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Newly discovered comet may be yet another interstellar visitor – CBC News

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The astronomical community is abuzz with the prospect that a recently discovered comet may actually have come from beyond our solar system.

This would make it only the second known interstellar interloper. The first — officially named 1I/’Oumuamua — was discovered in 2017.

But this visitor is very different.

“This one is actually nothing like ‘Oumuamua,” said Canadian astronomer Robert Weryk, who identified ‘Oumuamua as the first interstellar object while working at the University of Hawaii’s Institute for Astronomy.

“We were pretty sure right off the bat we had something pretty special. It was just the case that we’d never seen something like this before.”

An artist’s impression of the first known interstellar asteroid, ‘Oumuamua. (M. Kornmesser/ESO)

Astronomers had long believed that an interstellar visitor would be icy and comet-like, with gas and ice being released as it neared the sun. However, ‘Oumuamua didn’t do that. In fact, there was debate as to whether it was an asteroid — which has little to no water or ice — or a comet. In the end, scientists found evidence it was a comet.

“We were stunned, we were like, ‘What did we get wrong?” said Olivier Hainaut, an astronomer with the European Southern Observatory.

But C/2019 Q4, on the other hand, is behaving just as astronomers originally believed an interstellar object would.

“It’s a comet, there is no question,” said Hainaut. “Assuming that it’s interstellar … we now have a second interstellar object, and it does not look at all like the first one. Isn’t that amazing? I don’t know what would have been more exciting: to get a second one that looked exactly like ‘Oumuamua or to have one that is completely different.”

What we know

While ‘Oumuamua was discovered by Weryk using the Pan-STARRS telescope in Hawaii, which is dedicated to searching for asteroids and comets, the discovery of C/2019 was made by astronomer Gennady Borisov on Aug. 30 in Nauchnij, Crimea.

The comet, which has been designated C/2019 Q4 (Borisov), has a hyperbolic orbit, meaning that it isn’t captured by the gravity of the sun. This is why astronomers are fairly confident that C/2019 Q4 isn’t from our solar system.

The International Astronomical Union’s Minor Planet Center officially names solar system objects. The C in the name designates C/2019 Q4 as a comet, which means it’s not yet confirmed that it’s interstellar. More observations are needed in order to better refine its orbit. If it is confirmed it will designated 2I plus a name (the “I” stands for interstellar).

Amateur astronomer Greg Crinklaw imaged C/2019 Q4 (centre) using iTelescope’s remote observatory in New Mexico. (Supplied by Greg Crinklaw)

Weryk is being cautious about calling it an interstellar object.

“We need to observe this one for a lot more and be cautious before making any significant claims, because it is very different,” Weryk said. “And that is part of science: it being so different is what makes it so exciting.”

This illustration depicts Comet C/2019 Q4’s trajectory. Deemed a possible interstellar object, it will approach no closer to Earth than about 300 million kilometres. (NASA/JPL-Caltech)

But the good news is that astronomers have a lot of time.

In 2017, ‘Oumuamua was found on its way out of our solar system, while this comet is on its way in. This means that astronomers will have about a year to further study the object.

So far, astronomers have determined that C/2019 Q4 is fairly large, much larger than ‘Oumuamua was. It’s also icy, which means it’s fairly bright and will get brighter as it approaches the sun and more of the ice sublimates, or changes directly from a solid to a gas.

Right now C/2019 Q4 is roughly 420 million kilometres from the sun, travelling about 150,000 km/h. It will reach its closest point to our star — called perihelion — on Dec. 8, at a distance of roughly 300 million kilometres, taking it outside the orbit of Mars.

“We won’t have a super-close approach, but we can observe it for months and months and months,” said Hainaut.

“So that means that there are many things that we will be able to [learn] with 2I that we were not able to with 1I. Like what is its evolution? What is the non-gravitational force? Is it tumbling like 1I or does it have a stable rotation? What’s its shape? Is it a funky, elongated shape like 1I?”

Hainaut said that he’s ready to do followup observations with large, ground-based telescopes, and many astronomers will be vying for time on telescopes to do the same. 

In the meantime, Weryk and Hainaut said it will be interesting to see what unfolds as the comet gets closer to the sun. Will it get a lot brighter? Could it break apart?

