# What more could be learned from a rare astronomical event if we knew precisely when it would occur?

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This is actually related to a question I recently asked on Worldbuilding, but seemed more appropriately asked here.

To keep this from being too broad in scope, let's assume that someone figured out the exact moment that Eta Carinae will go supernova (I wouldn't hold it against anyone if they suggested a more scientifically interesting event).

Due to this foreknowledge, we could point every telescope we have in its direction for the main event. Is there any science we know we could do/learn from this event that we wouldn't get by reacting to it after the fact? I know such an event would generate data for a century or more to come, but I'm interest in the moment of the explosion.

Somewhat related, is there anything we would/could do now to prepare for it if this event were going to happen today?

I would argue that simply knowing that a star was about to undergo a supernova could be information enough.

It's not always easy to figure out what type of star a given supernova progenitor was. Sometimes, there were no observations of the relevant region of sky prior to the supernova, and so we can't simply look back at prior observations and extrapolate from that. We can definitely look at certain spectral lines and other information from the remnant, but it's rarely as sure as actually observing the progenitor.

There are some classes of stars which have yet to be conclusively identified as supernova progenitors, though there may be evidence suggesting that they should evolve as such. Red supergiants are one group, leading to the so-called "red supergiant problem" (see Smartt et al. (2009) and this question). If we knew that a red supergiant was a supernova progenitor, that would possibly solve the problem.

Wolf-Rayet stars, thought to produce Type Ib/c supernovae, are another group (see Yoon et al. (2012). Evolutionary models and indirect observational evidence predict that they should lead to these supernovae, but no observations of Wolf-Rayet supernova progenitors have been observed.

Eta Carinae A - which I assume is the star you're referring to - appears to be a luminous blue variable (LBV). We do know that LBVs lead to supernovae (see for instance the case of SN 2006jc, which underwent a major outburst two days prior). However, it can be harder to distinguish between supernovae and certain supernova imposter events, caused by LBVs. I'd speculate that we could try to observe Eta Carinae A in the period leading up to the supernovae, to try to observe the differences between outbursts and the actual supernova, which could give us better information on the nature of the evolution of these stars. Additionally, there is neutrino emission in the periods leading up to supernovae (see this question); perhaps detectors on Earth could monitor the progenitor and see if they can find anything.

We could also, given enough warning time, attempt to study the progenitor in the final phases of stellar evolution. This page gives a table for the time periods of various fusion phases in the life of a $25M_odot$ star: $$egin{array}{|c|c|} hline ext{Fusion phase}& ext{Length of phase} hline ext{Hydrogen} & ext{7 million years} hline ext{Helium} & ext{500,000 years} hline ext{Carbon} & ext{600 years} hline ext{Neon} & ext{1 year} hline ext{Oxygen} & ext{6 months} hline ext{Silicon} & ext{1 day} hline end{array}$$ This would let us figure out where the star is in its life and figure out what effects different fusion pathways could be having, if any.

Finally, I'm assuming that your question means that we know when the light from the supernova reaches Earth, and that this would happen in the near future.

## CHIME Detected Over 500 Fast Radio Burst in its First Year, Providing new Clues to What’s Causing Them

Much like Dark Matter and Dark Energy, Fast Radio Burst (FRBs) are one of those crazy cosmic phenomena that continue to mystify astronomers. These incredibly bright flashes register only in the radio band of the electromagnetic spectrum, occur suddenly, and last only a few milliseconds before vanishing without a trace. As a result, observing them with a radio telescope is rather challenging and requires extremely precise timing.

Hence why the Dominion Radio Astrophysical Observatory (DRAO) in British Columbia launched the Canadian Hydrogen Intensity Mapping Experiment (CHIME) in 2017. Along with their partners at the National Radio Astronomy Observatory (NRAO), the Massachusetts Institute of Technology (MIT), the Perimeter Institute, and multiple universities, CHIME detected more than 500 FRBs in its first year of operation (and more than 1000 since it commenced operations)!

To recap, astronomers have only been studying FRBs since 2007 when the first event was reported. Prior to mid-2017 when CHIME became operational, only about two dozen had ever been observed and their origin remains unknown. However, it has since been learned that as cosmological phenomena go, they are ubiquitous, with thousands of events arriving at Earth every day from every corner of the sky.

## Sepsis and COVID-19: Perspectives From a Sepsis Coordinator

Coronavirus disease 2019 (COVID-19) has brought difficulties and disruptions to all corners of the world. As a sepsis coordinator, I can attest that the scientific and healthcare community in the United States has been particularly turned upside down by the novel virus, as our daily tasks and responsibilities have been shifted to respond to the threats accompanied by this virus.

Over the past few months, healthcare workers have been challenged to quickly make assessments and adjust best practices as a result of the COVID-19 pandemic. Early on in the pandemic, many people believed that this novel virus led to a &ldquoflu-like&rdquo illness. However, we quickly learned from colleagues in Washington and California that this was definitely not like the flu.

### COVID-19 not &ldquojust like the flu&hellip&rdquo

During the 2018-2019 influenza season there were approximately 34,000 flu-related deaths recorded in the United States. 1 It is not uncommon for patients to develop pneumonia and subsequent sepsis, during flu season. However, unlike COVID-19, most healthcare workers are familiar with recognizing and treating influenza.There are fairly accurate tests, vaccines and antivirals, and we have established supportive care such as antipyretics and intravenous fluid. Additionally, we have a good idea of which individuals could be affected adversely by the flu and can be on the guard to quickly identify flu and sepsis. Although nothing is 100%, we have tools in our arsenal to treat and identify flu quickly and save a large number of people from developing the sequelae of pneumonia and sepsis. We are ready when the largest wave of flu begins in mid fall and are always anticipating the end of the season in spring.

COVID-19 has completely disrupted what we have come to expect from flu season and what we plan for each year. COVID-19 went from being thought of as a &ldquoflu-like illness&rdquo to overwhelming hospital systems, seemingly overnight. While experts had warned that a pandemic was imminent, the United States and the rest of the world were caught flat footed by the virus. Some intensive care units were overwhelmed by patients who quickly went from being moderately ill to critically ill and requiring ventilator support for long periods of time. As a result, patients overflowed into other areas of the hospital, such as post-anesthesia care units and operating rooms, which were turned into makeshift into COVID wards. Nursing staff were redeployed to other areas where nursing care was needed. Clinicians across the United States became very concerned with having enough medications to manage sedation for patients requiring prolonged intubations. &ldquoBurn rate&rdquo became a buzz word in trying to anticipate how to manage an existing personal protective equipment (PPE) supply and make it last. We were also challenged to evaluate how we used and could reuse PPE to keep healthcare workers safe during challenging times.

