Many Worlds

Author: Marc Kaufman (page 1 of 24)

The Juno Spacecraft Images Jupiter’s Moon Europa as it Speeds Past

September 30, 2022 / / 0 Comments

The first image from NASA’s Juno spacecraft as it passed close by Europa as part of its extended mission.  (NASA)

For NASA to extend its space science missions well past their original lifetime in space has become such a commonplace that it is barely noticed.

The Curiosity rover was scheduled to last on Mars for two years but now it has been going for a decade — following the pace set by earlier, smaller Mars rovers.  The Cassini mission to Saturn was extended seven years beyond it’s original end date and nobody expected that Voyager 1, launched in 1977,  would still flying out into deep space and sending back data 45 years later.

The newest addition to this virtuous collection of over-achievers is the Juno spacecraft, which arrived at Jupiter in 2016.  Its prime mission in and around Jupiter ended last year and then was extended until 2025, or beyond.

And now we have some new and intriguing images of Jupiter’s moon Europa thanks to Juno and its extension.

Traveling at a brisk 14.7 miles per second, Juno passed within 219 miles of the surface of the icy moon on Thursday and images from the flyby were released today (Friday.)  That gave the spacecraft only a two-hour window to collect data and images, but scientists are excited.

“It’s very early in the process, but by all indications Juno’s flyby of Europa was a great success,” said Scott Bolton, Juno principal investigator from Southwest Research Institute in San Antonio, in a NASA release.

“This first picture is just a glimpse of the remarkable new science to come from Juno’s entire suite of instruments and sensors that acquired data as we skimmed over the moon’s icy crust.”

Candy Hansen, a Juno co-investigator who leads planning for the Juno camera at the Planetary Science Institute in Tucson, called the released images “stunning.”

“The science team will be comparing the full set of images obtained by Juno with images from previous missions, looking to see if Europa’s surface features have changed over the past two decades,” she said.

An image of Europa taken by the Galileo spacecraft as it passed the moon in 1998. (NASA/JPL-Caltech)

During the flyby, the mission collected what will be some of the highest-resolution images of the moon (0.6 miles per pixel) taken so far and obtained valuable data on Europa’s ice shell structure, interior, surface composition, and ionosphere, in addition to the moon’s interaction with Jupiter’s magnetosphere.… Read more

Spacecraft Smashes Into A Near-Earth Asteroid in the First Major Test of NASA’s Planetary Defense Program

September 26, 2022 / / 0 Comments

The asteroid Dimorphos two minutes before the Dart spacecraft crashed into it on Sept. 26. (NASA/JHUAPL)

As a test of our ability to damage a potentially hazardous asteroid heading our way, or perhaps to give it enough of a push that the asteroid’s path is changed enough to render it harmless, a NASA spacecraft tonight successfully collided with an asteroid some 6.8 mllion miles away.

The Dart spacecraft – short for Double Asteroid Redirection Test – crashed at high speed into the asteroid Dimorphos and self-destructed yesterday evening.

It was unclear yesterday exactly how much damage was sustained by the asteroid, which is the size of a football stadium. But images taken aboard the 1,200-pound spacecraft showed that it got closer and closer to the asteroid and then the camera froze — presumably on impact.

The spacecraft was going at 14,000 miles-an-hour and hit the moon of a gravitationally-bound pair of near-Earth asteroids.

Asteroid 65803 Didymos is a binary near-Earth asteroid. The primary body has a diameter of around a half mile and a rotation period of 2.26 hours, whereas the Didymoon secondary body has a diameter of around 525 feet and rotates around the primary at a distance of around 9 miles from the primary surface in around 12 hours. (ESA)

With that impact, the orbit of Dimorphos around the larger asteroid is expected to be slightly altered, resulting in a change in the direction of the two asteroids.

While cameras and telescopes watched the crash, it will take days or even weeks to find out if it actually altered the asteroid’s orbit.

To calculate how much the moon’s orbit is altered over time it’s ‘light curve’ will be measured by observing the sunlight reflected from it with telescopes on the ground, and using this to calculate the change in the orbital period of the double-asteroid system. Satellites in orbit, including the Hubble and James Webb space telescopes will also join the effort.

This was the first  full-scale planetary defense test by the NASA, with others on the way.  Dart was launched in November, 2021.

Planetary defense experts have not found any decent-sized asteroids likely to head our way for at least a  century and likely much longer. But they also report that as many as 15,000 smaller, undetected asteroids are in the near-Earth region and their potential paths are not known.

