September 21 – Bye-bye, Galileo!

Posted on September 21, 2017

Today's historical anniversary is quite appropriate:

On this date in 2003, the spacecraft named Galileo ended its mission by entering Jupiter's atmosphere - to be crushed and to burn up.

Why did I say it was appropriate? Because this year (2017), on September 15 (about a week ago), the spacecraft named Cassini ended ITS mission by entering Saturn's atmosphere - to break apart and burn up.

These "death dives" were conceived to make sure that the planets' moons, which might possibly be homes to some primitive lifeforms, will not be contaminated with Earth organisms (bacteria, etc.). There is no way for the gas giants themselves to have any sort of life-as-we-know-it, and the extreme heat as the spacecraft burn up in the atmospheres would ensure that the remaining materials would be sterilized.

But the death dives are more than just a handy way to avoid contamination. These dives give us a bit more data to go along with all the data the probes already provided during their lifetimes. Scientists are pretty sure they know many aspects of the atmospheres and other conditions on the gas giants, and so they are able to make predictions of the conditions the spacecraft will encounter on their suicidal dives. The spacecraft keep transmitting until they break up, or are crushed, so we are able to compare the predictions with the actual measurements taken and with the behavior of the spacecraft. 

Here are some comparison stats of the two spacecraft:

Launch dates: 
Galileo - October 18, 1989
Cassini - October 15, 1997

Planned mission lengths, including travel time:
Galileo - a bit more than 8 years
Cassini - about 10 years

Actual mission lengths, including travel time:
Galileo - almost 14 years!
Cassini - almost 21 years!

Galileo lasted six years longer than planned, and Cassini lasted more than a full decade longer than planned! Wow!

Here are a few highlights of Galileo's findings: 

Discovered the first asteroid moon
First direct measurement of Jupiter's atmosphere
First asteroid flyby
Observed Comet Shoemaker-Levy 9's collision with Jupiter
Observed volcanoes erupting on Io (a moon)

Observed Io's interaction with Jupiter's atmosphere
Theory of liquid ocean under moon's ice supported (but not yet confirmed) - Europa
Probable liquid saltwater layers under moons' ice - Ganymede and Callisto

Magnetosphere detected on Ganymede
Exosphere detected around three large moons
Faint ring system detected around Jupiter

(I covered some of Cassini's findings here and here.)

September 20 - Happy Birthday, Judy Baca

Posted on September 20, 2017

Wow! Check out Judith Baca:



Professor of Chicano/a Studies (University of Texas, Los Angeles)

Professor of World Arts and Cultures (U. of Texas)
Artistic director of Social and Public Art Resource Center (Venice, CA)

Director of the project that created one of the largest murals in the world, the Great Wall of Los Angeles

That's a pretty amazing resume!

Above, Baca and her work in 1973.
Below, Baca and her work today.

Chicana artist Baca knew that all people should have a voice in public art, so she decided that "the people" could create murals all over Los Angeles, and she organized more than 1,000 young people to dream up and paint more than 250 murals. She encouraged youths from different ethnic backgrounds to explore their peoples' histories and to come up with murals that could connect those histories to their own lives today.

This citywide mural project started in 1974.

Another big project Baca took on, starting in 1987, was creating a huge-yet-portable mural called the World Wall. This mural promotes global peace.

I wondered what Baca was thinking about the Tr*mp administration's efforts to build a border wall and deport everyone from "bad hombres" to Dreamers. I was able to find a quote from her:

Chicano is about resistance and affirmation of a culture. And I think [this administration is] giving many young artists purpose again and a kind of focus for their work."

"Non-violent Resistance"

From now until next January (January, 2018), the Getty Museum in Los Angeles will include Baca's work in a special exhibit called Pacific Standard Time: LA/LA. (LA can mean Los Angeles, Latin America, and Latinx Art.) Two other exhibits this fall will feature Baca's work, and there are plans to extend the Great Wall mural and to add a viewing bridge, as well.

Also on this date:

September 19 – Armed Forces Day in Chile

Posted on September 19, 2017

Yesterday was Chile's Independence Day

Today is Day #2 of the national holiday, with a military parade and air displays in the capital city, Santiago, and in some other cities as well.

This super long-and-skinny South American country has some amazing features. Like these:

According to the Guinness Book of Records, Chile has the largest swimming pool. Here are the numbers for the saltwater pool:

   Length: 1,000 yards (about 1,000 m)
   Area: 20 acres
   Maximum depth: 115 feet!!!
   Volume: 66 million gallons

Another world record holder: the Atacama Desert is the driest non-polar desert in the world. There are parts of the desert that haven't seen rain in - get this! - over 400 years! (The desert as a whole receives an average of 15 mm, or about 0.6 inches, of precipitation per year.)

Chile has a lot of mountains - the Andes mountain range, which dominates South America. As a matter of fact, 80% of the country is mountainous!

One of Chile's mountains, the Ojos del Salado, is the highest active volcano in the world. And Chile has a lot of active volcanoes - about 500 of them! Yikes!

The Pacific islands that belong to Chile are volcanic. They formed from magma bubbling up from three different hotspots. Hotspots tend to create chains of islands, but in the case of some of the hotspots off the coast of Chile, underwater ridges were formed with only an occasional island rising high enough from the seafloor to reach the surface and become an island.

One of those hotspot islands is Easter Island, which is
famous for sculptures of giant heads / figures!!

Chile stretches from the tropics all the way to islands that are quite close to Antarctica!

Also on this date:

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September 18 – National Ceiling Fan Day

Posted on September 18, 2017

We are celebrating ceiling fans?

Well, actually, today is a giant experiment: We are asked to turn off our air conditioners and utilize only ceiling fans (and wall fans, desk fans, all kinds of fans) today.

If every American did that, in our homes and businesses and other buildings, just this one day, we would save enough electricity to power all of NYC for months.

That's because central air conditioning systems typically run on about 3 kilowatts and cost about 36 cents an hour to run, whereas a good ceiling fan only draws about 30 watts to run, and therefore costs about 1 cent per three hours of use.

That's HUGE!

Here is a source for those figures, updated to the first of the year.

Ceiling fans can look very cool. Here are some neato styles:

Also on this date:

Chile's Independence Day


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Check out my Pinterest boards for:
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