Friday, January 27, 2012

APOD 3.2

January 21, 2012
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Days in the Sun:

     This photograph is a compression of time (June 21st to December 21st in 2011) and is called a solargraph, a picture that captures the path of the Sun.  The picture was taken using a pinhole camera made from a drink can lined with photographic paper.  Pinhole cameras are typically used with time, the Sun, and astronomy in general. The gaps in the arcs are indicative of cloud cover, where as the continually bright streaks represent sunny weather.  The trails are higher in June due to the summer solstice and sink in December due to the winter solstice.

Tuesday, January 24, 2012

APOD 3.1

January 17, 2012: The Witch Head Nebula
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The Witch Head Nebula is a reflection nebula (meaning it reflects light from a star close to it).  It is linked to Rigel located in the constellation Orion.  Rigel provides the light primarily reflected by this nebula.  The blue color is partly caused by Rigel's color but also the blue color is due to the fact that the particles of dust reflect blue light more efficiently than red light.  For the same reason, Earth's sky appears blue.  The Witch Head nebula is roughly 1000 light-years away.

Friday, January 13, 2012

Astronomy Cast 2

The Tunguska Event
      One morning in Siberia (June 30th, 1908) something unknown caused massive destruction when it streaked across the early sky.  Investigations were not set up until 1921.  They found that the total area of damage spanned about 800 square miles.  When further investigation was done, nothing was found in the center of debris besides a tree stump. Finally, in 1978 (70 years later!) astronomer Lubor Kresak realized that the Tunguska event occurred at the height of a Beta Taurid meteor shower.  He believed that the destruction was caused by Comet Encke.  Today, scientists believe it to be a asteroid comet hybrid (possibly).  What I found most amazing about this entire thing was that it took decades to actually even begin to thoroughly investigate what happened.

Astronomy Cast 1

Galileo Galilei

     While reading over this astronomy cast, I was surprised that I actually learned a lot.  In his early years, Galileo was pushed to be a priest by his father but he instead chose to attend the University of Pisa to go to medical school.  There he decided to go into mathematics and he also studied art.  In the midst of things, he insulted the church and there was some conflict in his life due to that.  He taught geometry, mechanics, and astronomy until 1610.  He also had three children, all with the same woman, two of which were girls.  Another thing I learned about Galileo was that he was the first to observe Saturn's rings or "ears" since he thought they looked like handles.  I also learned that he was rather cocky, I suppose I would be too with his list of accomplishments.  What I found most interesting about this podcast were the facts about Galileo's personal life and personality because that's not really something we learn about in the classroom.

APOD 2.8

Jan. 11, 2012: Little Planet Lovejoy

See Explanation.
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     This photo of comet Lovejoy, taken on December 30th in the morning shows the comet on the edge of Earth.  The photo was put together using little planet projection, which is a type of stereographic projection used to map the image pixels.  The stars Sirius and Canopus are also visible in this photo (taken in Victoria, Australia) and are to the right of the planet.  Comet Lovejoy's tail is visible to the northwest of Earth.

Wednesday, January 11, 2012

Charles Messier Biography

            Charles Messier was born in Badonviller, Lorraine, France on June 26, 1730 and died in Paris, France on April 11 (or 12), 1817.  The exact date of Messier’s death is still unknown to this day.  He was the tenth out of a family of twelve children.  His father died when he was only eleven years of age, but that did not prevent him from achieving great things.  In 1751, he moved to Paris, where he did not know one soul. He was hired by astronomer Joseph-Nicolas Delisle to copy maps and record observations.  In 1755 Delisle got Messier a job as a clerk at the observatory in Paris with a salary of five hundred francs including room and board at the Hotel de Cluny. 
            In 1759, on January 21st, he spotted Halle’s comet but was told to keep this a secret by Delisle, who also swore him to secrecy a year later with a similar occurrence.  This was due to the fact that many other French astronomers had not yet seen Halle’s comet.  In total, Charles Messier observed roughly 41 comets and discovered 12.  He therefore became well noted in the world of astronomy and was admitted to the Royal Society of London in 1764 and became a member of the academies in Berlin and St. Petersburg.  He later changed his title from “clerk” to “astronome” and was admitted to the French academy in 1770.  In addition to this, he also became a member of the academies in Sweden, a member of the Netherlands Society of Sciences, and a member of the Institute of Bologna.  In 1806 he received the cross of the Legion of Honor and started to write memoirs of his observations complete with his own personal maps.  In his first memoir he included M1, M13, and the Andromeda Galaxy, among others.  He was an excellent observer (though not a mathematician) who added to his list of observed object throughout his entire life.  At times, he would use as many as 12 different telescopes to conduct observations. He is most well known for the catalogue of “Messier objects” that is still studied today.  However, on November 6, 1781 he had an accident that caused him to be unable to observe for an entire year. He continued making discoveries and in 1817 he had a stroke which left him partially paralyzed.  He passed away quietly in his home at age 87.

Sunday, January 8, 2012

APOD 2.7

January 5, 2012: Ringside with Titan and Dione
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     Titan and Dione are two of fifty-three Saturnian moons that orbit the planet in the plane of it's rings.  The above picture, captured by the Cassini spacecraft, features the two moons and Saturn's rings visibly in the background.  Titan is the largest moon of Saturn (with a radius of 2,575 kilometers) and is the second largest moon in our solar system, only smaller than Jupiter's Ganymede.  Dione is the third largest moon of Saturn and has a diameter of 1,123 kilometers.  Titan is 2.3 million kilometers from the Cassini spacecraft and Dione is 3.2 million kilometers.  The moons are much farther from the spacecraft than they are from the gas giant.