Our fingerprints are unique. Not even identical twins have
fingerprints that are the same. We leave fingerprints on everything
we touch. Fingerprints can help detectives solve a crime.
There are three main types of fingerprints - whorls, loops and
arches.
 nist database_247x231.jpg)
Whorl (c) NIST
Database
 nist database_249x233.jpg)
Arch (c) NIST
database
 nist database_246x231.jpg)
Loop (c) NIST
database
Can you be a Planet Science detective?
What you need
- Glass
- Pencil
- Paper
- Sellotape
- White card
- Pen
- Talcum powder
- Small paint brush
- Black card
Wipe a glass down. Leave it in the room and ask someone in your
family to pick it up - make sure you don't know who touches it!
Don't let anyone else touch it afterwards. Leave this for a few
hours.
Take your family's fingerprints. The easiest way to do this is
to rub a pencil over a small piece of paper. Press your family's
fingers onto the pencil. Put a piece of sellotape gently over the
finger and then stick it on a piece of white card. You should be
able to see the fingerprints clearly. Repeat if you can't. Make
sure you label the piece of card so you know whose fingerprint it
is!
To dust for fingerprints, sprinkle talcum powder over the glass.
Use a small paint brush to gently wipe off excess powder. Can you
see any fingerprints? Put sellotape lightly over the fingerprint
and peel it off. Stick the sellotape onto a piece of black card.
Compare the fingerprints on the glass to your family's
fingerprints. Can you identify who touched the glass?