File:Cleaning a VLT mirror (wallpaper).jpg

From Wikimedia Commons, the free media repository
Jump to navigation Jump to search

Original file ‎(3,888 × 2,592 pixels, file size: 1.9 MB, MIME type: image/jpeg)

Captions

Captions

Add a one-line explanation of what this file represents

Summary

[edit]
Description
English: The 8.2m diameter main mirror of Antu, the first Unit Telescope of ESO's Very Large Telescope, is being cleaned using carbon dioxide snow.

While the telescope enclosure is maintained extremely clean, the mirrors are exposed to the elements during the observations. Consequently, dust from the desert slowly accumulates over the surface of the mirror, making it less reflective over time.

The mirror's surface is so delicate that normal cleaners used for household mirrors are not appropriate for telescopes. Observatories have developed other methods, such as this one using carbon dioxide snow. The tiny CO2 snowflakes in the white plume have a temperature of almost minus 80 degrees Celsius; when they land on the mirror, which is at room temperature, they cause minuscule 'explosions' that detach the dust grains from the surface. The dust then floats away, leaving the mirror clean. The process is nevertheless very delicate: should Alain Gilliotte, the optician performing the cleaning, let the CO2 device touch the mirror, the fragile reflective Aluminium coating would be scratched. Also, hair or cloth lint should stay away from the mirror, which is why the optician is wearing a white suit made of special plastic.
Date
Source http://www.eso.org/public/images/vltmirrorcleaning/
Author ESO/Y. Beletsky

Licensing

[edit]
This media was created by the European Southern Observatory (ESO).
Their website states: "Unless specifically noted, the images, videos, and music distributed on the public ESO website, along with the texts of press releases, announcements, pictures of the week, blog posts and captions, are licensed under a Creative Commons Attribution 4.0 International License, and may on a non-exclusive basis be reproduced without fee provided the credit is clear and visible."
To the uploader: You must provide a link (URL) to the original file and the authorship information if available.
w:en:Creative Commons
attribution
This file is licensed under the Creative Commons Attribution 4.0 International license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current11:12, 8 April 2013Thumbnail for version as of 11:12, 8 April 20133,888 × 2,592 (1.9 MB)Stas1995 (talk | contribs)User created page with UploadWizard

You cannot overwrite this file.

The following page uses this file:

Metadata

This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.

Retrieved from "https://commons.wikimedia.org/w/index.php?title=File:Cleaning_a_VLT_mirror_(wallpaper).jpg&oldid=861909872"