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Cosmic Space

Did interstellar object come from an alien Pluto?

It’s not aliens, but it could be a slimmed-down piece of an alien Pluto.

That’s the claim laid out in a pair of studies about the mysterious interstellar object known as ’Oumuamua, which passed through our solar system in 2017.

The studies, published in the AGU Journal of Geophysical Research: Planets, suggest that the flattened chunk of cosmic material consists primarily of solid nitrogen ice, much like the stuff on Pluto’s surface.

The debate over ’Oumuamua — whose name is derived from the Hawaiian phrase for “messenger from afar” — is still raging years after it zipped around the sun and headed back into the celestial darkness. Based on its trajectory, astronomers were certain it came from far beyond the solar system. But was it an asteroid? A comet? Could it even have been an alien spaceship?

Harvard astronomer Avi Loeb favored the alien hypothesis, due to ’Oumuamua’s weird shape and unusually fast getaway. He doubled down on the idea in “Extraterrestrial,” a book published in January. But the authors of the newly published studies, Arizona State University’s Steven Desch and Alan Jackson, say there’s no need to invoke aliens.

“Everybody is interested in aliens, and it was inevitable that this first object outside the solar system would make people think of aliens,” Desch said in a news release. “But it’s important in science not to jump to conclusions. It took two or three years to figure out a natural explanation — a chunk of nitrogen ice — that matches everything we know about ’Oumuamua. That’s not that long in science, and far too soon to say we had exhausted all natural explanations.”

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Cosmic Space

Jupiter and Saturn pair up to make a Christmas Star

Are you ready for a remake of the Christmas Star story? Depending on how much stock you put in historical hypotheses, this year’s solstice on Dec. 21 could bring a replay of the phenomenon that the Three Kings saw in the Gospel of Matthew.

That’s when Jupiter and Saturn can be seen incredibly close together in the night sky. If the skies are clear, the two planets will be hard to miss in southwest skies just after sunset, as seen from mid-northern latitudes. Jupiter will sparkle brighter, and Saturn will be shining only a tenth of a degree to the upper right. With a small telescope, you might be able to see both planets and their moons in a single field of view.

“Some astronomers suggest the pair will look like an elongated star, and others say the two planets will form a double planet,” NASA says in a blog posting about the Dec. 21 conjunction. “To know for sure, we’ll just have to look and see. Either way, take advantage of this opportunity because Jupiter and Saturn won’t appear this close in the sky until 2080!”

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Cosmic Space

Collapse delivers death blow to Arecibo radio dish

The Arecibo radio telescope’s 900-ton instrument platform fell into the 1,000-foot-wide antenna dish this morning, adding to previous damage and putting Puerto Rico’s iconic scientific structure beyond repair.

The National Science Foundation, which funds the Arecibo Observatory through a management contract with the University of Central Florida, said no injuries were caused by the collapse.

“We are saddened by this situation but thankful that no one was hurt,” NSF Director Sethuraman Panchanathan said in a statement. “When engineers advised the NSF that the structure was unstable and presented a danger to work teams and Arecibo staff, we took their warnings seriously and continued to emphasize the importance of safety for everyone involved.”

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Cosmic Space

The long goodbye begins for iconic radio dish

The radio telescope at Puerto Rico’s Arecibo Observatory is on its way to extinction after 57 years of sparking dreams of alien contact — and after a grim three years of weathering nature’s blows.

Two of the cables supporting the telescope’s 900-ton instrument platform have slipped loose, ripping through the 1,000-foot-wide web of aluminum panels and steel cables that’s spread 450 feet below.

Engineers assessed the damage and determined that the risk of a catastrophic failure was too great to attempt repairs. If more cables snap, the entire platform could crash down, potentially causing the dish’s collapse and life-threatening injuries to workers.

“Although it saddens us to make this recommendation, we believe the structure should be demolished in a controlled way as soon as pragmatically possible, ” Thornton Tomasetti, the engineering firm that made the structural assessment, said in its recommendations to the National Science Foundation and the University of Central Florida, which manages operations at Arecibo on the NSF’s behalf.

