* The definition of "telescope" can be broad. It can include instruments with different purposes, such as X-ray telescopes, infrared telescopes, radio telescopes, and optical telescopes.
* "Actively observing" is not always clearly defined. Some telescopes might be in a dormant state or only observing specific targets occasionally.
* New telescopes are constantly being launched, while others become obsolete.
However, we can say that there are hundreds of space telescopes currently in operation. Here are some examples:
* Hubble Space Telescope: This iconic telescope has been observing the universe since 1990 and continues to provide stunning images and valuable data.
* James Webb Space Telescope: Launched in 2021, this powerful telescope is revolutionizing our understanding of the early universe and exoplanets.
* Chandra X-ray Observatory: It studies the X-ray emissions from hot, energetic objects in the universe, like black holes and supernova remnants.
* Spitzer Space Telescope: This infrared telescope, now retired, helped astronomers study the birth of stars and planets.
* Kepler Space Telescope: It revolutionized the study of exoplanets, discovering thousands of planets outside our solar system.
To find a more precise number of active space telescopes, you can consult online databases and resources dedicated to space exploration, such as NASA's website, the European Space Agency website, and other astronomical institutions.