This is part of the logic behind the planetary defense program:  The risks of an asteroid of any size hitting the Earth are extremely small, but they are not well defined and, of course, a large asteroid crash on Earth could be cataclysmic. 

… Read more

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

September 22, 2022 / / 0 Comments

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

September 14, 2022 / / 0 Comments

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.

… Read more

A Detailed New Mapping of Where Mars Once Had Plentiful Water

September 8, 2022 / / 0 Comments

Measurements from the OMEGA instrument of European Space Agency’s Mars Express and NASA’s Mars Reconnaissance Orbiter’s CRISM spectrometer were used to map where formed-in-water minerals can found across Mars. This is an especially concentrated spot at Jezero Crater, where the Perseverance rover is located. (ESA)

NASA’s long-time motto for exploring Mars has been “Follow the water.”  That has changed some in recent years, as the presence of long-ago H2O has been confirmed in many locales around the planet.   Moving on, the motto today is more “Follow the organics” — the carbon-based building blocks of life — in the search for habitable environments and maybe signs of ancient life.

But water remains crucial to any discussion of habitability on Mars, and so a new set of global water maps from the European Space Agency, ten years in the making, is both useful and intriguing.

Specifically, the map shows the locations and abundances of these aqueous minerals — rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts.

And the message that the maps deliver, said planetary scientist John Carter, is that these hydrated minerals are common across many parts of the planet.

Ten years ago, planetary scientists knew of around 1, 000 water-altered outcrops on Mars, he said.  This made them interesting as geological oddities.

But the new map has reversed the situation, revealing hundreds of thousands of such areas in the oldest parts of the planet.

“This work has now established that when you are studying the ancient terrains in detail, not seeing these minerals is actually the oddity,” says Carter, an assistant professor at the Institut d’Astrophysique Spatiale (IAS) in  France.

Global map of hydrated minerals on Mars. (ESA)

Now, Carter said in a release, the big question is whether the water was persistent or confined to shorter, more intense episodes. While not yet providing a definitive answer, the new results certainly give researchers a better tool for pursuing the answer.

“I think we have collectively oversimplified Mars,” says Carter, who was lead author in a paper published in the journal Icarus. 

He explained that planetary scientists have tended to think that only a few types of clay minerals on Mars were created during its wet period — roughly 3.5 billion to 4 billion years ago — then as the water gradually dried up salts were produced across the planet.

… Read more

NASA Suceeds in Making Precious Oxygen from Carbon Dioxide on Mars

August 31, 2022 / / 0 Comments

 

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 James Webb Space Telescope Begins Looking at Exoplanets

August 24, 2022 / / 0 Comments

 

Artist rendering of Gliese (GJ) 436 b  is a Neptune-sized planet that orbits a red dwarf  star.  Red dwarfs are cooler, smaller, and less luminous than the Sun. The planet completes one full orbit around its parent star in just a little over 2 days. It is made, scientists say, of extremely hot ice.  (NASA/JPL-Caltech/UCF)

The James Webb Space Telescope has begun the part of its mission to study the atmospheres of 70 exoplanets in ways, and at a depth, well beyond anything done so far.

The telescope is not likely to answer questions like whether there is life on distant planet — its infrared wavelengths will tell us about the presence of many chemicals in exoplanet atmospheres but little about the presence of the element most important to life on Earth, oxygen.

But it is nonetheless undertaking a broad study of many well-known exoplanets and is likely to produce many tantalizing results and suggest answers to central questions about exoplanets and their solar systems.

Many Worlds has earlier looked at the JWST “early release” program, under which groups are allocated user time on the telescope under the condition that they make their data public quickly.  That way other teams can understand better how JWST works and what might be possible.

Another program gives time to scientists who worked on the JWST mission and on its many instruments.  They are given guaranteed time as part of their work making JWST as innovative and capable as it is.

One of the scientist in this “guaranteed time observations program” is Thomas Greene, an astrophysicist at NASA Ames Research Center.  The groups he leads have been given 215 hours of observing time for this first year (or more) of Cycle 1 of JWST due to his many contributions to the JWST mission as well as his history of accomplishments.

In a conversation with Greene, I got a good sense of what he hopes to find and his delight at the opportunity.  After all, he said, he has worked on the JWST idea and then mission since 1997.

“We will be observing a diverse sample of exoplanets to understand more about them and their characteristics,” Greene said.  “Our goal is to get a better understanding of how exoplanets are similar to and different from those in our solar system.”

