
We covered spectra, light and how astronomers know what they know. Read chapters 6 & 7 to catch up.
Astronomers Homework was due today. No homework was assigned.

Quiz #1 covering everything up to this point except cycles.
We reviewed cycles and talked about eclipses
UPDATE to the Homework: Astronomers, it should be written as a press release, as if this astronomer is coming to town to give a talk. Make it exciting and interesting.
Class next week may start a few minutes late, the classrooms should be open on time.
End of day note: let me know if you’re more of a writer or more of an artist. Let me know if there’s anyone in the class you think you absolutely can’t work with.