Much of microscopic science remains abstract. While tools and experiments have allowed scientists to infer how things like electrons and atomic nuclei behave, no one has ever really seen an electron. At least, not until now.

While it's impossible to snap a photo of an electron in the strictest sense (the wavelength of visible light is much too large for direct measurement), scientists have done the next best thing. By modifying a piece of equipment called a scanning tunneling microscope, a team of researchers from IBM Research Zurich were able to produce the first-ever images of electrons in their orbitals, according to study in Nature reported by Science magazine.

A scanning tunneling microscope has a tiny finger that's only a few atoms wide at the tip. While able to probe the density of electrons in whatever it's scanning, it typically doesn't have the resolution to see those electron orbitals in detail. But by using a special molecule (carbon monoxide) on the scanning tip and insulating the substance being scanned with a layer of salt, the scientists were able to boost the sensitivity of the microscope, and scan electron orbitals for the first time.

Although electrons are often thought of as particles rapidly spinning around a nucleus, the truth, as described by quantum mechanics, is much different. An electron is said to be simultaneously in every point in space and in none, more accurately represented by a probability "cloud" that shows where it's likely to be rather than where it is.

The images bear that signature (see the pattern at right—the measured images are in the top row with the predicted patterns below). Scanning samples of the organic molecules pentacene and naphthalocyanine, the research team found the same pattern that quantum models predict for the same molecules, with the orbitals resembling smeared clouds in a regular pattern, separated by gaps (where the probability of an electron being present is very low).

Confirming predicted orbital models could be just the beginning, however. Now that the research team has created a technique for scanning atoms at that level, they hope it leads to scientists eventually custom-building molecules with specific orbital patterns. That could someday lead to building machines out of individual molecules, which would be a boon to .