Hexagon-shaped cloud on Saturn

From the Cassini mission

Direct link [via NASA.gov]

Elastic collision of equal masses

An elastic collision of two equal masses on a frictionless surface.

Direct link [via Simon Steinmann of Wikipedia]

Non-native North American inhabitants, from 1750-2008

Click to enlarge image

Direct link [via Esemono of Wikipedia]

June 7, 2011 Solar Flare

In video form:


Direct link to .gif and video

Effects of Tuberculosis Animated

In celebration for World Tuberculosis Day, here is animated demonstration of tuberculosis forming a small cavity in the lungs. When a collection of the diseased cells gather, this process is possible and can cause the area affected to become necrotic.

Direct link [via Archive.org; Encyclopaedia Britannica Films]

Mimosa pudica moves its leaves

From Wikipedia:

Mimosa pudica is well known for its rapid plant movement.

Like a number of other plant species, it undergoes changes in leaf orientation termed "sleep" or nyctinastic movement. The foliage closes during darkness and reopens in light.

The leaves also close under various other stimuli, such as touching, warming, blowing, or shaking.

Direct link [via Wikipedia, by Hrushikesh]

Mongol Empire Timeline

From Wikipedia:

At its greatest extent [the Mongol Empire] spanned 6,000 mi (9,700 km), covered an area of 33,000,000 km² (12,741,000 sq mi), 22% of the Earth's total land area, and held sway over a population of 100 million.

Direct link [by Astrokey44]

Voyager 1 flies to Jupiter

From Wikipedia:

These pictures were taken from 01/06 to 02/03, 1979 ; and Voyager 1 flew from 58 million to 31 million kilometers from Jupiter during that time. The small, round, dark spots appearing in some frames are the shadows cast by the moons passing between Jupiter and the Sun, while the small, white flashes around the planet, are the moons themselves.

Direct link