Saturday, October 29, 2011

NASA Astronomy Pictures of the Day

The NASA Astronomy Picture of the Day Archive is a large collection of astronomy-focused photographs taken by NASA and contributors since 1995. The incredible diversity in the photographs range from deep space images of galaxies, to our solar system and planets, down to the most extraordinary weather phenomena right here on earth. These photographs exhibit the natural universe and man-made technology on a grand scale. Listed below are Top 5 of the most interesting pictures I have personally handpicked from the 2010 archive*.  If you follow the link provided, it will take you to the official site, which includes a NASA explanation of what is happening in the picture.  I also provide a short summary of my own reasons why I think the picture is special.  I will be doing a “Part 2” follow up at the end of 2010 with another top 5 pictures, which will round-up the Top 10 of 2010, NASA Astronomy Picture of the Day.

5. Andromeda Island Universe- 2010 January

One of the most famous and studied galaxies in history, the Andromeda Galaxy offers a glimpse into how our own Milky Way Galaxy may look if we were to see it from an external point of view. It’s the closest spiral galaxy to our own galaxy, and is approximately 2.5 million light-years away.  Imagine that you point a laser light beam, and knowing the speed of light (299,792,458 m/s or 1,079,252,848.8 km/hr), which covers more than one billion km/hr, it would still take the laser 2.5 million years to reach Andromeda. Truly astronomical distances! Another mind bending implication of light traveling from a galaxy 2.5 million light-years away, is that the actual light we are seeing through our telescopes is 2.5 million years old as it takes so long for the light waves to reach earth. We are actually seeing the galaxy as it looked 2.5 million years ago, it’s like looking back into history in real-time.

4. Dark Shuttle Approaching – 2010 February 1:

At first glance this may look like a rare Pink Floyd album cover, but it actually is the Space Shuttle Endeavour in orbit around earth, taken by crew from inside the International Space Station.  What makes this picture superb, are the several visible layers of the earth’s atmosphere, each with it’s own color.  The earth is the entire left-hand side of the photograph, currently in darkness.  The orange layer is the troposphere where clouds are formed and daily weather patterns are observed. The stratosphere appears white and is where temperatures rise with altitude caused by heating of the upper ozone layer; and in the lower layers commercial jets fly above the troposphere where air is cooler and jet burn is maximized.  The blue hue behind and above the shuttle is the mesosphere, and here is where most meteorites “burn-up” in the earth’s atmosphere.  If interested, you can always learn more about each layer.
In the photograph we see the atmospheric transition that each rocket launched from earth must go through in order to reach earth orbit altitude or beyond. The dark silhouette of the shuttle against the colors of the atmosphere symbolizes humanity’s quest for technological breakthroughs that allow us to observe the earth and universe in new astonishing ways.  The encompassing “darkness” in the photo can be a metaphor to the great intellectual and spiritual unknowns we are seeking to illuminate, both on earth and in the heavens. The metaphorical darkness holds clues to how the universe was created, whether there exist other intelligent conscious beings, and in my view, insight into our own symbiotic relationship to the earth.

3. A Roll Cloud Over Uruguay, Las Olas Beach in Maldonado – 2010 January 5:

The earth’s troposphere is a very eventful place, and on some rare occasions when the weather conditions are just right, interesting cloud formations occur.  This incredible photograph documents the unusual roll cloud advancing towards the photographer, as it blocks out the blue skies with a low-pressure cold front.  Cool air downdrafts force warmer humid air to rise and cool below their dew point, hence creating Arcus clouds, or roll clouds.  Observing these cloud phenomena is an excellent way to understand how low and high pressure weather fronts interact with each other in the troposphere, especially when one sees how large these systems can be, spanning for hundreds of kilometres in the sky.
You can see more pictures of Roll cloud over ocean and  Three consecutive roll clouds, amazing!

2. Ash and Lightning Above an Icelandic Volcano – 2010 April 19:

A spectacular photograph of lightning during the volcanic explosion in Iceland, displays powerful forces at work during the eruption. A study in the journal Science indicated that electrical charges are generated when rock fragments, ash, and ice particles in a volcanic plume collide and produce static charges, just as ice particles collide in regular thunderstorms. Volcanic eruptions also release large amounts of water, which may help fuel these thunderstorms. See another famous photograph of a “dirty thunderstorm” and learn more here.
NASA Explanation

1. NGC 602 and Beyond – 2010 April 3:

With the help of super powerful telescopes, we have a window to the beautiful universal landscape surrounding the earth in every direction. A truly stunning picture taken by the Hubble Telescope, it is a portrait of how some stars are created in our universe.  Stars in these “clusters” are born out of vast clouds of moving gas and dust, which in the presence of gravitational forces create groups of new stars.  The space matter is easily seen being formed in the shape of enormous “pillars”, which surround the newly created stars groups in the centre.  Also notice the hundreds of various spiral galaxies seen dotting the photograph beyond the star cluster, further inspiring the human imagination to keep exploring the night time skies and the universe. This is my choice for the number 1 NASA picture of 2010, Part 1 of this series.