A resident dolphin mother and her new calf at the Hilton Waikoloa Village are helping scientists to evaluate the increasing pressures on wild dolphin populations such as Hawaiis spinner dolphins. The University of Hawaii at Mnoas Marine Mammal Research Program (MMRP) and Dolphin Quest are collaborating on a scientific drone study aimed at better understanding the health of dolphin populations.

Scientists are concerned that frequent human activities in the spinner dolphins environment are disrupting the dolphins natural behaviors, which may be adversely affecting their reproduction.

Fabien Vivier, a PhD student with MMRP, has been operating a drone over a pregnant bottlenose dolphin at the Dolphin Quest facility at the Hilton Waikoloa Village on Hawaii Island. He collected baseline data in order to do the same on the open ocean to detect pregnancy in female dolphins. This will help to estimate pregnancy rates for the populations of dolphins in the wild.

Studying dolphins at Dolphin Quest is really helpful, because it allows us to verify our methodologies at a specific known stage of pregnancy, which couldnt be accomplished working only in the wild, Vivier said. This information is quite relevant to studying and conserving other species such as Hawaiis spinner dolphins because, even though the species are different, they share many similarities. If we are able to detect pregnancy from a drone perspective in the bottlenose dolphin, the likelihood of detecting pregnancy in a spinner dolphin is very good.

Scientists said continuing reproduction supports critical wildlife conservation and is also good for the dolphin social group.

Reproduction and calf-rearing is important for dolphin welfare. It is a natural and enriching social behavior for dolphins in the wild and in modern zoos, aquariums and marine life parks, said Dolphin Quest Marine Mammal Reproduction Specialist Holley Muraco. Accredited facilities like Dolphin Quest have excellent reproductive success, which leads to long-term population sustainability and eliminates the need for collection from the wild.

Vivier said the next step of surveying spinner dolphins in the wild is scheduled for October. He plans to tweet about the experience through the MMRPs Twitter account.

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Dolphin reproductive research aided by UH drones - UH System Current News

Pupils wearing facemasks arrive to attend classes at Moor End Academy in Huddersfield, northern England on September 11, 2020.

OLI SCARFF | AFP | Getty Images

LONDON After months out of school, children around the world are returning to the classroom. And while parents feel it's best for their kids, shaking those first-day nerves has been a challenge.

Homeschooling has been the norm for many families over the last five months, as a lot of schools only stayed open to the children of key workers, due to the coronavirus pandemic.

Gillian Harvey, a writer who lives in a small town near Limoges in France, said that she was initially nervous about her five children returning to school.

"I made sure I told them all the facts properly before they went back, but also that they are human and there may well be a time when they forget a hygiene measure (e.g. forget to wash their hands properly) and that it's OK and human and they must just do their best and follow the rules to the best of their ability," Harvey told CNBC via email.

She's started to feel better about the situation since their return.

"I think the schools are handling it well," she said, with the use of social bubbles for younger children, along with social distancing and hand gel for older students.

Children in France returned to schools at the beginning of September. But by the end of the first week, French Education Minister Jean-Michel Blanquer said 22 schools had closed across the country and in its territories due to virus cases. On Mondayafter the sixteenth straight day of rising hospitalizations school trips and student parties were suspended in Marseille.

To date, France has reported 425,870 cases of Covid-19 and 30,958 related deaths, according to data compiled by Johns Hopkins University.

"I always thought there would be a couple of cases at first people are returning from holidays and I wish there'd been some sort of encouragement for families to stay at home the week before term started," Harvey said.

But she added that it was "a horrible time for parents you feel the risk of your decision no matter what it is."

Another mother in London, who preferred to remain anonymous, told CNBC over the phone that she felt her son's school had gone beyond the average measures to ensure a safe return to the classroom.

She welcomed her son's return to school, not only as a parent balancing childcare with working from home these past months, but also for his mental health.

U.K. Prime Minister Boris Johnson has emphasized this repeatedly in recent weeks, saying it is "vitally important" for children to return to school in September, with British parents possibly facing fines if they refuse to comply.

