Let’s try a demonstration that we all enjoyed in elementary school. Close one eye, hold out your thumb at arm’s length, and align it with an object on the other side of the room. Without moving your ...

Stars move slowly across the sky over very long periods. The closer a star is, the more easily we can see its movement. Stellar parallax is a shift in a star's apparent position due to Earth's orbit.

Forbes contributors publish independent expert analyses and insights. The Universe is out there, waiting for you to discover it. How far away are the most distant objects in the Universe? How has the ...

How is astronomical distance determined? Just cannot get my head around cepheid variables, parallax, etc. How is it possible to tell how far away something is when you cannot bounce a radar beam off ...

Astronomers quickly become used to dealing with huge numbers. For example, in any one lecture, I might declare that the sun emits some 400 billion trillion watts of power each second, that our Milky ...

THE determination of stellar parallaxes by photography has shown a striking improvement in recent years, and the results obtained with the Yerkes refractor are of the highest order of excellence. Two ...

PREVIOUS attempts to measure the annual parallax of intense radio stars 1,2 have indicated that their distances exceed 1/50 parsec. These results were obtained by using an interferometer arrangement ...

How can we grasp the enormity of space? One thing is sure: We should at least make our units of measurement as intuitive and friendly as possible. We often fail. Take, for example, cosmic expansion, ...

Don't miss the big stories. Like us on Facebook. Astronomers quickly become used to dealing with huge numbers. For example, in any one lecture, I might declare that the sun emits some 400 billion ...