Category: Featured (page 1 of 11)

“Nature Has Become More Beautiful.” Physicist Eugene Parker and his Life Unlocking Secrets Of The Sun

 

Parker with an image of the solar corona, the outermost portion of Sun’s atmosphere.  Parker brought new understanding to the nature and workings of the corona and the solar wind, which originates in the corona. (University of Chicago)

When  Eugene Parker was 16 years old,  he decided he didn’t want to spend the summer hanging out in suburban Detroit.  So Parker went up to the state capital looking to buy some tax delinquent land held by the state.

He selected a 40-acre piece of woods in far-off Cheboygan County, not far from Mackinac Island.  There was nothing on the land but trees.  He bought it with $120 from his own earlier summertime earnings.

Over the next three summers, Parker, his younger brother and sometimes a cousin and a friend constructed a log cabin on the land.  Because this was during World War II and gas was strictly rationed,  they couldn’t ask their parents for a ride up, and so they often bicycled the more than 300 miles to their homestead.

The cabin still doesn’t have electricity or indoor running water, but it has been used regularly by Parker and his family for almost 80 years.  And in many ways, that cabin reflects the basic character, the drive and the profound originality of the boy who built it and went on to become one of the great theoretical physicists of the 20th century.

The young Parker atop a birch  tree in 1943, on the site where his northern Michigan cabin would be built. (Courtesy of the Parker family.)

Eugene Parker, who passed away earlier this month at 94, has been hailed as the father of solar physics and is perhaps best known as the man who — basically single-handedly and despite many eminent critics –came up with the theory of the “solar wind,” a torrent of charged particles and magnetic fields that always and in all directions is blasting out from the Sun.

Parker’s innumerable achievements in his field, as well as his old-school civility and demeanor, earned him the first and only honor of its kind given by NASA — having a major space mission named after him while alive.

Ailing and aged 91, he nonetheless went with his family down to Florida in 2018 to watch the launch of the Parker Solar Probe — an extraordinary mission that flies through the blast furnace of the Sun’s corona in its effort to learn more about the origins of the solar wind and the forces at play that produce that still mysterious solar corona.… Read more

The World’s Most Capable Space Telescope Readies To Observe. What Will Exoplanet Scientists Be Looking For?

This artist’s concept shows what the TRAPPIST-1 planetary system may look like, based on available data about the planets’ diameters, masses and distances from the host star.  The James Webb is expected to begin science observations this summer. (NASA/JPL-Caltech)

The decades-long process of developing, refining, testing, launching, unfurling and now aligning and calibrating the most capable space telescope in history is nearing fruition.  While NASA has already released a number of “first light” images of photons of light moving through the James Webb Space Telescope’s optical system, the  jaw-dropping “first light” that has all the mirrors up and running together to produce an actual scientific observation is a few months off.

Just as the building and evolution of the Webb has been going on for years, so has the planning and preparation for specific team observation “campaigns.”   Many of these pertain to the earliest days of the universe, of star and galaxy formation and other realms of cosmology,  but an unprecedented subset of exoplanet observations is also on its way.

Many Worlds earlier discussed the JWST Early Release Science Program, which involves observations of gigantic hot Jupiter planets to both learn about their atmospheres and as a way to collect data that will guide exoplanet scientists in using JWST instruments in the years ahead.

Now we’ll look at a number of specific JWST General Observation and Guarantreed Time efforts that are more specific and will collect brand new information about some of the major characteristics and mysteries of a representative subset of the at least 100 billion exoplanets in our galaxy.

This will be done by using three techniques including transmission spectroscopy — collecting and analyzing the light that passes through an exoplanet’s atmosphere as it passes in front of its Sun.  The JWST will bring unprecedented power to characterizing the wild diversity of exoplanets now known to exist; to the question of whether “cool” and dim red dwarf stars (by far the most common in the galaxy) can maintain atmospheres; to newly sensitive studies of the chemical makeup of exoplanet atmospheres; and to the many possibilities of the TRAPPIST-1 exoplanets, a seven rocky planet solar system that is relatively nearby.

An artist’s interpretation of GJ 1214b,one of a group of super-Earth to mini-Neptune sized planets to be studied in the JWST Cycle1 observations. The planet is known to be covered by a thick haze which scientists expect the JWST to pierce as never before and allow them to study atmospheric chemicals below.