“It’s really one of these cases where we just need to wait,” Hainaut said. “We might have surprises.”

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Photos Show Evidence of Life on Mars, Claims Scientist – NDTV

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As scientists scramble to determine whether there is life on Mars, a researcher from Ohio University in US believes that there is evidence of insect-like creatures on the red planet.

Courtesy photographs from various Mars rovers, Professor Emeritus William Romoser’s research found numerous examples of insect-like forms, structured similarly to bees, as well as reptile-like forms, both as fossils and living creatures.

“There has been and still is life on Mars,” Romoser said, noting that the images appear to show both fossilised and living creatures.

“There is apparent diversity among the Martian insect-like fauna which display many features similar to Terran insects that are interpreted as advanced groups – for example, the presence of wings, wing flexion, agile gliding/flight, and variously structured leg elements,” Romoser added.

Romoser said that while the Martian rovers, particularly the Curiosity Rover, have been looking for indicators of organic activity, there are a number of photos which clearly depict the insect- and reptile-like forms.

Photo Credit: Ohio University

Numerous photos show images where arthropod body segments, along with legs, antennae and wings, can be picked out from the surrounding area, and one even appears to show one of the insects in a steep dive before pulling up just before hitting the ground.

Individual images were carefully studied while varying photographic parameters such as brightness, contrast, saturation, inversion, and so on. No content was added, or removed.

Criteria used in Romoser’s research included: Dramatic departure from the surroundings, clarity of form, body symmetry, segmentation of body parts, repeating form, skeletal remains, and observation of forms in close proximity to one another.

Particular postures, evidence of motion, flight, apparent interaction as suggested by relative positions, and shiny eyes were taken to be consistent with the presence of living forms.

“Once a clear image of a given form was identified and described, it was useful in facilitating recognition of other less clear, but none-the-less valid, images of the same basic form,” Romoser said. “

An exoskeleton and jointed appendages are sufficient to establish identification as an arthropod.

Three body regions, a single pair of antennae, and six legs are traditionally sufficient to establish identification as ‘insect’ on Earth.

These characteristics should likewise be valid to identify an organism on Mars as insect-like. On these bases, arthropodan, insect-like forms can be seen in the Mars rover photos.”

These creatures loosely resemble bumble bees or carpenter bees on Earth. Other images show these “bees” appearing to shelter or nest in caves. And others show a fossilized creature that resembles a snake.

“The presence of higher metazoan organisms on Mars implies the presence of nutrient/energy sources and processes, food chains and webs, and water as elements functioning in a viable, if extreme, ecological setting sufficient to sustain life,” Romoser said.

“The evidence of life on Mars presented here provides a strong basis for many additional important biological as well as social and political questions,” he added.

The study was presented at Entomological Society of America national meeting.

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Starlink Satellites Posing Issues For Astronomers – Hackaday

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Spotting satellites from the ground is a popular pastime among amateur astronomers. Typically, the ISS and Iridium satellites have been common sightings, with their orbits and design causing them to appear sufficiently bright in the sky. More recently, SpaceX’s mass launches of Starlink satellites have been drawing attention for the wrong reasons.

A capture from the Cerro Telolo observatory, showing the many Starlink satellite tracks spoiling the exposure.

Starlink is a project run by SpaceX to provide internet via satellite, using a variety of techniques to keep latency down and bandwidth high. There’s talk of inter-satellite laser communications, autonomous obstacle avoidance, and special designs to limit the amount of space junk created. We’ve covered the technology in a comprehensive post earlier this year.

The Starlink craft have long worried astronomers, who rely on a dark and unobstructed view of the sky to carry out their work. There are now large numbers of the satellites in relatively low orbits, and the craft have a high albedo, meaning they reflect a significant amount of the sunlight that hits them. With the craft also launching in a closely-packed train formation, there have already been impacts on research operations.

There is some hope that as the craft move to higher orbits when they enter service, this problem will be reduced. SpaceX are also reportedly considering modifications to the design to reduce albedo, helping to keep the astronomy community onside. Regardless, with plans on the table to launch anywhere from 12,000 to 42,000 satellites, it’s likely this isn’t the last we’ll hear about the issue.

