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James Webb telescope: How it could uncover some of the universe's best-kept secrets – Space.com

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This article was originally published at The Conversation. The publication contributed the article to Space.com’s Expert Voices: Op-Ed & Insights.

Martin Barstow, Professor of Astrophysics and Space Science, University of Leicester

If everything goes according to plan, we will soon enter a new era of astronomy. The James Webb Space Telescope (JWST), the largest and most expensive and complex space telescope ever built, is now in space, heading to its final destination.

The launch of the $10 billion James Webb Space Telescope on Christmas Day 2021, anticipated for over a decade, was both exciting and terrifying for the thousands of scientists, engineers, managers and support staff who brought the mission to this point. As chair of the Space Telescope Science Institute Council, which will run the operations centre for JWST, I shared their nervousness. JWST’s scientific potential is after all enormous and it could answer some of the biggest questions about the universe.

Related: James Webb Space Telescope: The engineering behind a ‘first light machine’ that is not allowed to fail

The mysterious early universe

JWST is often billed as a replacement for the Hubble Space Telescope, but I would prefer to view it as a successor. Hubble has now operated for more than 30 years and given us amazing views of the universe and many thousands of scientific results. We hope and anticipate that it will continue to operate for many more years.

But the relatively small 2.4-metre diameter mirror, compared to ground-based telescopes, limits its sensitivity and ability to observe the faintest objects. Also, although Hubble has some capability to observe in infrared light, it cannot access the wavelengths of light from the very earliest stars and galaxies. JWST, however, will be able to do so. It may even be able to see Population III stars (stars that formed from primordial material from the Big Bang) which have never been glimpsed before.

Knowing when the first stars were formed, soon after the Big Bang, and understanding how they produced the building blocks of the first galaxies is an important scientific question and one of the primary science goals of JWST. We know that the elements that are needed for life and modern technology, such as carbon, silicone and gold, were ultimately created in early stars — but we don’t currently have a good understanding of how this happened.

The need to detect faint objects in the distant universe has been an important driver for the design of the observatory, determining its size, wavelength coverage and need to keep it very cool to minimise undesirable background light.

Studying the first stars and galaxies is not the only scientific programme JWST will perform. It is conceived as a general-purpose observatory on which astronomers from around the world can apply for time to support their research. For example, observing in the infrared will allow JWST to see through the clouds of dust that enshroud very young stars, which are opaque to visible light.

Unlike Hubble, it will be able to see right into stellar nurseries, where stars and their planetary systems are being born. The observations will answer questions about how the clouds of dust and gas collapse to form stars and how planetary systems form around them.

Stars form inside dusty nebulas, such as the one in the constellation Orion. (Image credit: NASA,ESA, M. Robberto (Space Telescope Science Institute/ESA) and the Hubble Space Telescope Orion Treasury Project Team)

Exoplanet habitability

When the first plans for JWST were being discussed more than 20 years ago, no planets were known other than those in our own solar system. Since then, astronomers have discovered thousands of planets orbiting other stars in our galaxy (exoplanets). A significant fraction of the JWST observing programme will be devoted to the study of their atmospheres. The wavelength coverage of JWST is particularly well tuned to studying molecules in exoplanet atmospheres and the low infrared background from space, giving it a considerable advantage over Earth-based telescopes.

Two techniques are available. One takes advantage of the fact that planets can pass in front of their parent star (called a transit), creating a dip in the light we see from it. By analysing the light, broken down by wavelength, with great precision before and during a transit we can probe the planet’s atmosphere to unveil what molecules it consists of. Another technique uses a special instrument called a coronagraph to block the light from the parent star to enable direct imaging of the planet and study its atmosphere or surface. This could help unveil whether a planet is suitable for life, perhaps warranting further investigation and one day sending mini space probes there.

The ultimate goal is to find a planet similar to the Earth, but it would require a very lucky combination of circumstances, because they are likely to be rare in the solar neighbourhood and very faint compared to the parent star. Most likely, JWST will study gas giants like Jupiter and Saturn or ice giants similar to Uranus and Neptune in our own solar system. None of the known planetary systems resemble our own, with many giant planets in closer orbits than ours, and more extreme heating of their atmospheres and more dynamic weather conditions.

