The Puzzle of Martian Meteorites

Alien54 writes "Recent analysis of several new Martian meteorites is confounding planetary scientists. To put it simply, an awful lot of the Martian meteorites are way too young. According to this thi s story found at Space.com, standard theories predict that most meteorites from Mars should be billions of years old. However, almost half of the known rocks from mars are under 200 million years old. These results open up a Pandora's box of questions. The discussions should be interesting."

Comments

so certain are they?

[jafac]

The conclusion of the article says it all; that they need to send a lander to bring back samples from Mars as soon as possible.

IANAEG or CC (Exo-Geologist or Cosmo-Chemist):
I say this because until that happens, how can we be so sure that these rocks actually came from Mars? Yes, the chemistry is similar, to what we THINK Mars' chemistry is, based on our very limited (and no direct) observations, but if the planets, Mars included, formed by accretion of dust particles in space around the early Sun, then it stands to reason that maybe not ALL of the materials of similar Martian chemistry accreted to Mars. There could be any number of asteroids made of similar materials floating out there between Mars and Jupiter, and periodically colliding, getting melted, and sent Earthward. Sure, the stats may be against it, but I don't believe we really know all that much about the smaller residents of the asteroid belt.

I'm not saying that these rocks are not from Mars, but I'm saying that maybe it's time to entertain alternative theories as to these rocks origins, because the data doesn't jibe.

if it ain't broke, then fix it 'till it is!

John Varley answer

[Nidhogg]

It took them 3 pages to say what John did in one sentence.

Best scientific answer to date: It beats the shit outta me.

The scientists are just in denial about the really obvious answer.

The inhabitants of Mars are firing these little rocks at us just to mess with our heads.

"Here Earth-scum! Take a gander at *foom* this one! Just quit bombing us with those damned probes!"

Argh. Waaayyyy too much coffee today....

Re:Martian Source of Meteorites Inconclusive

[probejockey]

The reason that at least some of these rocks are thought to be from Mars is that bubbles in the the impact glass (i.e glass formed during the impact that ejected them from Mars) contain gasses whose isotopic rations could only be found in the Martian atmosphere. Others are believed to originate on Mars because the chemistry of the rocks indicate extensive geological processing that could have only occurred on a relative large (and wet) planet. Since these rocks have O isotope ratios that are unlike Earth's and it is really hard to get rocks up the gravity well from Venus, Mars is the only choice.

Interesting mind-game

[rho]

Had a conversation with my brother about something similar to this. The topic basically was, "The universe isn't as old as scientists believe". The posit: the universe (and all physical actions) are slowing down over time.

To explain: we know the age of X because of carbon dating. Carbon dating assumes that radioactive decay is a constant. What if, in the past, things happened much faster? Light travelled faster, radioactive isotopes decayed faster, etc. And as time went on, the physical properties assumed to be constant slowed down.

I dunno -- I know my VISA bill grows faster in the present than in the past, but VISA physics defies all rational thought. But, it's an interesting idea.

Re:Interesting mind-game

[(void*)]

No. There is no such universal scaling constant. It takes more than more one number to describe physics. Let me try to give you an idea of what I mean.

Suppose you doubled everything in size. You are two times large. Since everything doubles in size, it must mean that you can't tell the difference between now and before right? Wrong.

Since everything is doubled, the force of gravitation between say two planets would drop (increased distance). Nevermind, let's keep the force the same you say. So we have to increase the masses between any two objects (F = GMm/r^2 - remeber?). But having increased mass, do we now keep the forces between charges the same? If you do, then the charge to mass ratio of the elctrons and protons will change - this effect is measureable. Lots of physics - emission spectra of atoms and molecules would be different as a result. We might not even be around to observe this.

That was just playing around with distance. It does not work for time as well. Some combination of the two? Not even that.

In other words, if something was different in the past, we should be able to see that effect physcially as we look backword in time at the stars. The people who are selling this idea are not thinking broadly enough about the entirety of physical phenomena.