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This Is How Elon Musk Can Fix The Damage His Starlink Satellites Are Causing To Astronomy – Forbes

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CLARAE MARTÍNEZ-VÁZQUEZ / CTIO

In any field of business or industry, the prevailing rule has always been that if there isn’t a law against it, you are free to do it. If there are no rules protecting a resource, you are free to use or take as much of it as you want to further your own ends. Until regulatory measures are put into place, disruptors and innovators are free to regulate themselves, often to the extraordinary detriment of those who depended on those now-scarce resources.

In astronomy, the greatest resource of all is a dark, clear night sky: humanity’s window to the Universe. Traditionally, its enemies have been turbulent air, cloud cover, and artificial light pollution. But very recently, a new type of pollutant has begun to pose an existential threat to astronomy itself: mega-constellations of satellites. If Elon Musk’s Starlink project continues as it has begun, it will likely end ground-based astronomy as we know it.

Getty

Launching satellites to provide services to those of us living on the ground is an essential part of modern-day living. GPS and telecommunications satellites enable our cellular signals and support our mobile internet today. With the coming upgrade to 5G services, a new set of infrastructure will be required, and that necessarily means an upgraded set of satellites equipped to provide that service must be launched.

One of the first companies to attempt to serve this market is SpaceX, under the guidance of Elon Musk, which plans to initially deploy 12,000 satellites in a mega-constellation known as Starlink. Ultimately, the constellation hopes to extend to a total of 42,000 satellites. As of November 20, 2019, only 122 of these satellites have been deployed, and they’ve already had a detrimental impact on astronomy on a global scale.

If we hope to mitigate this, either regulators or SpaceX executives themselves will need to mandate a change.

Richard Ryer of Panoramio

From the darkest skies you can find on Earth, approximately 9,000 stars are visible to human eyes: down to a visual magnitude of +6.5, the limit of human vision. Yet the first 122 satellites launched by Starlink are not only brighter than the majority of these stars, they move quickly throughout the sky, leaving trails that pollute astronomers’ data.

If these satellites were either faint, few in number, or slowly moving, this would be only a mild problem. If you’re only observing a narrow region of the sky, you’d simply reject any exposure frames (or even just the pixels from them) where the offending objects streak across the sky. But with large numbers of bright, rapidly moving satellites, particularly if you’re searching for changes from frame-to-frame (like many current and future observatories are designed to do), you have to throw out any exposure frame with these artifacts in them.

CLIFF JOHNSON / CTIO / DECam

On November 18, 2019, a series of 19 of these Starlink satellites passed over the Cerro Tololo Inter-American Observatory’s site in Chile, lasting for more than 5 minutes and heavily affecting the wide-field DECam instrument, which images a field containing 3 square degrees at an outstanding 0.263 arcsecond-per-pixel resolution.

Even though this only represents 0.3% of the total number of proposed Starlink satellites that SpaceX wants to launch, the consequences are clear: wide-field astronomy designed to look for faint objects — prime goals of observatories like Pan-STARRS, LSST, and any observing program geared towards finding potentially Earth-hazardous objects — is going to be significantly hindered. Averaging over frames is not a desired option, because it erases astronomers’ ability to study the natural variability of object, another important science goal. Because Starlink satellites autonomously change their orbits and are extremely radio-loud, ground-based observations cannot be scheduled so as to avoid them.

NASA illustration courtesy Orbital Debris Program Office

In addition, these satellites are not in traditional low-Earth orbits, which will decay and fall back to Earth on timescales of months, years, or (at most) decades, these satellites are at elevations of over 1,000 km, where orbital decay will take millennia. Already, back in September, the ESA’s Aeolus satellite (used for Earth observation) had to make an emergency maneuver to avoid colliding with a SpaceX Starlink satellite, despite the fact that it was SpaceX’s responsibility to move.

Although SpaceX and Musk have issued statements claiming that:

all of these statements are not yet true as of November 20, 2019.

Getty

Previous constellations of satellites, such as the extremely successful Iridium constellation, proceeded in clearly defined and predictable orbits, were few in number (66 total), and only flared brightly when their orientation reflected sunlight in a particular manner. The Starlink satellites, along with similar planned constellations such as Kuiper Systems and OneWeb, pose a new and unique hurdle for ground-based astronomy.