### Unexpected challenges of COVID-19

It has been hard to predict who will be impacted by COVID-19 and how severely they could be affected. At times, COVID 19 respiratory presentation did not respond using conventional treatments typically used with COPD exacerbations or pneumonia such as steroids or nebulizer treatments.

From a sepsis coordinator&rsquos perspective, the golden hour for rapid antibiotic administration ticked by as we waited for CT scan results which might then reveal multifocal pneumonias and ground glass opacities. We needed to have a high index of suspicion looking for patients we knew could be at risk for COVID-19. Our patients with poorly managed diabetes also became quickly overwhelmed and in need of lifesaving care. Were fluids for patients with suspected COVID-19 infection the best thing to use for septic shock? We needed to carefully consider fluids and document good medical decision making.

Testing for COVID-19 has been problematic. In the first weeks of the pandemic, testing in the United States was not readily available nor was it quick. As a result, we had to treat presumptive COVID-19 cases. As the weeks have passed, testing is now more widely available and results have been returned faster. There is still concern in the validity of the testing. These concerns include what type of sample is collected and by whom, how it is transported, and how it may be affected by things like chlorhexidine gluconate (CHG) baths. Many patients that have had negative test results have later turned up as positive. It has been virtually impossible to predict who will develop symptoms and how severely.

### Deploying best practices in real time

So what have we in healthcare done? We have undertaken what healthcare professionals have set out to do from the beginning. We collaborated and we shared best practices as we learned them. Social media and networking helped clinicians share information from around the globe in real time. Organizations such as the Sepsis Alliance quickly distributed widespread education to sepsis coordinators around the country.

Was proning more effective than intubation? Were ferritin levels a better prognosis of outcome? New information and manifestations of COVID-19 have been rapidly shared. I saw &ldquoCOVID toes&rdquo in a child before anyone was talking about them because a colleague had shared skin manifestation photos with me. His parent had a difficult time finding someone who was familiar with this and able to diagnose him. He was not sick, and a telehealth visit aided in his diagnosis. No one else in this family was ever ill.

### Expanding and adapting sepsis surveillance

Sepsis accounts for a large number of hospitalizations and readmissions. However, COVID-19 has in fact added to the volume of patients we track for sepsis. An unmeasured, though unintended consequence of the pandemic is the number of individuals who may have delayed medical care out of fear of acquiring COVID-19. Anecdotally, we have seen patients that are very sick on arrival, even with ruptured appendixes. In some cases, patients have waited to call 911 until they could no longer breath on their own. The collateral damage will not be known for some time however, we can see anecdotally the impact COVID-19 has had. We do know that the Campaign for Surviving Sepsis Guidelines has positively influenced the care of these patients with COVID-19, and has led to quick identification and treatment

As the weeks have gone by during this pandemic, we have learned to adapt. We trust we have the PPE we need. We have watched entire communities come together with donated N95 respirators and cloth masks, along with hot meals and nightly cheering for healthcare workers. It seems like everyone is breathing a bit easier now as the United States has passed the peak strain of resources on our healthcare systems. Along the way, we have learned how to care for these patients while caring for ourselves and each other.

### Looking toward the future

One of the toughest parts of dealing with this health crisis has been watching friends and colleagues that are healthcare providers become ill. According to May 2020 statistics, approximately 90,000 healthcare workers worldwide had been diagnosed with COVID-19. 2 We are holding our breath for the &ldquonext wave&rdquo but I think we are better equipped to handle the illness and the emotional aspects of it. Additionally, many providers have developed elaborate disinfecting plans to keep their families safe.

As a sepsis coordinator, I am grateful for the sepsis community and its resources. I appreciate the virtual community and social media platforms that have empowered us all with knowledge and helped us do what we do best as coordinators which is to educate and advocate. It is critical, now more than ever that we spread facts and not fear. I look forward to all the lessons learned as we decompress from this crisis. In the event that a second wave does occur, we will be better equipped to save lives.

1. Centers for Disease C, Prevention. Estimated Influenza Illnesses, Medical visits, Hospitalizations, and Deaths in the United States &mdash 2018&ndash2019 influenza season https://www.cdc.gov/flu/about/burden/2018-2019.html#:

Access related articles, videos, webinars at PRECISELY, by GE Healthcare and Roche.

## BigBird a blazar?

The IceCube facility relies on an array of photodetectors suspended in the ice below the South Pole. The hardware is able to track incoming particles as they bump into the atoms of the ice, producing light in the process. Among these particles are neutrinos from a variety of sources, but of particular interest are the extremely high-energy ones.

What's extreme in this context? The Large Hadron Collider, our highest energy hardware, can accelerate protons to energies of a handful of Tera-electronVolts. Some of the neutrinos IceCube spotted were in the neighborhood of two Peta-electronVolts, three orders of magnitude higher. It's fair to wonder what could possibly give these lightweight, uncharged particles those sorts of energies.

One model for their production involves the jets produced by active supermassive black holes. Within these jets, protons and other charged particles get accelerated to high energies and are able to interact with high-energy photons in the environment. These interactions can produce pions, an unstable particle that decays in a process that produces a neutrino. The neutrino then inherits some of the energy of its parent pion and continues traveling in the same direction.

For the neutrino to reach Earth, the jets from the black hole must be pointing at us. We've already identified galaxies where this is the case they're called blazars, due to the incredible amount of energies the jets send in our direction. There's a large catalog of blazars that we've identified through various astronomical surveys.

Naturally, when IceCube identified its first Peta-electronVolt neutrinos (nicknamed Ernie, Bert, and BigBird), researchers started searching the blazar catalog for potential sources in the direction that the neutrino came from. Unfortunately, these searches came up blank.

But now, a large international team has found a possible candidate as the source of BigBird, a blazar known as PKS B1424–418. This blazar was included in the original analysis of PeV neutrinos but wasn't considered a good candidate, as it was relatively quiet at the time. But black hole jets are one of the rare astronomical phenomena that can change suddenly, within the span of a few years. And the team found that PKS B1424–418 had ramped up its activity at about the time BigBird was detected—an event they call a "blazar outburst."

The identity of the sources for Ernie and Bert are a mystery. But, as IceCube continues to gather data, the chances of identifying the sources should go up. And the same is true for the ongoing work with LIGO, where another four potential gravitational wave detections are still being analyzed.

The arXiv. Abstract number: 1602.03920 (About the arXiv). Under review at The Astrophysical Journal.

