Exoplanet hunters should check for N2O:
Scientists at UC Riverside are suggesting something is missing from the typical roster of chemicals that astrobiologists use to search for life on planets around other stars — laughing gas.
Chemical compounds in a planet's atmosphere that could indicate life, called biosignatures, typically include gases found in abundance in Earth's atmosphere today.
"There's been a lot of thought put into oxygen and methane as biosignatures. Fewer researchers have seriously considered nitrous oxide, but we think that may be a mistake," said Eddie Schwieterman, an astrobiologist in UCR's Department of Earth and Planetary Sciences.
[...] "In a star system like TRAPPIST-1, the nearest and best system to observe the atmospheres of rocky planets, you could potentially detect nitrous oxide at levels comparable to CO2 or methane, [CH4]" Schwieterman said.
[...] Others who have considered N2O as a biosignature gas often conclude it would be difficult to detect from so far away. Schwieterman explained that this conclusion is based on N2O concentrations in Earth's atmosphere today. Because there isn't a lot of it on this planet, which is teeming with life, some believe it would also be hard to detect elsewhere.
"This conclusion doesn't account for periods in Earth's history where ocean conditions would have allowed for much greater biological release of N2O. Conditions in those periods might mirror where an exoplanet is today," Schwieterman said.
[...] The research team believes now is the time for astrobiologists to consider alternative biosignature gases like N2O because the James Webb telescope may soon be sending information about the atmospheres of rocky, Earth-like planets in the TRAPPIST-1 system.
Journal Reference:
Edward W. Schwieterman et al 2022 Evaluating the Plausible Range of N2O Biosignatures on Exo-Earths: An Integrated Biogeochemical, Photochemical, and Spectral Modeling Approach [open] ApJ 937 109. DOI: 10.3847/1538-4357/ac8cfb
(Score: 4, Informative) by khallow on Friday October 07 2022, @09:20PM
A good portion of the Earth's lifespan would be hard to detect (due to almost no oxygen production for a couple billion years), but if the geologists are right, a third to half of Earth's lifespan would be spent with 1% or more oxygen gas in the atmosphere. That's way out of range of non-living physical processes.
There's a variety of other simple, moderately reactive chemicals that in atmosphere could indicate presence of life such as hydroxyl ions, carbon monoxide, cyanide, ozone, hydrogen sulfide, hydrogen fluoride, methane, etc. I'm favoring oxidizing agents somewhat because reducing agents tend to have higher boiling points.
(Score: -1, Spam) by aristarchus 2 on Saturday October 08 2022, @03:08AM
It is official; Netcraft now confirms: SN is dying
One more crippling bombshell hit the already beleaguered SN community when IDC confirmed that SN posting has dropped yet again, now down to less than a fraction of 1 percent of Slashdot. Coming close on the heels of a recent Netcraft survey which plainly states that SN has lost more users, this news serves to reinforce what we've known all along. SN is collapsing in complete disarray, as fittingly exemplified by failing dead last in a recent survey of news aggregators.
You don't need to be a Kreskin to predict SN's future. The hand writing is on the wall: SN faces a bleak future. In fact there won't be any future at all for SN because SN is dying. Things are looking very bad for SN. As many of us are already aware, SN continues to lose users and subscribers. Red ink flows like a river of blood.
SN is the most endangered of them all, having lost 93% of its users. The sudden and unpleasant departures of long time SN admins c0lo and The Mighty Buzzard only serve to underscore the point more clearly. There can no longer be any doubt: SN is dying.
Let's keep to the facts and look at the numbers.
Slashdot leader whipslash states that there are 7000 users of Slashdot. How many users of Pipedot are there? Let's see. The number of Slashdot versus Pipedot posts on Usenet is roughly in ratio of 5 to 1. Therefore there are about 7000/5 = 1400 Pipedot users. SN posts on Usenet are about one hundredth of the volume of Pipedot posts. Therefore there are about 14 users of SN. A recent article put Hacker News at about 80 percent of the news aggregator market. Therefore there are (7000+1400)*4 = 33600 Hacker News users. This is consistent with the number of Hacker News Usenet posts.
Due to the troubles of NCommander, abysmal management and so on, SN was taken over by martyb who is another troubled admin. Now martyb is also gone, and SN's corpse was turned over to Janrinok the Censor.
All major surveys show that SN has steadily declined in users and comments. SN is very sick and its long term survival prospects are very dim. If SN is to survive at all it will be among gun nuts like Runaway and khallow. SN continues to decay. Nothing short of a cockeyed miracle could save SN from its fate at this point in time. For all practical purposes, SN is dead.
Fact: SN is dying
(Score: 2) by hendrikboom on Saturday October 08 2022, @04:43PM (1 child)
There's room for crude jokes here.
Sildenafil operates by stimulating the production of the neurotransmitter nitrous oxide.
(Score: 2) by Ellis D. Tripp on Saturday October 08 2022, @08:15PM
"Society is like stew. If you don't keep it stirred up, you end up with a lot of scum on the top!"--Edward Abbey