木星的行星有非常厚的大气层，且由不同数量的氢、氦、甲烷和氨等元素组成。
The Jovian planets have very thick atmospheres consisting of varying amounts of hydrogen, helium, methane, and ammonia.
这个发现同时也是对行星形成理论的一次挑战，该理论认为恒星需要更多的氢和氦才能形成行星。
The finding also challenges theories of planet formation, which hold that stars need more than hydrogen and helium to produce planets.
就像比它更大的邻居-木星一样，土星也是气体行星，主要由氢和氦所组成。
Like its bigger neighbor Jupiter, Saturn is a gas planet made mostly of hydrogen and helium.
应用推荐