The largest asteroid is Ceres, which is about a quarter the size of the moon.

最大的小行星是谷神星，其体积大约是月球的四分之一。

《柯林斯英汉双解大词典》

The earth is 49 times the size of the moon.

地球的大小是月球的四十九倍。

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The same size of the moon or larger than that?

会与月球一样大，还是比它大些？

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The Asteroid Belt between Mars and Jupiter contains millions of these rocky fragments, the biggest among them measuring one-quarter the size of the Moon.

UNESCO: MEDIA SERVICES

For ten days of actual observing time, the Hubble pointed to an area on the sky less than one percent of the size of the full moon.

FORBES: Hubble Astronomers Ready Ambitious 'Deep Field' Encore

Try this analogy (thanks to Veritasium.com): if the Earth were the size of a basketball, the moon would be a tennis ball about 24 feet away, and the Sun would be like a house nearly two miles away.

CNN: The sun, the moon and the Titanic