Comet velocity at 1 A.U.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Astrodelugeologist</i>
<br />On average, at what speed do comets travel when they're in the vicinity of Earth's orbit? I've been searching the Internet for an answer, and I've found two or three with speeds of about 40 km/s...but I don't think I can generalize from so few pieces of data.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">40 km/s is a good average. The maximum possible is 42 km/s, which is escape speed from the solar system at 1 au. The minimum would arise from Comet Encke, which has the orbit with shortest period, and has a speed of 37 km/s at 1 au. These are relative to the Sun, of course. -|Tom|-

Tom,

At what distance from the Sun are the velocities of different comets closest together?

--Astro

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Astrodelugeologist</i>
<br />At what distance from the Sun are the velocities of different comets closest together?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The greater the distance, the closer the velocities. So the "Oort cloud" at 42,000 au would have the most similar speeds (in absolute terms) at about one meter/second. -|Tom|-