Australian officials say they're confident that signals heard in the Indian Ocean are coming from the black box of the missing Malaysia Airlines plane.
Flight MH370 disappeared mid-flight a month ago - something that's extremely rare.
Australia's been leading efforts to find the wreckage since then and their Prime Minister says the signals are helping them narrow down the search area.
The plane was flying from Kuala Lumpur to Beijing on 8 March when it disappeared.
Malaysian officials say they believe it crashed in the southern Indian Ocean, west of the Australian city of Perth far from its intended flight path.
It's extremely rare for something like this to happen. If this story or anything else in the news upsets you then you can click this link for lots of help and advice.