The Mauna Kea observatories on the Big Island of Hawaii.

Many of us do astronomy. Whether you just stand in your backyard this summer and go looking for planets, or you venture out to a dark sky destination to see a comet or catch some shooting stars, the terms astronomer and stargazer often go hand-in-hand.

The pandemic has gotten a lot of us into our backyards looking up. This rare planetary event has also given some a new perspective on our global community.

The night sky connects all humans wherever they are, but how many of us ever discover something new about whats out there? Or even have an original thought about the enormity above us each night?

In TheLast Stargazers: The Enduring Story of Astronomy's Vanishing Explorers, University of Washington astronomy professor Emily Levesque shares the tales of modern-day stargazers, the small band of 50,000 or so professional astronomers around the world that get to use humanitys greatest telescopes on the high altitude peaks such as Mauna Kea in Hawaii, Cerro Paranalin Chile and Roque de los Muchachos in the Canary Islands.

It sounds impossibly romantic. Is it?

If somebody wanted to come watch an astronomer work at night I think theyd be deeply disappointed, said Levesque. Were not out gazing at the stars and were not even sitting out at the telescopewere in a lit room in a different part of the telescope building.

This is a world of computer screens, laptops and data. In fact, many astronomers work 9 till 5 with data downloaded from remote telescopes.

Thats right; astronomers dont look through telescopes.

"The Last Stargazers" is a new book by astronomer Emily Levesque.

The title of Levesques book reflects the engaging texts many stories about discoveries made at mountaintop observatories, but in modern terms, its a little ironic because professional astronomers dont do all that much observing with their own eyes.

People imagine an astronomer to be somebody hunkered down at a telescope, but they would be surprised at the adventures we have, and the sheer variety of things that we do for our job, said Levesque. But we don't look through eyepieces anymore. In terms of the technology involvedfrom cameras to advanced detectorsthe way we do astronomy is so surprising to some people.

However, dont think that astronomers are stony-faced when theyre sat in front of a computer screen displaying something spectacular. Our responses to seeing something captured by a powerful telescope are the same as the responses of amateurs looking at Saturn for the first time, said Levesque, whos incredibly enthusiast about astronomy. We know all the science behind what were looking at, but we react in the same way as anyone enjoying looking at the night sky.

On Palomar Mountain in California lies the Hale Telescope, that has been in use for 60 years. Photo ... [+] by Joe McNally/Getty Images)

Anyone whos ever made a plan to look at the night sky has a nemesis; cloud.

Thats why the planets big telescopes are on mountaintops above the clouds. Thats the theory. The reality is that weather happens, and so does engineering. On the big telescopes that means only about 300 observing nights per year. So what happens if you get valuable telescope time, get yourself up the mountain for three nights, and the clouds come in?

Not much. Its all or nothingyou can get a string of good weather and a working telescope, or cloud and a broken instrument, said Levesque. If its the latter, tough luck.

You just come home and you have to apply again, and you dont get a special little star on your proposal saying she got clouded outyou have to go back and take your chances again, just like anyone else, said Levesque.

Since telescope time is scheduled six months in advance at most observatoriesand typically astronomers wait for a year to be assigned a slota single cloud or one windy night can make a huge difference to astronomical research plans. The stakes are highyou really hope for good weather, you really hope nothing goes wrong, and you really hope you don't make any mistakes, because the time is so precious, said Levesque.

Depending on what object they need to observe, astronomers can request a specific day or even hour (perhaps for an asteroid occultation), a season (say, anytime between November and May for observing Betelgeuse), and whether they require complete darkness or are happy with a full moon-lit night.

Sometimes astronomer will request to observe an object at a specific time to coincide with precisely when Hubble will be looking at it, so that data can be compared.

The flying observatory "SOFIA" (Stratospheric Observatory for Infrared Astronomy), a Boeing 747SP of ... [+] NASA. Photo: Christoph Schmidt/dpa (Photo by Christoph Schmidt/picture alliance via Getty Images)

So astronomers almost never look though telescopes, but they always hang out on mountain tops, right?

Well, no, not always. The Mauna KeaObservatories (MKO) in Hawaii are at 13,803 ft./4,207 meters above sea level, but thats not always enough.

Some telescopes fly, so astronomers have to sometimes become stratonauts.

Cue Levesques adventures in NASAs flying observatory, the Stratospheric Observatory for Infrared Astronomy (SOFIA).

Having written a couple of times recently about studies of Betelgeuse and Pluto from the specially-equipped Boeing 747SP aircraft (modified to carry a 2.7-meter/106-inch reflecting telescope), this part of the book particularly engaged me. Levesque recounts her evening with the stratonauts who operate SOFIA with incredible enthusiasm (a theme throughout the book).

As is the way with astronomers, she also got to see something truly exquisite.

I was flying on that telescope as an astronomer and we were down in the southern hemisphere, said Levesque. I saw the southern aurora from the cockpit of the plane flyingthe first time I've ever seen the aurora.

Never in my wildest dreams would I have imagined I would be in that place.

However, astronomical opportunities for such incredible experiences could be on the wane.

Professional astronomy is no longer about looking through telescopes or hanging about in freezing temperatures. Levesque has had many experiences of how astronomy is done nowmentioning the smell of engine grease and coffee as two dominant themesbut the disciplines next chapter seems far less exciting.

In the future will all telescopes be controlled remotely? Will astronomy be an office-based vocation?

Weve certainly seen a drift toward telescopes being operated remotely, said Levesque. One of the telescopes that I spend a lot of time using now is the Apache Point Observatory 3.5 meter telescope, which I can operate from my laptop on my couch.