“It is therefore our recommendation to expeditiously plan for decommissioning of the observatory and execute a controlled demolition of the telescope,” the firm said.

After consulting with other engineering firms and the U.S. Army Corps of Engineers, NSF decided to go ahead with the decommissioning.

“NSF prioritizes the safety of workers, Arecibo Observatory’s staff and visitors, which makes this decision necessary, although unfortunate,” NSF Director Sethuraman Panchanathan said in a statement.

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Cosmic Space

Fast radio bursts linked to a prime suspect

For years, astronomers have puzzled over the origins of phenomena known as fast radio bursts — cosmic emissions that last only a fraction of a second but blast out more than 100 million times more power than our sun. Some even wondered whether the bursts, known as FRBs, might serve as signals from extraterrestrial civilizations.

Now they’ve tracked down the source of the first fast radio burst detected in our own Milky Way galaxy — and it’s not aliens. Instead, it’s a magnetar, a type of neutron star with a powerful magnetic field.

Scientists have long suspected that fast radio bursts had something to do with magnetars. But the newly reported case, described in three studies published today by the journal Nature, serves as the astronomical equivalent of a smoking gun.

“There’s this great mystery as to what would produce these great outbursts of energy, which until now we’ve seen coming from halfway across the universe,” Kiyoshi Masui, a physicist at the Massachusetts Institute of Technology, said today in a news release. “This is the first time we’ve been able to tie one of these exotic fast radio bursts to a single astrophysical object.”

Masui is part of the team that picked up the first clues to the source, a magnetar 30,000 light-years from Earth that’s known as SGR 1935+2154. The team includes researchers from MIT, the University of British Columbia, McGill University, the University of Toronto and the Perimeter Institute for Theoretical Physics.

They made use of a radio telescope array called the Canadian Hydrogen Intensity Mapping Experiment, or CHIME, which began science operations in 2018 at the Dominion Radio Astrophysical Observatory in British Columbia’s Okanagan Valley.

In April, astronomers detected bursts of X-ray and gamma-ray activity from SGR 1935 — which led the CHIME team to turn their attention to that part of the sky, around the center of the Milky Way. Shortly after an X-ray burst on April 28, CHIME registered two sharp peaks in radio emissions, within a few milliseconds of each other.

That fit the pattern for a fast radio burst, emanating from a point in the vicinity of SGR 1935. “If it was coming from any other object close to the magnetar, it would be a very big coincidence,” Masui said.

The source was near the edge of CHIME’s field of view, which made it difficult to determine the radio burst’s brightness. So the team put out the word for other astronomers to check their records.

By a stroke of luck, another radio astronomy project —  known as the Survey for Transient Astronomical Radio Emission 2, or STARE2 — had a wide-field view of the same blast.

“When I saw the data, I was basically paralyzed,” Caltech graduate student Christopher Bochenek said in a news release. “At the radio frequencies we observe with STARE2, the signal was much stronger than what CHIME reported. We had caught the FRB head-on.”

STARE2 isn’t your typical radio telescope array: The heart of the Caltech-led, NASA-funded project is a handmade radio receiver that’s about the size of a large bucket. “It’s a piece of 6-inch metal pipe with two literal cake pans around it,” Bochenek told The Associated Press.

Three of the receivers are placed at widely separated locations in California and Utah, which makes it possible to triangulate on the source of cosmic radio emissions. They’re not as sensitive as the more traditional big-dish telescopes, but they can take in the whole sky.

The readings from STARE2, combined with data from other instruments, suggested that the April 28 burst was 3,000 times brighter than any previously observed magnetar radio signal.

Among the other instruments participating in the observational campaign was China’s Five-Hundred-Meter Aperture Spherical Radio Telescope, also known as FAST. Astronomers on the FAST team missed out on detecting FRB 200428, but they kept an eye on SGR 1935 as it emitted a series of 29 gamma-ray bursts. None of those bursts coincided with a blast of high-energy radio waves.

