Introduction
The planet Mercury is very difficult to
study from the Earth because of its
proximity to the Sun. It is the second
smallest planet (it was believed to be
the smallest until the discovery that
Pluto is actually much smaller than
originally thought), and also the
fastest in its orbit since it is the
innermost planet.
Mercury Orbit
Earth
Venus
Sun
Mercury
Mercury, the
innermost planet, is
35,983,095 miles
from the Sun on the
average. It revolves
about the Sun once
every 88 days in an
orbit that is the
most elliptical of
any planet except
Pluto.
Sun
Mercury
Because of its close proximity to the
Sun, Newtonian gravity doesn’t
quite work and general relativity is
needed to explain some of the
aspects of Mercury’s orbit. In fact,
this was one of the first tests of
general relativity. It was previously
thought that the deviations of the
motion of Mercury could be solved
by assuming planet (named Vulcan)
or possibly a second asteroid belt
inside Mercury's orbit.
A closer look at Mercury
Mariner 10
oblique view of
Wren crater and
surroundings on
Mercury. Wren
crater is barely
visible at the
lower center of
the image,
containing a
number of
craters within its
215 km diameter
floor.
Mariner 10
Mariner 10 flew over
Mercury at an altitude
of 756 km on in March
1974. It took many
photographs of the
surface of Mercury. Its
photographs cover
nearly half (the other
half is unexplored) the
surface area of the
planet Mercury.
Mercury Statistics
Diameter:
3,030 Miles
Distance from Sun:
35,983,095 miles
Revolution Period about
the Sun:
88 Days
Rotation Period about Axis:
58.85 Earth Days
Number of Moons:
None
Information on Mercury
Mercury
A planet of extremes
Mercury is a lump of
rock, barely larger than
the Moon, living under
the fierce heat of the
burning Sun. It
experiences extremes
in temperature from
over 400°C at noon to
less than -150°C at
night.
Information on Mercury
On the surface Mercury
is very similar to our
Moon, a battered world,
scarred by aeons of
impacts by meteorites.
The surface is also
wrinkled, with great
ridges hundreds of
kilometers long called
scarps, which probably
appeared when Mercury
cooled and shrunk soon
The inside of
Mercury is
more like the
Earth. It has a
core made of
iron, and the
centre may be
molten, kept
hot by
radiation deep
within the
core.
Roman God
Mercury originated as the
Roman god of commerce
and was prayed to mainly by
merchants. His name comes
from the Latin word "mercari"
meaning to deal or trade.
Later he came to be
associated with the Greek
God Hermes, adding
responsibility for messages
to his duties.
Artists rendition of Mercury
From Mercury, the
Sun appears two
and a half times
larger than it does
on Earth. The sky
would appear
black because
there's little
atmospheric
scattering of light.
One would be able
to see two bright
"stars," possibly
discernible as
cream-colored
Venus and bluecolored Earth.
MESSENGER,
launched Aug. 3,
2004, is only the
second U.S.
spacecraft sent
to the planet,
and it will be the
first to establish
an orbit.
Messenger will
enter Mercury
orbit on 30th
September 2009,
and complete its
mission one year
later.