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Asteroid-hunting algorithm passes a tricky test

Bird's eye view showing orbital paths for Earth and asteroid 2022 SF289 at closest approach
A bird’s-eye view of the solar system shows the orbital path for Earth in blue and the projected orbit for the asteroid known as 2022 SF289 at its closest approach in green. Orbits of Venus and Mars are shown in orange and red. (Credit: Joachim Moeyens / UW / OpenSpace)

A new technique for finding potentially hazardous asteroids before they find us has chalked up its first success.

In this case, the asteroid isn’t expected to threaten Earth anytime in the foreseeable future. But the fact that the technique — which uses a new computer algorithm called HelioLinc3D — actually works comes as a confidence boost as astronomers get set to step up the asteroid hunt with the Vera C. Rubin Observatory in Chile.

The University of Washington’s DiRAC Institute will play a leading role in analyzing the data from the Rubin Observatory, and HelioLinc3D is meant to make the job easier.

It’ll be another couple of years before the Rubin Observatory starts surveying the skies, but researchers put HelioLinc3D to the test by feeding it data from the NASA-funded Asteroid Terrestrial-impact Last Alert System, or ATLAS.

During the July 18 test run, the algorithm combined fragments of ATLAS data from four nights of observations to identify an asteroid that had been previously missed.

The asteroid, designated 2022 SF289 and described in a Minor Planet Electronic Circular, is thought to be about 600 feet wide. That’s wide enough to cause widespread destruction on Earth in the event of an impact. The good news is that projections of 2022 SF289’s orbital path show it staying 140,000 miles away from Earth at its closest. Nevertheless, the space rock fits NASA’s definition of a potentially hazardous asteroid because of its estimated size and the fact that it can come within 5 million miles of our planet.

UW researcher Ari Heinze, the principal developer of HelioLinc3D, said the algorithm’s success should carry over to the Rubin Observatory’s future database.

“By demonstrating the real-world effectiveness of the software that Rubin will use to look for thousands of yet-unknown potentially hazardous asteroids, the discovery of 2022 SF289 makes us all safer,” Heinze said in a news release.

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Scientists find evidence of a gravitational wave ‘hum’

Illustration: Ripples in spacetime caused by gravitational waves
Scientists monitor how ripples in spacetime affect the timing of signals from pulsars. (Credit: Aurore Simonnet for NANOGrav Collaboration)

Astrophysicists have found the best evidence yet for a low-frequency “hum” of gravitational waves rippling through the cosmos, based on 15 years’ worth of ultra-precise measurements checking the timing of radio pulses from distant stars.

The evidence, newly published in the Astrophysical Journal Letters, comes from several teams of researchers working in the U.S. and Canada as well as Europe, India, Australia and China.

The teams monitored radio emissions from a total of 115 ultra-dense, spinning stars known as pulsars. Nearly 70 of those pulsars were observed by the North American Nanohertz Observatory for Gravitational Waves, known as NANOGrav.

“This is key evidence for gravitational waves at very low frequencies,” Vanderbilt University’s Stephen Taylor, who co-led the search and is the current chair of the NANOGrav Collaboration, said today in a news release. “After years of work, NANOGrav is opening an entirely new window on the gravitational-wave universe.”

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Universe Today

AI produces a sharper image of M87’s black hole

Three views of M87's black hole
Three views of a black hole, from left to right: Event Horizon Telescope's original image, PRIMO reconstruction and image blurred to match EHT's resolution. (Credit: Lia Medeiros et al. / ApJL, 2023)

Astronomers have used machine learning to sharpen up the Event Horizon Telescope’s first picture of a black hole — an exercise that demonstrates the value of artificial intelligence for fine-tuning cosmic observations.

The image should guide scientists as they test their hypotheses about the behavior of black holes, and about the gravitational rules of the road under extreme conditions.

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Study documents satellite interference with Hubble

Satellite streaks on Hubble images
Satellite streaks cross these images from the Hubble Space Telescope. (NASA / ESA / STScI / Kruk et al. / Nature)

An analysis of more than 100,000 images from the Hubble Space Telescope, conducted with the aid of artificial intelligence and hundreds of human volunteers, confirms that satellites including SpaceX’s Starlink spacecraft are increasingly interfering with astronomical observations.

The images used in the study, which is the subject of a paper published today by Nature Astronomy, largely predate the deployment of Starlink broadband internet satellites. But the trend line suggests that more and more satellites will cause more and more interference.

“This is an attempt to define a baseline before the swarm of artificial satellites for future follow-up studies of the impact of megaconstellations on space-based astronomy,” said the research team, which is led by Sandor Kruk of the Max Planck Institute for Extraterrestrial Physics in Germany.

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Fireball lights up Seattle’s skies as webcams watch

Fireball blazing in skies over Seattle
Corey Clarke’s webcam captured the flash of a meteor. (Courtesy of Corey Clarke via Twitter)

It’s cool to see a fireball — but even cooler to capture it on video. At least that’s the way Seattle engineer/photographer Corey Clarke sees it.

Clarke’s webcam happened to be pointing in the right direction to record the fireball’s flash through wispy clouds at around 11 p.m. PT Monday night. His day job at ServiceNow focuses on hardware reliability, but he’s also a photographer who specializes in wildlife shots, landscapes and views of the night sky.

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Universe Today

Webb pioneer gives advice to future telescope builders

John Mather portrait
Nobel-winning physicist John Mather is the senior project scientist for NASA's James Webb Space Telescope. (NASA Photo / Chris Gunn)

After a quarter-century of development, NASA’s James Webb Space Telescope is a smashing success. But senior project scientist John Mather, a Nobel-winning physicist who’s played a key role in the $10 billion project since the beginning, still sees some room for improvement.