## What the Muon g-2 results mean for how we understand the universe

Peering down a row of magnets leading to the particle storage ring at Fermilab's Muon g-2 experiment. The results have theoretical physicists around the world frantically working through ideas for explanations. Credit: Cindy Arnold/Fermilab

The news that muons have a little extra wiggle in their step sent word buzzing around the world this spring.

The Muon g-2 experiment hosted at Fermi National Accelerator Laboratory announced April 7 that they had measured a particle called a muon behaving slightly differently than predicted in their giant accelerator. It was the first unexpected news in particle physics in years.

Everyone's excited, but few more so than the scientists whose job it is to spitball theories about how the universe is put together. For these theorists, the announcement has them dusting off old theories and speculating on new ones.

"To a lot of us, it looks like and smells like new physics," said Prof. Dan Hooper. "It may be that one day we look back at this and this result is seen as a herald."

Gordan Krnjaic, a fellow theoretical physicist, agreed: "It's a great time to be a speculator."

The two scientists are affiliated with the University of Chicago and Fermilab neither worked directly on the Muon g-2 experiment, but both were elated by the results. To them, these findings could be a clue that points the way to unraveling the last mysteries of particle physics—and with it, our understanding of the universe as a whole.

The problem was that everything was going as expected.

Based on century-old experiments and theories going back to the days of Albert Einstein's early research, scientists have sketched out a theory of how the universe—from its smallest particles to its largest forces—is put together. This explanation, called the Standard Model, does a pretty good job of connecting the dots. But there are a few holes—things we've seen in the universe that aren't accounted for in the model, like dark matter.

No problem, scientists thought. They built bigger experiments, like the Large Hadron Collider in Europe, to investigate the most fundamental properties of particles, sure that this would yield clues. But even as they looked more deeply, nothing they found seemed out of step with the Standard Model. Without new avenues to investigate, scientists had no idea where and how to look for explanations for the discrepancies like dark matter.

The Muon g-2 ring sits in its detector hall amidst electronics racks, the muon beamline, and other equipment. This impressive experiment operates at negative 450 degrees Fahrenheit and studies the precession, or "wobble," of particles called muons as they travel through the magnetic field. Credit: Reidar Hahn/Fermilab

Then, finally, the Muon g-2 experiment results came in from Fermilab (which is affiliated with the University of Chicago). The experiment reported a tiny difference between how muons should behave according to the Standard Model, and what they were actually doing inside the giant accelerator.

Murmurs broke out around the world, and the minds of Hooper, Krnjaic and their colleagues in theoretical physics began to race. Almost any explanation for a new wrinkle in particle physics would have profound implications for the history of the universe.

That's because the tiniest particles affect the largest forces in the universe. The minute differences in the masses of each particle affect the way that the universe expanded and evolved after the Big Bang. In turn, that affects everything from how galaxies are held together down to the nature of matter itself. That's why scientists want to precisely measure how the butterfly flapped its wings.

So far, there are three main possible explanations for the Muon g-2 results—if it is indeed new physics and not an error.

One is a theory known as "supersymmetry," which was very fashionable in the early 2000s, Hooper said. Supersymmetry suggests that that each subatomic particle has a partner particle. It's attractive to physicists because it's an overarching theory that explains several discrepancies, including dark matter but the Large Hadron Collider hasn't seen any evidence for these extra particles. Yet.

Another possibility is that some undiscovered, relatively heavy form of matter interacts strongly with muons.

Finally, there could also exist some other kinds of exotic light particles, as yet undiscovered, that interact weakly with muons and cause the wobble. Krnjaic and Hooper wrote a paper laying out what such a light particle, which they called "Z prime," could mean for the universe.

"These particles would have to have existed since the Big Bang, and that would mean other implications—for example, they could have an impact on how fast the universe was expanding in its first few moments," Krnjaic said.

That could dovetail with another mystery that scientists are pondering, called the Hubble constant. That number is supposed to indicate how fast the universe is expanding, but it varies slightly according to which way you measure it—a discrepancy which could indicate a missing piece in our knowledge.

There are other, further-out possibilities, such as that the muons are being bumped by particles winking in and out of existence from other dimensions. ("One thing particle physicists are rarely accused of is a lack of creativity," said Hooper.)

But the scientists said it's important not to dismiss theories out of hand, no matter how wild they may sound.

"We don't want to overlook something just because it sounded weird," said Hooper. "We're constantly trying to shake the trees to get every idea we can out there. We want to hunt this down everywhere it could be hiding."

The first step, however, is to confirm that the Muon g-2 result holds true. Scientists have a system to tell whether the results of an experiment are real and not just a blip in the data. The result announced in April reached 4.2 sigma the benchmark that means it's almost certainly true is 5 sigma.

"If it's really new physics, we'll be much closer to knowing in a year or two," said Hooper. The Muon g-2 experiment has much more data to sift through. Meanwhile, the results of some very complicated theoretical calculations—so complex that even the most powerful supercomputers in the world need to chew on them for months to years—should be coming down the pike.

Those results, if they get to a 5 sigma confidence level, will point scientists where to go next. For example, Krnjaic helped propose a Fermilab program called M3 that could narrow the possibilities by firing a beam of muons at a metal target—measuring the energy before and after the muons hit. Those results could indicate the presence of a new particle.

Meanwhile, at the French-Swiss border, the Large Hadron Collider is scheduled to upgrade to a higher luminosity that will produce more collisions. New evidence for particles or other phenomena could pop up in their data.

All this excitement over a wobble might seem like an overreaction. But tiny discrepancies can, and have, led to massive shakeups. Back in the 1850s, astronomers making measurements of Mercury's orbit noticed it was off a little from what Newton's theory of gravity would predict. "That anomaly, along with other evidence, eventually led us to the theory of general relativity," said Hooper.

"No one knew what it was about, but it got people thinking and experimenting. My hope is that one day we'll look back at this muon result the same way."

