High in the east, ruddy Aldebaran, anchor of the Hyades star cluster, fades as the morning light gathers. Well to its north, Capella, the Goat Star, shines just a little brighter. Looking along the horizon halfway between these two beacons, you should spot Mercury, the innermost planet, buried well inside the bright band of light that hugs the horizon. To Mercury's right, Orion, brightest of constellations, lifts slowly into the sky.
Mercury reaches greatest elongation its maximum angular separation from the Sun on July 20th. But this event has little practical significance. In fact, the planet hangs in nearly the same spot in the morning sky from July 1830. After that, it starts to plunge toward the Sun, becoming invisible some time in early August.
On July 18th the innermost planet is relatively faint and hard to spot at magnitude 0.6, roughly the same as Betelgeuse to its right. But it's quite a sight through a telescope a thin crescent more than 8" from horn to horn. By the 30th it's brightened to magnitude -0.8, far outshining any of Orion's stars. However, the view through the telescope is less interesting, with the planet shrunk to 6" and a fat gibbous phase of 70%.
Mercury is most gratifying if you can observe it on several days in succession, because it changes more rapidly than any other major celestial object besides the Moon.
If your schedule doesn't permit you to observe Mercury this July, this planet will have an even better morning apparition in early November, with exceptionally favorable circumstances for observers in the Northern Hemisphere.