The mother CNBC spoke to, however, did indicate that she was concerned about rising infections among the wider public and how transmission could then filter through schools, referring to the reported coronavirus outbreaks in 339 schools in England and Wales last week. In the U.K., 373,559 people have contracted Covid-19 and 41,726 have died from the virus.

She felt that the U.K.'s contact tracing system was "not sufficient."

"I advocate for a strong local contract tracing and informing system, like what (South) Korea has put in the place," she said.

Knowing about an outbreak in a local school, restaurant or supermarket would keep people better informed and help manage community transmission more efficiently, she argued.

Transitional kindergartner Caleb Simon, 4, waits with fellow students outside Weaver Elementary School on the first day of in-person learning in Rossmoor, CA, on Tuesday, September 8, 2020.

Jeff Gritchen | Getty Images

Indeed, experts have highlighted some points that might be reassuring to parents.

Mike Tildesley, an associate professor who specializes in infectious disease control at the University of Warwick in the U.K., told CNBC that the highest risk of transmission was actually "probably within households" with "unregulated mixing" between groups.

He said this was the reason behind a lot of the localized restrictions that have been imposed in the north of England in recent weeks, clamping down on meetings between different households, due to rising cases. The U.K. government announced measures last week that meant from Monday, people were unable to meet socially in groups from other households of more than six people.

Tildesley said that one of the difficulties is that schools are one of the last public areas to re-open.

He said it was "unfortunate timing" with the "R" number the virus' reproduction rate hovering around one, which is when it is considered dangerous. He referred back to research Warwick University published in June that suggested the re-opening of schools alone was unlikely to lead to a second wave of coronavirus cases.

"My real worry is that schools could end up getting the blame for cases starting to rise, because all this other stuff has happened, but actually there's an awful lot that's happened to get to this point," Tildesley added.

Olivia Swann, a clinical lecturer in pediatric infectious disease at the University of Edinburgh, told CNBC via email that she had worked on a study of 138 hospitals across England, Scotland and Wales, looking at children admitted with the coronavirus.

Admissions for children under 19 years' old accounted for less than 1% of those across all age groups. And, of those 651 children that were admitted, six died from the virus all of which had "complex health issues." What's more, more than 40% of children in that study had one or more underlying health conditions, some which were very complex. But Swann added that most did not need intensive care input and made good recoveries.

"As a parent, a children's doctor, and a scientist, I find our study very reassuring at a time when children are returning to school," Swann said. However, she stressed that she was not suggesting people become complacent, but carry on with practices such as physical-distancing and hand washing.

Data published Tuesday by the Department for Education estimated that 12% of state school pupils in England did not attend class in the first week of September. During the last academic year, the overall absence rate was 4.7%.

Examining this estimate together with data from the most recent school census, which reported a state-school pupil population of just over 8 million, indicated that as many as 974,400 pupils were not present at school during the first week of term.

Similar statistics released at the beginning of September by the Scottish Government showed that over 15.5% of pupils missed school on the first Friday backover 100,000 pupilsthough only 22,821 of those absences were designated "Covid-19 related." The data from England's Department for Education includes pupils absent for both Covid-19 and non-Covid-19 related reasons.

Attendance figures for Welsh and Northern Irish schools are yet to be made available by their respective governments.

CNBC's Jordan Butt contributed to this report.

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'You feel the risk of your decision no matter what': How parents feel about the return to school - CNBC

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Collection of cases data

We obtained data of confirmed COVID-19 cases that were reported in Guangdong province, Italy and other places in the world from the Health Commission of Guangdong Province, the Ministry of Health of Italy, and the World Health Organization [2831]. The data include infected cases in the world and Europe since January 26 to March 12, 2020, the cumulative confirmed cases, newly reported cases, death cases, and recovered cases in Italy from January 30 to March 13, 2020 and in Guangdong from January 19 to February 26, 2020. The number of cumulative confirmed cases in Italy was 2 between January 30 and February 5, 2020, and was 3 from February 5 to February 19, 2020. The numbers of cumulative death and recovered cases were 0 from January 30 to February 19, 2020. We exclude the data in these periods and will focus on the Italian data between February 20 and March 13 because this is the early stage of the Italian outbreak, which allows us to compare the effectiveness of the prevention and control measures used in Italy and Guangdong by analysis of those datasets.

