APOD 2.7

January 5, 2012: Ringside with Titan and Dione

     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.

Charles Messier Biography Sources

The Gale Encyclopedia of Science:

http://go.galegroup.com/ps/retrieve.do?sgHitCountType=None&sort=RELEVANCE&inPS=true&prodId=GVRL&userGroupName=fl_sarhs&tabID=T003&searchId=R1&resultListType=RESULT_LIST&contentSegment=&searchType=BasicSearchForm&currentPosition=2&contentSet=GALE%7CCX2830902928&&docId=GALE|CX2830902928&docType=GALE

http://messier.seds.org/xtra/history/biograph.html

 

http://www.astro-tom.com/messier/messier_files/messier_biography.htm

APOD 2.6

December 14th:

      This photo is of a lunar eclipse over an Indian peace pagoda.  This photo captured the moon several times during the eclipse on December 10th.  The photo sequence was captured in New Delhi, India and the red tint of the moon is due to sunlight passing through Earth's atmosphere.  The occurrence of a total lunar eclipse is extremely rare and the next occurs in 2014.

APOD 2.5

December 10th: Vesta Rocks



     The above photos are thin slices of meteorite as viewed through a polarizing microscope.  They are classified as HED's (formed from basaltic magma) and they have reflective spectra that match up with the spectra of asteroid 4 Vesta.  The asteroid is currently being explored by NASA's Dawn spacecraft.

APOD 2.4

Nov. 30 : Curiosity Rover Lifts Off for Mars



     The weekend of November 26th-27th, the Mars Science Lab which carried the Curiosity Rover took off "atop an Atlas V rocket".  An Atlas V rocket (built by Lockheed Martin) was the first rocket in the United States Air Force's Evolved Expendable Launch Vehicle program.  The first Atlas V was launched in August 2002.  The Mars Science Laboratory took off from Cape Canaveral.  Curiosity is five times the size of Opportunity (another Mars rover) and looks like a small car.  It is equipped with a camera, a rock crusher, and is powered by plutonium.

Curiosity:

APOD 2.3

Orange Sun Scintillating

The photograph above was captured using Hydrogen Alpha(usually the brightest wavelength of light in stellar astronomy), so it is falsely colored.  There are many spicules (jets with about a 500 km diameter) visible on the Sun's surface.  Also in the photograph there is noticable color change along the edges of the Sun, this phenomenon is known as limb darkening and is caused by the lower temperatures at the larger heights of the Sun (hence less intense, so darker).  The Sun's magnetic field is moving towards Solar Maximum, the period at which there is the greatest amount of solar activity and sun spots appear, in the next few years.  This means that we can expect a busier, more complex Sun to view in the near future.

APOD 2.2

Historical Supernova Remnant



     RCW 86 is thought to be a remnant of an exploding star that the Chinese discovered in 185 AD.  There was some editing done to this photograph to show the different composition of the supernova.  The blue and green are X-ray energies and the red and yellow are cooler temperatures in infrared.  Because there is a lot of iron present in this supernova but not a neutron star, it suggests that it is a type Ia supernova (thermonuclear explosion that destroys a white dwarf star).  RCW 86 is 8,200 light-years away and has a radius of about 50 light-years.