[meteorite-list] Lunar velocities...
From: Robert Beauford <wendirob_at_meteoritecentral.com>
Date: Thu Apr 22 09:44:43 2004 Message-ID: <003201c0b6ed$f4af2fc0$744897cc_at_wendirob> This is a multi-part message in MIME format. ------=_NextPart_000_002F_01C0B6B3.47901500 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable "These "stretch" tektites are a clear indication of terrestrial origin = as how could such a form survive if they had been formed on the moon and = then entered the Earth's atmosphere at 7+ miles per/sec?" Steve's comment above got me curious. It seems like ejecta from the = moon need not reach a cosmic velocity or earth orbital velocity, just an = escape velocity or orbital velocity of the moon. It seems, more = specifically, that any fragment with a speed over the escape velocity of = the moon, and a vector that points it inside the orbit of the moon = around the earth (slightly less than 50% of all lunar ejecta?), and = insufficient residual speed to send it back out of that orbit, would = fall to earth. This should alow for some very slow objects reaching = earth (and thus less ablation loss and entry alteration) What is this = necessary and maximum speed? Please note, I am not advocating a lunar = origin for tektites, just idly, and perhaps ignorantly, wondering if = lunar meteorites might enter the atmosphere slower than some other = meteorites. -Robert Beauford : ) ------=_NextPart_000_002F_01C0B6B3.47901500 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content=3D"text/html; charset=3Diso-8859-1" = http-equiv=3DContent-Type> <META content=3D"MSHTML 5.00.2314.1000" name=3DGENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=3D#ffffff> <DIV><FONT size=3D2>"These "stretch" tektites are a clear indication of=20 terrestrial origin as how could such a form survive if they had been = formed on=20 the moon and then entered the Earth's atmosphere at 7+ miles=20 per/sec?"</FONT></DIV> <DIV><FONT size=3D2></FONT> </DIV> <DIV><FONT size=3D2>Steve's comment above got me curious. It seems = like=20 ejecta from the moon need not reach a cosmic velocity or earth orbital = velocity,=20 just an escape velocity or orbital velocity of the moon. It seems, = more=20 specifically, that any fragment with a speed over the escape velocity of = the=20 moon, and a vector that points it inside the orbit of the moon = around=20 the earth (slightly less than 50% of all lunar ejecta?), and = insufficient=20 residual speed to send it back out of that orbit, would fall to = earth. =20 This should alow for some very slow objects reaching earth (and thus = less=20 ablation loss and entry alteration) What is this necessary and = maximum=20 speed? Please note, I am not advocating a lunar origin for = tektites, just=20 idly, and perhaps ignorantly, wondering if lunar meteorites might enter = the=20 atmosphere slower than some other meteorites.</FONT></DIV> <DIV><FONT size=3D2>-Robert Beauford : = )<BR><BR></DIV></FONT></BODY></HTML> ------=_NextPart_000_002F_01C0B6B3.47901500-- Received on Tue 27 Mar 2001 01:44:28 PM PST |
 StumbleUpon del.icio.us reddit Yahoo MyWeb
|