Unter einer Schneedecke
Wie lange können Sie es aushalten, bei Schnee im Freien zu stehen und das Universum zu beobachten? Sie brauchen es nicht auszuprobieren, denn mit den ALMA-Antennen in diesem Bild der Woche können Sie nicht mithalten. Auf der Chajnantor-Hochebene in Chile betreibt die ESO zusammen mit ihren internationalen Partnern das Atacama Large Millimeter/submillimeter Array (ALMA). Die Temperaturen können hier in Winternächten auf bis zu -20 °C sinken, aber die Radioantennen von ALMA lassen sich davon in der Regel nicht beeindrucken.
Im Vergleich zu optischen Teleskopen sind die Radioantennen ziemlich robust. Ihre grauen Metallreflektoren sind beißendem Wind und schwankenden Temperaturen ausgesetzt. Damit der Spiegel oder die Schüssel eines Teleskops das gesammelte Licht richtig reflektieren kann, müssen die Unebenheiten auf seiner Oberfläche kleiner sein als die Wellenlänge des Lichts. Die Spiegel optischer Teleskope müssen perfekt glatt sein, weil sie kurze Wellenlängen wie das sichtbare Licht mit Wellenlängen von weniger als einem Mikrometer beobachten. ALMA beobachtet jedoch längere Wellenlängen im Millimeterbereich, so dass robuste Metallplatten ausreichen.
Die ALMA-Antennen können außerdem rund um die Uhr arbeiten, denn Radioteleskope brauchen keinen dunklen Himmel, um Signale aus dem Weltraum einzufangen. Tag ein, Tag aus. Vom Schnee hier auf der Erde aus blicken die Antennen in die kalten, verborgenen Winkel des Kosmos.
Bildnachweis:S. Otarola/ESO
Über das Bild
| ID: | potw2452a |
| Sprache: | de-be |
| Typ: | Fotografisch |
| Veröffentlichungsdatum: | 23. Dezember 2024 06:00 |
| Größe: | 4346 x 7068 px |
Über das Objekt
| Name: | ALMA AOS |
| Typ: | Unspecified : Technology : Observatory : Telescope |
Bildformate
Our use of Cookies
We use cookies that are essential for accessing our websites and using our services. We also use cookies to analyse, measure and improve our websites’ performance, to enable content sharing via social media and to display media content hosted on third-party platforms.
ESO Cookies Policy
The European Organisation for Astronomical Research in the Southern Hemisphere (ESO) is the pre-eminent intergovernmental science and technology organisation in astronomy. It carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities for astronomy.
This Cookies Policy is intended to provide clarity by outlining the cookies used on the ESO public websites, their functions, the options you have for controlling them, and the ways you can contact us for additional details.
What are cookies?
Cookies are small pieces of data stored on your device by websites you visit. They serve various purposes, such as remembering login credentials and preferences and enhance your browsing experience.
Categories of cookies we use
Essential cookies (always active): These cookies are strictly necessary for the proper functioning of our website. Without these cookies, the website cannot operate correctly, and certain services, such as logging in or accessing secure areas, may not be available; because they are essential for the website’s operation, they cannot be disabled.
Functional Cookies: These cookies enhance your browsing experience by enabling additional features and personalization, such as remembering your preferences and settings. While not strictly necessary for the website to function, they improve usability and convenience; these cookies are only placed if you provide your consent.
Analytics cookies: These cookies collect information about how visitors interact with our website, such as which pages are visited most often and how users navigate the site. This data helps us improve website performance, optimize content, and enhance the user experience; these cookies are only placed if you provide your consent. We use the following analytics cookies.
Matomo Cookies:
This website uses Matomo (formerly Piwik), an open source software which enables the statistical analysis of website visits. Matomo uses cookies (text files) which are saved on your computer and which allow us to analyze how you use our website. The website user information generated by the cookies will only be saved on the servers of our IT Department. We use this information to analyze www.eso.org visits and to prepare reports on website activities. These data will not be disclosed to third parties.
On behalf of ESO, Matomo will use this information for the purpose of evaluating your use of the website, compiling reports on website activity and providing other services relating to website activity and internet usage.
Matomo cookies settings:
Additional Third-party cookies on ESO websites: some of our pages display content from external providers, e.g. YouTube.
Such third-party services are outside of ESO control and may, at any time, change their terms of service, use of cookies, etc.
YouTube: Some videos on the ESO website are embedded from ESO’s official YouTube channel. We have enabled YouTube’s privacy-enhanced mode, meaning that no cookies are set unless the user actively clicks on the video to play it. Additionally, in this mode, YouTube does not store any personally identifiable cookie data for embedded video playbacks. For more details, please refer to YouTube’s embedding videos information page.
Cookies can also be classified based on the following elements.
Regarding the domain, there are:
- First-party cookies, set by the website you are currently visiting. They are stored by the same domain that you are browsing and are used to enhance your experience on that site;
- Third-party cookies, set by a domain other than the one you are currently visiting.
As for their duration, cookies can be:
- Browser-session cookies, which are deleted when the user closes the browser;
- Stored cookies, which stay on the user's device for a predetermined period of time.
How to manage cookies
Cookie settings: You can modify your cookie choices for the ESO webpages at any time by clicking on the link Cookie settings at the bottom of any page.
In your browser: If you wish to delete cookies or instruct your browser to delete or block cookies by default, please visit the help pages of your browser:
Please be aware that if you delete or decline cookies, certain functionalities of our website may be not be available and your browsing experience may be affected.
You can set most browsers to prevent any cookies being placed on your device, but you may then have to manually adjust some preferences every time you visit a site/page. And some services and functionalities may not work properly at all (e.g. profile logging-in, shop check out).
Updates to the ESO Cookies Policy
The ESO Cookies Policy may be subject to future updates, which will be made available on this page.
Additional information
For any queries related to cookies, please contact: pdprATesoDOTorg.
As ESO public webpages are managed by our Department of Communication, your questions will be dealt with the support of the said Department.