Category: Planetary Systems (page 1 of 11)

Our Sun, as Never Seen Before

This animation shows a series of views of the sun captured with the Extreme Ultraviolet Imager (EUI) on ESA/NASA’s Solar Orbiter on May 30, 2020. They show the sun’s appearance at a wavelength of 17 nanometers, which is in the extreme ultraviolet region of the electromagnetic spectrum. Images at this wavelength reveal the upper atmosphere of the sun and the corona, which has a temperature of more than a million degrees. Solar Orbiter/EUI Team (ESA & NASA; CSL, IAS, MPS, PMOD/WRC, ROB, UCL/MSSL)

The first images of the sun from the European Space Agency/NASA’s Solar Orbiter have been released and are stupendous.  They are the closest photos ever taken of the star that we orbit, and have already revealed some fascinating features that nobody knew existed.

Launched early this year, the spacecraft completed its first close pass of the sun in mid-June and began sending back images and data.

“These amazing images will help scientists piece together the sun’s atmospheric layers, which is important for understanding how it drives space weather near the Earth and throughout the solar system.” aid Holly Gilbert, NASA project scientist for the mission at NASA’s Goddard Space Flight Center.

The orbiter has already found previously unknown found across the sun miniature versions of the gigantic solar flares that reach out far into space.  But these much smaller versions,  deemed to be “campfires,” are so far seen by not understood.

Normally, the first images from a spacecraft confirm the instruments are working; scientists don’t expect new discoveries from them. But the Extreme Ultraviolet Imager, or EUI, on Solar Orbiter returned data hinting at solar features never observed in such detail.

“The campfires we are talking about here are the little nephews of solar flares, at least a million, perhaps a billion times smaller,” said mission principal investigator David Berghmans an astrophysicist at the Royal Observatory of Belgium said.

“When looking at the new high resolution EUI images, they are literally everywhere we look.”

Solar Orbiter spots ‘campfires’ on the Sun. Locations of campfires are annotated with white arrows.
Solar Orbiter/EUI Team (ESA & NASA; CSL, IAS, MPS, PMOD/WRC, ROB, UCL/MSSL)

That the Solar Orbiter has been able to continue on its mission has been no simple feat.

The coronavirus forced mission control at the European Space Operations Center (ESOC) in Darmstadt, Germany to close down completely for more than a week. During commissioning, the period when each instrument is extensively tested, ESOC staff were reduced to a skeleton crew.… Read more

Sample Return in the Time of Coronavirus

 

Sample return from Mars. Artist rendering of a Mars sample return mission. The mission would use robotic systems and a Mars ascent rocket to collect and send samples of Martian rocks, soils and atmosphere to Earth for detailed chemical and physical analysis.  No rocket has ever taken off from Mars and this NASA and European Space Agency (ESA) project is in early planning stages. Still, blue-ribbon science panels have recommended efforts to begin preparing the public for an eventual Mars sample return. ( Wickman Spacecraft & Propulsion)

For space scientists of all stripes, few goals are as crucial as bringing pieces of Mars, of asteroids, of other planets and moons back to Earth for the kind of intensive study only possible here.  Space missions can, and have, told us many truths about the solar system,  but having a piece of Mars or Europa or an asteroid to study in a lab on Earth is considered the gold standard for learning about the actual composition of other bodies, their histories and whether they could — or once did — harbor life.

In keeping with this ambition, the last National Research Council Decadal Survey listed a Mars “sample return” as the top science priority for large Flagship missions.  And the Perseverance rover that NASA is scheduled to send to Mars next month will — among many other tasks — identify compelling rock samples, collect and cache them so a subsequent mission can pick them up and fly them to Earth.

Two asteroid sample return missions are also in progress, the NASA’s OSIRIS-REx mission to Bennu and the Japan Aerospace Exploration Agency (JAXA’s)  Hayabusa2 mission to the Ryugu.  Both spacecraft are at or have already left their intended targets now and are expected to return with rock samples later this decade, with Hayabusa2 scheduled to complete its round trip later this year.

An illustration of the coronavirus. (Centers of Disease Control)

So sample return is in our future.  And in the case of Mars the samples will not with 100 percent certainty be lifeless — a major difference from the samples brought back from the moon during the Apollo missions and the samples coming from asteroids.

This possibility of a spacecraft bringing back something biological — as in the 1969 book “The Andromeda Strain” — has always been viewed as a very low probability but high risk hazard, and much thinking has already gone into how to bring samples back safely.… Read more

Close and Tranquil Solar System Has Astronomers Excited

An artist’s impression of the GJ 887 planetary system of super Earths. (Mark Garlick)

From the perspective of planet hunters and planet characterizers,  a desirable solar system to explore is one that is close to ours, that has a planet (or planets) in the star’s habitable zone,  and has a host star that is relatively quiet.  This is especially important with the very common red dwarf stars,  which are far less luminous than stars such as our sun but tend to send out many more powerful — and potentially planet sterilizing — solar flares.

