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Webb telescope promises new age of the stars

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Paris (AFP) – The James Webb Space Telescope lit up 2022 with dazzling images of the early universe after the Big Bang, heralding a new era of astronomy and untold revelations about the cosmos in years to come.

The most powerful observatory sent into space succeeds the Hubble telescope, which is still operating, and began transmitting its first cosmic images in July.

“It essentially behaves better than expected in almost every area,” said Massimo Stiavelli, head of the Webb mission office at the Space Telescope Science Institute, in Baltimore.

Already scientists say the Webb telescope, now orbiting the sun at a million miles (1.6 million kilometres) from Earth, should last 20 years, twice its guaranteed lifetime.

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James Webb telescope provides new view of the universe © / AFP

“The instruments are more efficient, the optics are sharper and more stable. We have more fuel and we use less fuel,” said Stiavelli.

Stability is vital for the clarity of the images.

“Our requirement was similar to that of Hubble, in terms of pointing accuracy. And we ended up being seven times better,” the mission office chief added.

Public appetite for the discoveries has been fed by the colouring of the telescope’s images.

Light from the most distant galaxies has been stretched from the visible spectrum, viewable by the naked eye, to infrared — which Webb is equipped to observe with unprecedented resolution.

The rings of Neptune, high-altitude methane-ice clouds
The rings of Neptune, high-altitude methane-ice clouds © Space Telescope Science Institut / ESA/WEBB/AFP/File

This enables the telescope to detect the faintest glimmers from the distant universe at an unprecedented resolution, to see through the veil of dust that masks the emergence of stars in a nebula and to analyse the atmosphere of exoplanets, which orbit stars outside our solar system.

18 petals

“The first year (of observation) is a way to test out the tool for the small rocky planets in the habitable zone that could potentially be like Earth,” said Lisa Kaltenegger, associate professor in Astronomy at Cornell University.

“And the tests are beautiful. They’re spectacular.”

Webb blasted off aboard an Ariane 5 rocket at the end of 2021 crowning a 30-year project at the US space agency NASA.

It took 10,000 people and 10 billion dollars to put the 6.2-tonne observatory into space.

The Webb telescope's infrared sets off a kaleidoscope of colours for the 'Pillars of Creation'(R) compared to the Hubble telescope's 2014 view by visible light
The Webb telescope’s infrared sets off a kaleidoscope of colours for the ‘Pillars of Creation'(R) compared to the Hubble telescope’s 2014 view by visible light © Space Telescope Science Institut / NASA/ESA/CSA/AFP/File

En route to final orbit, Webb deployed a five-layer sunshield the size of a tennis court followed by a 6.5 metre primary mirror made up of 18 hexagonal, gold-coated segments or petals.

Once calibrated to less than a millionth of a metre, the 18 petals began to collect the light pulsing stars.

Last July 12, the first images underlined Webb’s capabilities unveiling thousands of galaxies, some dating back close to the birth of the Universe, and a star nursery in the Carina nebula.

Jupiter has been captured in incredible detail which is expected to help understand the workings of the giant gas planet.

‘Too many’ galaxies

The blue, orange and grey tones of the images from the “Pillars of Creation”, giant dust columns where stars are born, proved captivating.

Scientists saw the revelations as a way of rethinking their models of star formation.

Researchers using the new observatory have found the furthest galaxies ever observed, one of which existed just 350 millions years after the Big Bang some 13.8 billion years ago.

The galaxies appear with extreme luminosity and may have started forming 100 million years earlier than theories predicted.

“In the distant Universe, we have an excess of galaxies compared to models,” David Elbaz, scientific director for astrophysics at France’s Alternative Energies and Atomic Energy Commission, told AFP.

Another surprise has been that where Hubble essentially observed irregular shaped galaxies, the precision of the Webb telescope produces magnificent spiral galaxies similar to our own.

The first infrared image from the James Webb Space Telescope is seen during a briefing with US President Joe Biden and National Aeronautics and Space Administration (NASA) officials in the South Court Auditorium at the White House in Washington, DC, on July 11, 2022.The JWST is the most powerful telescope launched into space and it reached its final orbit around the sun, approximately 930,000 miles from Earths orbit, in January, 2022. The technological improvements of the JWST and distance from the sun will allow scientists to see much deeper into our universe with greater detail.
The first infrared image from the James Webb Space Telescope is seen during a briefing with US President Joe Biden and National Aeronautics and Space Administration (NASA) officials in the South Court Auditorium at the White House in Washington, DC, on July 11, 2022.The JWST is the most powerful telescope launched into space and it reached its final orbit around the sun, approximately 930,000 miles from Earths orbit, in January, 2022. The technological improvements of the JWST and distance from the sun will allow scientists to see much deeper into our universe with greater detail. © Handout / NASA/AFP/File

This has led to musings over a potential universal model which could be one of the keys to star formation.

Webb also opened up a profusion of clusters of millions of stars leading, which could be the potential missing link between the first stars and the first galaxies.

In the field of exoplanets, Webb honed in on a faraway gas giant called WASP-96 b, which was discovered in 2014.