In Fig.1, we select February 20 as the first day when there were 4 cumulative confirmed cases in Italy, and January 19 as the first day when Guangdong had one cumulative confirmed case. On February 28 Italy closed schools in Lombardy, the most serious epidemic area, when the number of cumulative confirmed cases was already 650 (Fig.1a). This number is similar to the confirmed cases (i.e. 683) in Guangdong on February 2. In comparison, the Guangdong government took Seven Measures policy (e.g. blockade of unnecessary public places) on the third day (January 21) to prevent the spread of the epidemic and shut down all schools on January 28, when there were only 241 cumulative confirmed cases (Fig.1b). Therefore, Italy closed schools about 5 days (January 28 February 2) later than Guangdong. In Fig.1c we see that the number of cumulative cases has already exceeded 10 thousand in Italy, however, the newly confirmed cases in Guangdong began to decline since the 37th day and reached the peak of cumulative cases at only 1347 (Fig.1d). In summary, it took 14 days for Guangdongs reported cases to decline since its cumulative confirmed cases exceeded 1000.

In the early stage of the epidemic in Italy, the government did not take many prevention measures across the country. Thus, to study the epidemic of this stage, we extend the classical deterministic susceptible-exposed-infectious-removed (SEIR) epidemic model by dividing the population into susceptible (S), exposed (E), symptomatic/asymptomatic infected (I/A), confirmed (H) and recovered (R) compartments. The susceptible and exposed populations are further partitioned into quarantined susceptible (Sq) and quarantined suspected individuals (Eq). Based on the previous research [22], we adopt an autonomous model to study the early stage of the outbreak. We assume that the individuals exposed to the virus are quarantined with a proportion q by contact tracing. If the quarantined individuals are successfully infected, they will move to Eq compartment, otherwise they move to the Sq compartment. The individuals who exposed to the virus but were missed in the contact tracing with rate 1q can either move to the compartment E or still stay in compartment S, depending on whether they are infected or not. We assume that the successful transmission probability is and the contact rate is c. The infected individuals can be detected and then isolated at a rate of I or move to the compartment R at the rate of I due to recovery. The death rate of the infectious individuals with symptoms I and the isolated infected individuals H is . We also assume that the asymptomatic infectious is neither dead nor hospitalized. With these assumptions the model can be described by

$$ begin{array}{l} frac{dS}{dt}=-left(beta c+cq(1-beta)right)Sfrac{(I+theta A)}{N}+lambda S_{q},\ frac{dE}{dt}=beta c (1-q)Sfrac{(I+theta A)}{N}-sigma E,\ frac{dI}{dt}=sigma rho E-left(delta_{I}+alpha+gamma_{I}right)I,\ frac{dA}{dt}=sigma(1-rho)E-gamma_{A}A,\ frac{{dS}_{q}}{dt}=(1-beta)cqSfrac{(I+theta A)}{N}-lambda S_{q},\ frac{{dE}_{q}}{dt}=beta cqSfrac{(I+theta A)}{N}-delta_{q}E_{q},\ frac{dH}{dt}=delta_{I}I +delta_{q}E_{q}-left(alpha+gamma_{H}right)H,\ frac{dR}{dt}=gamma_{I}I+gamma_{A}A+gamma_{H}H.\ end{array} $$

(1)

The more detailed definitions of variables and parameters for model (1) are provided in Table1. As the population size is much larger than the size of the outbreak, i.e. S(t)/N1, the basic reproductive number R0 of model (1) is given by the following formula by utilizing the next generation matrix [32].

$$R_{0}=frac{betarho c(1-q)}{delta_{I}+alpha+gamma_{I}}+frac{beta(1-rho) ctheta(1-q)}{gamma_{A}}. $$

The above model will be used to study the early stage of the outbreak. However, with a series of prevention and control measures being implemented by the government, the autonomous model needs to be modified. Because of the difference before and after the implementation of control measures, piecewise functions of the contact rate and diagnosis rate are introduced to the autonomous model.

