Category: Uncategorized (page 1 of 5)

How Planetary Orbits, in Our Solar System and Beyond, Can Affect Habitability

Varying degrees of orbital eccentricity around a central star. (NASA/JPL-Caltech)

As scientists work to understand what might make a distant planet habitable, one factor that is getting attention is the shape of the planet’s orbit, how “eccentric” it might be.

It might seem that a perfect circular orbit would be ideal for habitability because it would provide stability, but a new model suggests that it is not necessarily the case.  The planet in question is our own and what the model shows is that if Jupiter’s orbit were to change in certain ways, our planet might become more fertile than it is.

The logic play out as follows:

When a planet has a perfectly circular orbit around its star, the distance between the star and the planet never changes and neither does the in-coming heat. But most planets — including our own — have eccentric orbits around their stars, making the orbits oval-shaped. When the planet gets closer to its star it receives more heat, affecting the climate.

Using multi-factored models based on data from the solar system as it is known today, University of California, Riverside (UCR) researchers created an alternative solar system. In this theoretical system, they found that if Jupiter’s orbit were to become more eccentric, it would in turn produce big changes in the shape of Earth’s orbit.  Potentially for the better.

“If Jupiter’s position remained the same but the shape of its orbit changed, it could actually increase this planet’s habitability,” said Pam Vervoort, UCR Earth and planetary scientist and study lead author.

The paper upends two long-held scientific assumptions about our solar system, she said.

“Many are convinced that Earth is the epitome of a habitable planet and that any change in Jupiter’s orbit, being the massive planet it is, could only be bad for Earth,” Vervoort said in a release. “We show that both assumptions are wrong.”

Size comparison of Jupiter and Earth shows why any changes relating to the giant planet would have ripple effects. (NASA)

 

As she and colleagues report in the Astronomical Journal, if Jupiter pushed Earth’s orbit to become more eccentric based on its new gravitational pull, parts of the Earth would sometimes get closer to the sun.  As a results, parts of the Earth’s surface that are now sub-freezing would get warmer, increasing temperatures in the habitable range.

While the Earth-Jupiter connection is a focus of the paper and forms a relationship that’s not hard to understand, the thrust of the paper is modeling how similar kinds of exoplanet orbits and solar system relationships can affect habitability and the potential for life to emerge and prosper.… Read more

The Virtual Planetary Lab and Its Search for What Makes an Exoplanet Habitable, or Even Inhabited

As presented by the Virtual Planetary Laboratory, exoplanet habitability is a function of the interplay of processes between the planet, the planetary system, and host star.  These interactions govern the planet’s evolutionary trajectory, and have a larger and more diverse impact on a planet’s habitability than its position in a habitable zone. (Meadows and Barnes)

For more than two decades now, the Virtual Planetary Laboratory (VPL) at the University of Washington in Seattle has been at the forefront of the crucial and ever-challenging effort to model how scientists can determine whether a particular exoplanet is capable of supporting life or perhaps even had life on it already.

To do this, VPL scientists have developed or combined models from many disciplines that characterize and predict a wide range of planetary, solar system and stellar attributes that could identify habitability, or could pretty conclusively say that a planet is not habitable.

These include the well known questions of whether water might be present and if so whether temperatures would allow it to be sometimes in a liquid state, but on to questions involving whether an atmosphere is present, what elements and compounds might be in the atmospheres, the possible orbital evolution of the planet, the composition of the host star and how it interacts with a particular orbiting planet and much, much more, as shown in the graphic above.

This is work that has played a significant role in advancing astrobiology — the search for life beyond Earth.

More specifically, the VPL approach played a considerable part in building a body of science that ultimately led the Astro2020 Decadal Study of the National Academy of Sciences to recommend last year that the NASA develop its  first Flagship astrobiology project — a mission that will feature a huge space telescope able to study exoplanets for signs of biology in entirely new detail.  That mission, approved but not really defined yet, is not expected to launch until the 2040s.

With that plan actually beginning to move forward, the 132 VPL affiliated researchers at 28 institutions find themselves at another more current-day inflection point:  The long-awaited James Webb Space Telescope has begun to collect and send back what will be a massive and unprecedented set of spectra  of chemicals from the atmospheres of distant planets.

The Virtual Planetary Laboratory has modeled the workings of exoplanets since 2001, looking for ways to predict planetary conditions based on a broad range of measurable factors.

