Can You Find Mercury
The Planet Closest To The Sun
Mercury the planet of incredible speed and swiftness. Because of it's
closeness to the sun Mercury is able to complete a year before it
completes a day.
The planet is so fast it circles the sun in about 88 Earth days,
sunrise to sunrise on Mercury though is about 176 Earth days.
Unfortunately, this closeness is what makes viewing Mercury so hard.
Viewed from Earth you are always looking towards the sun and
Mercury tends to get lost in the glare.
Because of this Mercury is only visible for a short time either
just before sunrise or just after sunset, depending on where
it is in its orbit.
The best time to hunt for Mercury is when it is near greatest
elongation from the Sun, when the distance between the two in our
sky is farthest. Greatest elongations occur often.
The spring and early summer prove to be the best times of year for
observers in the Northern Hemisphere during evening elongations,
while the fall and early winter are best in the early morning.
The exact opposite is true from the Southern Hemisphere. Even then,
binoculars and finder scopes can help isolate the planet.
In a telescope, Mercury the planet appears as a tiny gray disk. Like Venus
and the Moon,it goes through different
The apparent size of its disk varies with phase.
Because Mercury hugs so close to the horizon, the disk
usually shimmers from atmospheric turbulence.
A better image can be obtained when the planet is higher
in the sky, during evening or morning twilight,
even though the contrast won't be as good.
Mercury is brightest as seen from Earth when it is at a gibbous phase.
This is between either quarter phase and full.
Although the planet is further away from Earth when it is gibbous
than when it is a crescent, the greater illuminated area visible more
than compensates for the greater distance.
The opposite is true for
Venus the planet
which appears brightest when it is a thin crescent.
Because it is much closer to Earth than when gibbous.
Elongations occur when an inner planet's position, in its orbital path,
is at tangent to the view from Earth.
Because these inner planets are inside the Earth's orbit
their positions as viewed from the Earth are never very
far from the position of the Sun.
When a planet is at Elongation, it is furthest from the Sun as viewed from Earth,
so it's view is best at that point.
There are two kinds of Elongations: The Eastern Elongation
occurs when the planet is in the evening sky and
the Western Elongation Occurs when a planet is in the morning sky.
Views Of Mercury
Because Mercury is an inner planet it will never resolve to a whole disk
in a telescope. When Mercury is in the position to be "Full"
it is located on the far side of the Sun relative to the Earth.
When viewing Mercury the planet will appear as a crescent or
gibbous shape. It will appear pinkish with gray markings.
Mercury’s apparent magnitude varies between about
−2.3, which is brighter than Sirius, and 5.7.
Mercury is similar in appearance to the Moon: it is heavily cratered
with regions of smooth plains, has no natural satellites or moons of its own and
no substantial atmosphere.
Greek astronomers believed the planet to be two separate objects:
one visible only at sunrise, which they called Apollo;
the other visible only at sunset, which they called Hermes.
Mercury is only about one-third the size of the Earth.
It is smaller than any other planet. Mercury is the
second most dense planet after Earth.
The apparent motion of objects in the sky due to the
rotation of the Earth is 15 degrees per hour.
Mercury the planet is not visible, due to the brightness of the Sun until
45 minutes after sunset or before sunrise. At the very best position
Mercury would only be visible about 1 hour and 7 minutes for a given day.
mercury the planet to order of the planets
constellations and backyard stargazing