Many are now operated using queue-based scheduling; an astronomer send instructions to the telescope ahead of time, it makes observations when the conditions are right, and the data arrives in the astronomers inbox.

We will see many more telescopes run that way, said Levesque. However, there is still a telescope operator at the telescope itself, and there are still engineers and staff on site taking care of the telescope. Its just that the astronomy is increasingly being done remotely.

I dont think well ever truly remove the idea of people at telescopes, except in the case of robotic telescopes, which are amazing at some things, but cant do some things, said Levesque. The variety of questions were trying to answer with telescopes means that were probably always going to demand human participation at some level.

Sunset at the Mauna Kea Observatories on the Big Island of Hawaii.

So are astronomers still stargazers?

Levesque tells a story about what astronomers do before an observing session at most mountaintop observatories. When we watch the sunset before an observing session we pretend were checking to see how clear the sky is looking, said Levesque.

Its a wonderful chance to enjoy the planet, enjoy the observatory, get a moment of silence and see our nearest star doing something beautiful from the edge of the world.

Wishing you clear skies and wide eyes.

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The Last Stargazers? Why You Will Never See An Astronomer Looking Through A Telescope - Forbes

Welcome to the age of the satellite megaconstellation. Within the next few years, vast networks, containing hundreds or even thousands of spacecraft, could reshape the future of Earths orbital environment.

Much of the attention on these strings of satellites has been placed on the prolific launches of SpaceX and OneWeb, but the focus is now turning to Amazon. Last month, the Federal Communications Commission approved a request by the online marketplace to launch its Project Kuiper constellation, which, like SpaceXs Starlink and OneWebs network, aims to extend high-speed internet service to customers around the world, including to remote or underserved communities hobbled by a persistent digital divide.

The Kuiper constellation would consist of 3,236 satellites. Thats more than the approximately 2,600 active satellites already orbiting Earth. While Amazons hardware is a long way from the launchpad, SpaceX has already deployed hundreds of satellites in its Starlink constellation, including 57 additional satellites that it launched on Friday. It may expand it to 12,000, or more. Facebook and Telesat could also get into the internet constellation business.

The rapid influx of satellites into low-Earth orbit has prompted pushback from professional and amateur astronomers. Starlink satellites are notorious for photobombing astronomical images with bright streaks, damaging the quality and reducing the volume of data that scientists collect for research. While SpaceX plans to mitigate the effects of its launches on astronomical observations, scientists and hobbyists in the community worry about the lack of regulation of constellations as more entrants such as Project Kuiper join the action.

We dont yet have any kind of industrywide guidelines, said Michele Bannister, a planetary astronomer at the University of Canterbury in New Zealand. We dont have an industry body thats producing good corporate citizenship on the part of all of these enthusiastic companies that want to launch, and we dont have any regulatory setup in place thats providing clear guidelines back to the industry.

She added, To me, honestly, it feels like putting a bunch of planes up and then not having air traffic control.

Since the first group of Starlink satellites launched in May 2019, many skywatchers have lamented their bright reflected glare. The light pollution is particularly pronounced when the satellites are freshly deployed and headed toward their operational orbits. At this point, they are perfectly positioned to catch sunlight at dawn and dusk, scuttling astrophotos and telescope observations. Starlink must be replenished constantly with new satellites, so these trails will be an ongoing problem.

Most ground-based observatories actually start in twilight, said Julien H. Girard, a support scientist at the Space Telescope Science Institute in Baltimore. We start taking data even when the sky is not completely dark, especially in the near-infrared and infrared wavelengths.

The satellites may create the most problems for wide-field observatories that survey expansive regions of the night sky at once. The motion of satellites through the frame can obstruct observational targets or overwhelm them with light. Astronomers can use software to remove satellite trails to some extent, but that may not completely fix the images.

Theres no doubt that the astronomical community can still do science with the presence of those constellations, but its a burden, Dr. Girard said.

The light pollution could mess with our view of countless tantalizing astronomical targets. For instance, scientists are beginning to discover interstellar objects in our own solar neighborhood, such as Oumuamua, a weirdly elongated rock spotted in 2017 that hails from an unknown star system, or Comet Borisov, which was spotted more recently.

Megaconstellations are uniquely positioned to interfere with detections of these cosmic wanderers. One of the prime discovery times for interstellar objects is in that period of sky near astronomical twilight, or dawn and dusk, which is when these satellites have their biggest impact, Dr. Bannister said.

So far, astronomers have put most of their attention on Starlink because SpaceX was the first company to launch big batches of satellites. OneWebs constellation poses a different set of problems for radio astronomers because of the altitude of its orbit. Its future has been uncertain since it declared bankruptcy and began acquisition talks.

But now that Amazon has the F.C.C.s approval, the Starlink satellites will have company both in orbit and in the discussion about the effects of these networks on astronomy.

Kuiper would easily have as much of an impact on both optical and radio astronomy as other satellite constellations, said Jeff Hall, the director of the Lowell Observatory in Arizona and the chair of the American Astronomical Societys Committee on Light Pollution.

The Amazon constellation will have far fewer satellites compared with Starlink, but its array will be deployed into three orbits, all higher in altitude than SpaceXs currently deployed network. (Starlink is licensed to occupy higher orbits than Amazon, although SpaceX recently sought FCC permission to operate at altitudes comparable to Project Kuiper, too).

Some of those higher orbits are looking like they are actually going to be more problematic for astronomical imaging, because they are going to be, basically, visible for longer, Dr. Bannister said, though its not clear how the light pollution from these constellations will compare.

The companies dont publish what reflectance their satellites are going to have, so its hard to model, she said.

