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If we look at Zeta Ophiuchi with the naked eye, what we see is an unremarkable, reddish star of magnitude 2.5, without any trace of nebulosity.
The image recently released by NASA (above) shows quite a different picture: a luminous blue star surrounded by a vast nebula, compressed in the direction in which Zeta Ophiuchi is moving.
The reason for this difference lies in the wavelength of observation, the image above was actually taken in the infrared, by the Wide-field Infrared Survey Explorer (WISE).
So that we can interpret the infrared data, the image is presented in standard false colour, with blue and cyan corresponding to 3.4 and 4.6 microns, and green and red 12 and 22 microns respectively (other colours come from the combination of these).
Blue is actually the intrinsic, "true", colour of Zeta Ophiuchi, but it appears red at visible wavelengths because the dust in which it is embedded absorbs preferentially the blue light (a similar effect makes the evening sky red). This dust is only visible in the infrared. If this star were in a completely transparent region, despite being 458 light years away, it would be one of the brightest stars in the sky (having an absolute magnitude 65 thousand times that of the Sun).
The most interesting feature revealed by WISE is the bow-shaped shock wave that has been generated in front of the star (yellow in the image), clearly showing that the star is moving towards the upper left of the picture.
The bow-shock, as it's called, is caused by the compression of interstellar gas and dust by the powerful stellar wind typical of young blue giants like Zeta Ophiuchi. Estimated to be only 4 million years old, having a mass of 20 solar masses, this star will live no longer than twice this long.
The bow-shock is seen only on one side of the star because there is another important component in its formation, and that is the velocity with which the star is moving through space. Zeta Ophiuchi is flying through this dusty region of the Galaxy at 24 km/s, most probably due the demise of an even more massive companion star with which it was in orbit. Once this companion ended its life as a supernova, Zeta Ophiuchi was no longer gravitationally bound in the system and was left to speed through space alone.
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