In addition to studying planets outside our solar system, JWST will be able to observe our home planetary system. Its great sensitivity will enable the identification and characterisation of comets and other icy bodies in the outermost regions of the solar system. In such a remote location, these objects are largely unchanged since their formation, and may contain clues to the origins of Earth, particularly the source of its water, which may be the result of bombardment by such bodies early in its lifetime.

JWST will also be able to observe all the planets that lie outside Earth’s orbit of the sun, studying their atmospheres and seasonal weather variations.

Detailed plans and ideas for what will be discovered are essential justification for the expense of building an ambitious, game-changing telescope such as JWST. But there will be discoveries that nobody can anticipate. When Hubble was launched, the idea of exoplanets was largely science fiction, yet studying exoplanets became one of its major tasks. I wonder what surprising science awaits us with JWST.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook and Twitter. The views expressed are those of the author and do not necessarily reflect the views of the publisher.

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Consistent Asteroid Collisions Rock Previous Thinking on Mars Impact Craters – SciTechDaily

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This image provides a perspective view of a triple crater in the ancient Martian highlands. Credit: ESA/DLR/FU Berlin

New Curtin University research has confirmed the frequency of asteroid collisions that formed impact craters on <span aria-describedby="tt" class="glossaryLink" data-cmtooltip="

Mars
Mars is the second smallest planet in our solar system and the fourth planet from the sun. Iron oxide is prevalent in Mars’ surface resulting in its reddish color and its nickname "The Red Planet." Mars’ name comes from the Roman god of war.

“>Mars has been consistent over the past 600 million years.

New Curtin University research has confirmed the frequency of asteroid collisions that formed impact craters on Mars has been consistent over the past 600 million years.

The study, published in Earth and Planetary Science Letters, analyzed the formation of more than 500 large Martian craters using a crater detection algorithm previously developed at Curtin, which automatically counts the visible impact craters from a high-resolution image.

Despite previous studies suggesting spikes in the frequency of asteroid collisions, lead researcher Dr. Anthony Lagain, from Curtin’s School of Earth and Planetary Sciences, said his research had found they did not vary much at all for many millions of years.

Impact Craters on Mars

One of the 521 large craters that has been dated in the study. The formation age of this 40km crater has been estimated using the number of small craters accumulated around it since the impact occurred. A portion of these small craters are shown on the right panel and all of them have been detected using the algorithm. In total, more than 1.2 million craters were used to date the Martian craters. Credit: Curtin University

Dr. Lagain said counting impact craters on a planetary surface was the only way to accurately date geological events, such as canyons, rivers, and volcanoes, and to predict when, and how big, future collisions would be.

“On Earth, the erosion of plate tectonics erases the history of our planet. Studying planetary bodies of our Solar System that still conserve their early geological history, such as Mars, helps us to understand the evolution of our planet,” Dr. Lagain said.

“The crater detection algorithm provides us with a thorough understanding of the formation of impact craters including their size and quantity, and the timing and frequency of the asteroid collisions that made them.”

Past studies had suggested that there was a spike in the timing and frequency of asteroid collisions due to the production of debris, Dr. Lagain said.

“When big bodies smash into each other, they break into pieces or debris, which is thought to have an effect on the creation of impact craters,” Dr. Lagain said.

“Our study shows it is unlikely that debris resulted in any changes to the formation of impact craters on planetary surfaces.”

Co-author and leader of the team that created the algorithm, Professor Gretchen Benedix, said the algorithm could also be adapted to work on other planetary surfaces, including the Moon.

“The formation of thousands of lunar craters can now be dated automatically, and their formation frequency analyzed at a higher resolution to investigate their evolution,” Professor Benedix said.

“This will provide us with valuable information that could have future practical applications in nature preservation and agriculture, such as the detection of bushfires and classifying land use.”