As the quantity of satellites spirals upward, the risk of crashes does as well. Collisions between satellites add to hazardous orbital debris. Imagine if all the broken glass and prickly detritus from a car wreck kept moving at high speeds above the highway, requiring vehicles to plow through it. Thats how the orbital lanes in space work, so it will be essential that protocols governing space traffic are able to keep pace with these megaconstellations to prevent clips and crashes.

Already, there was one alarming incident in which an Earth-observation spacecraft operated by the European Space Agency had to fire its thrusters to dodge a Starlink satellite. A dust-up between the spacecraft was not certain, but the trajectories posed enough of a threat that ESA decided the maneuver was necessary. These encounters may become more frequent as thousands of additional satellites take to the sky.

If this is what were having right in the testing phase of these megaconstellations, whats it going to be like when we have 5,000 of these up, which is what were predicted to have launching in the next couple of years? Dr. Bannister said.

While these concerns have been raised, there is no other obvious way to stop, or slow, the development of these megaconstellations.

One of the things that I think is most problematic is that there isnt any legal prevention, or legal protection, for the night skies, said Chris Newman, professor of space law and policy at Northumbria University in the United Kingdom.

With hundreds of Starlink and OneWeb satellites already launched, and thousands more expected in the next few years, astronomers feel mounting pressure to find a workable compromise with the companies. Decisions made now may affect the sky for decades.

For the moment, that means hashing out a vision of a safe and clear night sky that would rely on voluntary mechanisms.

In response to the light pollution concerns, SpaceX is experimenting with dark coatings and sunshades for its Starlink satellites.

Representatives from Amazon and SpaceX, as well as a consultant formerly with OneWeb, attended a recent workshop called Satellite Constellations 1, organized by the AAS and the National Science Foundation, according to Dr. Hall. A report summarizing the results and recommendations of the workshop will be made public in a few weeks. But Amazon has already stated a desire to work with astronomers.

Reflectivity is a key consideration in our design and development process, and were engaging with members of the astronomy community to better understand their concerns and identify steps we can take to minimize our impact, an Amazon spokesman said. Well have more to share as we release additional detail on our plans for the project.

But many astronomers, and dark-sky advocates, are seeking a robust regulatory approach to these issues.

I think the only real way in which, going forward, this is going to develop, is if national regulators make it part of the licensing requirement that satellite companies putting constellations up take into account the needs of ground-based astronomy, Dr. Newman said. I think thats very possible, and I dont think that would require too much accommodation by companies.

Of course, the night sky is not only a resource for professional astronomers. Across generations and cultures, people have gazed up after sunset to seek solace, enchantment and perspective from the stars. Broadening internet access around the world has an obvious public benefit, but so does the preservation of clear skies and bright stars.

Were talking about changing something that is shared across the entire planet, Dr. Bannister said.

This is environmental impact, she added. This is something we know how to discuss and regulate in all the other spheres of corporate activity. Why should this be any different?

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Amazon Satellites Add to Astronomers Worries About the Night Sky - The New York Times

The Dawn mission was launched in 2007 with an unconventional ion engine that let it first orbit Vesta, the asteroid belts second largest object, for 14 months before venturing on to Ceres in 2012. No single mission had ever orbited two extraterrestrial worlds before.

Vesta is a dry body almost like the Moon, Dawn Principal Investigator Carol Raymond of JPL tells Astronomy. Ceres we knew was a very water-rich object that had retained volatiles from the time it had formed. The two were sitting there like plums. The low-hanging fruit.

Ceres started to tease its secrets to astronomers with Dawns first glimpses of the dwarf planet in early 2015. A pair of weird white spots stood out from afar, shining like cats eyes in the dark. More of these bright features became apparent on approach, and they ended up at the center of scientists efforts to understand Ceres.

Much of Ceres story was apparent within just a few of Dawn's arrival, but scientists still felt they had more to learn, so NASA extended Dawns mission for a second run. This let the spacecraft keep collecting data until 2018, when it finally ran out of fuel. This latest batch of research was collected during that extended phase.

And as Dawn gathered higher resolution images, it started to unravel intimate details of the worlds surface and its ancient history. Among other things, the spacecraft spotted a lone mountain that stretches some 21,000 feet (6,400 meters) above the surface, taller than Denali, North Americas tallest peak.

Ceres' white spots sit inside Occator Crater, which stretches across 57 miles (92 kilometers) of the world's northern hemisphere. Another place with a prominent bright spot is within smaller Haulani Crater, named for the Hawaiian goddess of plants. Its one of the dwarf planet's youngest features.

Original post:

Ceres: An ocean world in the asteroid belt - Astronomy Magazine

The researchers then traced the evolution of the white dwarfs back in time, deriving their initial masses with the help of an important relationship in astrophysics, the initial-final mass relation (IFMR), which, despite its ubiquity, still has its quirks. The initialfinal mass relation connects the mass of a white dwarf with the mass of its progenitor in the main sequence, says Ramirez-Ruiz. By understanding this relationship, we are able to put stringent constraints on the carbon-containing mass that was ejected during the evolution of the star.

Generally speaking, the more massive a progenitor star, the more massive its remnant. But the team discovered an apparent kink in that relationship. Stars starting with about 1.8 to 1.9 times the mass of the Sun seem to be leaving behind larger-than-expected corpses.

The break in the IFMR was noticed independently by both Cummings and the studys lead author, Paola Marigo, a theoretical astrophysicist at the University of Padova in Italy. Importantly, Cummings found the kink through observations, while Marigo uncovered it in her theoretical modeling.

According to the researchers, the fact that stars with just under two solar masses seem to produce plus-sized white dwarfs suggests these stars were still forging carbon in the final stages of their lives. This carbon was then passed into the interstellar medium by stellar winds, which is a far more gentle process than being violently propelled by supernova shock waves. This revelation places a constraint on the evolution of low-mass stars, as well as how they chemically enrich their surroundings.