Nearly 1,150 light-years from Earth, WASP-96 b is about half the mass of Jupiter and zips around its star in just 3.4 days

Webb provided the first confirmation that carbon dioxide is present in the atmosphere of Wasp 39-b.

But for Stiavelli, “Some of the big things either haven’t been observed yet, or haven’t been revealed yet.”

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Is there life on Mars? Maybe, and it could have dropped its teddy

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Larger than the average bear: there’s a 2-kilometer-wide bear’s face on the surface of Mars, space scientists say.

Yogi, Paddington and Winnie the Pooh, move over. There’s a new bear in town. Or on Mars, anyway.

The beaming face of a cute-looking teddy bear appears to have been carved into the surface of our nearest planetary neighbor, waiting for a passing satellite to discover it.

And when the Mars Reconnaissance Orbiter passed over last month, carrying aboard the most powerful camera ever to venture into the Solar System, that’s exactly what happened.

Scientists operating the HiRISE (High Resolution Imaging Science Experiment), which has been circling Mars since 2006, crunched the data that made it back to Earth, and have now published a picture of the face.

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“There’s a hill with a V-shaped collapse structure (the nose), two craters (the eyes), and a circular fracture pattern (the head),” said scientists at the University of Arizona, which operates the kit.

Each one of the features in the 2,000-meter (1.25-mile)-wide face has a possible explanation that hints at just how active the surface of the planet is.

“The circular fracture pattern might be due to the settling of a deposit over a buried impact crater,” the scientists said.

“Maybe the nose is a volcanic or mud vent and the deposit could be lava or mud flows?”

HiRISE, one of six instruments aboard the Orbiter, snaps super-detailed pictures of the Red Planet helping to map the surface for possible future missions, either by humans or robots.

Over the last ten years the team has managed to capture images of avalanches as they happened, and discovered dark flows that could be some kind of liquid.

They’ve also found twirling across the Martian surface, as well as a feature that some people thought looked a lot like Star Trek’s Starfleet logo.

One thing they have not found, however, is the little green men who were once popularly believed to inhabit the planet.

© 2023 AFP

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Is there life on Mars? Maybe, and it could have dropped its teddy (2023, January 31)
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Why I Hunt for Sidewalk Fossils – The New York Times

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These oft-overlooked records invite us to imagine what has been and what might be.

A paleontologist once told me that city sidewalks hold snapshots. If I trained my gaze toward my feet, he said, I would find evidence of all kinds of commutes: traces of hopping birds, the soles of humans’ shoes, restless leaves that fell and sank into wet concrete at just the right moment. I might see a smattering of little paw prints zigging, zagging, doubling back, evidence of important rodent business that didn’t often overlap with mine.

These marks are too recent to pass muster with scientific sticklers, but in all respects except age, they are fossils. There are many ways to make one. Some form when a creature is entombed in sediment: Water percolates through, flush with minerals, and over time the mixture infiltrates the bones, where it settles and forms stone. Other fossils are casts, made, for instance, when a shell dissolves and leaves behind a mold that eventually fills with sediment, which hardens into rock. But not all fossils involve remains; some catalog movements. These are the kind that stipple our sidewalks — nascent trace fossils, records of fleeting contact.

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Throughout the pandemic, I turned to nature to track time and step outside myself. I photographed the sweetgum tree outside my Brooklyn window, noting when it leafed into a bushy chlorophylled curtain or when it dropped fruit that fell to the ground like unshattered ornaments. Most afternoons of that first lonely spring, I roamed a cemetery. When magnolia blossoms smudged the scene pink, I stood under the canopies until wind splashed the petals against my shoulders.

I was lucky, of course, to be simply scared and lonely — not dead, not intubated, not choosing between peril and paycheck. But time was slippery, and I felt stuck in my own brain, a foggy, trembling ecosystem I had no interest in studying. By early 2022, I was cocooned in my partner’s Morningside Heights apartment. On weekend mornings, we shuffled around the neighborhood, and each volunteered to notice something new: a startling mushroom, the pale bellies of pigeons waterfalling down a facade before flocking skyward. I became fixated on sidewalk fossils. Fossil-finding outings were a relief — an invitation to crouch, touch, lose myself in evidence of skittering and scrabbling, tethering myself to a past and a future.

Once I started noticing these impressions, it was fun to imagine myself as a paleontologist of the urban present.

Because sidewalk fossils are essentially the same color as the surrounding concrete, they’re most visible when light rakes across them; a fossil that’s elusive at noon might announce itself at dawn or dusk. So I timed a second daily walk for the hour when the light fled. Late afternoons introduced me to tiny forked footprints that marked the scene of, perhaps, an avian skirmish. There were others: a dog’s paws, three-quarters of a shoe. Though ichnologists, who study trace fossils, might discount leaves, I marveled at those too: most of a London plane and a ginkgo, with its corrugated fan. Across from a closed-up snack cart, I knelt until the cold concrete prickled my knees. I wriggled out of my mitten and traced a leaf’s sharp, diagonal veins, its saw-toothed sides.