The contact rate is a constant in the autonomous model, i.e. the average number of susceptible individuals that an exposed people can contact without any control measures in a unit time. As the action of regional or national lockdown came into effect, peoples contact will gradually decrease. Thus, we assume that the contact rate is an exponential decreasing function of time t after the government has taken the control measures. The contact rate c(t) is assumed to take the following form:

$$ c(t)=left{begin{array}{l} c_{0}, tleq t^{*}+tau,\ left(c_{0}-c_{b}right)e^{-r_{1}(t-t^{*}-tau)}+c_{b}, t>t^{*}+tau.\ end{array}right. $$

(2)

Here c0 denotes the contact rate at the initial time without control measures, cb denotes the minimum contact rate under the current control strategies (cb

Similarly, because the efficiency of detection and availability of medical resources vary, we assume that the diagnosis rate is a time-dependent piecewise function rather than a constant. It is an increasing function when medical resources are adequate and a decrease function when they are not. The duration of diagnosis 1/I(t) is given by the following form:

$$ frac{1}{delta_{I}(t)}=left{begin{array}{l} frac{1}{delta_{I0}}, tleq t^{*},\ left(frac{1}{delta_{I0}}-frac{1}{delta_{If}}right)e^{-r_{2}(t-t^{*})}+frac{1}{delta_{If}}, t>t^{*},\ end{array}right. $$

(3)

where I0 is the diagnosis rate at the initial time. If the efficiency of detection is increasing with time t, then the diagnosis rate I(t) will increase. The parameter r2 measures how fast the diagnosis rate increases (i.e. the duration of diagnosis decreases) as more medical equipments or resources become available. The final diagnosis rate If is usually larger than I0. However, if the medical resource is inadequate, the diagnosis rate I(t) can decrease and the final diagnosis rate If can be less than I0.

According to the basic reproductive number R0, time-varying contact rate Eq. (2) and diagnosis rate Eq. (3), the effective reproductive number Rc(t) of time-dependent model is given by the following formula:

$$R_{c}(t)=frac{betarho c(t)(1-q)}{delta_{I}(t)+alpha+gamma_{I}}+frac{beta(1-rho) ctheta(1-q)}{gamma_{A}}. $$

Although the governments mandatory intervention plays a major role in epidemic control, peoples behavior changes such as keeping social distancing, wearing facial masks and washing hands due to media and expert suggestions cannot be ignored. Hence, the piecewise function similar to the previous contact rate and diagnosis rate is applied to the transmission rate . Considering that the impact of behavior change on the spread of the disease is not as great as the government mandatory intervention, the exponential change form is not used. If the number of reported confirmed cases increases, the public will enhance self-protection measures. Thus, we assume that the transmission rate is inversely proportional to reported confirmed cases H(t). The time-dependent transmission rate (t) takes the following form:

$$ beta(t)=left{begin{array}{l} beta_{0}, if frac{1}{klog(H(t))}>1,\ beta_{0}frac{1}{klog(H(t))} \ end{array}right. $$

(4)

where k represents the indicator measures strength of peoples awareness of self-prevention. The larger the value of k, the smaller the transmission rate.

According to the total population of Italy and the epidemic situation on February 20, 2020, we set initial values to be S(0)=60 480 000, H(0)=3 and R(0)=0. According to the WHO [33], the incubation period of COVID-19 is about 7 days. Thus, =1/7. The quarantined individuals were quarantined for 14 days, thus =1/14. We obtain other unknown parameter values by fitting data on reported number of cumulative confirmed cases, death cases and recovery cases from February 20 to March 10 in Italy. We utilized the nonlinear least-square (NLES) method in Matlab to fit model solution to the real data sets, as shown in Fig.2. The estimated parameter values are listed in Table1.