This new low-mass star theory of chemical enrichment doesnt so much compete with previous ideas as it does bolster them. Its not that low-mass stars are solely responsible for enriching their host galaxies with carbon, but they do work with their bulkier counterparts to get it done.

There is ample evidence that both exploding massive stars and low-mass stars contribute to the production and distribution of carbon in the universe, says Ramirez-Ruiz. This is evident by looking at the fossil stellar record in the Milky Way. Ramirez-Ruiz goes on to suggest that massive stars could contribute more to carbon-enrichment early on, while low-mass stars might inject more carbon into galaxies at later times. After all, smaller stars live much longer than larger stars.

With all of the complex processing that can occur in astronomy, the production of elements is never an only A or only B type of process, Cummings stresses. Both processes are likely major contributors, and our work does not rule out the contribution of more massive stars and their supernovae.

However, one thing is for sure, there is still much to learn about low-mass stars and their evolution, as well as the role they play in the chemical enrichment of their host galaxies. Cummings says astronomers need to intensely study stars ranging from about one to two times the mass of the Sun, as well as the white dwarf remnants they leave behind.

Whilst I do hope to be involved at some level in future work of this nature, the researcher says, I am just as excited about the prospect of this current study inspiring a younger astronomer to take the lead.

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Small stars are vital to dispersing the building blocks of life - Astronomy Magazine

Join PEEC the week of Aug. 10 for a variety of live-streamed programs. On Tuesday, Aug. 11, Kaitlin Haase of the Xerces Society will discuss Southwest pollinators. Then, on Friday, Aug. 14, Galen Gisler will talk about medieval Islamic astronomy. Both events will begin at 7 p.m. and registration is required at peecnature.org/events. Photo Courtesy PEEC

Join the Pajarito Environmental Education Center (PEEC) on Tuesday, Aug. 11 and Friday, Aug. 14 at 7 p.m. for live-streamed programs. On Aug. 11, Kaitlin Haase, the Southwest Pollinator Conservation Specialist with the Xerces Society, will discuss what is happening in the world of pollinators in the Southwest. Then, on Aug. 14, astronomer Galen Gisler will give a talk on medieval Islamic astronomy.

In Tuesdays pollinator program, Haase will give an update on pollinators in the Southwest and discuss what we can do in our backyards and communities to help these important animals. In her position Haase works to create climate-resilient, connected pollinator habitat in the Santa Fe and Albuquerque areas. She collaborates with and educates public and private urban land managers in New Mexico and the desert Southwest on pollinator-friendly practices for landscaping, gardening and open space restoration.

During Fridays astronomy talk, Gisler will talk about the dozens of profound thinkers in physics, mathematics, philosophy and astronomy in places from Samarkand to Spain that prepared the groundwork for the rebirth of science in Renaissance Europe. He will introduce al-Kwarizmi (from whose name we derive algorithm), al-Tusi (whose Tusi couple is fundamental to Copernicuss model) and the precision astrometry of Ulugh Beg. The audience will also see where our names for most named stars have come from during this talk.

In addition to these two programs, join PEECs weekly virtual vinyasa flow yoga class on Sunday, Aug. 16 with Christa Tyson. This class is held every Sunday from 10 11 a.m. Tyson is the Visitor Services Manager at PEEC and has been teaching yoga since 2003.

All events will be hosted via the live-streaming platform Zoom. Registration is required atpeecnature.org/eventsto receive the meeting link and password. The pollinator and astronomy programs each have a suggested donation of $5 to attend. The yoga class is free for PEEC volunteers, $5 for PEEC members and $7 for non-members. Event registration donations and fees help PEEC continue to be able to offer live-streamed programming while the Los Alamos Nature Center is closed due to COVID-19.

For more information about this and other PEEC programs, visitwww.peecnature.org, emailpublicity@peecnature.orgor call (505) 662-0460.

PEEC was founded in 2000 to serve the community of Los Alamos. It offers people of all ages a way toenrich their lives by strengthening their connections to our canyons, mesas, mountains and skies. PEEC operates the Los Alamos Nature Center at 2600 Canyon Road, holds regular programs and events and hosts a number of interest groups from birding to hiking to butterfly watching. The Los Alamos Nature Center is currently closed due to COVID-19, but there are many ways to learn about nature and interact with PEEC online. PEEC activities are open to everyone; however, members receive exclusive benefits such as discounts on programs and merchandise. Annual memberships start at $35. To learn more, visitwww.peecnature.org.

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Explore Pollinators And Islamic Astronomy This Week With PEEC - Los Alamos Reporter

I hope everyone was able to get out to see Comet Neowise over the last few weeks. I had the thrill one recent night of viewing Neowise just as a meteor flashed into my field of vision right underneath it, as if to underscore that this comets appearance was a once-in-every-6,700-years phenomenon.

Theres always something to see in the night sky, as University of Washington-based astronomer Emily Levesque reminds us in her new book, The Last Stargazers.

With that title, Levesque is not suggesting that future generations will fail to look up and marvel at the moon, planets and stars, but she does note a concerning shift that is occurring due to the dictates of economics and changing technologies.

With limited funding being directed toward the field of astronomy, massive new automated survey telescopes are now being prioritized over telescopes that allow human-driven observation. Levesque points out that while these larger telescopes will do a fantastic job of providing data about new corners of the universe, the data will have impenetrable heaps of zeroes and ones unless observational astronomy is also able to continue.

That means we still need scientists who are able to study the data, interpret it and investigate the anomalies through telescopes that, unlike the new pre-programmed behemoths, are allowed to manipulate. Thats what will allow them to hone in on new understandings about physics or possibly to even detect signals from distant realms of the universe.

