Let's take a peek inside one of the ALMA antennas! 📡
The 66 antennas of ALMA are all used to observe the cool Universe. But how does a radio-telescope really ‘see’? 🤔
First, light is collected by the large dish of an antenna, which is focussed onto the secondary reflector that we can see in the foreground. From there, it goes through one of the several circular windows seen at the centre of this image. Each window leads to a receiver, a device that registers the light collected by the antenna.
And did you know? The receivers need to be sealed inside a cryostat that cools them down to –269 ºC, just 4 degrees above absolute zero 🥶
Find out more: https://www.eso.org/public/images/potw2517a/
📷 S. Otarola/ESO