The prolific members of the mostly European and Chilean Red Dots astronomy team believe they have found such a system about 11 light years away from us.  The system — GJ 887 — has an unusually quiet red dwarf host, has two planets for sure and another likely that orbits at a life-friendly 50-day orbit.  It is the 12th closest planetary system to our sun.

It is that potential third planet, which has shown up in some observations but not others, that would be of great interest.  Because it is so (relatively) close to Earth, it would be a planet where the chemical and thermal make-up of its atmosphere would likely be possible to measure.

The Red Dots team — which was responsible for the first detection of a planet orbiting Proxima Centauri and also Barnard’s star — describes the system in an article in the journal Science.  Team leader Sandra Jeffers of Goettingen University in Germany said in an email that GJ 887  “will be an ideal target because it is such a quiet star — no starspots or energetic outbursts  or flares.”

In an accompanying Perspective article in Science,  Melvyn Davies of Lund University in Sweden wrote that “If further observations confirm the presence of the third planet in the habitable zone, then GJ 887 could become one of the most studied planetary systems in the solar neighborhood.”

An artist’s impression of a flaring red dwarf star and a nearby planet. Red dwarfs are by far the most common stars in the sky, and most have planetary systems.  But scientists are unsure if they can support a habitable planet because many send out more large and powerful flares than other types of stars, especially at the beginnings of their solar lives. (Roberto Molar Candanosa/Carnegie/NASA)

GJ 877 is roughly half as massive as our sun — large for its type of star — and is the brightest red dwarf in the sky.… Read more

Thinking About Life (or Lyfe) Through The Prism of “Star Trek”

This column was written for Many Worlds by Michael L. Wong and Stuart Bartlett.  Wong is a postdoctoral research associate at the University of Washington’s Astronomy and Astrobiology program and is a member of  NASA’s Nexus for Exoplanet System Science (NExSS) initiative as part of the university’s Virtual Planetary Laboratory team.  Bartlett is a postdoctoral scholar in Geochemistry at the California Institute of Technology and has been a fellow at the Earth-Live Science Institute (ELSI) in Tokyo.

 

Spock communicates with a Horta,  a fictional silicon-based life form composed of molten rock and acid.  (Star Trek; CBS Studios)

By Michael L. Wong and Stuart Bartlett

 

The search for extraterrestrial life is in its early phase still  and, the truth is, we don’t yet know if life exists beyond our pale blue dot.  Or, if it does, whether it will be easily recognizable or truly bizarre.

Predicting what might be out there, and how to find it, is a hypothesis-driven area of research at present — one that has given rise to hundreds of possible definitions for the “life” we are looking for.

But after grounding ourselves in scientific principles, it may be that our greatest tool is to let our imaginations fly. Science fiction often helps us embrace our ignorance of what might be out there.

In the Star Trek universe, our galaxy is teeming with life—both astonishingly familiar and incredibly different.

The familiar variety includes Mr. Spock, the U.S.S. Enterprise’s half-human, half-Vulcan science officer. He is the product of an extraordinary cosmic coincidence: the emergence of nearly identical biochemical machinery on two completely separate worlds. Vulcans—despite their pointy ears, upswept eyebrows, and a nearly religious devotion to bowl cuts—are incredibly similar to humans on the cellular, genetic, and metabolic level.

We can share meals, share air, and, yes, share intimacy. Even their green, copper-based blood is not as alien as it might seem; this trait is typical of most mollusks and crustaceans on Earth.

 

The Crystalline entity was a powerful, spaceborne creature characterized by a crystalline structure that resembled a large snowflake. (Star Trek;  CBS Studios)

But Star Trek also depicts life forms that are incredibly dissimilar from you, me, or Mr. Spock.

Take the Horta, for example. This lumpy mass, like a misshapen meatball crossed with a child’s volcano science experiment, is a silicon-based life form composed of molten rock and acid.

Then there’s Q, a non-corporeal being that possesses god-like powers which, it seems, are directed solely upon harassing Captain Jean-Luc Picard.… Read more

For First Time, Tiny CubeSat Locates a Distant Exoplanet

 

The image above, courtesy of NASA’s Jet Propulsion Laboratory, shows the CubeSat ASTERIA as it was being launched from the International Space Station in 2017.

The size of a briefcase, ASTERIA is part of a growing armada of tiny spacecraft being launched around the world and adding an increasingly important (and inexpensive) set of new tools for conducting Earth, space and exoplanet science.

ASTERIA, for instance, was designed to perform some of the complex tasks much larger space observatories use to study distant exoplanets outside our solar system.   And a new paper soon to be published in the Astronomical Journal describes how ASTERIA (short for Arcsecond Space Telescope Enabling Research in Astrophysics) didn’t just demonstrate it could perform those tasks but went above and beyond, detecting the known exoplanet 55 Cancri e.