In The Last Stargazers, Levesque incorporates the stories and experiences of more than 100 of her astronomer colleagues from around the world to describe the essential human component of astronomy.

She describes the bitter frustrations of cloudy nights as only an astronomer can experience them.

But theres also the thrill of new discoveries. In 2017, at a specialized observatory in eastern Washington, a gravitational wave was detected for the first time ever, confirming something that Albert Einstein had hypothesized 101 years earlier as part of his theory of relativity.

And somewhere in between, theres the more typical night-in-the-life work of astronomers.

When astronomers are awarded a coveted turn at one of the powerful telescopes scattered on mountaintops around the globe, they bring along music playlists to keep themselves awake. They have favorite snacks like Goldfish crackers and peanut M&Ms.

And theres the congenial custom of gathering outside to watch the sunset with colleagues before heading in to work with the telescopes all night.

Outside the telescopes in Chile, the sunset-watching is usually attended also by a complement of resident viscachas, members of the Chinchilla family that look like long-tailed rabbits.

Depending on the location, animals that astronomers have encountered inside the buildings housing telescopes have included tarantulas, scorpions, skunks, even a bear.

Surprising, inspiring and relatable, The Last Stargazers is a fine summer read.

The Bookmonger is Barbara Lloyd McMichael, who writes this weekly column focusing on the books, authors and publishers of the Pacific Northwest. Contact her at bkmonger@nwlink.com.

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Bookmonger: 'The Last Stargazers' is a behind-the-scenes look at astronomy - Discover Our Coast

An amateur astronomer must always be prepared for the unexpected. This preparedness really helped when Clinton Willis and I photographed our "mystery object" on the night of April 20th.

Preparedness helped again with the advent of Comet Neowise. I had planned for the August column to be about an entirely different subject, but nature surprised me, as it often does.

When I heard of Comet Neowise, people were seeing it in the morning sky, before dawn. I got up, looked carefully around the horizon, but never found it in the morning.

A few days later, I learned that Comet Neowise was passing behind the Sun and that it might survive the meltdown that often occurs when even a bright comet rounds the Sun. Such comets literally can't take the heat! The previous two comets that had appeared in the night sky this year simply broke up or fizzled. I suspected Neowise would do the same.

By the time Neowise had rounded the Sun and was an evening object, there were maps for its location all over the internet and thousands of people across the world had seen it and photographed it. It had survived the Sun! Some of those pictures were absolutely astonishing! I vowed to myself I would photograph this beautiful object.

Along with my observing friend, Clinton Willis, we set up our instruments in my backyard and pointed them northwest. However, we never found the comet from this location. It occurred to Clinton and me at about the same time, that we should try to find it from a different place. We pondered a location with an unobstructed horizon to the west that had as little light pollution as possible. First, we tried the casino in West Siloam Springs but there were too many trees and too much traffic and ambient light. We cruised further on Highway 412, towards the west, keeping a lookout for a good place. We found such a spot near a golf driving range that appeared closed or abandoned. We parked in the parking lot and quickly set up our cameras.

At first, we could not find it and I thought we would have another fruitless search. Frustrating! However, I tried the technique of taking several overlapped images of the northwestern horizon about one fist-width above it. On one of the images, I spotted the comet, just barely in the frame. From there, Clinton and I took several images of the comet and I present one of them to you in this column.

Jupiter and Saturn are in the southeast sky by 9 p.m. Jupiter will be the brighter of the two and Jupiter leads Saturn across the night sky all night. A good pair of binoculars, braced against something solid, should reveal some of Jupiter's moons -- perhaps all of the four moons Galileo spotted with his homemade telescope in about the year A.D. 1610.

From a dark spot, the Milky Way is splendid! To the direct south is the constellation Sagittarius. It lies over the center of our galaxy and, if you use binoculars or a medium telescope, there is nearly an inexhaustible range of wonderful objects to see. I have been looking at this area since I was a boy and I am still awed.

None of us knows what the future holds and, certainly, we don't know that something brand new that might appear in the night sky. Be prepared!

-- David Cater is a former faculty member of JBU. Email him at [emailprotected] Opinions expressed are those of the author.

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ASTRONOMY: When it comes to night sky, be prepared! - Mdcp.nwaonline.com

Jupiter's moon Ganymede is a pretty special chunk of rock.

It's the largest and most massive moon in the Solar System. It's the only Solar System moon that generates its own magnetic field. It has the most liquid water of any Solar System body. And now, scientists have discovered, it may have the largest impact structure ever identified.

Astronomers have found that the tectonic troughs known as furrows, thought to be the oldest geological features on Ganymede, form a series of concentric rings up to 7,800 kilometres (4,847 miles) across, as though something had slammed into the moon.

This has yet to be confirmed with more observations, but if the rings were indeed formed by an impact, it will vastly outstrip all other confirmed impact structures in the Solar System.

Ganymede's furrows are troughs with sharp, raised edges, and it's long been considered that they are the result of large impacts early in Ganymede's history, when its lithosphere was relatively thin and weak. But a reanalysis of Ganymede data led by planetologist Naoyuki Hirata of the Kobe University Graduate School of Science tells a slightly different story.

To try to better understand the history of Ganymede, Hirata and his colleagues took a closer look at images obtained by spacecraft - both Voyager probes, which flew by Jupiter in 1979, and the Galileo Jupiter orbiter, which studied the planet and its satellites from 1995 to 2003.

These images show that Ganymede has a complex geological history. The moon is divided into two types of terrain - the Dark Terrain and the Bright Terrain. The Bright Terrain is lighter in colour, and relatively lacking in craters - suggesting it is much younger than the heavily scarred Dark Terrain.

