In comparison, Mercury orbits the Sun every 87.97 days at a distance of 0.387 AU.

To compare, Mercury orbits the sun at .3871 AU every 87.97 days.

Thus Mercury orbits the Sun in 0.24 of an Earth year, while Phobos and Deimos orbit Mars in a similar 4:1 time ratio.

Mercury orbited closest to the Sun and the rest of the planets fell into place in order outward, arranged in distance by their periods of revolution.

In comparison, Mercury orbits the Sun every 87.97 days at an average distance of 0.387 AU; therefore, Kepler-40b's orbit is approximately thirteen times faster than that of Mercury's and five times closer to its host star than Mercury is to the Sun.

The observation demonstrated conclusively that Mercury orbited around the Sun.

It orbits the star very close, over 2.5 times as close as Mercury orbits the Sun.

To compare, Mercury orbits the Sun at a distance of 0.387 AU every 87.97 days with an orbital eccentricity of 0.2056.

Following a circuitous trip through the inner solar system, the craft will become only the second to visit mysterious Mercury and the first to orbit it for long-term study.

His planetary system was a partially heliocentric model in which Mercury, Venus, Mars, Jupiter and Saturn orbit the Sun, which in turn orbits the Earth, similar to the Tychonic system later proposed by Tycho Brahe in the late 16th century.