:: 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 main characteristics.
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 dwarf-planet Pluto and correspondent suggested textures:
- Aluminum foil;
- Thick fabric;
- Black and white prints of image (x1) 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 ::
Since its discovery by the US astronomer Clyde Tombaugh in 1930, Pluto has been considered the ninth planet in the solar system. But, in 1986, the International Astronomical Union established an official definition for planets and following this definition, it decided to change the category to which Pluto belongs. It is now considered a “dwarf planet”, and the prototype of the “Plutoid” class.
Indeed, by the characteristics of its orbit, Pluto differs from the eight “official” planets of the solar system. First, this orbit is strongly elliptical, or like a flattened circle. Second, this orbit is not in the same plane as the orbits of the eight “official” planets. It takes 248 years for the planet to complete this elongated orbit. The third difference is that Pluto is not at all unique in its region of space, other objects, called plutinos, occupying very similar orbits.
By its dimensions, Pluto is also much smaller than the eight planets. Its diameter is 2306 km or about half the size of Mercury, and its mass is about six times less than that of the Moon. Because it is a small object situated very far from Earth, its surface features are poorly known. Using the Hubble Space Telescope, one of the most powerful instruments available to astronomers, it has been possible to make crude maps of Pluto’s surface, which show bright areas (materialized by the aluminium on the tactile image) probably covered with a mixture of different ices: nitrogen, methane, carbon monoxide, water, and ethane. It is not surprising that most gases are frozen on the surface since its average temperature is -220°C. As a consequence, Pluto does not really have an atmosphere; the very thin gaseous layer surrounding Pluto is only due to the sublimation of ices covering its surface.
Pluto is surrounded by five natural satellites: Charon, Nyx, Hydra, P4, and P5 (materialized by the circular spots of thick aluminium foil on the tactile image: Charon at the bottom, Nyx, Hydra, and P5 on the left, and P4 on the right). The last two satellites were discovered in 2011 and 2012 with the Hubble Space Telescope.
Charon is closest to Pluto and in fact, it is more appropriate to consider Pluto-Charon as a double system because they have very similar masses, and they revolve around a common orbit centre located between them.
:: Full Activity Description ::
Prior to the activity:
- Gather the children in groups of 5 elements – visually impaired and non-visually impaired (ideally three non-visually impaired to 2 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:
Print image 012_Pluto_Image and 012_Pluto_Mold, in a regular black and white printer;
Cut the section on 012_Pluto_Mold and with a pen outline the cut sections on 012_Pluto_Mold in the thick fabric;
Cut the fabrics accordingly to the round areas in 012_Pluto_Mold;
Wrap aluminium foil around the thick fabric;
Place abundant glue on the circled areas place the thick fabric on top of the glue;
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 Pluto’s schematic tactile image.
(1) Explore the different round sections on the tactile image and identify Pluto (2) and it’s (3) larger moons.