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The James Webb Space Telescope And Its Exoplanet Mission (Part 1)

 

This artist’s conception of the James Webb Space Telescope in space shows all its major elements fully deployed. The telescope was folded to fit into its launch vehicle, and then was slowly unfolded over the course of two weeks after launch. (NASA GSFC/CIL/Adriana Manrique Gutierrez)

 

The last time Many Worlds wrote about the James Webb Space Telescope, it was in the process of going through a high-stakes, super-complicated unfurling.  About 50 autonomous deployments needed to occur after launch to set up the huge system,  with 344 potential single point failures to overcome–individual steps that had to work for the mission to be a success.

That process finished a while back and now the pioneering observatory is going through a series of alignment and calibration tests, working with the images coming in from the 18 telescope segments to produce one singular image.

According to the Space Telescope Science Institute,  working images from JWST will start to appear in late June, though there may be some integrated  “first light” images slightly earlier.

Exciting times for sure as the observatory begins its study of the earliest times in the universe, how the first stars and galaxies formed, and providing a whole new level of precision exploration of exoplanets.

Adding to the very good news that the JWST successfully performed all the 344 necessary steps to unfurl and that the mirror calibration is now going well is this:  The launch itself went off almost exactly according to plan.  This means that the observatory now has much more fuel on hand than it would have had if the launch was problematic. That extra fuel means a longer life for the observatory.

 

NASA announced late last month that it completed another major step in its alignment process of the new James Webb Space Telescope, bringing its test images more into focus. The space agency said it completed the second and third of a seven-phase process, and had accomplished “Image Stacking.” Having brought the telescope’s mirror and its 18 segmented parts into proper alignment, it will now begin making smaller adjustments to the mirrors to further improve focus in the images. (NASA/STScI)

Before launch, the telescope was expected to last for five years.  Now NASA has said fuel is available for a ten year mission and perhaps longer.  Quite a start.

(A NASA update on alignment and calibration will be given on Wednesday. … Read more

Will The ISS Fall Victim to Russia’s Ukraine Invasion and Resulting Sanctions? Can The ExoMars Project Survive?

NASA and the Russian space agency Roscosmos have been cooperating (with other national agencies) on the International Space Station since development began in the early 1990s. . But the director of Roscosmos has said that cooperation could end abruptly due to mounting sanctions against Russia. (NASA)

The United States and Russia have cooperated extensively and well in building and operating the International Space Station since the plan was formalized in 1993.  The European Space Agency, the Japan Aerospace Exploration Agency, and the Canadian Space Agency have played major roles since the beginning, but it was first and foremost a U.S.-Russian venture.

That deep cooperation has been failing for some years but the bloody Russian invasion of Ukraine and resulting Western sanctions may well put a final end of that.

Late last week, as Russia invaded Ukraine and Western nations responded with increasingly harsh sanctions, the director of Russia’s space agency chief sent out a harsh, sarcastic and threatening tweet about that ISS partnership.

After President Biden announced Thursday that the U.S. would sanction major Russian banks and impose export controls on Russia to curtail high-tech imports, Roscosmos Director General Dmitry Rogozin tweeted that the sanctions could “destroy our cooperation on the ISS.”

Not only that, he said that the current orbit and location of the ISS is under his nation’s control since Russian Progress spacecraft keep it from losing altitude.  He went on in a long tweet that threatened: “If you block cooperation with us, who will save the ISS from an uncontrolled de-orbit and fall into the United States or Europe? There is also the option of dropping a 500-ton structure to India and China. Do you want to threaten them with such a prospect?”

“The ISS does not fly over Russia, therefore all the risks are yours.  Are you ready for them?”  Rogozin, a longtime Putin ally, has been at the helm of Roscosmos since May 2018 and was previously a deputy prime minister in charge of the Russian defense industry.

In a statement, NASA said that “The new export control measures will continue to allow U.S.-Russia civil space operation. No changes are planned to the agency’s support for ongoing in-orbit and ground-station operations.” 

There are four NASA astronauts, two Russian cosmonauts, and one European astronaut now aboard the ISS.

