New Data Shatters Theory of Origin of Water on Earth

Fanghawk

New member
Feb 17, 2011
3,861
0
0
New Data Shatters Theory of Origin of Water on Earth

The Rosetta Space Probe has not found comet water matching the type available on Earth, meaning the water we drink may have come from another source.

There are still all kinds of mysteries science is trying to solve about our planet Earth, including this one: <a href=http://www.escapistmagazine.com/news/view/137696-Water-Predates-Earth-Sun-and-Solar-System-Formation>How the heck did we end up with so much water? The prevailing theory was that comets brought this water to Earth during one of our historic large-scale impacts. But now that <a href=http://www.escapistmagazine.com/news/view/138607-ESA-Rosetta-Probe-Philae-Lander-Comet-67p-Gallery>the Rosetta space probe had a chance to look at a comet up close, we might be back at the drawing board again.

The problem? The European Space Agency's Rosetta probe brought back results that the comet's water is heavy water, which means it contains an above-average amount of deuterium, an isotope of hydrogen. Scientists had hoped that comets from the Kuiper Belt would be a perfect match for Earth's water, much like one that we observed three years ago. But the heavy water content from this comet suggests the previous observations might be an anomaly, meaning we need to think of other possibilities.

One popular theory is that water was brought here by asteroids instead, since they likely carried it roughly 4 billion years ago. But not all scientists are in agreement with the asteroid idea. Another theory is that Earth carried its original water in its crust or ice at the poles, that melted and spread over the course of several warming and cooling periods.

Another possibility is that Earth just happened to be hit with a comet that, like the one observed in the Kuiper Belt, had the correct water content. But that's something difficult to prove reliably. Regardless, Rosetta is clearly already expanding our knowledge of outer space, an incredibly exciting prospect even if we were originally wrong.

Source: <a href=http://www.cbc.ca/news/technology/rosetta-mission-comets-not-source-of-earth-s-water-1.2869569>CBC

Permalink
 

Lightknight

Mugwamp Supreme
Nov 26, 2008
4,860
0
0
Wait, it's different water? Different because of the heavy water content?

Since water had however many millennia of time to be impacted by organic life and other things, is there really no way that they could be different than when they first got here?
 

Albino Boo

New member
Jun 14, 2010
4,667
0
0
Lightknight said:
Wait, it's different water? Different because of the heavy water content?

Since water had however many millennia of time to be impacted by organic life and other things, is there really no way that they could be different than when they first got here?
The ratio between the different isotopes of hydrogen is different on the comet than here on Earth. Heavy water is Hydrogen with an extra neutron. This is a physical property of the atom and is unaffected by any chemical process. Exposure to radiation will cause small variations in the ratio but not 3 times the amount of deuterium that is on the comet than on Earth.
 

CGAdam

New member
Nov 20, 2009
159
0
0
How easy would it be to add an extra neutron in space, rather than subtract one on Earth? Could something have affected the comet while it was drifting around out there, making its water heavy, while the ones that crashed landed on Earth weren't changed?
 

Nohvarr

New member
Nov 27, 2014
5
0
0
When it comes right down to it, this recent discovery is telling us we need more data. I'm thinking we need a larger sample size for our comets just for starters.
 

Joccaren

New member
Mar 29, 2011
2,600
0
0
Correct me if I'm wrong, but shouldn't
Fanghawk said:
which means its hydrogen atoms carry extra isotopes.
be 'contain extra neutrons'?
Isotopes are variants of the same chemical element, say Hydrogen, that contain a differing number of neutrons.
So, the way its worded in the article makes it sound like the Hydrogen atoms carry extra hydrogen atoms, which isn't true, they simply have extra neutrons in their nucleus, doubling their weight, and making the water 'heavy'.
 

Rhykker

Level 16 Scallywag
Feb 28, 2010
814
0
0
Joccaren said:
Correct me if I'm wrong, but shouldn't
Fanghawk said:
which means its hydrogen atoms carry extra isotopes.
be 'contain extra neutrons'?
Isotopes are variants of the same chemical element, say Hydrogen, that contain a differing number of neutrons.
So, the way its worded in the article makes it sound like the Hydrogen atoms carry extra hydrogen atoms, which isn't true, they simply have extra neutrons in their nucleus, doubling their weight, and making the water 'heavy'.
You are correct; that slipped by me. Clarified the verbiage.
 

Daaaah Whoosh

New member
Jun 23, 2010
1,041
0
0
As I recall, this is the first comet we've ever gotten close enough to check. Considering how different Earth is from the other planets in our solar system, I daresay not all comets will have the same amount of heavy water.
 

BoogieManFL

New member
Apr 14, 2008
1,284
0
0
Major_Tom said:
That is a hypothesis, not a theory. Theories don't get "shattered" that easily.
Indeed, but it's a mistake I've come to expect on this forum. Many of the news article titles are just terrible or flat out wrong. You shouldn't write something like it's definitive when it's not. Let alone when both theories are just that - theories.