Cleaning The VLT Reflector Mirrors - Filip Alerić 8.a (2011)

Cleaning The VLT Reflector Mirrors: 

Cleaning The VLT Reflector Mirrors

New words:: 

New words : Sensitive -osjetljivo Dust storms - pješćane oluje Unit -jedinica Resently -nedavno Dim-mutno,zamutiti Acid -kiselina

PowerPoint Presentation: 

There has been a lot of searching of the life in universe. Scientist from 14 countries have been working on this project. They are searching with huge sensitive telescope VLT. But because of the dust storms they have to be cleaned more often.

PowerPoint Presentation: 

At night falls VLT opens it's four giant eyes. Each unit has a mirror more than 8 metres in diameter. Their reflectors collect light from incred i bly distan t worlds . Throw clouds of dust they have discovered stars that are still growing.

PowerPoint Presentation: 

The p ictures thr ill the astronomy c ommunity . But overtime the eyes of very large telescope begin to dim. The dust glues to the mirrors surfaces and it loses it's reflective power.

PowerPoint Presentation: 

Mirrors have to be cleaned regularly. Or their surfaces have to be renewed. It's really hard work. First they collect the mirror. When it's secured, the workers remove the mirror, but they have to be really careful because it takes years to make that eye of the telescope.

PowerPoint Presentation: 

Then they carry it to the special factory where they renew the glass. The d river has to be careful to avoid any jumping. They rel ea se the glass by hand to make sure it's been rel ea sed , because the mirror could be eas i ly br o k en when it's lifted. They first clean the dirty spots by hand but they have to be careful not to scratch the glass.

PowerPoint Presentation: 

The mirror is first washed with ultra pure water. The old reflecting s urface is removed with acid. After its done they take the mirror back to the telescope. So they can again search for the new worlds in the depths of space.

Grammar spot:: 

Grammar spot: Present Perfect Continuous: There has been a lot of search ing ... Present Continuous : They are search ing with huge ... Present Simple: The pictures thrill the astronomy...

Questions:: 

Questions : Who opens it ’s four giant eyes ? How many countries are working on this project ? What begins to dim? With what is removed old reflecting spot?

THE end: 

THE end Made by : Filip Alerić