Recent content by Mustellus

When fantasy involved Harry Potter or the Wizard of Oz, we understand that its a pleasant diversion. When someone slips math into the fantasy, suddenly its a question of 'making the math work'. Nope. Momentum equals mass times velocity divided by the square root of one minus speed...

As a 76 year old professional astronomer, I had never, ever seen the Hubble constant cited in MPH/ MPC. It kinda rhymes that way, and yes, Km / Sec / MPC is still a set of bastardized units. But we are trying to ease everyone else into using metric....

Incoming asteroids? Sadly, one problem radars have is that they can 'see' the ionization trails left by meteorites as they burn up in earth's atmosphere. To avoid this clutter, most ignore anything coming at us at above escape velocity. This means the entire Aurcturian Empire invasion...

Planets are 'wanderers'..... nope Planets orbit the sun ... but asteroids and comets orbit the sun, but aren't planets Planets clear out their orbit.... no, only ones where the orbital period is 'short' . Pluto and Eris will never qualify. And grins.. .if Planet X exists.. it can't be a...