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NASA Suceeds in Making Precious Oxygen from Carbon Dioxide on Mars

 

Technicians in the Jet Propulsion Laboratory clean room lowered the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) instrument into the belly of the Perseverance rover in 2019. MOXIE was designed to  “breathe in” the CO2-rich atmosphere and “breathe out” a small amount of oxygen, to demonstrate a technology that could be critical for future human missions to Mars.  (NASA/JPL-Caltech)

Of the many barriers to a human trip to Mars where astronauts would land, explore and return to Earth,  the absence of oxygen in the Martian atmosphere is a big one.  Without oxygen that can be collected to support life and to provide fuel for a flight home,  there can be no successful human mission to the planet.

So the results of a proof-of-concept trial on Mars that turned carbon dioxide into oxygen is positive news for sure.  The instrument — called MOXIE on the rover Perseverance — successfully produced oxygen from carbon dioxide seven times last year, and convinced its inventors (and NASA) that it is a technology that can be of substantial importance.

While the amount of oxygen was not great — about 50 grams of the gas combined from the seven trials — the process worked well enough to strongly suggest that it could some day produce oxygen on a large scale.

“MOXIE has shown that (the deployed) technology for producing oxygen on Mars from the atmosphere is viable, is scalable, and meets expectations for efficiency and quality,” an MIT team led by Jeffrey Hoffman wrote in a Science Advances article released today.

They wrote that although long-term durability and resilience remain to be demonstrated and future efforts need to improve the instrument’s monitoring and controlling capabilities,  “all indications are that a scaled-up version of MOXIE could produce oxygen in sufficient quantity and with acceptable reliability to support future human exploration.”

The perseverance rover, in a selfie taken in late 2020, is the first to carry an instrument that can produce oxygen on Mars. (NASA)

The size of both the problem and the opportunity can be seen in the fact that carbon dioxide makes up more than 95 percent of the Martian atmosphere while oxygen is only a miniscule 0.13 percent of the atmosphere.  (Oxygen makes up 21 percent of the atmosphere on Earth.)

Transporting oxygen to Mars to fuel for a trip home is considered impractical because to burn its fuel a rocket must have substantial and weighty supplies of oxygen.… Read more

The First Major Image From The James Webb Space Telescope is a Show-Stopper

The first James Webb image to be released  brings out faint structures in extremely distant galaxies, offering the most detailed view of the early universe to date (NASA, ESA, CSA, and STScI)

The first of what will no doubt be a future flood of images from the James Webb Space Telescope — which has the largest telescope mirror to ever be sent into space — was released today and it shows the spectacular deep-field world of the galaxy cluster SMACS 0723.

The image shows the galaxy cluster as it appeared 4.6 billion years ago, the amount of time that it took for light to reach us.  The combined mass of this galaxy cluster acts as a gravitational lens, magnifying much more distant galaxies behind it.

Webb’s Near-Infrared Camera (NIRCam) has brought those distant galaxies into sharp focus – they have tiny, faint structures that have never been seen before, including star clusters and diffuse features. Researchers will soon begin to learn more about the galaxies’ masses, ages, histories, and compositions, as Webb seeks the earliest galaxies in the universe.

What you are seeing is thousands of galaxies – including the faintest objects ever observed in infrared wavelengths. As a NASA release put it, this slice of the vast universe covers a patch of sky approximately the size of a grain of sand held at arm’s length by someone on the ground.

This deep field is a composite made from images at different wavelengths taken over 12.5 hours.  The telescope imaged galaxies in infrared wavelengths that are beyond the distance and quality of the Hubble Space Telescope’s deepest fields, which took weeks to image.

This image was released in the White House by President Joe Biden.  He praised NASA for its work — over several decades — that enabled the telescope and the images it will produce.

“We can see possibilities no one has seen before,” he said, “we can go places no one has gone before.”

The Webb has the capacity to see to the edges of black holes and of the very early universe.  It is expected to revolutionize astronomy, especially regarding that earliest phase of the universe. It also has the capacity to see and read the chemical signatures in distant atmospheres of exoplanets.

A fuller suite of images will be released Tuesday, July 12, beginning at 10:30 a.m. EDT, during a live NASA TV broadcast. Learn more about how to watch.… Read more

A Spectacular Look at Things to Come from the James Webb Space Telescope

NASA/JPL-Caltech (left), NASA/ESA/CSA/STScI (right

NASA and the James Webb Space Telescope team have spoken for years about how the observatory, once it is in place and fully aligned and calibratated, will revolutionize astronomy and lead to a bounty of space discoveries.

