If arrive on Monday, and want to reach your hotel downton, we suggest you take a taxi (see radiotaxi below) or go with the Alibus (tickets can be purched onboard).
To reach Catania Observatory (located at Città Universitaria, via Santa Sofia) from the airport we warmly suggest to use a taxi (see radio taxi below)
RadioTaxi (095 330966)
Radiotaxi provide fares that from and to the airport are frozen accordinf to the arrival/depertura place.
From the airport:
When out of the plane call "RadioTaxi" 095 330966, and ask for a taxi at the airport. Say your destination.You will get the fare, the name of the car, and the time to wait for it (tipically few minutes).
The taxi will pick up you otside the airport at the "departure" level. To be there, when out from the baggage claim, turn to left and take the escalator in front of you to the level above (departures), then take the first door on the right leaving the building; the taxi will pick up you there.
For more information on how to reach Catania Observatory look here: https://www.oact.inaf.it/come-raggiungerci/