Microscope images of a thin section of a meteorite. The Allende meteorites fell in 1969 at Pueblito de Allende, Mexico. (Flickr/Jeff Barton)

A thin section of a Vaca Muerta meteorite. The left half of the slide, along a diagonal arc from upper left to lower right, is part of a large chondrule that has been melted and then shocked after recrystallization. (Flickr/Jeff Barton)

Jeff Barton, photographer and director of sciences for an educational non-profit, decided to see what was inside the mystical space rocks he had been collecting.

Tens of thousands of protesters have marched in the Tunisian capital, Tunis, to demand the resignation of the Islamist-led government.

It is the largest demonstration of its kind since the latest political crisis began two weeks ago when a prominent opposition politician was assassinated.

The human race knows very little of itself, almost like a race with amnesia. As we continue to move forward through time, new discoveries are made that make old theories obsolete and false. It’s a good lesson that shows us how we can attach ourselves to “truths” and believe them whole-heartedly, often forgetting that truth is constantly changing and new paradigms of perception always lurk around the corner.

Decades after scientists described our “chemical code” of life using the double helix DNA, researchers have discovered four-stranded DNA within human cells. The structures are called G-quadruplexes, because they form in regions of DNA that are full of guanine, one of the DNA molecule’s four building blocks. The others are adenine, cytosine and thymine. A hydrogen bond is responsible for holding the four guanines together. The four stranded DNA usually presents itself right before cell division.