(NASA/Hirata et al.)

This older terrain is pocked and cratered. And those craters were made on top of previous scarring - the furrows that can be found throughout most of the Dark Terrain.

The team carefully catalogued all the furrows, mapping them across the surface of Ganymede. They found that almost all of these structures, rather than being haphazardly arranged around many impact points, were concentrically focussed on a single point.

Furthermore, the troughs wrapped around the moon, spanning up to 7,800 kilometres. Ganymede's diameter is 5,268 kilometres (3,273 miles) - so that's a pretty enormous ripple, to put it mildly.

(Hirata et al., Icarus, 2020)

The next step in the research was to determine what could have caused such a structure. The team ran simulations of various scenarios, and found that the most likely culprit was an asteroid 150 kilometres (93 miles) across, slamming into the moon at a velocity of around 20 kilometres per second (12 miles per second).

This would have taken place during the Late Heavy Bombardment, around 4 billion years ago, when Ganymede was quite young. During this period, the moon is thought to have taken an absolute cometary pummelling due to gravitational focusing by Jupiter - so a giant impact is certainly plausible.

In addition, a similar structure can be found nearby. On Jupiter's moon Callisto, the Valhalla crater is a multi-ring impact crater with a diameter of up to 3,800 kilometres (2,360 miles), thought to be between 2 and 4 billion years old.

The Valhalla crater is also the current record-holder for biggest impact structure in the Solar System, followed by the Utopia Planitia on Mars, an impact basin (not a multi-ring structure) 3,300 kilometres (2,050 miles) across.

The new discovery awaits confirmation, but we may not have to wait long to find out. If the furrows were caused by a giant impact, there should be a gravitational anomaly at the impact site, as seen in other large impact structures such as the South Pole-Aitken Basin on the Moon.

Now that we know to look for it, perhaps Jupiter probe Juno could be used to search for this anomaly. In addition, the European Space Agency's Jupiter Icy Moon Explorer (JUICE) probe will be launching in 2022, the first dedicated mission to study Jupiter's moons. It, even more than Juno, could illuminate the cause of these mysterious structures.

The research has been published in Icarus.

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Astronomers May Have Identified The Biggest Impact Structure in Our Solar System - ScienceAlert

We know that planets like the ones in our solar system form in flat disks of gas and dust called protoplanetary disks. We can actually see that happening all over the galaxy.

But a team of astronomers wondered if that were the only place they could be born. So they figured why not see if planets can form in the very worst place you can imagine in the entire Universe: Near a supermassive black hole.

No, seriously, stop laughing. Its at least theoretically possible, and the astronomers dubbed them blanets.

Yeah, Im not crazy about the name either. And I know it seems silly at first, but in fact all this makes a weird sort of sense.

Supermassive black holes are found in the centers of big (and some small) galaxies. They are like normal black holes except they are extremely huge (supermassive, you might say), with masses millions and even billions of times that of the Sun. They form and grow along with their host galaxy, fed by gas and dust (and the occasional star) that flow into the galaxys core.

Before falling in, this material forms a huge flat disk around the black hole called an accretion disk. The disk can be incredibly hot, and blast out truly staggering amounts of radiation (we call galaxies like this active). But sometimes, much farther out than the superhot accretion disk, there is a second co-planar disk of much cooler gas and dust surrounded by a puffy donut of dust.

This part of the disk can extend from a few to a few dozen light years out from the black hole, and even though the scale is much, much vaster many the conditions are similar to the disk of gas and dust around a newly forming star. Lets take a look at what we know about how this works around a star.

Close in to the baby star its hot, but when you get far enough out the temperature cools considerably. At some distance, what astronomers call the snow line, the temperature drops enough that molecules like water, carbon monoxide, and ammonia can condense to form ices. Dust (little silicate bits) can clump together too, at first forming tiny microscopic grains that bump and stick, becoming fluffy, porous aggregates a millimeter or so across.

At that point different complex processes take hold, but in the end those stick together to form pebbles, then rocks, then boulders once they grow to a few hundred meters in size gravity kicks in and they actively draw material toward them, and the growth increases rapidly, and you get a planet.

The weird thing is, the same can be true for a supermassive black hole. The disk is exceptionally hot close in to the black hole, but a few light years out the temperature drops enough to have a snow line. The disk is much larger, of course (hundreds of trillions of kilometers across versus some hundreds of millions for a star) but that also means theres a lot more material to form objects from. A lot: Millions or even billions of times as much material. Enough to make a fleet of planets.

Conditions arent exactly the same around stars and huge black holes, of course, and the astronomers found some issues with things like turbulence in the disk (and even its viscosity) hampering blanet formation. But after running the numbers, they find that in lots of circumstances its entirely possible to form blanets around a black hole. If conditions are right, a black hole with a mass a million times the Suns can form blanets in about 70 80 million years, which is slower than around a star, but they can grow in size from 20 times the mass of the Earth (roughly that of Neptune) up to 3000 times Earths mass ten times that of Jupiter! Thats a big blanet.

A bigger black hole has a bigger disk and can grow bigger planets, enough that they could edge into brown dwarf territory (objects from 13 to about 80 times Jupiters mass, more massive than planets but less than stars).

Mind you, being anywhere in the accretion disk of a supermassive black hole can be unfortunate. If the black hole is actively gobbling down matter the inner disk gets so hot it blasts out high-energy radiation that could cook blanets. However, the astronomers found that a more politely nibbling black hole could still form blanets, and its even likely that planets could form during a galaxys active phase.

