Ask Astro

Science

What is the source of the term “right ascension”? Why is it right ascension and not simply ascension, as with declination?

Science, Solar System

Do the giant planets – Jupiter, Saturn, Neptune, and Uranus – have solid cores? If so, what are they made of?

Science

How can CCD images just a few minutes long be combined into one photo that shows details not visible in the originals?

Observing

Many articles and books on observing refer to small, medium, and large telescopes, but what are the borderlines in objective size that define small, medium, and large?

Observing

I have quickly come to find out that my 3.5-inch refractor is completely useless on faint objects, such as nebulae, galaxies, globular clusters, and comets. Will they be well within my reach with an 8-inch telescope?

Science

I recently found out about a great meteor shower that occurred on November 14, 1833. What actually caused this great event, and is there anything today that compares to it?

Observing

Are either of the moons of Mars large enough to eclipse the Sun as seen from the surface of Mars?

Science

Why doesn’t NASA attach the Hubble Space Telescope to the International Space Station (ISS) to service the telescope safely? Is that technically feasible?

Human Spaceflight, Solar System

What does Mars smell like?

Observing, The Sun

How can I safely view the Sun?