## Contents

Stonehenge has an opening in the henge earthwork facing northeast, and suggestions that particular significance was placed by its builders on the solstice and equinox points have followed. For example, the summer solstice Sun rose close to the Heel Stone, and the Sun's first rays shone into the centre of the monument between the horseshoe arrangement. While it is possible that such an alignment could be coincidental, this astronomical orientation had been acknowledged since William Stukeley drew the site and first identified its axis along the midsummer sunrise in 1720. [1]

Stukeley noticed that the Heel Stone was not precisely aligned on the sunrise. The drifting of the position of the sunrise due to the change in the obliquity of the ecliptic since the monument's erection does not account for this imprecision. Recently, evidence has been found for a neighbour to the Heel Stone, no longer extant. The second stone may have instead been one side of a ‘solar corridor’ used to frame the sunrise. [2] [3]

Stukeley and the renowned astronomer Edmund Halley attempted what amounted to the first scientific attempt to date a prehistoric monument. Stukeley concluded the Stonehenge had been set up “by the use of a magnetic compass to lay out the works, the needle varying so much, at that time, from true north.” He attempted to calculate the change in magnetic variation between the observed and theoretical (ideal) Stonehenge sunrise, which he imagined would relate to the date of construction. Their calculations returned three dates, the earliest of which, 460 BC, was accepted by Stukeley. That was incorrect, but this early exercise in dating is a landmark in field archaeology. [4]

Early efforts to date Stonehenge exploited changes in astronomical declinations and led to efforts such as H. Broome’s 1864 theory that the monument was built in 977 BC, when the star Sirius would have risen over Stonehenge's Avenue. Sir Norman Lockyer proposed a date of 1680 BC based entirely on an incorrect sunrise azimuth for the Avenue, aligning it on a nearby Ordnance Survey trig point, a modern feature. Petrie preferred a later date of 730 AD. The relevant stones were leaning considerably during his survey, and it was not considered accurate.

An archaeoastronomy debate was triggered by the 1963 publication of Stonehenge Decoded, by Gerald Hawkins an American astronomer. Hawkins claimed to observe numerous alignments, both lunar and solar. He argued that Stonehenge could have been used to predict eclipses. Hawkins’ book received wide publicity, in part because he used a computer in his calculations, then a novelty. Archaeologists were suspicious in the face of further contributions to the debate coming from British astronomer C. A. ‘Steve’ Newham and Sir Fred Hoyle, the famous Cambridge cosmologist, as well as by Alexander Thom, a retired professor of engineering, who had been studying stone circles for more than 20 years. Their theories have faced criticism in recent decades from Richard J. C. Atkinson and others who have suggested impracticalities in the ‘Stone Age calculator’ interpretation.

Gerald Hawkins’ work on Stonehenge was first published in Nature in 1963 following analyses he had carried out using the Harvard-Smithsonian IBM computer. Hawkins found not one or two alignments but dozens. He had studied 165 significant features at the monument and used the computer to check every alignment between them against every rising and setting point for the Sun, Moon, planets, and bright stars in the positions they would have been in 1500 BCE. Thirteen solar and eleven lunar correlations were very precise in relation to the early features at the site but precision was less for later features of the monument. Hawkins also proposed a method for using the Aubrey holes to predict lunar eclipses by moving markers from hole to hole. In 1965 Hawkins and J.B. White wrote Stonehenge Decoded, which detailed his findings and proposed that the monument was a ‘Neolithic computer’.

Atkinson replied with his article “Moonshine on Stonehenge” in Antiquity in 1966, pointing out that some of the pits which Hawkins had used for his sight lines were more likely to have been natural depressions, and that he had allowed a margin of error of up to 2 degrees in his alignments. Atkinson found that the probability of so many alignments being visible from 165 points to be close to 0.5 (or rather 50:50) rather that the “one in a million” possibility which Hawkins had claimed. That the Station Stones stood on top of the earlier Aubrey Holes meant that many of Hawkins’ alignments between the two features were illusory. The same article by Atkinson contains further criticisms of the interpretation of Aubrey Holes as astronomical markers, and of Fred Hoyle's work.

A question exists over whether the English climate would have permitted accurate observation of astronomical events. Modern researchers were looking for alignments with phenomena they already knew existed the prehistoric users of the site did not have this advantage.

In 1966, C. A. ‘Steve' Newham described an alignment for the equinoxes by drawing a line between one of the Station Stones with a posthole next to the Heel Stone. He also identified a lunar alignment the long sides of the rectangle created by the four station stones matched the Moon rise and moonset at the major standstill. Newham also suggested that the postholes near the entrance were used for observing the saros cycle. [5]

Two of the Station Stones are damaged and although their positions would create an approximate rectangle, their date and thus their relationship with the other features at the site is uncertain. Stonehenge's latitude ( 51° 10′ 44″ N ) is unusual in that only at this approximate latitude (within about 50 km) do the lunar and solar alignments mentioned above occur at right angles to one another. More than 50 km north or south of the latitude of Stonehenge, the station stones could not be set out as a rectangle.

Alexander Thom had been examining stone circles since the 1950s in search of astronomical alignments and the megalithic yard. It was not until 1973 that he turned his attention to Stonehenge. Thom chose to ignore alignments between features within the monument, considering them to be too close together to be reliable. He looked for landscape features that could have marked lunar and solar events. However, one of Thom's key sites – Peter's Mound – turned out to be a twentieth-century rubbish dump.

Although Stonehenge has become an increasingly popular destination during the summer solstice, with 20,000 people visiting in 2005, scholars have developed growing evidence that indicates prehistoric people visited the site only during the winter solstice. The only megalithic monuments in the British Isles to contain a clear, compelling solar alignment are Newgrange and Maeshowe, which both famously face the winter solstice sunrise.

The most recent evidence supporting the theory of winter visits includes bones and teeth from pigs which were slaughtered at nearby Durrington Walls, their age at death indicating that they were slaughtered either in December or January every year. Mike Parker Pearson of the University of Sheffield has said, “We have no evidence that anyone was in the landscape in summer.” [6]

## Venus makes rare trek across Sun

The transit was a very rare astronomical event that would not be seen again for another 105 years.

Observers in north and central America, and the northern-most parts of South America saw the event start just before local sunset.

The far northwest of America, the Arctic, the western Pacific, and east Asia witnessed the entire passage.

While the UK and the rest of Europe, the Middle East, and eastern Africa waited for local sunrise to try to see the closing stages of the transit.

Venus appeared as a small black dot moving slowly but surely across the solar disc. The traverse lasted more than six and a half hours.

Some of the best pictures of the event were provided by the US space agency's (Nasa) Solar Dynamics Observatory , which studies the Sun from a position 36,000km above the Earth.

"We get to see Venus in exquisite detail because of SDO's spatial resolution," said agency astrophysicist Dr Lika Guhathakurta.

"SDO is a very special observatory. It takes images that are about 10 times better than a high-definition TV and those images are acquired at a temporal cadence of one every 10 seconds. This is something we've never had before."

Many citizens keen to observe the transit first hand attended special events at universities and observatories where equipment for safe viewing had been set up.

In Hawaii, one of the best places to see the whole event, the university's Institute of Astronomy set up telescope stations on Waikiki beach.

"We've had 10 telescopes and the queues have been 10 deep to each telescope all day long," said the institute's Dr Roy Gal.

