Studying smoke plumes from late December, the space agency said that the smoke had traveled "halfway across Earth" and affected air quality in other countries.
At least 28 people have died nationwide, and in the state of New South Wales (NSW) alone, more than 3,000 homes have been destroyed or damaged. State and federal authorities are struggling to contain the massive blazes.
All this has been exacerbated by persistent heat and drought, and many point to climate change as a factor making natural disasters go from bad to worse.
By January 8, the smoke had traveled "halfway around Earth," NASA said, crossing South America to cause hazy skies and creating colorful sunrises and sunsets.
"Unprecedented conditions" of searing heat combined with dryness have led to an "unusually large" number of pyrocumulonimbus (pyrCbs) events -- fire-induced thunderstorms, triggered by an uplift of ash, smoke and burning material -- the space agency has said.
PyroCb events provide a pathway for smoke to reach the stratosphere more than 10 miles in altitude, and once there, the smoke can travel thousands of miles from its source and affect atmospheric conditions around the world, NASA said.
Nicolas Bellouin, a climate scientist at the University of Reading told CNN that while it is not uncommon for the type of particles emitted from the fires to travel around the world, the concentration of particles created by the fires in Australia was unusual, and could affect air quality elsewhere, including in Chile and Argentina.
"If we started to see fires of this level in Australia every year, or every couple of years, then the impacts on air quality and climate will become both concerning and noticeable," he said.
CNN's Jessie Yeung contributed to this report.