(CNN) — The numbers are growing, even if the answers may not be.
On Sunday, eight airplanes will fly over the southern Indian Ocean searching for missing Malaysia Airlines Flight 370, said Australian Maritime Safety Authority spokeswoman Andrea Hayward-Maher.
That's two planes more than Saturday and the most aircraft involved in the search lead by Australia so far, she said.
The planes will base their searches on Chinese satellite images of debris and drift modeling, the AMSA said. The Sunday search has been split into two areas that cover 59,000 square kilometers (22,800 square miles) about 2,500 kilometers (1,553 miles) southwest of Perth.
The AMSA said in a press release that "this is a challenging search operation and continues to hold grave fears for the passengers and crew on board the missing flight."
But those satellite images provided a sense of hope to one official, Australian Prime Minister Tony Abbott.
"We have now had a number of very credible leads, and there is increasing hope -- no more than hope, no more than hope -- that we might be on the road to discovering what did happen to this ill-fated aircraft," Abbott said at a press conference.
In one of the great aviation mysteries in history, the airliner carrying 239 people disappeared March 8 after it took off from Kuala Lumpur on a flight to Beijing, China. An exhaustive search covering 2.97 million square miles -- nearly the size of the continental United States -- has yielded some clues, but no evidence of where the Boeing 777 is or what happened to it.
The international search for the missing aircraft resumed early Sunday near Perth, with a U.S. Navy P-8 Poseidon rejoining the effort, according to a naval spokesman.
Planes from the United States, New Zealand, Australia and China will be flying. Three planes -- two civilian aircraft and the P-8 -- have already been airborne.
NASA satellites to be employed
The P-8 Posideon, grounded for two days to give its crew rest, will likely refocus on an area highlighted in Chinese satellite images of a large object floating in the area. The object the Chinese satellite photographed is 22.5 meters long and 13 meters wide (74 feet by 43 feet), officials said.
But Australian-led search teams in the southern Indian Ocean found no sign of it Saturday.
As a result of the satellite sighting, plans are underway to acquire more imagery within the next few days, NASA said Saturday.
The space agency said it will check archives of satellite data and use space-based assets such as the Earth-Observing-1 (EO-1) satellite and the ISERV camera on the International Space Station to scour for possible crash sites. The resolution of these images could be used to identify objects of about 98 feet (30 meters) or larger.
The floating object reported in the Chinese satellite images was about 77 miles from where earlier satellite images issued by Australia spotted floating debris.
During Saturday's search, a civil aircraft reported sighting with the naked eye some small objects floating, including a wooden pallet, AMSA said. These objects were within a radius of 5 kilometers (3 miles).
A New Zealand Air Force P-3 Orion reported seeing clumps of seaweed, AMSA said.
Debris is a common sight in that part of the ocean and includes containers that fall off ships.
Countries from central Asia to Australia are also engaged in the search along an arc drawn by authorities based on satellite pings received from the plane hours after it vanished. One arc tracks the southern Indian Ocean zone that's the focus of current attention.
The other arc tracks over parts of Cambodia, Laos, China and into Kazakhstan.