Do blanets exist? Well, maybe. Theres a lot more work to be done here, but the scenarios the scientists lay out arent ridiculous. If they do exist theyd be really weird, floating free in space surrounded by a thick disk of dust revolving madly around a supermassive black hole just a few light years away. Not exactly prime real estate.

This is all so strange that Id love for them to exist just because its so cool! But given their location, I certainly wouldnt recommend visiting one.

Tip o the Schwarzschild radius to Jonathan OCallaghan.

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Because the Universe isn't weird enough: Black hole planets may exist. - SYFY WIRE

Behold The Blanet

A team of scientists was studying how new exoplanets could form around black holes when they ran into a serious problem: figuring out what to call the class of theoretical worlds.

But fret not. They now have a name, ScienceAlert reports, and that dubious name is blanet.

The actual process,according to the Kagoshima University scientists behind the research submitted to The Astrophysical Journal for peer review last week, would be fairly similar to how regular planets form around stars, just under more extreme conditions.

As dust and gas whirl around a black hole, it could gradually clump together to form a new world just so long as its far enough away to not get gobbled up by the black holes gravitational pull.

Though the processes of blanet and planet formation are fairly similar, the end results can be extremely different.

For instance, the research found that blanets could theoretically grow to be anywhere between 20 and 3,000 times more massive than Earth, which Science Alert notes is the highest possible mass a world can reach before it stops being a pla- sorry, a blanet, and is instead classified as a brown dwarf.

READ MORE: We Have Ploonets. We Have Moonmoons. Now Hold Onto Your Hats For Blanets [Science Alert]

More on exoplanets: NASA Scientist Ponders Life on Planets Orbiting Black Holes

Excerpt from:

Astronomers Say That Planets Orbiting Black Holes Are Called "Blanets" - Futurism

It probably wouldnt surprise you to know that if you put a supermassive black hole in the middle of a party, itll have a pretty big impact.

We know this is true if the party is actually a galaxy cluster. These are like cities of galaxies, collections of hundreds and sometimes thousands of galaxies all orbiting one another. They make up some of the largest structures in the Universe (called superclusters) and are themselves some of the dominant structures in the Universe.

Galaxy clusters tend to have a lot of hydrogen gas floating around between the galaxies, and it can even be the most massive component of the cluster, outweighing the galaxies themselves. That gas tends to be hot, like really hot, tens of millions of degrees. For a long time this was a mystery, because gas like that should cool pretty rapidly (in a few hundred million years, which is short compared to the age of the Universe).

But now we understand that theres usually a really massive galaxy in the center of the cluster, and it hosts a supermassive black hole. As material falls toward the black hole it piles up into a disk, which gets extremely hot so hot that it heats the gas around it violently, literally blowing it away. This stuff then moves out into the cluster, heating the gas there, and preventing it from cooling.

That happens nearly every time, but astronomers have looked for years to see if theres an exception out there.

It looks like now theyve found one. The cluster SpARCS104922.6+564032.5 (yeah, lets just call it SpARCS 1049) is located about 10 billion light years away, so we see it as it was 10 billion years ago. Its fairly beefy, with a total mass of well over 100 trillion times that of the Sun. Thats enough material to make a lot of galaxies like our own.

Like other clusters, its loaded with hot gas. But observations in the infrared using Spitzer Space Telescope revealed something weird: The existence of much cooler material called polycyclic aromatic hydrocarbons (or PAHs; they are literally organic molecules very similar to soot). This is the kind of thing you expect to see where lots of stars are being born.

And thats weird. The gas in a cluster is so hot that it cant form stars. When you heat up a gas it expands, and gravity has a hard time collecting it. Its only when gas cools that it can form stars, and it would have to cool a lot to do so.

It gets weirder: The Spitzer observations show that a huge number of stars are being born, over 850 times the Suns mass worth of stars per year. Thats hundreds of times the rate theyre born in our galaxy, by comparison. Hundreds. Thats a staggering rate.

Even more weirder, the star formation appears to be happening in region about 80,000 light years from the center of the cluster, where no galaxy is seen. These are orphan stars, born outside a galaxy, just out there in the cluster.

So whats happening here? The astronomers think that the supermassive black hole in SpARCS 1049s central galaxy is lazy. Or at least its pantry has run dry. Its not actively feeding on material, so theres no wind blowing from it that heats the cluster gas up. This allows the gas to cool, which in turn means it can form stars. Nothing quite like this has ever been seen before.

Why isnt the gas falling into the black holes maw? Its not clear, but the astronomers note that there may have been whats called a minor merger, a collision with a much smaller galaxy cluster. This could have stirred things up a bit, moving the gas away from the core of SpARCS 1049, away from the supermassive black hole lurking there. If it had been a big merger, with another massive cluster, that could have released a torrent of gas toward the black hole (and then wed see it, since that central galaxy host would be blazingly bright from all the activity), but with a much smaller one the effect is more subtle.

So this is pretty neat. It provides a counterexample to the more usual process in clusters of an active black hole suppressing star formation, in a way proving the consensus view of how it works by showing a quiet black hole allows star formation. The exception to the rule proving the rule.

When I was in grad school the question of what happens to the gas in a cluster was a big one. It was reasoned it should fall to the cluster center as it cooled, forming stars there. This even had a name: a cooling flow. Now we know why that doesnt happen usually. Its actually pretty cool and even satisfying to see that it actually can happen. Its just rare. But if you look hard enough, even the rare can be found.

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When the supermassive black hole's away, the stars will play - SYFY WIRE

But very red! he wrote in an email. I still remember that exclamation point in the Large Magellanic Cloud.

According to astronomers, there are three possible fates for a star that has run out of fuel and died. It can end up as a hot dense cinder called a white dwarf, as an even hotter and denser neutron star or as a black hole, depending on its initial mass and other details of its composition.