When scientists encounter a fossil, they often try to puzzle out an explanation of how it got there. Maybe an animal was stranded or washed off its feet or chased by predators. Once I started noticing these impressions, it was fun to imagine myself as a paleontologist of the urban present. A bonanza of bird feet made me wonder if someone had sprinkled seeds or dropped a bagel. How long ago? What kind? When a leaf didn’t seem to match any of the nearby trees, I wondered if it was an interloper, blown in from blocks away or if it testified to an ecological eviction — a tree yanked out and replaced with another species or swapped for sidewalk. The fossils fastened my attention to something tangible but also invited it to wander and to think about city streets as collages of past and present, about how our nonhuman neighbors are architects, too. How we all shed traces of ourselves, whether we know it or not.

Of course, there is more significant proof of the past. Mammoths sometimes turn up in farmers’ fields, their tusks curved like scythes abandoned in the dirt. Parades of dinosaur footprints still march along the banks or beds of some prehistoric rivers and seas. Those are awesome, showy and obvious. I line up to see them; I happily gawk. But it was a tiny thrill to encounter evidence of the past that was subtle and recent, proof that others were out there. The sidewalk fossils felt intimate — the paleontological equivalent of a raft of letters secreted away beneath a floorboard.

Only they’re not actually rare. When sidewalks are repaired, birds and other animals ignore attempts to keep them pristine. Leaves do whatever the wind demands. These fossils are easy to find, and we’re lucky to have them. When I was lingering in the worst parts of my brain, sidewalk fossils dislodged me. Unlike the many fossils that represent stillness, the moment when an animal died and the place it remained unless humans carved it free, sidewalk fossils are often peeks into lives that continued. The birds flew somewhere; the dogs, I hope, went on to wag over many sticks and smells. As the sun sank and I trudged home, the fossils — these little flukes, these interesting accidents — were reminders of small, exhilarating life.


Jessica Leigh Hester is a science journalist whose first book is “Sewer” (Bloomsbury Academic, 2022).

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Green comet expected to be visible for first time in 50 millennia

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Comet C/2022 E3 (ZTF) is visible with binoculars, telescopes and in some areas, the naked eye – and it will grow brighter.

A green-hued comet is expected to be the most visible to stargazers on Wednesday as it shoots past Earth and the sun for the first time in about 50,000 years.

Discovered less than a year ago, the dirty snowball last passed near Earth during Neanderthal times, according to NASA.

The cosmic visitor will swing by our planet within 42 million kilometres (26 million miles) Wednesday before speeding away again, unlikely to return for millions of years.

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This harmless comet already is visible in a clear northern night sky with binoculars and small telescopes, and possibly the naked eye in the darkest corners of the Northern Hemisphere.

It’s expected to brighten as it draws closer and rises higher over the horizon through the end of January, and is best seen in the predawn hours. By February 10, it will be near Mars, a good landmark.

Stargazers in the Southern Hemisphere will have to wait until next month for a glimpse.

Finding a remote location to avoid light pollution in populated areas is key to catching a nice view of the comet as it journeys past our planet heading away from the sun and back toward the solar system’s outer reaches.

While plenty of comets have graced the sky over the past year, “this one seems probably a little bit bigger and therefore a little bit brighter and it’s coming a little bit closer to the Earth’s orbit,” said NASA’s comet-and asteroid-tracking expert, Paul Chodas.

Nicknamed “dirty snowballs” by astronomers, comets are balls of ice, dust and rocks and wander towards the inner solar system when they’re dislodged from various gravitational forces, becoming more visible as they venture closer to the heat given off by the sun.

Fewer than a dozen comets are discovered each year by observatories around the world.

The green comet was discovered on March 2, 2022 by astronomers using the Zwicky Transient Facility, a wide-field camera at Caltech’s Palomar Observatory in Palomar Mountain, California, the United States. That explains its official, cumbersome name: comet C/2022 E3 (ZTF).

Its greenish, emerald hue reflects the comet’s chemical composition – it is the result of a clash between sunlight and carbon-based molecules in the comet’s coma, the cloud around the nucleus that makes the comet appear fuzzy in the sky.

This comet last passed Earth at a time when Neanderthals still inhabited Eurasia, the human species was expanding its reach beyond Africa, big Ice Age mammals including mammoths and saber-toothed cats roamed the landscape, and northern Africa was a wet, fertile and rainy place.

The comet can provide clues about the primordial solar system because it formed during the solar system’s early stages, according to California Institute of Technology physics professor Thomas Prince.

NASA plans to observe the comet with its James Webb Space Telescope, which could provide clues about the solar system’s formation.

The Virtual Telescope Project at the Bellatrix Astronomical Observatory in Ceccano, Italy will have a live feed accessible here.

The comet — a time capsule from the emerging solar system 4.5 billion years ago — came from what’s known as the Oort cloud well beyond Pluto. This deep-freeze haven for comets is believed to stretch more than one-quarter of the way to the next star.

While comet ZTF originated in our solar system, we can’t be sure it will stay there, NASA’s Chodas said. If it gets booted out of the solar system, it will never return, he added.

But don’t fret if you miss it.

“In the comet business, you just wait for the next one because there are dozens of these,” Chodas said. “And the next one might be bigger, might be brighter, might be closer.”

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