IC 1805: The Heart Nebula

Explanation: Sprawling across almost 200 light-years, emission nebula IC 1805 is a mix of glowing interstellar gas and dark dust clouds, its nickname is the Heart Nebula. About 7,500 light-years away in the Perseus spiral arm of our galaxy, stars were born in IC 1805. In fact, near the cosmic heart's center are the massive hot stars of a newborn star cluster also known as Melotte 15, about 1.5 million years young. A little ironically, the Heart Nebula is located in the constellation Cassiopeia. From Greek mythology, the northern constellation is named for a vain and boastful queen. This deep view of the region around the Heart Nebula, cropped from a larger mosaic, spans about 2.5 degrees on the sky or about 5 times the diameter of the Full Moon.

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Amazing natural phenomena to see before it's too late

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TV Show : Nature's Most Amazing Events

Origin of current influenza H1N1 virus

A Triple Sunrise

Explanation: How can the same Sun rise three times? 2009 July 10, a spectacular triple sunrise was photographed at about 4:30 am over Gdansk Bay in Gdansk, Poland. Clearly, our Sun rises only once. Some optical effect is creating at least two mirages of the Sun -- but which effect? In the vast majority of similarly reported cases, mirages of the brightest object in the frame can be traced to reflections internal to the camera taking the images. Still, the above image is intriguing because a sincere photographer claims the effect was visible to the unaided eye, and because the photographer took several other frames that show variants of the same effect. Therefore, polite readers are invited to debate whether the above image captures a particularly spectacular example of common reflections inside a standard digital camera, shows one of the most spectacular examples of atmospheric lensing yet recorded, or was caused by something completely different.
http://antwrp.gsfc.nasa.gov/apod/ap090804.html

The Same Color Illusion

Explanation: Are square A and B the same color? They are. Are too. The above illusion, called the same color illusion, illustrates that purely human observations in science may be ambiguous or inaccurate. Even such a seemingly direct perception as relative color. Similar illusions exist on the sky, such as the size of the Moon near the horizon, or the apparent shapes of astronomical objects. The advent of automated, reproducible, measuring devices such as CCDs have made science in general and astronomy in particular less prone to, but not free of, human-biased illusions.

http://apod.nasa.gov/apod/ap091004.html