And the JWST spectra will tell them about the chemistry, the composition and the thermal conditions on those exoplanets, leading to insights into how they formed, diversified and evolved into planets often so unlike our own.… Read more

Icy Moons, And Exploring The Secrets They Hold

August 18, 2022 / / 0 Comments

Voyager 2’s flew by the Uranian moon Miranda in 1986 and the spacecraft spent 17 minutes taking  photos to make this high-resolution portrait.  Miranda has three oval and trapezoid coronae, tectonic features whose origins remain debated. (NASA / JPL / Ted Stryk)

When it come to habitable environments in our solar system, there’s Earth, perhaps Mars billions of years ago and then a slew of ice-covered moons that are likely to have global oceans under their crusts.  Many of you are familiar with Europa (a moon of Jupiter) and Enceladus (a moon of Saturn) — which have either been explored by NASA or will be in the years ahead.

But there quite a few others icy moons that scientists find intriguing and just possibly habitable.  There is Ganymede,  the largest moon of Jupiter and larger than Mercury but only 40 percent as dense, strongly suggesting a vast supply of water inside rather than rock.

There’s Saturn’s moon Titan, which is known for its methane lakes and seas on the surface but which has a subterranean ocean as well.  There is Callisto, the second largest moon of Jupiter and an subsurface-ocean candidates and even Pluto and Ceres, now called dwarf planets that show signs of having interior oceans.

And of increasing interest are several of the icy moons of Uranus, particularly Ariel and Miranda.  Each has features consistent with a subsurface ocean and even geological activity.  Although Uranus is a distant planet, well past Jupiter and Saturn and would take more than a decade to just get there, the possibility of a future Uranus mission is becoming increasingly real.

The National Academy of Sciences (NAS) Decadal Survey for planetary science rated a Uranus mission as the highest priority in the field, and just today (Aug. 18) NASA embraced the concept.

At a NASA Planetary Science Division town hall meeting, Director Lori Glaze said the agency was “very excited” about the Uranus mission recommendation from the National Academy and that she hoped and expected some studies could be funded and begun in fiscal 2024.

If a Uranus mission is fully embraced,  it would be the first ever specifically to an ice giant system — exploring the planet and its moons.  This heightened interest reflects the fact that many in the exoplanet field now hold that ice giant systems are the most common in the galaxy and that icy moons may well be common as well.… Read more

Despite Everything, American-Russian Relations on the International Space Station Appear To Be Solid

August 5, 2022 / / 0 Comments

The International Space Station, which orbits 248 miles above Earth,  in what is called low-Earth orbit. Its long success as an international collaboration has been tested by the Ukraine war. (NASA)

Late last month, it appeared that Russian participation in the International Space Station would end in 2024 — or so seemed to say the head of the Russian space agency, Roscosmos  Thirty years of unusual and successful cooperation would be coming to a close as the Ukraine war appeared to make longer-term commitments impossible, or undesirable for the Russian side.

But on a day when the Ukraine war raged for its 163rd day, when new Western sanctions were being put into place, when a Russian judge gave WNBA star Brittney Griner a provocative 9-year prison term for carrying small amounts of cannabis oil as she left Moscow, and just a short time after what seemed to be the Russian announcement of that 2024 departure,  NASA officials held a commodious press conference with Roscosmos Executive Director for Human Space Programs Sergei Krikalev and others involved with the ISS.

Together they spoke yesterday (August 4) of expanding American-Russian cooperation on the mission and discounted talk of a 2024 Russian exit.

“We always talk of spaceflight as being team support,” said Kathy Lueders, NASA’s associate administrator of NASA’s Space Operations, which oversees the ISS. “And this news conference will exemplify how it is a team sport.”

She then discussed  how and why a Russian cosmonaut would soon take a SpaceX flight to the ISS as part of a new program under which Russian cosmonauts and American astronauts can fly on each other’s ISS-and-homeward-bound spacecraft.  The flight by veteran cosmonaut Anna Kikina will mark the first time a Russian has flown on an American spacecraft.

In the press conference, Krikalev then insisted that Russia had no intention of leaving the station in 2024 but rather would begin looking at the logistics of departing at that time — with an eye to leaving for their own planned space station in the years ahead.

“As far as the statement for 2024, perhaps something was lost in translation,” he said. “The statement actually said Russia will not pull out until after 2024.  That may be in 2025, 2028 or 2030.”   He said the timetable “will depend on the technical condition of the station.”

In the good-natured spirit of the press conference, Krikalev said that he was “happy to see so many faces I’ve known for many years.” 

… Read more

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

July 11, 2022 / / 1 Comment

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

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