"It's a great opportunity to get people excited and teach them stuff. I was hoping for a big turn-out, and it's been fantastic," he told BBC News.

Joe Cali viewed the transit on the edge of the Outback in New South Wales, Australia, another ideal vantage point.

"It is exciting. It may look like just a black dot on the Sun but if you think about it, it's one of the few times you get to see a planet in motion," he said.

UK skywatchers had to deal with quite extensive cloud conditions across the country.

"We've had total cloud and rain," said Brian Sheen from the Roseland Observatory in Cornwall .

"But we've been improving our chances by connecting with the Shetland Islands and the people up there have done rather better than we have. We've been seeing the transit through [a feed] of one of their telescopes," he explained.

Scientists observed the transit to test ideas that will help them probe Earth-like planets elsewhere in the galaxy, and to learn more about Venus itself and its complex atmosphere.

Venus transits occur four times in approximately 243 years more precisely, they appear in pairs of events separated by about eight years and these pairs are separated by about 105 or 121 years.

The reason for the long intervals lies in the fact that the orbits of Venus and Earth do not lie in the same plane and a transit can only occur if both planets and the Sun are situated exactly on one line.

This has happened only seven times previously in the telescopic age: in 1631, 1639, 1761, 1769, 1874, 1882 and 2004.

The next pair will not now occur until 2117 and 2125.

The phenomenon has particular historical significance. The 17th- and 18th-Century transits were used by the astronomers of the day to work out fundamental facts about the Solar System.

Employing a method of triangulation (parallax), they were able to calculate the distance between the Earth and the Sun - the so-called astronomical unit (AU) - which we know today to be about 149.6 million km (or 93 million miles).

This allowed scientists to get their first real handle on the scale of things beyond Earth.

Modern instrumentation now gives us very precise numbers on planetary positions and masses, as well as the distance between the Earth and the Sun. But to the early astronomers, just getting good approximate values represented a huge challenge.

This is not to say the 2012 Venus transit was regarded as just a pretty show with no interest for scientists.

Planetary transits have key significance today because they represent one of the best methods for finding worlds orbiting distant stars.

Nasa's Kepler telescope , for example, is identifying thousands of candidates by looking for the tell-tale dips in light that accompany a planet moving in front of its host sun.

These planets are too far away to be visited by spacecraft in the foreseeable future, but scientists can learn something about them from the way the background star's light is affected as it passes through the planetary atmosphere.

And observing a transiting Venus, which has a known atmospheric composition, provides a kind of benchmark to support these far-flung investigations.

Researchers also took a close look at Venus itself during the transit, used the occasion to probe the middle layers of the planet's atmosphere - its mesosphere.

They were looking for a very thin arc of light, called the aureole , which can only be seen when Venus appears to just touch the edge of the Sun's disc at ingress and egress.

The brightness and thickness of the aureole depends on the density and temperature of the atmospheric layers above Venus's cloud tops.

Observations of the aureole were being combined with data from Europe's Venus Express spacecraft in orbit around the planet to provide information on high-altitude winds.

The Venusian atmosphere experiences super-rotation. That is - the whole atmosphere circles the planet in four Earth days, on a body that turns around just once in 243 Earth days.

## A Stroke of Astronomical Luck for Solar Science

NSF's Cerro Tololo Inter-American Observatory (CTIO) at sunset.

Sunspots visible on the surface on the Sun.

Solar Corona during an eclipse

Illustration of Moon's shadow on the Earth during an eclipse

On July 2, 2019 a total solar eclipse will pass over Chile and Argentina, and through a stroke of astronomical luck, the path of totality crosses directly over the National Science Foundation&rsquos (NSF) Cerro Tololo Inter-American Observatory located in the foothills of the Andes, 7,241 feet (2200 meters) above sea level in the Coquimbo Region of northern Chile. Five science teams chosen by NSF&rsquos National Solar Observatory will perform experiments at Cerro Tololo during the eclipse four of them will have their equipment trained on the Sun&rsquos elusive corona and one will study eclipse effects on the Earth itself.

The Sun&rsquos Corona

Throughout history, total solar eclipses have amazed humankind. Many cultures&rsquo eclipse myths and legends portray them as divine, fortuitous or even ominous events. Today we understand the science behind why total solar eclipses occur. But we can still learn a lot about the Sun during the brief minutes of totality, when the Sun is completely blocked by the Moon. For scientists, a total solar eclipse offers a rare opportunity to study a part of the Sun they don&rsquot normally see, its inner corona.

The corona is a region of magnetism and extraordinarily hot gasses that makes up the outermost part of the Sun&rsquos atmosphere. It has mysterious properties we have yet to understand, like why it is extremely hot, hotter than the surface of the Sun. It is especially difficult to study because it is less dense and millions of times dimmer than the visible disk of the Sun and thus hard to see in the sun&rsquos full glare. However, when the bright disk of the Sun is completely covered by the Moon, as in a total solar eclipse, we can see its corona shining.

Scientists study the corona because it is important for predicting space weather, a phenomena that can potentially damage our electrical grids, telecommunications and satellites. Space weather occurs when the Sun occasionally spews magnetic plumes called coronal mass ejections into space. If one of those plumes is aimed at Earth, we could experience electrical and telecommunication disruptions like the super solar storm of 1859 known as the Carrington event, that burned up telegraph wires around the world. Such magnetic storms carry a much greater risk today in our electronically connected and dependent world.

Each of the following five science teams are taking advantage of the 2 minutes and 6 seconds of totality on Cerro Tololo to increase our understanding of the Sun&rsquos mysteries and its impact on Earth.

Observations Over 20 Plus Years

An international team led by Jay Pasachoff (Williams College) will image the Sun&rsquos corona as a continuation of an experiment started in the 1990s. The experiment will measure the corona&rsquos current color, shape, and temperature.

Pasachoff explained why he has been doing this experiment for so many years, &ldquoThe Sun varies from day to day, and also over the 11-year solar cycle. Each glimpse we get of the Sun during a total solar eclipse&mdashonly a couple of minutes every 18 months or so&mdashgives us a different set of features to look at. One of our interests is understanding the eruptions on the Sun that could damage all the satellites now orbiting the Earth, so when we measure the speeds of the coronal mass ejections we sometimes see at eclipses, our work has potential major security implications for us on Earth.&rdquo

The location of the large coronal structures called streamers &ndash pointy regions that appear in most images of the corona is known for &ndash vary throughout the solar cycle. The 2019 eclipse occurs during a minimum of the 11-year solar cycle, a time when solar eruptions are infrequent and the Sun appears to be calm. Eclipses taking place near solar-cycle minimum, like this one, will provide Pasachoff&rsquos team with a rare view of solar polar plumes &ndash tufts of open magnetic field that emanate from the solar north and south poles, which are hidden from our view by high-latitude streamers at other eclipses. &ldquoI&rsquom also looking forward to comparing our observations of the corona taken during the eclipse (and combined in computers subsequently) with predictions that colleagues make before the eclipse based on the Sun&rsquos magnetic field and sunspots over the preceding month,&rdquo explains Pasachoff.

