:: Description ::
In this activity groups of visually impaired students and their sighted peers are invited to use daily basis items and recycled materials to build a tactile schematic image of a celestial object from our solar system. In a group activity, they are also encouraged to research about our celestial neighbour and its key features.
This activity is planned for groups of children from 6 to 12 years old, and their educators gathered in groups of 3 to 5 children (for example 3 sighted children and two visually impaired). The activity can be implemented at three stages that can be done separately:
- Research on the celestial object by the children prior to the activity;
- Build the tactile image in a hands-on performed by the sighted children closely interacting with their visually impaired peers;
- Tactile exploration of the final schematic image by visually impaired children.
Variations of the activity can also be conducted. For instance, promote activities for sighted children in which they learn and build the tactile images and then promote explanatory sessions to their visually impaired peers.
In all stances, it is strongly advised to stimulate interactions between sighted children and their visually impaired peers.
:: Materials ::
Tactile features present in asteroid Vesta and correspondent suggested textures:
- Curved sequins (large and small);
- Wavy fabric;
- Thick fabric;
- Black and white prints of image (x2) and mold (x1). Click links to Download.
These materials are only suggestions; all textures can be replaced by local low-cost materials from each community that plans to implement “Meet our Neighbours!”.
:: The Scientist Explains ::
Vesta is an asteroid belonging to the main belt of asteroids, which contains hundreds of thousands of small rocky objects and is located between the orbits of Mars and Jupiter. Asteroids are thought to be the building blocks from which the planets formed 4.5 billion years ago. The main asteroid belt might be the leftover blocks that could have formed another planet between Mars and Jupiter if it had not been for the strong gravitational influence of Jupiter that prevented these asteroids to accumulate into a single body.
Vesta was discovered in 1807 Its distance from the Sun is 353 million kilometres, and it takes 75 years for Vesta to complete its orbit. It is the second largest asteroid, with a mean diameter of 530 km. In fact, it is not exactly a spherical object since its diameter varies between 460 and 580 km, depending on the axis along which it is measured.
[While you explore the tactile schematic image you can find: ]
In July 2011, the NASA probe Dawn placed itself into orbit around Vesta and studied it until its departure for Ceres in July 2012. Thanks to Dawn, the surface of Vesta is now much better known: the most significant feature is an impact crater, named Rheasilvia, measuring about 500 km in diameter and located near the south pole. At the centre of this crater is a mountainous peak 18 km high (showing as a prominence in the outline of Vesta at the bottom of the tactile image).
Vesta’s surface is also marked by many small impact craters (materialized by curved sequins on the tactile image). Some of them have been dubbed the “snowman” craters because, together, they resemble a snowman (materialized by the group of sequins at the upper left of the tactile image). Another depressed area with an oblong shape has been named Saturnalia Fossa (materialized by the patch of wavy fabric at the upper right of the tactile image). It is about 40 km wide and at least 365 km long and it is thought to be a shock fracture resulting from the impact that created the larger craters.
Near the equator, there is a high plateau named Vestalia Terra (materialized by the thick patch of fabric on the tactile image). It stands about 20 km above the surrounding terrain, and it is characterized by high-density material. It is thought to be the ancient bedrock of the asteroid that was exposed during the violent collisions experienced by the asteroid. Planetary geologists call this type of features “mascons” (for “mass concentrations”); they can be detected because they have a stronger gravitational effect on a space probe orbiting a celestial body.
The interior of Vesta is thought to be composed of an iron-nickel nucleus surrounded by a rocky mantle and a thin outer crust. In that way, it seems to be the only asteroid to be “differentiated”, which means that heavier metallic materials have sunk to the centre of the body, while lighter rocky materials crystallized to form the outer layers.
:: Full Activity Description ::
Prior to the activity:
- Gather the children in groups of 3 to 5 elements – visually impaired and non-visually impaired;
- Present one image per group;
- Distribute materials accordingly;
During the activity:
- Close supervision – follow each group and explain each of the tactile elements and their correspondence to the each object feature;
- Understand the different needs of each group of students to promote interaction between the children during the building of the tactile image – visually impaired children need to be familiarized with the different materials involved;
Building the tactile image:
STEP 1: Print two copies of 07_Vesta_Image.pdf, in a regular black and white printer;
STEP 2: Cut the outer shape of the asteroid on one of the paper prints;
STEP 3: Place the mold on top of the thick fabric and with a pen draw the outer shape, then cut it;
STEP 4: Cut the outer shape again on the thick fabric;
STEP 5: Place abundant glue on the paper image and then place the fabric on top of the glue;
STEP 6: Cut the inner shape of the asteroid and place it on top of the thick fabric and with a pen draw the shape;
STEP 7: Cut the fabric accordingly to the area outlined;
STEP 8: Glue the different sequins on top of the glued fabrics;
WAIT FOR THE IMAGE TO DRY. IT MIGHT TAKE A WHILE BEFORE YOU CAN EXPLORE THE IMAGE.
:: Exploring the tactile image ::
There are several ways in which you can explore the scientific content of the tactile schematic images.
If you’re presenting the final tactile image to the children, first let them explore and feel the different textures. Questions will arise as the child explores and it is important to guide them. Read “The Scientist Explains” to understand the different features present in the Vesta’s schematic tactile image.
(1) Explore the shape of the asteroid; (2) the craters; (3) depressed area with an oblong shape has been named Saturnalia Fossa, the patch of wavy fabric at the upper right of the tactile image and (4) the high plateau named Vestalia Terra, the thick patch of fabric on the tactile image.