The star that exploded was subsequently identified as a giant blue star known as Sanduleak -69 202, which promptly vanished from the sky. In its prime it was about 19 times as massive as the sun, which puts it in the range that astronomers think should produce a neutron star.

Reinforcing that conviction was the subsequent discovery that two or three hours before the supernova was discovered, a pulse of two dozen lightweight subatomic particles called neutrinos had splashed into particle detectors on Earth. Messengers from the inside of the inferno, they had outraced the visible light in escaping the collapsing star.

Neutrinos are indeed key to the supernova and neutron star process, Dr. Burrows said.

As a massive star like this one undergoes its thermonuclear immolation, he noted, it develops onionskin layers of helium, oxygen, carbon and other newly minted elements. At the center is a growing core of iron, the most stable element. When it reaches a limit called the Chandrasekhar limit, at which atomic forces can no longer support its weight, it implodes and then rebounds, leaving behind a hot, dense neutron star.

A shock wave ripples out through the onion layers. Accompanying it, and powering it by absorptive heating, are copious quantities of neutrinos, created from the energy of the collapse. Indeed, as much as 99 percent of the energy of a supernova goes into these particles and out into the cosmos.

Neutrinos are famous for their spooky ability to pass through solid lead like moonlight through glass, but even neutrinos have trouble escaping the core of a dense proto-neutron star. It is the energy supplied by neutrinos, astronomers think, that provides the oomph to blow the star apart. If the neutrinos cannot emerge fast enough to heat an explosion, the supernova is likely to fizzle and the newly-birthed neutron star will collapse into a black hole, Dr. Burrows said.

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A Star Went Supernova in 1987. Where Is It Now? - The New York Times

An artists impression of the thin stream of stars torn from the Phoenix globular cluster, wrapping around our Milky Way (left). For the study, the astronomers targeted bright Red Giant stars, to measure the chemical composition of the disrupted Phoenix globular cluster (right). Illustration is courtesy of James Josephides (Swinburne Astronomy Productions) and the S5 Collaboration. Top right image: An artists impression of the thin stream of stars torn from the Phoenix globular cluster, wrapping around our Milky Way (left). For the study, the astronomers targeted bright Red Giant stars, to measure the chemical composition of the disrupted Phoenix globular cluster (right). Illustration is courtesy of James Josephides (Swinburne Astronomy Productions) and the S5 Collaboration.

A team of astronomers that includes Ting Li and Alexander Ji of the Carnegie Observatories in Pasadena has discovered a stellar stream composed of the remnants of an ancient globular cluster that was torn apart by the Milky Ways gravity 2 billion years ago, when Earths most-complex lifeforms were single-celled organisms.

The finding, published in the magazine Nature, upends conventional wisdom about how these celestial objects form, according to a statement issued July 29 by Carnegie Observatories.

A globular cluster is a sphere made up of as many as a million stars bound by gravity and orbiting a galactic core. The Milky Way is home to about 150 of them, which form a tenuous halo that envelops our galaxy.

But the globular cluster that spawned this newly discovered stellar stream had a lifecycle that was very different from the globular clusters we see today.

This is stellar archaeology, uncovering the remnants of something ancient, swept along in a more-recent phenomenon, explained Ji.

In this study, the collaborative focused on a stream of stars in the Phoenix constellation.

The globular cluster remnants that make up the Phoenix Stream were disrupted many years ago, but luckily retain the memory of its formation in the very early universe, which we can read from the chemical composition of its stars, said Li.

Led by Li, the initiative aims to map the motion and chemistry of stellar streams in the Southern Hemisphere, according to the Carnegie press release.

This study was part of the Southern Stellar Streams Spectroscopic Survey, S5 for short, an international collaboration using the 2dF/AAOmega instrument on the Anglo-Australian Telescope at Coonabarabran, NSW, to survey streams of stars uncovered during the Dark Energy Survey (DES).

Ji and Li are both Hubble fellows. Li is also a Carnegie-Princeton fellow.

The team measured the abundances of heavier elements what astronomers call a stars metallicity. A stars makeup mirrors that of the cloud of galactic gas from which it is born. The more prior generations of stars have seeded this material with heavy elements that they produced during their lifetimes, the more enriched, or metallic, the stars are said to be. Therefore, a very ancient, primitive star, will have almost no heavy elements.

We were really surprised to find that the Phoenix Stream is distinctly different to all of the other globular clusters in the Milky Way, explained lead author Zhen Wan of the University of Sydney. Even though the cluster was destroyed billions of years ago, we can still tell it formed in the early universe.

Because other known globular clusters are enriched by the presence of heavy elements forged by stellar earlier generations, it was theorized that there was a minimum abundance of heavier elements required for a globular cluster to form.

But the Phoenix Stream progenitor is well below this predicted minimum metallicity, posing a significant problem for previous ideas about how globular clusters are born.

One possible explanation is that the Phoenix Stream represents the last of its kind, the remnant of a population of globular clusters that was born in radically different environments to those we see today, Li said.

The researchers proposed that these no-longer-with-us globular clusters were steadily depleted by the Milky Ways gravitational forces, which tore them to pieces. The remnants of other ancient globular clusters may also live on as faint streams that can still be discovered before they dissipate over time.

There is plenty of theoretical work left to do, and there are now many new questions for us to explore about how galaxies and globular clusters form, said co-author Geraint Lewis, also of the University of Sydney.

Carnegie Observatories is headquartered at 813 Santa Barbara Street in Pasadena.

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Astronomers Part of Pasadena-Based Carnegie's Team Reveal 'Last of its Kind' Remnant of Ancient Globular Cluster - Pasadena Now