The corona&rsquos overall temperature also changes with the 11-year sunspot cycle. The team will use observations of superheated iron to follow the overall temperature of the corona over the sunspot cycle.

Pasachoff added, &ldquoWe are hopeful that observing from the 7,241 feet (2,200 meters) high altitude of NSF&rsquos Cerro Tololo Inter-American Observatory will give us an especially clear view of the corona.&rdquo

The Solar Wind Sherpas from Hawai&rsquoi

Shadia R. Habbal (University of Hawai&rsquoi) will be leading an international team called the &ldquoSolar Wind Sherpas&rdquo that will study the Sun&rsquos corona from three different locations across South America. The sites include Cerro Tololo and two locations in Argentina.

The team successfully used this multi-site observing strategy during the August 21, 2017 total solar eclipse over the United States, with five observing sites spanning 1,200 miles (1,931 kilometers). The strategy, with identical instruments at each site, maximizes the chances for observations in the event of poor weather at any one site. It also allows the teams to track changes in coronal structures that occur over a very short timescale. The team&rsquos goal for 2019 is to increase the suite of imagers and spectrometers used in 2017, and to include additional wavelengths of light which have not been observed so far.

Habbal explained, &ldquoWe will explore the physics of the solar corona through imaging and spectroscopy (breaking up the light into its component wavelengths). We have a number of telescope systems with special filters to isolate emission from different elements in the corona, mainly iron, argon and nickel. Our spectrometers will enable us to detect motions in the corona. Our white light images will yield very high spatial resolution images of all coronal structures.&rdquo

Multi-wavelength imaging and spectroscopic measurements can detect the chemical composition, temperature, density, non-thermal motions and outflows of the different parts of the corona. These measurements allow the team to explore the dynamics and thermodynamics of the corona close to the solar surface. This is the region of the corona where the largest changes in the solar magnetic field occurs, and where the solar wind and coronal mass ejections originate and accelerate.

This eclipse will be unique, Habbal said, &ldquobecause it occurs late in the afternoon and the Sun will be at very low altitude. Also, the Sun is close to solar minimum, so the distribution of structures in the solar corona will be different from 2 years ago (2017).&rdquo

Citizen Science from Japan

Yoichiro Hanaoka&rsquos team from the Solar Science Observatory of National Astronomical Observatory of Japan is also undertaking multi-site observations in Chile and Argentina. This team will be performing observations of the corona close to the surface of the Sun that will fill in an area not visible to spaceborne observatories like NASA&rsquos LASCO and STEREO coronagraphs. Hanaoka will then combine the data of both space and ground-based observations to construct a complete image of the corona.

Hanaoka commented, &ldquoWe are going to collaborate with amateur observers, widely spread along the total eclipse path in Chile and Argentina, to organize multi-site observations. By combining all of these observations, we can trace the time variations of the corona. It will be a great achievement for citizen science.&rdquo

UCAR Team Explores Magnetic Fields

A team led by UCAR researcher Paul Bryans will investigate the magnetic field of the Sun&rsquos corona. Magnetic structures in the corona play a fundamental role in causing the explosive events that contribute to space weather and its effects on the Earth. Measuring the orientation of the magnetic field can help in understanding the Sun-Earth system, and ultimately aid in predicting what drives space weather events. Reliable measurements of the magnetic field in the corona are, however, among the most challenging problems of observational solar physics.

Bryans explained how he is planning on taking these measurements during the eclipse, &ldquoIf we measure the intensity, or brightness, of the light coming from the Sun then we can tell many things about it &ndash how hot it is, how dense. But the only way to measure the magnetic field is to measure the polarization of the light. We will do this at the eclipse by using polarizers on our telescope. They work in exactly the same way as sunglasses, blocking light that is polarized in a certain direction. By rotating these polarizers, we can piece together the shape of the magnetic field on the Sun. This will help us understand what types of magnetic field configurations can lead to eruptive events.&rdquo

Studying the Corona in the Future

&ldquoOn July 2, NSF funding will enable scientists to seize the precious opportunity of a total solar eclipse to study the Sun&rsquos corona,&rdquo explained NSF Program Director David Boboltz, &ldquoBut next year, scientists will no longer have to wait for an eclipse to engage in cutting-edge research. NSF&rsquos Daniel K. Inouye Solar Telescope, which begins operations in 2020, will allow direct imaging of the solar corona anytime, shedding light on fundamental questions regarding solar magnetic fields and the heating to over a million degrees of the coronal plasma.&rdquo

Changes on Earth during a Total Solar Eclipse

One team won&rsquot be observing the Sun&rsquos corona during the total solar eclipse but instead will be monitoring changes happening here on Earth. M. Serra-Ricart&rsquos team, from the Institute of Astrophysics of the Canary Islands, will observe changes in the Earth&rsquos atmosphere including drops in temperature and charging of the ionosphere, the layer of the Earth&rsquos atmosphere that makes long-distance radio reception possible at night.

M. Serra-Ricart explained, &ldquoA total solar eclipse produces a broad, round area of darkness and greatly reduced sunlight that travels across Earth&rsquos atmosphere in a relatively narrow path during the daytime. Its effect on solar radiation intensity is remarkably similar to what happens at sunrise and sunset and it creates changes in the Earth&rsquos atmosphere we want to measure.&rdquo

Observers of total solar eclipses feel the dramatic temperature drop when the Sun is completely covered by the Moon. The team will track how much and how fast the temperature changes during the eclipse on Cerro Tololo. They will also track changes in the ionosphere to better understand how it impacts nighttime long distance radio reception.

&ldquoThe loss of sunlight due to the passage of the shadow of the moon during the eclipse is going to briefly produce a night-time like ionosphere. But it is considerably different than ordinary night-time. The moon&rsquos shadow is relatively small on the Earth and travels at supersonic speeds. It will likely produce some interesting effects that might be detectable on ordinary radios or small receivers.&rdquo added M. Serra-Ricart. &ldquoAlthough the ionospheric effects of solar eclipses have been studied for over 50 years many unanswered questions remain. We know roughly how this happens, but not precisely. The eclipse will give researchers a chance to examine the charging and uncharging process in almost real time.&rdquo

In addition to the science experiments, the team will also transmit a live video feed of the eclipse on YouTube Live, FaceBook, and Periscope.

