An Australian plane searching for missing Malaysia Airlines Flight 370 has detected yet another signal in an area where four others have been picked up so far, prompting officials to say that traces of MH370 could be found within days. 

Over the weekend, a Chinese patrol ship picked up two signals thought to be coming from 
the missing flight's black box, and yesterday two additional pings were detected by an Australian ship. Today, only one ping was heard by the black-box locating buoy dropped down by the plane, raising suspicion that the battery on one of the black box "pingers" may have already run out.  
Angus Houston, the Australian official coordinating the search, warned that the ping was not definitely coming from the plane's black box, calling it a "possible signal," and adding that "The acoustic data will require further analysis overnight." Still, the new information has bolstered hopes of concluding the mission. On Wednesday, Houston said the search crews could find the remainders of the plane in the "not-too-distant future," and that he was optimistic the search will be fruitful because the new information has allowed investigators to significantly narrow the search parameters to about 22,300 square miles. Per Houston: 
Hopefully with lots of transmissions we’ll have a tight, small area and hopefully in a matter of days we will be able to find something on the bottom that might confirm that this is the last resting place of MH370.
Houston has another reason to hope in addition to this possible fifth signal. Searchers have been increasingly anxious that the black box battery will die now that we have passed 30 days since the search began, but experts think the device's battery-life could be longer than at first thought. The Associated Press reports: 
An Australian government briefing document circulated among international agencies involved in the search on Thursday said it was likely that the acoustic pingers would continue to transmit at decreasing strength for up to 10 more days, depending on conditions.
And some experts told the Telegraph they think it unlikely that the black box would have sunk too far into Ocean silt: 
All the signals have been detected along a narrow strip of the Indian Ocean in an area known as Wharton Basin, a mostly flat underwater region that has not been mapped in 50 years. The basin’s ocean floor has thick layers of silt, but experts said an object with a large surface area – such as the fuselage of a plane – would not be deeply buried.
Once investigators are more confident with their analysis, they will send a submarine to search for traces of MH370.