(CNN) -- It's been nearly three weeks since Malaysia Airlines Flight 370 vanished. Malaysian authorities say the plane went down in the southern Indian Ocean. Search efforts are concentrated in an area far off Australia's west coast.
What's the latest?
There's been a huge shift in where searchers are looking for Flight 370, and planes sent to the new zone have found lots of objects. But what those objects are isn't known yet.
Wait, I thought everyone was confident the old search zone was the right place to look. What happened?
More math, apparently.
Based on radar and satellite data, investigators have concluded the plane was traveling faster than initially thought in the early part of its flight. Because of that, it burned through more fuel than first believed.
So, like a car driven by a leadfoot through city streets, the plane had less fuel for its long, desolate flight over the Indian Ocean. That means, authorities have concluded, that it could not have traveled as far south as they once thought.
They now say the data shows the plane probably went down in an area about 680 miles (1,100 kilometers) northeast of the previous search zone.
But what about all those floating objects spotted by satellites?
Forget about them, the Australians say.
\"In regards to the old areas, we have not seen any debris,\" said John Young, general manager of emergency response for the Australian Maritime Safety Authority. \"And I would not wish to classify any of the satellite imagery as debris, nor would I want to classify any of the few visual sightings that we made as debris. That's just not justifiable from what we have seen.\"
But couldn't currents have carried the debris there?
No way, according to University of Western Australia oceanographer Charitha Pattiaratchi.
Pattiaratchi modeled currents in the search zone and said objects floating in the water moved east, not south or west, and tended to stay trapped in eddies \"barely leaving the search area.\"
\"There is absolutely no connection, in terms of the debris between the two locations which are 1000 km apart,\" Pattiaratchi said in an e-mail.
He said currents are much milder in the new search zone, meaning that if the plane did go down in this new search zone, debris should be located in a smaller area because there is much less drift there.
Another oceanongrapher, Curt Ebbesmeyer, said objects would likely drift about 10 miles a day, and smaller objects that continue to float could reach the west coast of Australia in about three months.
Where is the new search area?
It's 680 miles (1,100 kilometers) to the northeast of where search operations had been focused. That puts it 1,150 miles (1,850 kilometers) off the west coast of Australia. That's about 400 miles (644 kilometers) closer to land than the previous area.
So what does this mean for efforts to find the plane?
Australian officials say the new search area is closer to land and in a gentler region of ocean, making for longer, safer and more consistent searches.
But it's still a huge area at 123,000 square miles (319,000 square kilometers) and will take some time to search.
\"We're kind of starting from square one with a whole new search and a whole new set of premises,\" CNN aviation analyst Jeff Wise said Friday.
How many countries are involved in search efforts?
Malaysia is coordinating the search, which involves crews from six countries. Australia is leading the effort, based out of Perth, with China, New Zealand, the United States, South Korea and Japan contributing aircraft. China has also sent ships to help the search effort.
How are the families of those on board?
Family members are anguished as they wait for answers. One-third of the plane's passengers were Chinese, and Malaysian authorities' announcement Monday that families should give up hope that their loved ones were alive angered many Chinese.
\"My heart can't handle it. I don't want to hurt my children,\" Cheng Li Ping told CNN as she waited in Kuala Lumpur, Malaysia, for evidence about what happened to her husband.
CNN's Ashley Fantz, Jethro Mullen and Michael Pearson contributed to this report.