The agency has now released some early images, produced before the process of fine-tuning the telescope is finished.  And they visually certainly do make the case for the JWST to be precisely the ground-breaking pioneer long promised.

Its goals are to explore the earliest light in the universe, to possibly observe the first stars and galaxies being born and — for the exoplanet and astrobiology community — to study exoplanets and their atmospheres with unprecedented precision.

A sample of the extraordinary precision Webb will provide can be seen in the images above, which are of the same region of the Large Magellanic Cloud, a satellite galaxy of the Milky Way.

The image on the left was taken with one of the earliest Great Observatory telescopes — the retired Spitzer Space Telescope, and its Infrared Array Camera.  The observatory was launched in 2003 and was a pioneering instrument in its time.

But on the right is the new JWST image of the Large Magellenic Cloud, taken with its Mid-Infrared Instrument, or MIRI camera.   The galaxy’s  wispy gases and bright stars make it apparent why astronomers are ecstatic about the new worlds that will become visible to them.

“This is a really nice science example of what Webb will do for us in the coming years,” Christopher Evans, a Webb project scientist with the European Space Agency, said of the images in at a recent NASA press conference.

“This is just going to give us an amazing view of the processes in a different galaxy for the first time, cutting through the dust,” Evans said.

Michael McElwain, a Webb observatory project scientist at NASA’s Goddard Space Flight Center,  said he was “delighted to report that the telescope alignment has been completed with performance even better than we had anticipated.”

The Large Magellenic Cloud, from Spitzer image to JWST, ( NASA/ESA/CSA/STScI)

The Webb observatory can see so much better because it has a significantly larger primary mirror than on past observatories (the Hubble Space Telescope main mirror is 2.4 meters in diameter versus meters for JWST) and has improved detectors.  Webb sees the cosmos in the infrared and near-infrared wavelengths, but the images will be translated into visible light

The preparation and testing of the telescope’s science instruments (a process called commissioning) will take about two months to complete.… Read more

The European Space Agency Cuts Ties to Russia On Its ExoMars Mission. But U.S-Russian Cooperation Continues on the ISS

ESA’s Rosalind Franklin rover had been set to search for signs of life on the surface of Mars, with its launch set for this year. Its future is now in doubt because of a suspension of relations with its Russian partners due to the sanctions imposed following of the Russian invasion of Ukraine . (ESA/ ATG medialab)

The European Space Agency has decided that is currently impossible to continue any ongoing cooperation with the Russian space agency Roscosmos, and is moving forward with a “fast-track industrial study” to define how the mission can proceed without the Russians on its ambitious ExoMars astrobiology mission.

In a release, ESA said that “as an intergovernmental organization mandated to develop and implement space programs in full respect with European values, we deeply deplore the human casualties and tragic consequences of the aggression towards Ukraine. While recognizing the impact on scientific exploration of space, ESA is fully aligned with the sanctions imposed on Russia by its member states.”

The decision to rethink the mission without the Russians involved came as Roscosmos has also moved to break space ties with ESA by withdrawing personnel from Europe’s Spaceport in French Guiana and putting all ESA missions scheduled for launch by Russian Soyuz rockets on hold.  In all, five Soyuz launches of missions — Galileo M10, Galileo M11, Euclid, Earthcare and one other — have been cancelled.

The ESA statement said that the agency has begun looking for potential alternative launch services for those  missions, too.

ESA has 22 European member nations and has worked frequently with NASA and the Canadian Space Agency, as well as Roscosmos.

American and Russians astronauts, as well as those from Europe, Japan, Canada and elsewhere, have cooperated on the ISS now for decades. In this image from 2013 are Expedition 35 Commander Chris Hadfield (right) from Canada, then clockwise NASA astronauts Tom Marshburn and Chris Cassidy, and Russian cosmonauts Alexander Misurkin, Roman Romanenko and Pavel Vinogradov.   Can the cooperation last?  (NASA Marshall Space Flight Center)

At the same time that the European-Russian space partnership has been put on hold and possibly cancelled, the cooperation between Russia and the NASA, ESA, the Japanese Space Agency and the Canadian Space Agency has continued on the International Space Station.