According to Cees Bassa from the Netherlands Institute for Radio Astronomy, up to 140 such satellites will be visible at any one time from every observatory on Earth. However, if the companies behind these new constellations are willing to take just a few simple steps, all of these hurdles can be overcome. Here’s what a responsible steward of the night sky ought to do, and how SpaceX can undo the damage they’re in the process of inflicting on astronomy.

NASA/ESA/Bill Moede and Jesse Carpenter

1.) De-orbit the current batch of Starlink satellites, and place a moratorium on the launch of new ones until the proper modifications have been made. Unlike most of the GPS and communications satellites we have today, the current Starlink satellites are large, reflective, and already causing some astronomers to throw out significant portions of their data. Currently at an altitude of 280 km, where they’re visible to the naked eye, they can now easily and safely be de-orbited.

But once they’re raised to their operational altitude of 550 km, they become a much more permanent problem. In addition, public awareness will drop, but they will remain visible to all binoculars and telescopes: the astronomer’s most essential tools. Every moment that these satellites are up there is the astronomical equivalent of callously rollin’ coal in the face of every scientist, researcher, and especially the undergraduate and graduate students who rely on hard-to-obtain telescope time in order to start their careers.

SpaceX / Space.com

2.) Either redesign or coat the satellites to significantly reduce their reflectivity. Part of the problem with these new satellites is that they’re both large and highly reflective. But these problems are unnecessary: they’re choices. Choosing a different design, where the satellites can be oriented to minimize the impact on astronomy, would ameliorate the problem. Even more cost-effectively, simply coating the satellites with a very dark, low-albedo outer layer would go a long way to reducing the astronomically polluting effects of this constellation.

Albedo reduction, it is very clear from the current Starlink satellites, was not even considered as part of the design. By incorporating some common sense steps to reduce it — and I know plenty of astronomers willing to help with recommendations — the apparent brightness of these satellites can be reduced by a factor of approximately ~100.

IAU/ Victoria Girgis/ Lowell Observatory

3.) Provide real-time trajectory plans, predictions, and adjustment information for each satellite to observatories worldwide. One of the worst things about these satellites is that they come without predictable trajectories. If their paths were known, astronomers could schedule observations that absolutely minimized their impact on the science, making good use of every moment of good seeing.

It should be not only easy, but mandatory, to set up a global network that tracked the predicted paths of each satellite in real-time, updated continuously to account for any maneuvers or course-corrections that were taken. By providing this information to astronomers, the polluted areas can be avoided at any moment in time, while still taking quality observations of as much of the sky as possible.

SpaceX via Twitter

4.) Provide funding to assist astronomers in the development of hardware and software-driven solutions to subtracting out as much of the satellite pollution as possible. Even if all of these steps are taken, it will still be an arduous and expensive task for astronomers to account for the contamination that remains in their data. It’s unreasonable to expect that Starlink or any satellite-based company will have no impact on astronomy at all, but it’s extremely reasonable to demand that they fund the mitigation efforts astronomers will need to take.

This is how literally every other industry in the world works: if you plunder some aspect of the natural environment, you must make restitution for the damage that you caused. The astronomers that I know don’t care that you have satellites up there; they care that they’re still able to do their work despite them. It really isn’t too much to ask.

Starlink (simulation)

Right now, the Outer Space Treaty only prohibits the militarized use of space; all peaceful purposes are allowed. There are no consequences for damages done to the night sky and no regulations on pollution or contamination. So long as you register your satellite(s) and don’t cause an in-orbit or on-Earth collision, there is no legal liability to what you do.

The astronomical community’s only options are either to attempt to get laws passed protecting the night sky, or to hope that the industry will self-regulate. If companies like SpaceX, Kuiper Systems and OneWeb take the altruistic route of addressing these issues in advance of causing widespread problems, they will truly be worthy captains of this burgeoning industry. But it’s very scary to be entering an era where the future of one of humanity’s oldest sciences depends on the ethical compasses of a few profit-driven companies. Our understanding of the Universe, from nearby hazardous objects to the distant recesses of space, is no longer in the hands of astronomers.

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