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Collecting Stardust
An anonymous reader writes "Washington University in St. Louis space scientists are reporting the first definitive laboratory dissection of an interstellar dust particle, thus pulling out each grain's history individually. When collected at high-altitude, the origin of six grains are from outside our solar system. 'Space' is full of dust, or ejected material from long-dead stars. In this case, 3 of the 6 dust grains are from red giant stars, and perhaps 2 are from supernovae. In the next 5 years, there are six missions targeting a rendezvous with either a comet or asteroid, including the Stardust mission to return the first extraterrestrial samples since Apollo. That only leaves 100 billion comets left to explore in our own solar system's Oort cloud." Update: 02/28 17:22 GMT by M : Fixed university name.
You mean Washington University in St. Louis...
*not* "University of Washington"
Washington University
Give a man a fish and he will eat for a day.
Teach him to eat and he will fish forever.
Background: 28/M/Bi-Sexual; Owner of a Linux company; MBA Harvard 2003; B.S. Comp Sci MIT 2000
The usual way to trace the place of origin of a sample (meteorites, dust, whatever) is to look at the ratio of isotopes of certain elements. In this case, they used two oxygen isoptopes. Objects in our solar system tend to have a particular ratio, all the material having formed from the same nebula 4.6 billion years ago. Material with a very different isotope ratio probably comes from outside the system, then.
This method isn't without it's risks, of course. There are processes which might enhance or deplete a body in a particular isotope over it's kin. But I'm not thinking of any that would work on a dust grain, assuming it had ever been part of a planet.
A little reading would go a long way in your search for truth.
From the linked article:
Using the NanoSIMS probe, the Washington University investigators then measured the relative amounts of two isotopes of oxygen in more than a thousand grains from nine IDPs. The data told them which grains had come from stars.
From a link in the article:
The NanoSIMS is a first-of-its-kind ion microprobe in the Laboratory for Space Sciences in Arts & Sciences and is housed on the fourth floor of Compton Hall. The $2 million instrument is the first in the world built to analyze the isotopic and elemental composition of extremely small samples, such as interplanetary dust particles, at a sub-micrometer scale, allowing a first-time look at those particles' subcomponents.
And from a link on the NanoSIMS homepage:
Results: Of all the subgrains defined in 25 images from 9 cluster IDPs, roughly 1031 were measured with sufficient precision to distinguish solar material from circumstellar dust as shown in Figure 1. Only grains > 200 nm were measured with this level of precision. Six of these grains have O isotopic compositions which fall well outside the range of solar system materials, marking them as stellar condensates.
Seems to me like these cats know what they are doing.
"Gold still represents the ultimate form of payment in the world." - Alan Greenspan, 1999
according to the article...
"Using the NanoSIMS probe, the Washington University investigators then
measured the relative amounts of two isotopes of oxygen in more than a
thousand grains from nine interplanetary dust particles. The data told them which grains had come from stars."
A pizza of radius z and thickness a has a volume of pi z z a
I go to Washington University right now. We Wash U people are used to this. Anytime we talk to family they say things like "Seattle is pretty rainy isn't it?" You'd think more people would have heard of a major research university with billions of dollars in its endowment. Sadly this is not the case. No love lost, we understand :)
It's mostly the college administration that is upset by "Wash U", since they're ever seeking higher ratings in the USN&WR college ranking and feel that Wash U isn't "respectable" enough.
As far as I know, the women who went to Wash U don't feel any differently... no, just polled one alumna, my wife, and she doesn't care.
If you really want to upset Wash U alums remind them their school is responsible for foisting wu-ftpd on the world....