Mather looked back at what went right during JWST’s creation, as well as what could be done better the next time around, during a lecture delivered today at the American Astronomical Society’s winter meeting in Seattle.

The seeds for JWST were planted way back in 1989, a year before the launch of the Hubble Space Telescope. Mather said the scientists who were planning for what was initially known as the Next Generation Space Telescope took a lesson from the problems that plagued Hubble — problems that required an on-orbit vision correction.

“No. 1 lesson from Hubble program was, figure out how you’re going to do this before you do it, and make sure the technologies are mature,” he said.

The JWST team designed a segmented mirror that could be folded up for launch, and then unfolded in space to create a 21-foot-wide reflective surface. An even wider sunshade blocked out the sun’s glare as the telescope made its observations from a vantage point a million miles from Earth.

Mather cycled through the new space telescope’s greatest hits — including a deep-field view with a gravitational-lensing galaxy cluster that brought even more distant objects into focus. “There is actually a single star which is magnified enough that you can recognize it in the image,” Mather said. “When we talked about this in the beginning, I thought the odds of this happening are too small. … I am completely stunned with this result.”

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Webb Space Telescope scores big at astronomy meet-up

JWST view of star cluster NGC 346
NASA’s James Webb Space Telescope captured this view of NGC 346, a star cluster in a nebula 200,000 light-years away. Science: NASA, ESA, CSA, Olivia Jones (UK ATC), Guido De Marchi (ESTEC), Margaret Meixner (USRA). Image processing: Alyssa Pagan (STScI), Nolan Habel (USRA), Laura Lenkić (USRA), Laurie E. U. Chu (NASA Ames).

It’s not yet clear whether the Seahawks will be in the Super Bowl, but Seattle is in the spotlight this week for the “Super Bowl of Astronomy” — and there’s already an obvious choice for MVP.

NASA’s James Webb Space Telescope is taking center stage at the 241st meeting of the American Astronomical Society, which has drawn more than 3,400 masked-up registrants to the Seattle Convention Center to share astronomical research and figure out their next moves on the final frontier.

The twice-a-year AAS meetings are often compared to scientific Super Bowls — although the fact that this week’s meeting came on the heels of the soccer world’s biggest event led the National Science Foundation’s NOIRLab to call it the “World Cup of Astronomy and Astrophysics” instead.

This is the second post-pandemic, in-person meeting for AAS, following up on last June’s AAS 240 meeting in Pasadena, Calif. The $10 billion James Webb Space Telescope was launched a little more than a year ago, but the telescope’s first full-color images and science data weren’t released until July — a month after AAS 240. That makes this week’s gathering something of a coming-out party for JWST.

Jane Rigby, an astrophysicist at NASA’s Goddard Space Flight Center who serves as JWST’s operations project scientist, said there’s “nothing but good news” about the telescope’s performance. “The science requirements are met or exceeded across the board,” she said during a plenary lecture. “It’s just all so gorgeous.”

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Universe Today

How to see the bigger picture from the Webb Telescope

Carina Nebula as seen by JWST and Terapixel DSS
The James Webb Space Telescope's infrared image of the Carina Nebula is embedded within a wider optical-wavelength view from the Terapixel Digitized Sky Survey. (JWST / DSS via AAS WorldWide Telescope)

MEMPHIS, Tenn. — Side-by-side pictures from NASA’s 32-year-old Hubble Space Telescope and the brand-new James Webb Space Telescope may draw oohs and ahhs, but they don’t give you a full sense of just how much more astronomers are getting from the new kid on the cosmic block.

Fortunately, new tools for data visualization can get you closer to the sense of wonder those astronomers are feeling.

“The public is just presented with these beautiful pictures, and they think, ‘Oh, wow, that’s great,’” says Harvard astronomer Alyssa Goodman. “But in my opinion, they could learn a lot more from these images.”

Goodman laid out strategies for getting a better appreciation of JWST — and a better appreciation of the technologies that are transforming modern astronomy — this week at the ScienceWriters 2022 conference in Memphis.

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Universe Today

Neptune and its rings glow in Webb Telescope’s portrait

JWST view of Neptune
An infrared image from NASA's James Webb Space Telescope shows Neptune. Credit: NASA / ESA / CSA / STScI / Joseph DePasquale

The first picture of Neptune to be taken by NASA’s James Webb Space Telescope reveals the latest, greatest details of the ice giant’s atmosphere, moon and rings in infrared wavelengths.

Some of those details — for example, faint bands of dust that encircle Neptune — haven’t been brought to light since the Voyager 2 probe zoomed past in 1989.

“It has been three decades since we last saw those faint, dusty bands, and this is the first time we’ve seen them in the infrared,” astronomer Heidi Hammel, an interdisciplinary scientist on the JWST team who specializes in Neptune, said today in a news release. Neptune’s brighter rings stand out even more clearly.

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Webb Telescope sees Jupiter and auroras in a new light

JWST view of Jupiter
Jupiter as seen by JWST. Credit: NASA, ESA, CSA, Jupiter ERS Team; image processing by Ricardo Hueso (UPV/EHU) and Judy Schmidt.

NASA’s James Webb Space Telescope is designed to probe the farthest frontiers of the universe, but newly released images of Jupiter prove that the observatory can also bring fresh perspectives to more familiar celestial sights.

The infrared images reveal Jupiter’s polar auroras and its faint rings as well as two of its moons — plus galaxies in the far background. The planet’s Great Red Spot is there as well, but because it’s seen through three of JWST’s specialized filters, it looks white rather than red.

JWST’s new perspective should give scientists a better sense of how the complex Jupiter system is put together.

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