Fitting of the autonomous model to the data of COVID-19 in Italy from February 20 to March 10. (a) shows the number of cumulative confirmed cases, (b) shows the number of death cases, and (c) shows the number of recovered cases

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The effect of control measures on COVID-19 transmission in Italy: Comparison with Guangdong province in China - Infectious Diseases of Poverty -...

Sep 14th 2020

OF EARTHS TWO planetary neighbours, Mars and Venus, it is Venus which shines brighter in the sky, comes closer in space, and is more similar in size and physical structurealmost Earths twin. But over the past 60 years it has been to Mars that science has paid the most attention. There are currently six operational spacecraft in orbit around it and two more on its surface; more are on their way. Venus is observed by a single small satellite. Yet following a new discovery made with telescopes on Earth, it is Venus which arguably now looks more likely to harbour the thing that planetary science cares most about: life.

The telescopesthe James Clerk Maxwell Telescope (JCMT) in Hawaii and ALMA in Chilework not in visible light, but with sub-millimetre- and millimetre-wave radiation, which lies in between infrared light and radio waves. The hot depths of Venuss atmosphere give off a fair bit of radiation at these wavelengths. The molecules in the cooler air above them absorb some of it as it passes out into space; the specific wavelengths absorbed depend on the molecules doing the absorbing. As a team of scientists from various institutions has now reported in Nature Astronomy, one of the chemicals thus revealed appears to be PH3, or phosphine, a molecule composed of phosphorous and hydrogen.

This is a striking anomaly. In an atmosphere composed mostly of carbon dioxide, like Venuss, phosphine should be able to survive only briefly before chemistry destroys it. So for it to be present persistentlythe observers reckon it makes up perhaps 20 parts per billion of the atmospheresomething must be producing it at the same rate as atmospheric chemistry gets rid of it. But what?

On Earth, where there are on average a few parts per trillion of phosphine in the atmosphere, its presence seems to be almost entirely because of chemists (among other things, it is a potentially deadly by-product of badly run meth labs) and microbes. That means it has strong potential as what astrobiologists, who look for life and the things that make it possible in extraterrestrial contexts, call a biomarker.

This would be tantalising enough in itself. What makes it yet more fascinating is that for decades a small band of scientists has been suggesting that Venus might be able to support microbial life. The discovery in the 1960s that the surface of Venus was far hotter than the ovens used to sterilise surgical instruments seemed to rule out any chance of life there; the challenge which the extreme conditions pose both to life and to human technology did a lot to swing attention out towards Mars. But a few scientists wondered if there might be life above the searing surface. The water droplets in Earths clouds contain living bacteria; though Venuss clouds are incredibly acidic, might they too be inhabited by some sort of super-hardy bug? The detection of phosphine is thus a potential sign of life in a place people have previously imagined as habitable.

From the farthest planets to the nearestThe idea of detecting life through an otherwise inexplicable anomaly in a planets spectrum dates back to the 1960s, when it was given voice by James Lovelock, a British chemist and inventor. It came into its own when astronomers started discovering planets around other stars, or exoplanets. Most of these planets are in inhospitably unearthlike orbits, but some sit within what astronomers call the habitable zonethe zone in which, under various conditions, the surface might support liquid water. Astrobiologists like Sara Seager of MIT started putting real effort into working out what anomalous gases might be visible once they got telescopes good enough to analyse the spectra of such planets atmospheres.

A few years ago some of the scientists who work with Dr Seager and in her team started to get interested in phosphine. Though it is not clear how microbes make it, or something which decomposes into it, its association with life is pretty clear (among other things, penguin guano seems rich in the stuff). There seem to be no appreciable mechanisms for making it abiotically either in the depths of the Earth or through the photochemical reactions driven by sunlight which create other short-lived gases in the atmosphere. And it has some nice distinct spectral lines which should be eventually observable in the infrared light from some sorts of exoplanet.

