This fluorescence micrograph shows the vascular system of a developing chicken embryo, two days after fertilization. Injecting fluorescent dextran revealed the entire vasculature used by the embryo to feed itself from the rich yolk inside the egg.
These high cliffs occur on the surface of a comet. They were discovered to be part of the dark nucleus of Comet Churyumov–Gerasimenko (CG) by Rosetta, a robotic spacecraft launched by ESA which began orbiting the comet in early August.
☤ MD ☞ ☆☆☆ Colored scanning electron micrograph (SEM) of squamous cell carcinoma (cancer) cells from a human mouth. The many blebs (lumps) and microvilli (small projections) on the cells' surfaces are typical of cancer cells.