There are times when news about J-ALERT is broadcast on TV.
J-ALERT is the system which provides the emergency information regarding earthquakes, Tsunami, or Armed-conflicts from the government immediately via manmade satellites and etc.
Please take a look at the Portal Sites below for more details.
Cabinet Secretariat Civil Protection Portal Site: Actions in case of missiles flying to Japan ↓
https://www.kokuminhogo.go.jp/en/pc-index_e.html
Cabinet Secretariat Civil Protection Portal Site: Multilingual ↓
https://www.kokuminhogo.go.jp/en/pc-index_e.html