"Even in the best scenario of supply, these [rare earth-based] magnets are very expensive," Mr. Crane said.

“即便是供应情况最好的时候，利用稀土材料制成的磁钢也是非常昂贵的，”Crane说。

youdao

SOFIA will complement the Hubble, Spitzer, Herschel and James Webb space telescopes and major Earth-based telescopes.

索菲亚将弥补诸如哈勃、史匹哲、赫歇尔和詹姆士·韦伯一系列天文望远镜以及主要的地面望远镜的不足。

youdao

The difficulty is the viewing geometry that puts any Trojan, from the perspective of an Earth-based telescope, in bright skies.

观测特洛伊小行星的难点在于，在通过地面望远镜观测时，几何角度总是使其位于明亮的天空中。

youdao

Scientists say extensive observations from earth-based telescopes are needed to confirm the existence of the planets.

VOA: special.2011.02.09

They could compare it with images taken by Earth-based telescopes.

VOA: special.2009.09.30

Earth-based observations might not be sufficient to rule out an impact in 2036.

BBC: Foresight mission spacecraft Image

Astrobiological researchers have discovered significant regions below the surface of Mars that could be habitable for Earth-based life.

FORBES: Parts Of Mars May Be Habitable For Earth-Based Life

What they found is that about 3% of the total volume of Mars is capable of supporting Earth-based lifeforms.

FORBES: Parts Of Mars May Be Habitable For Earth-Based Life