“The weak correlation could be explained by special geometry and/or limited bandwidth of FRBs,” study co-author Zhang Bing of the University of Nevada at Las Vegas said in a news release. “The observations of SGR J1935 start to reveal the magnetar origin of FRBs, although other possibilities still exist.”

Astrophysicists haven’t yet figured out the mechanism for producing fast radio bursts, but one hypothesis is that they can occur when a magnetar throws off a flare of charged particles that interact with debris surrounding the star. The resulting shock wave could set electrons gyrating wildly, throwing off radio waves as well as X-rays.

To unravel that part of the mystery, the CHIME team and other astronomers are keeping a close watch on SGR 1935.

“We’ve got our eyes open for other magnetars,” Masui said, “but the big thing now is to study this one source and really drill down to see what it tells us about how FRBs are made.”

The CHIME/FRB Collaboration’s study, described in a Nature paper titled “A Bright Millisecond-Duration Radio Burst From a Galactic Magnetar,” was funded by the Canada Foundation for Innovation and other supporting institutions. The second Nature study, “A Fast Radio Burst Associated With a Galactic Magnetar” counts Bochenek as well as V. Ravi, K.V. Belov, G. Hallinan, J. Kocz, S.R. Kulkarni and D.L. McKenna among its authors. Zhang is among 48 authors of the third Nature paper, titled “No Pulsed Radio Emission During a Bursting Phase of a Galactic Magnetar.”

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Cosmic Space

It’s prime time for the sky show in your backyard

Ready for a star party?

The COVID-19 pandemic has put a damper on summer star parties and other public gatherings, and skywatching isn’t exactly the kind of thing best done via a Zoom session. But you can still experience the wonders of the universe, just by looking up into dark, clear skies.

“The Backyard Astronomer’s Field Guide,” a newly published handbook by science writer David Dickinson, can help you do it.

“I pitch it as a star party in a book,” Dickinson explained.

This week is the summer’s big week for skywatchers:

  • The Globe at Night campaign is asking citizen scientists to report what they see in evening skies, to assess the effects of light pollution.
  • The Perseid meteor shower peaks on the nights of Aug. 10-13.
  • Four planets are on view: Jupiter and Saturn after sunset, and Mars and Venus before sunrise.
  • Although now is not the best time for Americans to spot the International Space Station, you just might be able to track the latest batch of SpaceX Starlink satellites as the stream across the sky. (Plug in your coordinates on Heavens-Above.com to check viewing times.)

Dickinson’s guide is designed to cover the more established targets of the night sky, ranging from the constellations to star clusters, nebulae and galaxies.

Forty-four sky charts, organized by month, point out wonders that can be found with the naked eye, with binoculars or with a telescope like the one that Dickinson sets up in his backyard or on the top floor of a nearby parking garage.

“Your observatory is wherever you’re observing,” he said.

Backyard Astronomer's Field Guide
“The Backyard Astronomer’s Field Guide” is spiral-bound for convenient use in the field. (Page Street Publishing / Laura Benton)

Dickinson also provides context that goes beyond latitude and longitude: Which naked-eye stars have planets orbiting them? What are the myths behind the constellation’s names, and what did other cultures see in them? What makes a planetary nebula “planetary”?

The guide includes a list of online tools, websites and publications to help you plot out your observing strategy — including Stellarium, a free planetarium program that’s priceless.

So what are the best deep-sky objects to turn your telescope toward while you’re waiting for the Perseids? Dickinson recommends M13, a globular star cluster in Hercules, the Ring Nebula in Lyra, the variable star Algol (a.k.a. the Demon Star) in Perseus … and Epsilon Lyrae, the “double-double” star in the constellation Lyra.

The double-double is famous, but somehow it was left out of the deep-sky catalog created by French astronomer Charles Messier in the 1700s. “I was always amazed that he missed things like the double-double,” Dickinson said.