Reference: “Has the impact flux of small and large asteroids varied through time on Mars, the Earth and the Moon?” by Anthony Lagain, Mikhail Kreslavsky, David Baratoux, Yebo Liu, Hadrien Devillepoix, Philip Bland, Gretchen K. Benedix, Luc S. Doucet and Konstantinos Servis, 7 January 2022, Earth and Planetary Science Letters.
DOI: 10.1016/j.epsl.2021.117362

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B.C. researchers uncover mechanism that keeps large whales from drowning while feeding on krill – CTV News Vancouver

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Vancouver –

New research from the University of British Columbia is shedding light on the ways that whales feed underwater without flooding their airways with seawater.

The research, published this month in Current Biology, shows that lunge-feeding whales – the type that lunge and gulp at large schools of krill – have a special mechanism in the back of their mouths that stops water from entering their lungs when eating.

“It’s kind of like when a human’s uvula moves backwards to block our nasal passages, and our windpipe closes up while swallowing food,” says lead author Dr. Kelsey Gil, a postdoctoral researcher in the department of zoology, in a statement.

Specifically, a fleshy bulb acts as a plug, to close off upper airways, while a larynx closes to block lower airways.

The humpback whale and the blue whale are both lunge-feeders, but the scientists’ research focused on fin whales, thanks in part to being able to travel to Iceland in 2018 and examine carcass remains at a commercial whaling station.

“We haven’t seen this protective mechanism in any other animals, or in the literature. A lot of our knowledge about whales and dolphins comes from toothed whales, which have completely separated respiratory tracts, so similar assumptions have been made about lunge-feeding whales,” Gil said.

Lunge-feeders are impressive, Gil said, because sometimes the amount of food and water they consume is larger than their bodies. After snapping at krill, and while blocking the water from their airways, the whales then drain the ocean water through their baleen, leaving behind the tasty fish.

The study’s senior author Dr. Robert Shadwick, a professor in the UBC department of zoology, says the efficiency of the whales’ feeding is a key factor in their evolution.

“Bulk filter-feeding on krill swarms is highly efficient and the only way to provide the massive amount of energy needed to support such a large body size. This would not be possible without the special anatomical features we have described,” he said in a statement. 

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Study confirmed the frequency of asteroid collisions that formed Mars craters – Tech Explorist

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Mapping and counting impact craters are the most commonly used technique to derive detailed insights on geological events and processes shaping the surface of terrestrial planets. Scientists from Curtin University have used a crater detection algorithm to analyze the formation of more than 500 large Martian craters.

The algorithm they used automatically counts the visible impact craters from a high-resolution image. Scientists found that the frequency of asteroid collisions that formed Mars craters has been consistent for over 600 million years.

Lead scientist Dr. Anthony Lagain from Curtin’s School of Earth and Planetary Sciences said, “Despite previous studies suggesting spikes in the frequency of asteroid collisions, this research had found they did not vary much at all for many millions of years.”

“Counting impact craters on a planetary surface was the only way to accurately date geological events, such as canyons, rivers, and volcanoes, and to predict when, and how big, future collisions would be.”

“On Earth, the erosion of plate tectonics erases the history of our planet. Studying planetary bodies of our Solar System that still conserve their early geological history, such as Mars, helps us to understand the evolution of our planet.”

“The crater detection algorithm provides us with a thorough understanding of the formation of impact craters, including their size and quantity, and the timing and frequency of the asteroid collisions that made them.”

“Past studies had suggested that there was a spike in the timing and frequency of asteroid collisions due to the production of debris.”

“When big bodies smash into each other, they break into pieces of debris, which is thought to affect the creation of impact craters.”

“Our study shows it is unlikely that debris resulted in any changes to the formation of impact craters on planetary surfaces.”

Co-author and leader of the team that created the algorithm, Professor Gretchen Benedix, said“the algorithm could also be adapted to work on other planetary surfaces, including the Moon.”

“The formation of thousands of lunar craters can now be dated automatically, and their formation frequency analyzed at a higher resolution to investigate their evolution.”

“This will provide us with valuable information that could have future practical applications in nature preservation and agriculture, such as the detection of bushfires and classifying land use.”

Journal Reference:

  1. Anthony Lagain et al. Has the impact flux of small and large asteroids varied through time on Mars, the Earth, and the Moon? DOI: 10.1016/j.epsl.2021.117362

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