If the moon's diameter (3,476 km) is the yardstick for comparison, then Australia (about 4,000 km) is indeed wider. But the moon's land area is far larger than the continent.
An assertion we've encountered repeatedly on social media purports to compare the width of the continent of Australia with that of the moon. "Australia is wider than the moon," this popular bit of trivia goes.
This example was posted on Twitter:
Comparing objects in the solar system with those on our planet is not unusual. The size of celestial objects has been a hobby or even a matter of research for many people.
How accurate is the claim?
Australia, an island continent, is the sixth largest country after Russia, Canada, China, the United States, and Brazil. Its total land area is 7.69 million square kilometers. At 25.69 million people, the country's population is less than that of California's 39.24 million.
So how does Australia compare with the Earth's satellite, the moon?
According to NASA, the moon's equatorial diameter is 3,476 km (2,159 miles) whereas Australia's width from east to west is almost 4,000 km (2,485 miles). By that measure, Australia is indeed wider than the moon, but not by much. Also, we need to consider that the moon's shape is spherical. This is an important distinction. Think of the moon as a ball, a 3-dimensional object, whereas the island continent is like a 2-dimensional surface.
While Australia's total land area is 7.69 million square kilometers as noted above, the moon's surface area is 37.94 million square kilometers (14.65 million square miles). (One square mile is equal to 2.59 square kilometers; 1 square kilometer = 0.3861 square miles.)
The tweet only made a narrow claim: that the continent was wider than the Earth's satellite. Therefore, based on the specific wording of the claim in the tweet, Australia is wider than the moon. However, if we take the satellite's total land area into consideration, then it is way larger than the continent.