A new method for identifying molecules in distant dust clouds may lead to a more comprehensive understanding of the first chemical steps on the way to the formation of life
In ancient times surveyors would be sent to mining areas. Their job was to check which metals exist in those areas, and what are the chances of mining them successfully. The equipment they had was simple, sometimes to the point of being ridiculous - a sieve, a sieve, hammers and chisels - but they did their work faithfully. And yet, as times have changed, so have the reviewers. Today the reviewers are experienced astronomers, they use a huge telescope worth millions of dollars and their destination is among the stars.
In the last three years, scientists have harnessed the power of the Robert S. Bird Green Bank (GBT) for surveying molecule-rich clouds in our Milky Way galaxy. Anthony Ramijn, of the National Radio Astronomy Observatory, and his colleagues managed to discover ten new interstellar molecules in just three years – a record that has not yet been broken by other groups or using other telescopes.
"Clouds like this are the raw material for creating new planets and stars. We know that prebiotic molecules are built in complex chemistry in such clouds long before the planets and stars are formed. There is a good chance that some of these interstellar molecules will find their way to the surface of young stars like the early Earth, and give the jump-start to the chemistry of life.” Remigen said. "For the first time, we now have the ability to perform a very thorough and methodical search to find all the chemicals in the clouds."
Molecules, by nature, tend to vibrate and rotate around their axis, emitting radio waves at specific frequencies. Each molecule has its own unique pattern of such frequencies, called spectral lines. This pattern serves as a 'fingerprint' that can be used to identify the molecule. Most discoveries in the past were made by identifying the frequency pattern of a certain molecule in the laboratory, and searching for that pattern with a radio microscope in a certain area of the sky. So far, over 140 different molecules have been discovered in outer space in this way.
Despite the successes of the method, its major drawback is that only the molecules that are being searched for can be discovered. Now the scientists from the observatory change the strategy and start scanning the clouds without knowing in advance what they will find. The researchers will also share any information they find with other scientists, hoping to speed up the pace of discoveries. The researchers' plan was presented at the meeting of the American Astronomical Society in St. Louis.
Astronomers will use the GBT to closely study a cloud of gas and dust called Sagittarius B2(N), located near the center of our galaxy, 25,000 light-years from Earth. They plan to record all the spectral lines they pick up, and then try to 'match' them to existing molecular patterns using data-gathering software.
"Complex organic molecules formed in interstellar space are, without a doubt, the basic building blocks of astrobiology. "Catalogizing all the molecules present in this cloud will greatly advance the understanding of the physical conditions prevailing in the cloud and the first chemical steps towards life," said Phil Jewell, from the observatory team.
The astronomers will conduct a careful scan of the interstellar cloud in the wide range of radio frequencies between 300 MHz and 50 GHz. This technique, they say, will allow them to discover molecules that would have eluded less ambitious observations. "Based on previous studies, there are a number of complex prebiotic molecules that we think exist in such clouds, but only by using a large-scale method with the GBT will we be able to find the evidence we need to discover them," Remijan said.
"This strategy was not possible at frequencies between 300 MHz and 50 GHz before the GBT. The great capabilities of this telescope allow us to usher in a whole new era of astrochemistry," said Jan M. Hollis, of NASA's Goddard Space Flight Center.
For the news on the website of the American National Radio Observatory
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Evidence of the complexity of the problem and information about the solution directions appear in the article:
"They plan to record all the spectral lines they pick up, and then try to 'match' them to existing molecular patterns using data collection software."
It is interesting - in the current context - that the term used by Roy - "gathering information" is actually a not entirely successful translation of Data Mining - the term that appears in the original, whose accepted translations into the Hebrew language are "information mining" or "data mining". In this article I would, of course, use "information mining".
Avner:
In relation to the shift/displacement (not "distraction") of the spectrum as a result of the Doppler effect - this also exists in our galaxy and is caused not only by speed differences but also by gravitational fields.
The solution to this problem was already hinted at in your words when in one of the responses you mentioned that the distances between the spectrum lines are looked at more than the lines themselves.
Lesbadramish Yehuda
Regarding the Doppler effect = redshift, which you mentioned, in principle it must certainly be taken into account, especially when measuring distant stars and galaxies - however, for our case here, in the clouds of our galaxy, the distances are closest in astronomical km and therefore, in my opinion, the redshift, if it exists at all ,neglect.
I had an idea
What can be done is to prove the non-existence of matter. For example, no combination will give us iron or copper, etc. And against this, we can assume the existence of substances only with some doubt.
That is, according to the example I gave on the article, we can say that the word philosophy does not appear, nor does the word Sabdarmish. On the other hand, the existence of words like "Sagittarius" can only be doubted.
Good day to those who get involved
Sabdarmish Yehuda
and not just this,
There are areas in the dust clouds that move towards us and there are areas that move away from us, therefore, according to the Doppler effect, there is a deviation of the absorption lines.
The result? Go find out how they overcome all the mess!.
Have a good day
Sabdarmish Yehuda
I assume that the software not only checks the appearance of certain emission frequencies but also their appearance together with other frequencies. In fact, what identifies the emission-absorption spectrum of a given material is the characteristic distances between its emission-absorption lines. For example: if the emission spectrum of a given molecule is:
5-00-8-000-6 So it is clear that we are not looking for 5 alone or 8 alone or 6 alone but rather their joint appearance known as the emission spectrum of a known substance.
It is clear that in practice it is more complex because there is a mixing of emission lines of many materials. Therefore, the resolution of the spectrometer is very important.
The intensity of certain emission-absorption lines indicate on the one hand the relative concentration of the material in the cloud and on the other hand help in verifying the spectroscopic analysis.
Yehuda,
The error has been fixed, thanks. Throughout the writing I had to consciously try not to write 'microscope' instead of 'telescope', and probably at some point the mistake was bound to happen.
As for the sorting itself, it comes from programs that use high-level mathematics. Although I have no real knowledge as to how these particular programs work, I know control algorithms that are able to locate certain waves out of the chaos of mixed frequencies, by using various transformations. I assume these are similar programs.
Good Day,
Roy.
two things:-
In line 15 of the article, correction, "or in the use of other microscopes." There should probably be "telescopes".
And about the article itself. What bothers me is the lack of explanation of how the sorting is done. We take this article or any article and place all the words one above the other. Would we be able to sort all the words out of this pile that is a night of letters? That's what we did here, we get a collection of absorption lines, many of which overlap with many molecules, so how from all this overlap is it possible to reach the molecules with certainty?
In the example I gave of the words in our articles one above the other, we might have been able to guess the existence of the word "telescope" in the article, but short words we could only guess that they exist. For example:- Could we say with confidence that the words:- tal, kol, wo, zach, would also appear? As a possibility, yes, but not with confidence that they exist.
I hope I understood.
Have a good day
Sabdarmish Yehuda