Another star of La Silla is the 3.58-metre New Technology Telescope (NTT). This telescope is not new anymore, but at the time of its inauguration in 1989, it was a real technological breakthrough. Firstly, it is the first telescope in the world built with active optics. The main mirror is flexible and its shape is actively adjusted by actuators during observations to improve the image quality. Indeed, if you have the chance to visit the telescope, you will be able to see these pistons under the mirror. Secondly, the telescope does not rotate inside its housing, but it is the entire building that is small and light enough to rotate allowing the telescope to point to different fields in the sky.
Another telescope worth mentioning is the Transiting Planets and Planetesimals Small Telescope-South, better known as TRAPPIST-South. This is a Belgian telescope and, in fact, the name TRAPPIST was given in honour to the famous Belgian Trappist beer! In 2016, a team of astronomers led by Michaël Gillon (University of Liège) used the telescope to observe an ultracool dwarf star 2MASS J23062928-0502285, now also known as TRAPPIST-1. Around this star they discovered a compact planetary system composed of seven terrestrial planets, three of which orbit within the habitable zone.
La Silla was the first ESO observatory, before Paranal and Llano de Chajnantor. For decades hundreds of astronomers, engineers, and ESO staff have come to this site, working in what was the biggest observatory of the Southern hemisphere. Now, after the inauguration of Paranal and Llano de Chajnantor, many telescopes in La Silla have been decommissioned and a large number of ESO staff have been reassigned to the new observatories, leaving only a few people in La Silla. However, signs of La Silla's heyday are still visible! Going downhill on the main road, after the control room, it is possible to find the old gymnasium, the clubhouse and even a soccer field used in the old days by ESO staff and visitors. Looking at the bleachers in the gymnasium and those of the soccer field or walking into the old clubhouse it is possible to imagine a very different La Silla from how it appears today. The passing of decades can truly be felt in La Silla...
- Do you wish to visit all the major telescopes in La Silla? Every Saturday, around 1pm, you will find a group of students from the University of La Serena having lunch in the refectory. They run guided tours for general public, starting around 2pm. Feel free to ask the students if you can join the tour. They will be happy to have a true astronomer with them!
- Have you ever seen a viscacha? Viscachas are rodents native to South America. They are similar to rabbits, but with a tail that resembles the squirrel's one - see the pictures above. There is a family of viscachas living very close to the Swiss 1.2-metre Leonhard Euler Telescope.
- Other animals around the observatory? In La Silla you will have the chance to see a large variety of animals. Besides viscachas, there are donkeys, guanacos (see below), foxes, hawks, and condors. Beware of corner spiders, they are not aggressive like our funnel-web spiders as they usually bite only when pressed against human skin, but they are venomous. I have already found one of these in the toilets of the control room! Also, beware of vinchucas, a blood-sucking bug that can be a vector of diseases. It is very rarely seen indoors thanks to the implementation of a thorough and systematic spraying program by ESO. I have never seen one so far.