In 2017 Jane Greaves of the University of Cardiff, thinking along similar lines, decided to see if the JCMT could be used to detect longer-wavelength phosphine lines (which are less affected by Earths atmosphere) in the atmosphere of Venusnot an exoplanet, but much easier to study. She and her colleagues saw something in the appropriate part of the spectrum; but the signal was weak. Dr Greaves decided to pursue the idea further using ALMA, an array of 66 antennae in the Atacama Desert which is much more powerful than the JCMT. Those observations, made last year, provided a significantly better signal-to-noise ratio.

After the first observations, Dr Greaves team and Dr Seagers heard about each other and pooled their resources. Dr Seagers team has worked out that any microbial metabolism producing phosphine would probably work best in a very acidic environmentrather like that of Venus, where much of the cloud deck is almost pure sulphuric acid. In the early 2000s some scientists suggested that curious features in the way that the clouds absorb ultraviolet light might be down to microbes making some sort of pigment or other compound to protect themselves from itperhaps pure sulphur, which could be made through photosynthesis. Dr Seager, Dr Greaves and some of their colleagues developed a new model for how such life might function, with cells reproducing in the cloud droplets and turning into desiccated spores as the droplets fall towards the surface; rising winds then bring some of these spores back up to the clouds, where they get absorbed intoor possibly catalyse the creation ofnew droplets in which to reproduce once again. This hypothesis is being published in the journal Astrobiology.

This speculation is fascinating, but also of a sort which might raise alarm bells. The team did not look at the whole spectrum dispassionately to see what was there; it specifically sought out a feature that could be explained by phosphine, a molecule in which at least some of the scientists were already invested, and found what they were looking for. What is more, as they say in their paper, we emphasise that the detection of PH3 is not robust evidence for life, only for anomalous and unexplained chemistry. Two things need to happen before things get truly exciting. Other teams need to make their own observations, ideally at other wavelengths. And a really thorough search for ways of making phosphine without biology under the conditions seen on and above Venus needs to draw a blank.

Mars retreatsOn the first of these two requirements, the history of methane on Mars provides a cautionary tale. In 2004 scientists using three Earth-based telescopes and a spacecraft orbiting Mars all thought they had detected what appeared to be the spectral signature of methane in the planets atmosphere. It was a classic Lovelock anomaly. Chemical models insist that methane does not last all that long in the Martian atmosphere, so these observations suggested there had to be a continuous source of the gas. And on Earth most, though not all, methane is produced by microbes. What was more, there was an increasingly widespread belief that, although there is now only a smidgen of water on the surface of Mars, there might be plenty more below it, perhaps in deep aquifers. On the Earth microbesincluding microbes that produce methaneare found many kilometres below the surface. Maybe Mars had a similar deep biosphere?

Maybe. But if so, there is currently no persuasive evidence that it is producing methane. In 2018 the European Space Agencys ExoMars Orbiter started to look at trace gases in Marss atmosphere with much more sensitive instruments than had been used before. It has seen no evidence of methane at anything like the level previously claimed, which makes it hard to credit the earlier observations. It is true that NASAs Curiosity rover has detected methane more recently; but with ExoMars coming up empty, those detections are hard to take at face value.

This tale of woe makes it very clear that looking through the Earths thick atmosphere for signs of a tiny amount of gas in the atmosphere of another planet is an exacting and error-prone undertaking. Hence the need for observations of phosphine over Venus from other groups using other instruments. At the same time, though, the chain of reasoning which made a deep Martian biosphere plausible applies to theories about life above Venus, too.

Mars appears always to have been a pretty cold, dry place. But in the distant past, when it had a thicker atmosphere, it clearly had running and standing water at its surface, at least sporadically; Curiosity is currently studying mudstones laid down in an ancient lake. As Mars lost its atmosphere its surface became ever more arid and frigid. That put evolutionary pressure on any microbes previously living in those surface waters to migrate deeper and deeper into the still warm and moist subsurface.

