APOD 4.8

This picture, "The Elusive Jellyfish Nebula" is a very interesting one. The nebula itself is described as elusive because it is usually very faint and therefore it is hard to find. This picture is in false-color and it shows the arcing ridge of emission and its dangling "tentacles." The nebula contains two bright stars, Mu and Eta Geminorum. This nebula is supposed to be part of the bubble-shaped supernova remnant IC 443. The Jellyfish Nebula is about 5,000 light-years away, and so this image is about 300 light-years across. The false color shows emissions from oxygen, hydrogen, and sulfur atoms in blue, green and red colors

APOD 4.7

This picture, "Tentacles of the Tarantula Nebula", is a very vibrant picture that grabbed my attention immediately when I clicked on the link for it. The picture has an array of reddish to black and gray colors within it. The article is very interesting, and tells about the Tarantula Nebula. This Nebula is apparently THE largest and most active star forming region that we know of, and lies within the nearby Large Magellanic Cloud. It is so large in fact, that if it was at the distance away that the Orion Nebula is, it would take up an entire half of the sky alone. While perusing the relevant links in the article, I learned that the red and pink colors that can be seen in the picture are caused by emission nebula, with a scattering of supernova remnants and dark nebula.

APOD 4.6

This picture, "Herschel Crater on Mimas of Saturn" was taken by the Cassini spacecraft. Orbiting Saturn is of one of the smaller round moons of Saturn, Mimas. It features the Herschel crater, one of the largest impact craters in the Solar System. The Cassini came within 10,000 km of the moon when it took the picture, setting a new record. The image has been composited with previous images to show detail in the landscape of the moon. It has been false colored and contrast enhanced to show the cratered terrain. The crater itself spans about 130 km. The low mass of Mimas creates enough gravity to keep it spherical, but to also allow features like this exist. Mimas is made mostly of water ice and rock.

APOD 4.5

This image, "A Hall of Mountain Glory" is very interesting and vibrant to behold. The picture itself depicts a very strange phenomenon, which is 3 rainbows almost one on top of the other, in a misty mountain area. However, the mist in this picture is actually a very odd optical illusion that is created by the air in the area. Light is being backscattered off of a cloud passing below the peak of a mountain. The 'fog' itself, would actually seem to dissipate, if one tried to walk through it and experience it. The refraction, reflection, and diffraction of Sunlight on water droplets in the air, is what causes this. While perusing the relevant links in the article, I learned two very different things. One, is that such phenomenons are often called 'Broken Spectres', and also that 'In The Hall of the Mountain King', an orchestral piece which I have heard before, was composed by Edvard Grieg.

APOD 4.4

In this image,"Virgo Cluster Galaxy NGC 4731", the spiral galaxy NGC 1055 is clearly prominent. NGC 1055 rests 60 million light years away and is a dominant part of a small galaxy group near the constellation Cetus. The galaxy spans 100,000 light years, comparable in size to our own Milky Way Galaxy. The stars in the foreground appear spiky and colorful. This "spiky" appearance is actually caused by light deflecting as it passes by the support rods of the reflecting telescope. The spikes steal light away from the central images. In the background of the image are more distant galaxies and also a box shaped inner halo. The halo extends beyond this galaxy's dusty plane.10 billion years ago a a satellite galaxy was disrupted by the larger spiral.

Galaxy Interaction Images

http://imgsrc.hubblesite.org/hu/db/images/hs-2008-37-a-large_web.jpg

http://www.daviddarling.info/images/interacting_spiral_galaxies.jpg

http://www.imagingtheuniverse.com/Galaxies/Canon--400D/2009-05-M51b/636636618_BgpLT-S-1.jpg

http://images.astronet.ru/pubd/2005/03/01/0001203081/ngc1532_gemini.jpg

http://cas.sdss.org/dr6/en/proj/basic/galaxies/images/752-6-410.jpg

http://www.astronomy-blog.com/images/blogs/3-2008/two-galaxies-interacting.jpg

http://www.scientificamerican.com/media/img_gallery/CE97F2A0-AF80-BADE-104D0ECF00733138.jpg