I believe the answer is "bilateral" activity. Hope this helps!
Phenomena such as star explosions, neutron stars, black holes etc. are studied with the help of extremely powerful and sensitive telescopes.
These sophisticated instruments are able to see more than our own eyes can. Thus, they detect wavelengths outside of those found in our visible spectrum, such as X-rays etc.
The most sophisticated telescopes are those that are placed in space such as the Hubble or Spitzer Space Telescope. In this way, these instruments are able to circumvent the Earth's atmosphere that may block the view of the sky. Thus, in space, they have the optimal conditions to observe and study in detail such phenomena.
Which disease symptoms u would like to know?