Cerro Tololo Inter-American Observatory (CTIO) is a complex of astronomical telescopes and instruments located at 30.169 S, 70.804 W, approximately 80 km to the East of La Serena, Chile, at an altitude of 2200 metres. The complex is part of the National Optical Astronomy Observatory (NOAO) along with Kitt Peak National Observatory (KPNO) in Tucson, Arizona. The principal telescopes are the 4-m Victor M. Blanco Telescope and the 4.1-m Southern Astrophysical Research (SOAR) telescope, dedicated in April of 2004. The NOAO is operated by the Association of Universities for Research in Astronomy (AURA), which also operates the Space Telescope Science Institute and the Gemini Observatory. One of the two 8-m telescopes comprising the Gemini Observatory is co-located with CTIO on AURA property in Chile. The National Science Foundation (NSF) is the funding agency for NOAO. The Observatory headquarters are located in La Serena, Chile, about 300 miles north of Santiago.

About The National Solar Observatory

The National Solar Observatory (NSO) is the national center for ground-based solar physics in the United States (www.nso.edu) and is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation Division of Astronomical Sciences.

The Association of Universities for Research in Astronomy (AURA) is a consortium of 46 US institutions and 4 international affiliates that operates world-class astronomical observatories for the National Science Foundation and NASA. AURA&rsquos role is to establish, nurture, and promote public observatories and facilities that advance innovative astronomical research. In addition, AURA is deeply committed to public and educational outreach, and to diversity throughout the astronomical and scientific workforce. AURA carries out its role through its astronomical facilities.

AURA is responsible for the successful management and operation of its five centers: the Gemini Observatory the Large Synoptic Survey Telescope (LSST) the National Optical Astronomy Observatory (NOAO) the National Solar Observatory (NSO) and the Space Telescope Science Institute (STScI).

The National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 to promote the progress of science. NSF supports basic research and people to create knowledge that transforms the future. Please refer to www.nsf.gov.

National Solar Observatory
Claire Raftery
[email protected]

Cerro Tololo Eclipse Team
Manuel Paredes
[email protected]

## What If It's Just Us?

The ideal 'Earth 2.0' will be an Earth-sized, Earth-mass planet at a similar Earth-Sun distance from . [+] a star that's very much like our own. We have yet to find such a world, but even if we do, we must take care that we distinguish between what we think of as biosignatures, like oxygen, produced by life versus that produced by inorganic processes.

NASA Ames/JPL-Caltech/T. Pyle

When it comes to the question of extraterrestrial life, humans optimistically assume the Universe is prolific. After all, there doesn't appear to be anything particularly special about Earth, and life not only took hold here on our world, but evolved, thrived, became complex and differentiated, and then intelligent and technologically advanced. If the same ingredients are everywhere and the same rules are at play, wouldn't it be an awful waste of space if we're alone?

But this is not a question that can be answered by appeals to either logic or emotion, but by data and observation alone. While our investigations have revealed the existence of an enormous number of candidate planets for life, we have yet to find one where intelligent aliens, complex life, or even simple life is known to exist. In all the Universe, humanity may truly be alone.

Once intelligence, tool use and curiosity combine in a single species, perhaps interstellar . [+] ambitions become inevitable. But this is an assumption that isn't backed in science, and we must be careful (and suspicious) about any such conclusions we draw from it.

Dennis Davidson for http://www.nss.org/

A generation ago, we knew almost nothing about the planets that exist in the Universe beyond our own Solar System. We knew then — as we do now — that there were hundreds of billions of stars in our Milky Way alone, and thought there were hundreds of billions of galaxies throughout the visible Universe. (We know now that there are more like 2 trillion galaxies throughout our observable Universe.)

All told, there are some 10 24 stars in the observable Universe. For a very long time, all we could do was speculate as to whether they had planetary systems around them. We didn't know what fraction of planets were likely to be Earth-sized we didn't know what their orbital distances from their stars would be we didn't know how common or rare a world like ours might be.

But over the past 30 years, the landscape of exoplanet science has changed irrevocably.

A visualization of the planets found in orbit around other stars in a specific patch of sky probed . [+] by the NASA Kepler mission. As far as we can tell, practically all stars have planetary systems around them.

A combination of direct imaging, radial velocity studies, and measurements of transiting exoplanets have revolutionized what we know is out there. Led by NASA's now-defunct Kepler mission, we've learned so much about what's out there, including that:

• somewhere between 80%-100% of stars have planets or planetary systems associated with them,
• approximately 20%-25% of those systems have a planet in their star's "habitable zone," or the right location for liquid water to form on their surface,
• and approximately 10%-20% of those planets are Earth-like in size and mass.

A substantial fraction of stars out there (around 20%) are either K-, G-, or F-class stars, too: Sun-like in mass, luminosity, and lifetime. Putting all these numbers together, there are around 10 22 potentially Earth-like planets out there in the Universe, with the right conditions for life on them. In our Milky Way alone, there may be billions of planets with Earth-like chances for life.

Most of the planets we know of that are comparable to Earth in size have been found around cooler, . [+] smaller stars than the Sun. This makes sense with the limits of our instruments these systems have larger planet-to-star size ratios than our Earth does with respect to the Sun.

But knowing there's a bird in the bush is not the same as having one in your hand. Similarly, having a planet with the raw ingredients for life and similar conditions to what we had in the early days of Earth doesn't necessarily guarantee that life will arise on such a planet. Even if life does arise, what are the odds that it will persist, thrive, and become complex and differentiated? And beyond that, how often does it become intelligent and then technologically advanced?

Given all the events and circumstances that have transpired over the past 4.5 billion years — including the evolutionary twists and turns that occurred as the result of seemingly random processes — it's safe to say that the exact way life unfolded on Earth is cosmologically unique. But what about life, complex life, or technologically advanced life at all?

The crashed X-Files' alien spaceship, used as a promo for season 10 of the show, represents our . [+] hopes and fears concerning making contact with an intelligent alien species. But we have no evidence for their existence, thus far, anywhere in the galaxy or Universe.

X-Files / Fox / Rodrigo Carvalho

If we demand that we be scientifically honest and scrupulous, and look at the evidence without judgment in either optimistic or pessimistic directions, this is truly the limit of what we can say as far as the odds of life elsewhere are concerned. Our hopes and fears about the existence of aliens, of being cosmically alone, or any other point on the spectrum of possibilities have no decisive evidence to support or refute them.