You’re unlikely to repeat Messier’s mistake, as long as you have Dickinson’s field guide sitting next to your lounge chair (preferably consulted by the light of a red flashlight to preserve your night vision).

To celebrate the summer’s big week for skywatching — and reward you for reading down this far — I’m giving away a copy of “The Backyard Astronomer’s Field Guide.” Just be the first to answer this Cosmic Log quiz question in the comment section below:

What is the name of the closest planetary nebula to Earth?

The first person to answer correctly, based on my assessment of the time stamp, will be eligible to receive the book by mail (U.S. postal addresses only). If I can’t get in touch with that person via email in a timely fashion, I’ll move on to the next person on the list.

Back in the old days, Cosmic Log was known for its community of commenters, and I’m hoping we can revive that spirit. If you have a favorite night-sky object to observe, or a favorite resource for skywatching, pass it along in a comment. Your recommendation may end up in a future Cosmic Log roundup.

Update for 11:25 a.m. PT Aug. 9: We have a winner! Boris Zuchner was the first to answer the quiz question correctly, with an assist by Professor Google. As revealed on page 160 of “The Backyard Astronomer’s Field Guide,” the closest planetary nebula to Earth is the Helix Nebula, a.k.a. NGC 7293. Assuming that Boris’ mailing address is in the United States, he’ll be able to look that fact up himself in the future, thanks to the book I’ll be sending him.

As I wrote in the comments, don’t be a stranger! It took me a while to approve the comments this time around, but I’ll try to be faster on the draw for the next book giveaway.

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GeekWire

Space telescope named after ‘Mother of Hubble’

The telescope formerly known as WFIRST has a new name that honors Nancy Grace Roman, who served as NASA’s first chief astronomer and came to be known as the “Mother of Hubble.”

Get the news brief on GeekWire.

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GeekWire

Xplore works with gravity-lens telescope team

Solar sail
An artist’s conception shows Xplore’s advanced solar sail for NASA’s Solar Gravity Lens Focus mission. (Visualization by Bryan Versteeg, SpaceHabs.com / via Xplore)

NASA has awarded a $2 million grant to the Jet Propulsion LaboratoryThe Aerospace Corp. — and Xplore, a Seattle-based space venture — to develop the design architecture for a far-out telescope array that would use the sun’s gravitational field as a lens to focus on alien planets.

The Phase III award from the NASA Innovative Advanced Concepts program, or NIAC, would cover two years of development work and could lead to the launch of a technology demonstration mission in the 2023-2024 time frame.

Xplore’s team will play a key role in designing the demonstration mission’s spacecraft, which would be launched as a rideshare payload and propelled by a deployable solar sail.

Get the full story on GeekWire.

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GeekWire

Telescope project honors astronomer and billionaire

LSST
Artwork shows the Vera Rubin Observatory’s Simonyi Survey Telescope scanning the sky. (LSST Illustration)

The next great ground-based astronomical observatory, previously known as the Large Synoptic Survey Telescope, has been named after the late astronomer Vera Rubin — with a nod to Seattle software billionaire Charles Simonyi as well.

Get the news brief on GeekWire.

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GeekWire

Mega-constellations spark fears about space traffic

Starlink streaks
An image of the NGC 5353/4 galaxy group, made with a telescope at Arizona’s Lowell Observatory on May 25, shows the trails of reflected light left by SpaceX’s freshly launched Starlink satellites as they pass through the telescope’s field of view. The brightness diminishes once the satellites reach their intended altitude. (Lowell Observatory Photo via IAU / Victoria Girgis)

The retired commander of the U.S. Strategic Command says the tens of thousands of satellites that SpaceX, OneWeb and Amazon are planning to put into orbit over the next few years will require a new automated system for space traffic management — and perhaps new satellite hardware requirements as well.

Retired Gen. Kevin Chilton laid out his ideas for dealing with potentially catastrophic orbital traffic jams at the University of Washington on Friday, during the inaugural symposium presented by UW’s Space Policy and Research Center.

Get the full story on GeekWire.