Astronomer Stephen Edberg captured this sequence of the full moon as it enters Earth's shadow and then is completely covered by it on August 28, 2007. The moon's passes through nearly the same portion of Earth's shadow during the total lunar eclipse on April 14-15, 2014 but the coloring may be different. A lunar eclipse occurs when the Moon passes directly behind the Earth into its umbra (shadow). This can occur only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, a lunar eclipse can only occur the night of a full moon. The type and length of an eclipse depend upon the Moon's location relative to its orbital nodes. When the Moon travels completely into the Earth's umbra, one observes a total lunar eclipse. View more images of lunar eclipses
Did you know that your body houses millions of vessels that are circulating blood at this very moment? In fact, if all the blood vessels in the average adult were connected in one line from beginning to end, they would stretch 100,000 miles. The circulatory (or cardiovascular) system carries blood all throughout your body to transport nutrients, allow for essential body functions like breathing, and maintain an overall homeostasis.
Arteries, veins, and capillaries are the three different types of blood vessels that make blood circulation possible. Veins transport deoxygenated or waste-rich blood that will eventually be filtered, and arteries carry the filtered, oxygenated blood. Capillaries are the middleman of blood circulation, as they enable the exchange of blood between arteries and veins. Stock Video of Blood Flow and Circulatory Anatomy
There are two types of blood circulation: pulmonary and systemic. Pulmonary circulation is the transportation of blood to the lungs so that the …
You may associate nature and medical illustration with dusty old tomes, but it's more relevant and beautiful than ever. In a world that's getting more complicated and where technical knowledge can make or break careers, precise and informative illustration is more critical than ever.Stock Images of Nature & Medical Illustration
Illustration can show the unseen and explain the unclear. Think about a photograph of internal human anatomy. Even if it is a high resolution, super sharp image, it may still be difficult to decipher. A science or medical illustration, on the other hand, can show each anatomical part in a different color, label it, and indicate its function. Unimportant details can be left out and critical information highlighted.
In many cases, a photograph can't display the same level of detail as a well-designed illustration. Volcanos are spectacular on the outside but their inner workings are hidden from view without a well-placed cross-section. Illustratio…
Zombies? Science Fiction? Fantasy? No, it’s the very real flu virus, cold virus, rabies, HIV, ebola or any other viruses.
Viruses are microscopic nonliving organisms that can only reproduce by hijacking the production mechanism inside a living host’s cells. The virus replicates itself until the cell bursts, spreading the virus further. This usually means death to each cell that becomes infected. If the host’s immune system cannot destroy the virus, ultimately it can mean a very bad outcome for the host as well.
They differ from bacteria in that bacteria are alive, reproduce through fission (splitting apart) and carry on metabolic functions such as digestion.Stock Images of Bacteria and Viruses
Viruses cannot reproduce on their own. They need to attach themselves to a host’s cells and inject it with their DNA/RNA, taking over the cell’s “machinery” to manufacture and reproduce. This continues until the cell literally bursts. The new viruses go on the hunt for more cells to continue th…