Dmitry Rogozin, head of the Russian space agency Roscosmos, has warned that U.S. sanctions against the Russian space sector could have serious consequences for the International Space Station.

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“Tantalizing” Carbon Signals From Mars

This mosaic was made from images taken by the Mast Camera aboard NASA’s Curiosity rover on the 2,729th Martian day, or sol, of the mission. It shows the landscape of the Stimson sandstone formation in Gale crater. In this general location, Curiosity drilled the Edinburgh hole, a sample from which was enriched in carbon-12. (NASA/JPL-Caltech/MSSS.)

The rugged and parched expanses of Western Australia are where many of the oldest signs of ancient life on Earth have been found, embedded in the sedimentary rocks that have been undisturbed there for eons.  One particularly significant finding from the Tumbiana Formation contained a substantial and telltale excess of the carbon-12 isotope compared with carbon-13.

Since carbon 12 is used by living organisms, that carbon-12 excess in the rocks was interpreted to mean that some life-form had been present long ago (about 2.7 billion years) and left behind that “signature”  of its presence. What was once a microbial mat that could have produced the carbon-12 excess was ultimately found nearby.

After nine years of exploring Gale Crater on Mars, scientists with NASA’s Curiosity rover have collected a substantial number of rock samples that they have similarly drilled, pulverized, gasified and analyzed.

And as explained in an article in the Proceedings of the National Academy of Science (PNAS,) researchers have found quite a few Martian specimen that have the same carbon-12 excesses as those found in Western Australia.

Paul Mahaffy of NASA’s Goddard Space Flight Center, long-time principal investigator for the instrument that found the carbon-12 excess on Mars, called the results “tantalizingly interesting.”

And the lead author of the PNAS paper, Christopher House of Penn State University, said that “On Earth, processes that would produce the carbon signal we’re detecting on Mars are biological.”  Like from Western Australia and elsewhere.

So something unusual and important has been discovered. But exactly what it is and how it came to be remains very much a work in progress.

Perhaps biology did play a role, the team writes.  If so, it would involve ancient bacteria in the Martian surface that would have produced a unique carbon signature when they released methane into the atmosphere. Ultraviolet light would have then converted that gas into larger, more complex molecules that would rain down and become part of Martian rocks.

Scientists with NASA and European Mars missions traveled to the Western Australian Outback to hone their research techniques before their missions launched.

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The Amazing Unfurling Of The James Webb Space Telescope

The last view of the JWST and its unfurled solar arrays after it separated from the Ariane 5 launch vehicle and started it’s month-long and extraordinarily complicated deployment. (NASA)

Over the next three weeks-plus, the James Webb Space Telescope will play out an unfurling and deployment in deep space unlike anything this world has seen before.

It took decades to perfect the observatory — a segmented telescope on a heat shield  the length of a tennis court that was squeezed for launch into a rocket payload compartment less than 30 feet in diameter.  The unfurling has begun and will continue over 25 more days, with 50 major deployments and 178 release mechanisms to set the pieces free.

The process has been likened to the undoing of an origami creation, or like the opening of a massive, many-featured Swiss army knife but without a human to pull the parts out.

Adding to the stress of these days,  the JWST will be much further out into space than the Hubble Space Telescope, which is in a very close orbit around the Earth at an altitude of about 340 miles.  The JWST will be over 930,000 miles away from Earth at the stable orbital point called the second Lagrange point 2 (L2) — way too far away for any manual fixes or upgrades like the ones accomplished by astronauts for the Hubble.

Four days after liftoff, the observatory has unfurled some of its solar panels, has deployed some of the pallet that will hold the sunshield and has extended the tower assembly about 6 feet from its storage space.   Here is a video from the Goddard Space Flight Center illustrating all the steps needed to make JWST whole:

 

And here is a more detailed depiction of the many stages of deployment, what is being deployed and how.

JWST will  have the largest telescope mirror ever sent into space — 21 feet in diameter compared with the Hubble’s 8-foot diameter.  Because it is so large, it had to be divided into 18 hexagonal segments of the lightweight element beryllium, each one roughly the size of a coffee table. Together, the segments must align almost perfectly, moving in alignment within a fraction of a wavelength of light.

