Means messenger to the gods (greek: hermes)
|Mercury is the closest planet to the sun. It is also the
second smallest planet (pluto being smallest). It was
visited in 1974-75 three times by the mariner 10 spacecraft.
However, it didn't map the whole planet so some of it's
surface is still a mystery. It's appearance is much like our
own moon. It is a heavily cratered world with a negligible
- OBSERVING-NAKED EYE
planet is difficult to observe. Being the innermost planet, it
doesn't stray far from the sun. It is rarely seen in a dark sky.
Not much can be seen through a telescope. The phases of
the planet can be seen in a small telescope though. (both
inner planets, mercury and venus, show phases like our
moon). Trying to see any surface detail requires the
perseverance of a real tn (telescope nut).
|Image of mercury from mariner
10 showing it's southwestern quadrant. Notice the similar appearance
to our moon. It's internally quite different though.
Mosaic of Mercury
This photomosaic of the planet Mercury was assembled from
individual high-resolution images taken by Mariner 10 shortly
before closest approach in 1974. The sun is shining from the
right, and the terminator is at about 100 degrees west longitude.
Crater Kuiper, named after astronomer Gerard P.Kuiper, can
be seen just below the center of the planet's illuminated
side. Thelandscape is dominated by large craters and basins
with extensive plains between craters.
Seen here is part of the enormous Caloris Basin, which is thought
to be similar to the large circular basins found on the moon.
Probably formed by a giant impact early in Mercury's history,
this basin was subsequently filled by lava flows. The nature
of the wrinkle ridges on its floor is arguable: some scientists
claim tectonics while others suggest they are due to volcanic
flows escaping from fractures.
The southwest quadrant of Mercury is seen in this image taken
March 29, 1974, by the Mariner 10 spacecraft. The picture was
taken four hours before the time of closest approach when Mariner
was 198,000 km (122,760 mi) from the planet. The largest craters
seen in this picture are about 100 km (62 mi) in diameter.
"Weird terrain" best describes this hilly, lineated
region of Mercury. Scientists note that this area is at the
antipodal point to the large Caloris basin. The shock wave produced
by the Caloris impact may have been reflected and focused to
the antipodal point, thus jumbling the crust and breaking it
into a series of complex blocks. The area covered is about 800
km (497 mi) on a side.
||Mercury Close Up
The small, bright halo crater (center) is 10 km (6 mi) in diameter.
The prominent crater further left, which has a central peak,
is 30 km (19 mi) across. The darker, lightly cratered area (upper
left) may be an ancient lava flow. Mercury's surface is similar
to that of Earth's moon, where a history of heavy cratering
is followed by volcanic filling.