There was earlier some doubt about Russian participation on the ISS after Roscosmos director general Dmitry Rogozin  threatened to pull out of the space station and allow it to fall back to Earth in an uncontrolled deorbit to protest of international sanctions on Russia for its Ukraine invasion.… Read more

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.

Read more

Venus, as Never Seen Before

The darkside of Venus, as imaged by an optical and near infrared camera on NASA’s Parker Solar Probe. (NASA)

For the first time, the surface of Venus has been imaged in visible wavelengths from space. The camera on the Parker Solar Probe pierced through the thick Venusian cloud cover and captured blurred but extremely valuable images of the highlands and lowlands of the planet.

The breakthrough images came thanks to a spacecraft with an entirely different mission — the Parker Probe, which has been exploring and progressively nearing the Sun in unprecedented ways.  And to get ever closer, it uses trips around Venus to slow down and thereby fly closer to the Sun.

It was during two of those trips around Venus in 2000 and 2001 that the Parker camera, which sees in visible and near infrared wavelengths, was able to  image the night side of Venus.  This was a first and totally unexpected, since Venus is known to have a dense cover of clouds.

The planet is also, of course, stunningly hot, with a mean temperature of 867 degrees Fahrenheit on the surface.  But the temperatures are lower on the elevated Aphrodite Terra, the largest highland region on the Venusian surface, and that is the area that shows as being dark in the images.

“Venus is the third brightest thing in the sky, but until recently we have not had much information on what the surface looked like because our view of it is blocked by a thick atmosphere,” said Brian Wood, lead author on the new study in Geophysical Research Letters and a physicist at the Naval Research Laboratory in Washington.  “Now, we finally are seeing the surface in visible wavelengths for the first time from space.”

The presentation below, put together by NASA, the John’s Hopkins University Applied Physics Lab and Naval Research Lab, is a stitched together video of the Parker Probe’s  Feb. 20, 2021 pass by the dark side of the planet.

Clouds of sulfur dioxide and sulfuric acid obstruct most of the visible light coming from Venus’ surface and so observing from both the ground and from space has relied on radar and observing wavelengths in the infrared that can pierce through the clouds.

But on two passes, the the Parker Probe’s Wide-field Imager for Solar Probe (WISPR) picked up a range of wavelengths from 470 nanometers to 800 nanometers. Some of that light is the near-infrared – wavelengths that we cannot see, but sense as heat – and some is in the visible range, between 380 nanometers and about 750 nanometers.… Read more

More On The Very Hot Science of Stellar Flares and Their Implications For Habitability

A solar flare, imaged by NASA’s Solar Dynamics Observatory.

Among the many scientific fields born, or reborn, by the rise of astrobiology and its search for life beyond Earth is the study of stars, including our own Sun.  Now that we know that planets — from the large and gaseous to the small and rocky — are common in our galaxy and number in the many, many billions, there is suddenly vast amount of real estate where life potentially could arise.

We already know that many of those planets large and small are not candidates for habitability for any number of reasons, and that makes the understanding of what general conditions are required for life all the more pressing.

And as the astrobiological effort speeds ahead, it has become clear that the make-up, behavior and location of the stars that host exoplanets is central to that understanding.

Many stellar issues are suddenly important, and perhaps none more so than the nature, frequency and consequences of the constant stellar eruption of  flares, superflares and coronal mass ejections.

Created as intense bursts of radiation coming from the release of magnetic energy following reconnections in stars’ coronas, flares and related coronal mass ejections are the largest explosive events in solar systems. The energy released by a major flare from our Sun is about a sixth of the total solar energy released each second and equal to 160,000,000,000 megatons of TNT

The current focus of study is flares coming off red dwarf stars — much smaller and less energetic than our Sun, but the most common stars in the galaxy, by a lot.  Many are already known to have multiple rocky planets within a distance from the star termed the “habitable zone,” where in theory water could sometimes be liquid.

But red dwarf stars universally experience intense flaring in their early periods, and the planets orbiting in the those red dwarf habitable zones can be 20 times closer to their stars than we are to the Sun.

The crucial question is whether those flares forever sterilize the planets in their systems, which is certainly a possibility.  But a related question is whether the flares might also deliver amounts of ultraviolet radiation that may be essential to the formation of the chemical building blocks of life.

Not surprisingly, this is a subject of not only intense study but of heated debate as well.

Violent stellar flares from young red dwarf stars, as illustrated here, could potentially evaporate the atmosphere of a planet.

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