# Can the Earth be seen to transit the sun from the outer planets?

Transit of Mercury as seen from Mars The Curiosity rover on the planet Mars observed the planet Mercury transiting the Sun, marking the first time a planetary transit has been observed from a celestial body besides Earth, on the 3rd June 2014.

This question may be answered by astronomy software, that's the reason I think there may be an answer. I have some similar programs, but none has this option.

Transit of Mercury from Earth.

I ask this question, can the Earth (actually the Earth Moon system), be viewed in transit across the sun, from pure curiosity, as I can't imagine it has much practical value, although I don't know enough about the subject to judge that. Possibly it gives an indication of the "flatness" of the orbital planes of the outer planets, although I am sure that this has long since been established

It may only be answerable by computer generated data, although I do not want to underestimate the astronomical achievements of generations of astronomers, who may well have worked out the dates of Earth transits a long time ago.

• – CuriousOne Sep 23 '15 at 11:41
• As a sidenote to "to me this image this really brings home the relative size scales involved between the sun and it's planets", I would say that no it doesn't. Actually Mercury is closer to the camera than the Sun is and so it appears bigger with respect to the Sun than it really is. – thermomagnetic condensed boson Sep 23 '15 at 12:29
• @no_choice99 Mercury is at 0.387 a.u. from the sun, so it will be magnified by about 1.6x compared to the Sun. That means that Mercury is even smaller than the picture suggests - either way it gives a sense of the massive size of the Sun. – Floris Sep 23 '15 at 13:10

Actually, any planet $X$ can be see to transit the sun from any other planet $Y$ with a larger orbit. That being said, the frequency for which the a particular transit happens tends to decrease as the planets you choose are further away from the Sun.