While it may be exciting to speculate about thousands of spacefaring civilizations in the Milky Way right now, or intelligent aliens modifying their cosmic backyard or deliberately hiding from Earth, there is simply no evidence for this. Hypothesizing a slew of possibilities that haven't been ruled out might be a clever exercise that will someday lead to greater knowledge, but we can say nothing definitive about them today.

Atoms can link up to form molecules, including organic molecules and biological processes, in . [+] interstellar space as well as on planets. If the ingredients for life are everywhere, then life may be ubiquitous, too. It was all seeded by prior generations of stars.

All we know is that, if a planet was formed similar to Earth in the distant past, there are three big steps that must have occurred in order to get a recognizably advanced civilization like our own.

1. Life must have somehow arisen from non-life. This is the problem of abiogenesis, or the origin of life from nonliving precursor molecules. To go from the raw ingredients associated with organic processes to something that's classified as life, which means it has a metabolism, responds to external stimuli, grows, adapts, evolves, and reproduces, is the first big step.

It occurred at least once, more than 4 billion years ago, on our world. Has it occurred elsewhere in our Solar System? In our galaxy? In the Universe? We have no idea how frequently, out of the multibillion planetary candidates in our galaxy or out of the 10 22 candidates in the visible Universe, this may have occurred.

Both reflected sunlight on a planet and absorbed sunlight filtered through an atmosphere are two . [+] techniques humanity is presently developing to measure the atmospheric content and surface properties of distant worlds. In the future, this could include the search for organic signatures as well, and might potentially reveal a surefire sign of an inhabited planet.

2. Life must have thrived and evolved to become multicellular, complex, and differentiated. For billions of years, life on Earth was single-celled and relatively simple, with copying errors from one generation to the next providing the overwhelming amount of variation in organisms. Wherever resources abound, the simplest organisms to first make use of them fill that ecological niche. Under most circumstances, they find a way to persist.

It's only when something changes, such as resource availability, the survivability of the environment, or from competition, that extinctions occur, leaving open the possibility for a new organism to rise to prominence. Extinction events and selection pressures gave rise to many critical evolutionary steps on Earth: DNA absorption, eukaryotic organisms, multicellularity, and sexual reproduction, among others. This could be an inevitable occurrence on a planet with life, or it could be an ultra-rare event that happened to take place many times on Earth. We don't know.

Alan Chinchar's 1991 rendition of the proposed Space Station Freedom in orbit. Any civilization that . [+] creates something like this would definitely count as scientifically/technologically advanced, but inferring their existence is no more than wishful thinking at this point.

3. Intelligent life must have evolved, with the right traits to also become a technologically advanced civilization. This may be the step with the greatest uncertainty of all. It's been over 500 million years since the Cambrian explosion, and it's only over the past few hundred years that life on Earth has achieved the technologically advanced state that an extraterrestrial observer would recognize as a sign of intelligent life.

We can broadcast our presence to the Universe we can reach out beyond our home world with space probes and crewed space programs we can look and listen for other forms of intelligence in the Universe. But we have no known instances of success on this front in our Universe beyond our own planet. Life like us could be common, or we could be the only example within the limits of our observable Universe.

The Drake equation is one way to arrive at an estimate of the number of spacefaring, technologically . [+] advanced civilizations in the galaxy or Universe today. But until we know how to estimate these parameters, we're just guessing at the possible answers.

The notion that we can quantify the odds that a form of intelligent life arises in our Universe based on the scientific knowledge we have today is old: it goes back to the mid-20th century at least. Enrico Fermi, whom the famous Fermi Paradox is named after, posited that such estimates led to the notion that intelligent life in the Universe should be common, so, then, where is everyone?

The Drake equation was a famous way to parameterize our ignorance, but we still remain ignorant about the presence of alien life and alien intelligence. Hypothesized solutions have included:

• that they're there, but we aren't listening properly,
• that intelligent life self-destructs too quickly to maintain a technologically advanced state for very long,
• that intelligent life is common but usually chooses isolation,
• that Earth is purposely excluded,
• that interstellar transmission or travel is too hard,
• or that aliens are already here, but choose to remain hidden from us.

These proposed solutions usually leave out the most obvious option: that one or more of the three big steps is hard, and that when it comes to intelligent life in all the Universe, it's just us.

Intelligent aliens, if they exist in the galaxy or the Universe, might be detectable from a variety . [+] of signals: electromagnetic, from planet modification, or because they're spacefaring. But we haven't found any evidence for an inhabited alien planet so far. We may truly be alone in the Universe, but the honest answer is we don't know enough about the relevant probability to say so.

Our scientific discoveries have led us to a remarkable point in the quest for knowledge about our Universe. We know how big the Universe is, how many stars and galaxies are in it, and what fraction of stars are Sun-like, possess Earth-sized planets, and have planets in orbits that are potentially habitable. We know the ingredients for life are everywhere, and we know how life evolved, thrived, and gave rise to us here on Earth.

But how did life arise to begin with, and how likely is a planet to develop life from non-life? If life does arise, how likely is it to become complex, differentiated, and intelligent? And if life achieves all of those milestones, how likely is it that it becomes spacefaring or otherwise technologically advanced, and how long does such life survive if it arises? The answers may be out there, but we must remember the most conservative possibility of all. In all the Universe, until we have evidence to the contrary, the only example of life might be us.

## A BOOK: TESTAMENT OF THE MAGI

With this book the mysteries of Magi, the Bethlehem Star and much more are certifiably solved. The data, still working for Jesus issues and events to this day, is fingerprint exact down to the last descriptive asteroid and Part. The book radically develops a theory about Christ’s birth first proposed in the 70s by a notable Austrian astronomer Ferrari D’Occhieppo and enlarged upon in some aspects by the British astrophysicist, David Hughes. In his The Infancy Narratives (2012) Pope Benedict cited the D’Occhieppo thesis which he thought plausible but wondered what we should make of it. What indeed when the theory was still incomplete?

This book completes the edifice to a point it could not now be improved upon or seriously rivalled….. A big claim but that is almost the problem. Many may prefer to ignore the evidence simply because it is so impossible to dismiss and of course within religion let along the secular world, there is a huge prejudice against “astrology” to the point it is almost impossible to be heard. But here is a picture that defies statistical probability, one it that couldn’t be invented. No previous theories work or not sufficiently across the range of issues that must always be addressed in advancing any claim to have discovered the holy grail of all stargazing. Arguably this book belongs to the times discussed in the article above. Secrets of the beginning of the era can perhaps only be disclosed at that same era’s end.