Webb mission systems engineer Mike Menzel, of NASA’s Goddard Space Flight Center, said in a deployment-explaining video called “29 Days on the Edge” that every single releases and deployment must work.… Read more

What The James Webb Space Telescope Can Do For Exoplanet Science and What It Cannot Do

The James Webb Space Telescope, as rendered by an artist. The telescope is scheduled to launch later this month. (NASA)

When the James Webb Space Telescope finally launches (late this month, if the schedule holds) it will forever change astronomy.

Assuming that its complex, month-long deployment in space works as planned, it will become the most powerful and far-seeing observatory in the sky.  It will have unprecedented capabilities to probe the earliest days of the universe, shedding new light on the formation of the first stars and galaxies.  And it will observe in new detail the most distant regions of our solar system.

Deep space astrophysics is what JWST was first designed for in the early 1990s, and that will be its transformative strength.

But much is also being made of what JWST can do for the study of exoplanets and some are even talking about how it just might be able to find biosignatures — signs of distant life.

While it is probably wise to never say never regarding an observatory with the power and capabilities of JWST,  the reality is that it was not designed to look for the exoplanets most likely to be habitable.  Actually, when it was first proposed, the observatory had no exoplanet-studying capabilities at all because no exoplanets had yet been found.

What was added on is substantial and exoplanet scientists say JWST can help advance the field substantially.  But there are definite limits and finding biosignatures — life — is almost certainly a reach too far for JWST.

When starlight passes through a planet’s atmosphere, certain parts of the light are absorbed by the atmosphere’s elements. By studying which parts of light are absorbed, scientists can determine the composition of the planet’s atmosphere. (Christine Daniloff/MIT, Julien de Wit)

Astronomer Jacob Bean of the University of Chicago, who has played a leadership role in planning JWST exoplanet observations for the telescope’s early day, says that people need to know these limitations so the pioneering exoplanet science that will be possible with JWST is not seen as somehow disappointing.

As he explained, it is essential to understand that the kind of exoplanet observing that the JWST will mostly do is “transit spectroscopy.”  This involves staring at a star when an exoplanet is expected to transit in front of it.  When that happens, light from the star will pass through the atmosphere of the exoplanet (if there is one) and through spectroscopy scientists can determine what molecules are in that hoped-for atmosphere.… Read more

Why Does Our Solar System Have No Super-Earths, and Other Questions for Comparative Planetology

An artist’s impression of the exoplanet LHS 1140b, which orbits a red dwarf star 40 light-years from Earth. Using the European Southern Observatory’s telescope at La Silla, Chile, and other telescopes around the world, an international team of astronomers discovered this super-Earth orbiting in the habitable zone around the faint star LHS 1140. This world is a little larger and much more massive than the Earth. (ESO)

Before the explosion in discovery of extrasolar planets, the field of comparative planetology was pretty limited  — confined to examining the differences between planets in our solar system and how they may have come to pass.

But over the past quarter century, comparative planetology and the demographics of planets came to mean something quite different.  With so many planets now identified in so many solar systems, the comparisons became not just between one planet and another but also between one solar system and another.

And the big questions for scientists became the likes of:  How and why are the planetary makeups of distant solar systems often so different from our own and from each other; what does the presence  or absence of large planets in a solar system do to the distribution of smaller planets;  how large can a rocky planet can get before it turns to a gas giant planet; and on a more specific subject, why do some solar systems have hot Jupiters close to the host star and others have cold Jupiters much further out like our own

Another especially compelling question involves our own solar system, though as something of an outlier rather than a prototype.

That question involves the absence in our solar system of anything in the category of a “super-Earth” — a rocky or gaseous extrasolar planet with a mass greater than Earth’s but substantially below those of our solar system’s planets next in mass,  Uranus and Neptune.

The term “super-Earth” refers only to the mass and radii of the planet, and so does not imply anything about the surface conditions or habitability. But in the world of comparative planetology “super-Earths” are very important because they are among the most common sized exoplanets found so far and some do seem to have planetary characteristics associated with habitability.

Yet they do not exist in our solar system.  Why is that?

