Re: Fungal strains in space spark worry - we might have already contaminated --

"a425couple"  wrote in message news:[email protected]...

On 5/8/26 09:31, Kualinar wrote:
> Le 2026-05-08 à 10:58, Jim Wilkins a écrit :
>> "Jim Wilkins"  wrote in message news:[email protected]...
>>
I had some doubts because of our now thick atmosphere,
BUT, I'm reading   --
(What can go  11,200 m/s (or about 25,000 mph) without
burning up?)
to break free from Earth's gravity and reach the moon,
------------------------

Rockets start off slowly and gain most of their velocity at low to near-zero 
drag altitude (there's measurable drag on the ISS). At only a minute or so 
into the flight the engines are throttled down to limit increasing air 
resistance until reaching higher thinner air, this is the "throttling down 
for Max q" announcement.
https://en.wikipedia.org/wiki/Max_q

This Moon origin theory posits that a giant impact threw massive debris into 
orbit, mainly from Earth's outer layers rather than the iron core. The Moon 
is only 60% as dense as Earth, not a smaller copy from the same ingredients.
https://en.wikipedia.org/wiki/Origin_of_the_Moon

The larger and heavier the ejected object, the less the air will slow it. 
Drag increases as the square of size, inertia as the cube. That may mean 
that only very large rocks from very massive impacts made it through the air 
with enough remaining velocity to escape Earth gravity and rise to Martian 
orbit. Fortunately we don't know from experience how massive that impact 
might have been. The Space Gun I referenced can reach orbital height but not 
nearly the velocity needed to stay there.

Analysis of returned samples with a mass spectrometer might suggest Earth 
origin if Mars minerals have a significantly different isotopic distribution 
(it varies here too).

Mars offers far less air resistance and a downward falling trajectory to 
Earth, so the trip is easier. It's significant that we haven't traced any 
meteorites to Venus.