Physics
of Earth and Planetary Forming Materials
Members
of the department are exploring the physical behavior
of minerals and rocks that make up the surface
and interior of the Earth and other solid bodies
in the solar system. This research is multi-disciplinary,
based on experiment and theory. It combines the
expertise of the rock physics and mineral physics
experimental laboratories with that of the computational
mineral physics group.
Tectonic
Evolution of the Crust & Lithosphere of the
Earth and Terrestrial Planets
Members of the department are determining the
chemical and mechanical evolution of the Earth’s
crust, and are using this to interpret the surface
evolution of other solid bodies in our solar system.
They combine rock physics, palaeomagnetic and
fission track laboratory studies with field studies
and planetary imagery to develop models for terrestrial
processes.
|
Mars In The Classroom
This
is an exciting program of hands-on and thought-provoking
science activities for children aged 13 to 16. Students
plan their own manned mission to Mars in a series
of modules carried out in small groups. The experiments
within each module of ‘Mars in the Classroom’
can be used either as stand-alone projects or in
combination with any or all of the other modules
provided. In this way, the educator has complete
control over the duration and level of the program
undertaken. The aim of the project is to provide
a stimulating program that can compliment the National
Curriculum, introducing students and educators to
the excitement of planetary science. |
Ass.Curator
Jayne Dunn with one of the participants. |
Aorounga Impact Crater, Chad
Impacts of asteroids or comets several hundred million
years ago left scars on the Earth, such as this
one buried in the Sahara Desert of northern Chad.
Space radar imaging can penetrate thin layers of
dry sand to reveal details of geologic structures
that are otherwise invisible.
|
Explaining
Planetary Geological Processes
Impact
Craters:
A n approaching meteorite strikes the planet. It
then vaporizes and shock waves fracture the rock
and blast the surface away to form a circular crater.
Ejected material (ejecta) forms a raised crater
rim. The rebound of the rock can form a raised central
peak, and slumping along the crater wall can form
terraces. The rock below the crater is severely
fractured. |
Every
old, solid surface in the solar system is scarred
by craters. It is thought that a heavy bombardment
cratered all of these worlds as the last debris
of the solar nebula was swept up. Brecciae, rocks
that are made up of fragments of earlier rocks cemented
together by heat and pressure, are commonly found
on these worlds since meteorite impacts have broken
up the rocks and fused them together time after
time (see objects from the collection).
From
the collection |
Basalt
|
Volcanic Breccia |
|
Volcanism
All
rocky planets have or have had volcanic episodes
that resurface the planet. The moon has cooled sufficiently
to no longer have eruptions, but the lava flows
of the past have created much of the current surface
geology in the Maria region. These rocks are dark-coloured,
dense basalts much like the solidified lava produced
by the Hawaiian volcanoes. Many of these are vesicular
basalt, containing numerous bubbles frozen into
the rock when it solidified from a lava flow (see
objects above). Anorthosite is commonly found in
the lunar highlands, and forms as it floats to the
top of the cooling molten magma. Earth, Io, and
possibly Venus still have active volcanoes, while
it is believed that Mars does not. |
Io,
moon of Jupiter
This is one of the most volcanically active bodies
in the solar system today. The close-up of A suggests
that the lava and sulfurous deposits are composed
of complex mixtures. Close-up B shows bright, whitish,
high latitude deposits, which appear similar to
frost. However, close-up C appears to have both
the whitish diffuse deposits and sharp linear features
believed to be volcanic fissures. Other volcanic
centres have bright and colourful central flows,
perhaps due to flows of sulfur (rather than silicate,
as on Earth) lava.
|
|
Plate
Tectonics
Earth
is the only planet known to have plate tectonics.
These plates, a part of the Earth called the lithosphere,
rest upon the deeper, hot, flowing asthenosphere.
This inner furnace of the Earth is the engine that
powers the movement of the plates, moving some apart,
sliding some parallel to each other, and even forcing
some plates to collide. Photographs and radar imagery
of other planets can reveal if any other world has
indicators of plate tectonics, such as subduction
zones. The planets Mars and Venus are considered
one-plate planets. |
|
Did
you know that because Magellan was to be a low cost
mission, major components were obtained from flight
spares from other programs, including Galileo, Viking,
Mariner, Sky Lab, Ulysses, and the shuttle? Spare
parts were even borrowed from the Voyager replica
spacecraft while it was on public display at the
National Air and Space Museum in Washington, D.C.
Low
cost?…the mission rang up a total cost of
$680 million!
|
Remote
Sensing
As
most planets and moons in our Solar System are too
far away or have environments too hostile for humans
to visit in person, the only way to study many of
them is by using remotely sensed data. Venus, for
example, has temperatures reaching 470 degrees Celsius
and an atmospheric pressure 90 times greater than
that of our own planet Earth. That is enough to
melt or crush a human being! Until technology permits
us to visit these faraway and uninhabitable places,
we have to rely on remotely sensed data as our only
source of information. |
This
image, taken from the Clementine spacecraft, has
been image-processed to show different qualities
of the Moon, such as Albedo and Topography
Resources |
Members
of the Department of Earth Sciences at UCL help to
analyse the remotely sensed data gathered from planetary
missions. Two of these such missions are featured
in our exhibit: the Magellan mission, which returned
data on the surface of Venus, and the Clementine mission,
which uncovered valuable information on the composition
of the Moon. Visit the Rock Room to learn more about
these missions, including the innovative technologies
they used and the exciting results they returned to
scientists. You will also have an opportunity to see
some of the NASA images taken from both spacecraft
of the surface of Venus and the Moon. |
|
Download
Classification of Planets (Word File)
Physics
of Earth and Planetary Forming Materials
Tectonic
Evolution of the Crust & Lithosphere of the
Earth and Terrestrial Planets
Mars
In The Classroom
|
