A ring or sphere could, apparently, be stable if surrounded by the right sizes and gravities of other stars.
SPHEREx will survey hundreds of millions of galaxies, as well as search the Milky Way for water and organic molecules ...
Hipparchus, in the second century BCE, put the discrepancy down to a slow rotation of the celestial sphere about a certain point in the sky – the so-called “poles of the elliptic” – which ...
is a new infrared telescope that will orbit around Earth's poles every 100 minutes or so, continuously scanning the celestial sphere around our planet with a heat-sensing camera that serves a dual ...