Objects from space????

[dashelwinter]

hello.
question: if an object, like an meteorite, hits the earth...
how can we tell if it was from space originally?

are there chemical tests or some indication that it had been from space?
as well as metal that may have been in space for a long time? How could anyone tell if something metallic on earth had been in space for long periods?

what if some scientist/archaeologist digs up metal on earth and claims it had been from some UFO craft, what could someone do to debunk this claim? or prove that claim?

[Jens]

hello.
question: if an object, like an meteorite, hits the earth...
how can we tell if it was from space originally?

Others may correct me, but I don't think there is any particular marker that shows that something is a meteorite. It's more like this: we know that many meteorites are iron. So if you are walking in the middle of a sandy area, mostly silicon and aluminum, for example, and then you come across a hole and at the bottom of the hole is a lump of iron, then you are pretty sure it's a meteorite.

[ronin]

Here's a decent article that discusses how to tell if a rock is a meteorite or not.

https://geology.com/meteorites/meteo...fication.shtml

[DaveC426913]

are there chemical tests or some indication that it had been from space?

Yes. Rocks not from Earth have a different composition of elements and isotopes.

[Hornblower]

I remember reading about a rock that was traced to outer space because it had traces of argon that were primarily of isotope 36. The argon on Earth is mostly isotope 40, a beta decay product of potassium 40. Apparently this rock had somehow retained measurable traces of primordial argon. Since argon is a gas at ambient temperature, it would leak out unless in tightly bound inclusions.

[nota]

Yes. Rocks not from Earth have a different composition of elements and isotopes.

some do but more common are molecules that donot form in an oxidizer environment like ours

[trinitree88]

nota. Take note of this: http://www.openminds.tv/test-confirm...bris-733/10835

pete....note that AH-1 sample on the magnesium isotope ratio chart.

[DaveC426913]

some do but more common are molecules that donot form in an oxidizer environment like ours

Sure, but you don't have to go all the way up to molecules. The atoms themselves can have their ratios measured and distinct differences from Earth material are noted - for example high concentrations of Iridium - as well as the ratios of different isotopes of the same element.

[speach]

To extend this question further, how do we know that a meteorite is from say Mars or the Moon?

[DaveC426913]

To extend this question further, how do we know that a meteorite is from say Mars or the Moon?

We have extant samples of rocks from the Moon that we can compare to.

And we can do some pretty good research on what other planets are made of and the proportions of their elements through spectrographic analysis.

eg. The landing sites of the Mars probes were largely based on the presence of hematite - a mineral known for being created in the presence of water - by observing the spectral properties of light observed.

"The spectral signature of hematite was seen on the planet Mars by the infrared spectrometer on the NASA Mars Global Surveyor ("MGS") and 2001 Mars Odyssey spacecraft in orbit around Mars."
https://en.wikipedia.org/wiki/Hematite#Mars