The surface of Venus, too, has dried out over its history: but through heating, not cooling. For billions of years the Sun has been growing brighter, thus changing the boundaries of its habitable zone. In the case of Mars, this warming was not enough to offset the cooling effect of losing most of the atmosphere. On Venus, though, it prompted what atmospheric scientists call a runaway greenhouse effect, boiling away the seas which many scientists believe to have graced the planets youth. If there had been microbes in the surface waters of Venus before this catastrophe, evolution would have urged them not into the depths, as it did on Mars, but into the skies, where even today the temperature remains bearable and water remains liquid, though admittedly in droplets not oceans.

This idea has been much further from the mainstream than that of subsurface life on Mars. One reason may be that, though the existence of Earths deep biosphere is quite widely appreciated, beyond some recherch microbiological circles the fact that there are also bacteria busily metabolising up in the sky is widely ignored. And to be fair, the high-biosphere analogy is not perfect. Though bacteria live in Earths cloud droplets there is as yet no evidence that they reproduce there. That may be because actually proving that it is happening is technically very difficult, but it may also be because the aerial microbes have no particular need to do so; the Earths surface, and the creatures that roam across it, provide bacteria with all the locales for reproduction they could possibly require.

The idea of Venuss atmosphere as a refuge is a beguiling story of life finding a way. But it remains very speculative. If the phosphine is indeed present as described, there needs to be a strenuous effort to find, or rule out, non-biological sources. The team behind the detection has done some of this; it argues convincingly that the phosphine cannot come up from volcanoes, drift down from comets, or be made in mid-air through photochemistry. But the chemistry that happens on surfaces can be very different to what happens in mid air, and Venuss atmosphere, as well as offering extremes of temperature, pressure and acidity, has surfaces to spare, both in its cloud decks and in the hazes that float above and below them. Imaginative chemists should have a field day working through ever more abstruse possibilitiesand may make some very interesting discoveries of their own on the way.

Then there is the possibility of going to take a closer look. NASA has not launched a mission to Venus since the 1980s, though some of its spacecraft have swung past it on their way elsewhere. But two Venus missions have reached the final stage of the selection process for the next round of its Discovery program of small planetary missions. One, VERITAS, is an orbiter mainly intended to map the surface in more detail; the other, DAVINCI+, features a small chemistry lab that would descend through the atmosphere beneath a parachute. If it can be made capable of detecting phosphine at a few parts per billion, the case for sending it would become even stronger than it already is. The next mission to Venus, though, is not American but Indian: the Shukrayaan-1 orbiter is currently pencilled in for launch in 2023, which should be enough time to put on a phosphine-optimised instrument.

If you can make it here...Carl Sagan, who wrote a rather remarkable article about the possibility of balloon-like creatures in the clouds of Venus in the 1960s, is well remembered in astrobiological circles for the dictum that extraordinary claims require extraordinary evidence. Planetary observations are full of anomalies: you cannot invoke extraterrestrials willy nilly to explain them, creating what the astrobiologist David Grinspoon calls aliens of the gaps.

No one is yet claiming that there is life on Venus, and so the current evidence can get by simply by being intriguing, which it definitely is. But if it does turn out that the phosphine is biological, the first half of Sagans dictum will need re-examining, at least as far as the hunt for life is concerned.

Not that long ago scientists had pretty much given up on finding life anywhere in the solar system beyond Earth. Now astrobiologists are investigating the possibility of life on, in or above Saturns moon Titan, or in the ice covered ocean of one of the planets other moons, Enceladus. Jupiters moon Europa is also a possibility, as are various other bodies which may contain subsurface oceans. And there is always Mars.

If science finds life on or in any of those bodies, the idea that its presence is in itself extraordinary will take a knock. If they find it over hellish Venus as well, or instead, life will come to look yet less like an odd exception. Indeed, at the microbial level at least, life may turn out to be quite ordinary.

But that will make it no less wonderful. In some ways, it may make it more so.

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Scientists find possible signs of life in the clouds of Venus - The Economist