Artist rendition of Earth in comparison to one of the many super-Earth planets. (NASA)

In a recent article in The Astrophysical Journal Letters,  planetary demographer Gijs D.… Read more

Touching the Sun

An illustration of NASA’s Parker Solar Probe flying past the sun. The spacecraft has a carbon-carbon heat shield (carbon fibers in a carbon matrix) that can protect it from temperatures of up to 2500 F, about the melting point of steel.  (NASA’s Goddard Space Flight Center)

The Parker Solar Probe is the stuff of superlatives and marvels.

Later this week, it will pass but 5.3 million miles from the sun — much closer than Mercury or any other spacecraft  have ever come — and it will be traveling at a top speed of 101 miles per second, the fastest human-made object ever created.

It’s designed to withstand temperatures of 2,500 degrees Fahrenheit and solar radiation 475 times the intensity at Earth orbit.

And as it reaches its perihelion, or closest pass of this orbit, it will be on only its 10th of 24 planned progressively closer solar passes.  In the years ahead, it will ultimately skim into the upper corona, the atmosphere of charged and unimaginably hot plasma that surrounds the sun and other stars.  The Parker Probe will, quite literally, touch the sun.

Something rather awe-inspiring to think about this coming Sunday, when the next pass takes place.

The mission, however, surely does not have record-setting as its goal.  Rather, those records are necessary to achieve the scientific goals — to fly close enough to the sun to understand how and where the gravity-defying force of the “solar wind” originates; to determine the structure and dynamics of the magnetic fields and switchbacks that are hotly debated as a possible source of that solar wind; and to resolve the mystery of why the sun’s corona is unexpectedly hotter than the solar “surface” below it.

“Parker Solar Probe is already telling us many important things about the sun that we didn’t know,” said Nour Raouafi, Parker Solar Probe project scientist at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland.  “We are definitely getting closer to understanding some of the big questions we had before, such as the source of the solar wind.  But we have to be mindful that in whatever we find, the Sun is always changing.”

And incidently, he said, more than 99.9 percent of all the matter in our solar system is in and around the sun.

 

Solar wind activity at different scales as imaged by the Parker Probe’s Wide-field Imager (WISPR) instrument earlier this year during.
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NASA Should Build a Grand Observatory Designed to Search For Life Beyond Earth, Top Panel Concludes

The National Academy of Sciences has released it’s “Decadal Survey,” with guidance and recommendations for the fields of astronomy, astrobiology and astrophysics.(NASA)

NASA should begin developing a mission that can tell us whether life in the near galaxy is abundant, rare or essentially absent, The National Academy of Sciences recommended yesterday.

The call for a next Grand Observatory telescope with this ambitious goal represents the first time that the Academy, in its Decadal Survey for Astronomy and Astrophysics, has given top priority to the science of  exoplanets and the search for life far beyond Earth.

The long-awaited NAS survey did not select a single mission concept, although several NASA-commissioned studies were extensively researched and assembled for the Decadal over the past four years.

Rather, they set the science goal of giving an answer – as complete as possible – to the eternally-asked question of whether life exists solely on Earth or can be found on the billions of other planets we now know orbit their own suns.

Decadal steering committee co-chair Robert Kennicutt Jr., a professor at University of Arizona and Texas A & M University, said that a flood of discoveries and astronomical and technological advances in recent decades made clear that the time for such a mission had come.

“We’re laying down a marker here,” Kennicutt said  in a press conference.  “We think that progress in this field has taken us to the point that within the planning horizon of this survey, we can really contemplate imaging  Earth-like planets in their habitable zones around other stars and spectroscopically studying them for atmospheric composition, perhaps including biomarkers. with the ultimate goal of answering one of the most profound questions:  Are we alone in the universe?”

The proposed mission, he said, would as a result have the transformative scientific power of the Hubble Space Telescope and the James Webb Space Telescope, which is scheduled to launch next month.  It would change the way that scientists and citizens see the world.

The telescope envisioned by Decadal Survey would search for small rocky planets in the habitable zone of heir sun — where the temperatures would allow for liquid water to exist rather than just water vapor or ice.  This artist’s concept ia of Kepler-452b, the first near-Earth-size world found in the habitable zone of a distant sun-like star. ( NASA/Ames/JPL-Caltech.)

But the road to an actual mission will be long and definitely uphill.… Read more

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