Next learn what the future holds for the great observatory in the sky.

This will be the second of four planned "great observatories" to be launched by the space agency, with X-ray and infrared satellites to come later in the decade.

But now, great observatories that were once safely distant from the scattered glow of city lights are seriously threatened.

It is the second of the agency's four planned "great observatories" for investigating the cosmos from different radiation perspectives.

He moved here, he said, because this mesa is one of the world's great natural observatories.

At the present day, astronomers of the great national observatories are assiduously engaged in the determination of the places of the stars.

The telescopes in the great observatories were trained and ready.

What does the future hold for the great observatory, and will its space telescope successor measure up to Hubble?

Hubble is one of three "great observatories" involved in this survey.

These great observatories got a boost from the added magnification of a natural "cosmic gravitational lens" in space that further amplifies the brightness of the distant object.