[RayG (OP)]

We have photos of Venus and Mercury transiting the sun.. Are there any photos from outer Solar System probes that have captured an Earth transit of the sun? TIA

[Radium]

I don't think there is. I think they want to capture images of the other planets, not ours.

[jeffreyH]

This isn't a trivial question. If we are looking to detect exoplanets then studying our own from afar is quite a good benchmark for comparison with results from other sources of data.

[evan_au]

This web page has an image of a transit of Earth & Moon, as seen from Mars (in 2084!).

Transits seen from another planet around the same star are fairly rare - in fact, the Kepler telescope had better chances of seeing an exoplanet transit than an astronomer orbiting the distant star where the exoplanet resides.

If we are going to the expense of sending a probe to another planet, we don't want to burden that mission with the mass of a solar telescope - we want to fill it with planet-observing instruments.

It's only the really distant telescopes (like the ones on Voyager), where they are so remote that the Sun is merely a brighter-than-average star, where they can safely turn their telescope and look back towards the Sun, to spot that "Pale Blue Dot".