While it was not the first detection of that exoplanet — which orbits close to its host star 41 light years away — it was the first time that a CubeSat had measured the presence of an exoplanet, something done so far only by much more sophisticated space and ground telescopes.

“Detecting this exoplanet is exciting because it shows how these new technologies come together in a real application,” said Vanessa Bailey, who led the ASTERIA  exoplanet science team at JPL.  The project was a collaboration between JPL and the Massachusetts Institute of Technology.

“We went after a hard target with a small telescope that was not even optimized to make science detections – and we got it, even if just barely,” said Mary Knapp, the ASTERIA project scientist at MIT’s Haystack Observatory and lead author of the study. “I think this paper validates the concept that motivated the ASTERIA mission: that small spacecraft can contribute something to astrophysics and astronomy.”  Both made their comments in a JPL release.

 

Artist rendering of planet Cancri 55 e. (NASA; JPL/Caltech)

 

ASTERIA was originally designed to spend 90 days in space.  But it received three mission extensions before the team lost contact with the satellite in late 2019.

The mission was not even designed to look for exoplanets.  It was, rather, a technology demonstration, with the mission’s goal to develop new capabilities for future missions. The team’s technological leap was to build a small spacecraft that could conduct fine pointing control — essentially the ability to stay focused very steadily on a distant star for long periods.… Read more

The WFIRST Space Observatory Becomes the Nancy Grace Roman Space Telescope. But Will it Ever Fly?

An artist’s rendering of NASA’s Wide Field Infrared Survey Telescope (WFIRST), now  the Nancy Grace Roman Space Telescope, which will search for exoplanets that are small rocky as well as Neptune sized at a greater distance from their host stars than currently possible.  It will also study multiple cosmic phenomena, including dark energy and other theorized Einsteinian phenomena. (NASA’s Goddard Space Flight Center)

Earlier last week, NASA put out a release alerting journalists to  “an exciting announcement about the agency’s Wide Field Infrared Survey Telescope (WFIRST) mission.”

Given the controversial history of the project — the current administration has formally proposed cancelling it for several years and the astronomy community (and Congress) have been keep it going — it seemed to be a  newsworthy event, maybe a breakthrough regarding an on-again, off-again very high profile project.

And since WFIRST was the top large mission priority of the National Academies of Sciences some years ago — guidance that NASA almost always follows — the story could reflect some change in the administration’s approach to the value of long-established scientific norms.  Plus, it could mean that a space observatory with cutting-edge technology for identifying and studying exoplanets and for learning much more about dark matter and Einsteinian astrophysics might actually be launched in the 2020s.

But instead of a newsy announcement about fate of the space telescope, what NASA disclosed was that the project had been given a new name — the Nancy Grace Roman space telescope.

As one of NASA’S earliest hired and highest-ranking women, Roman spent 21 years at NASA developing and launching space-based observatories that studied the sun, deep space, and Earth’s atmosphere. She most famously worked to develop the concepts behind the Hubble Space Telescope, which just spent its 30th year in orbit.

This is a welcome and no doubt deserving honor.  But it will be much less of an honor if the space telescope is never launched into orbit.  And insights into the fate of WFIRST (the Nancy Grace Roman Space Telescope) are what really would constitute “an exciting announcement.”

What’s going on?

Nancy Grace Roman at NASA’s Goddard Space Flight Centre in the early 1970s (NASA)

 

I have no special insights, but I think that one of the scientists on the NASA Science Live event was probably on to something when she said:

“I find it tremendously exciting that the observatory is being  renamed,”  said Julie McEnery, deputy project scientist for the (now) NASA Roman mission.  … Read more

Mapping the Surfaces of Our Solar System

 

A portion of the new “unified” geological map of the moon. (NASA/GSFC/USGS.)

It was not all that long ago that a “map” of our  moon, of Mars, of a large asteroid such as Vesta, of Titan, or of any hard-surfaced object in our solar system would have some very general outlines, some very large features identified,  and  then the extraterrestrial equivalent of the warning on Earth maps of yore that beyond a certain point “there be dragons.”  Constructing a map of the topography and geology of a distant surface requires deep understanding and data and lot of hard work.

Yet such an in-depth mapping is underway and has already resulted in detailed surface rendering of Mars,  of Jupiter’s moons Ganymede and Io, and of our moon.  And now, using both Apollo-era data for the moon and measurements from the Japanese lunar orbiter and currently flying American orbiter, the U.S. Geological Survey, in partnership with NASA and the Lunar and Planetary Institute,  has produced a rendering of our moon that moves extraterrestrial mapping significantly further.

It unifies all the data collected using a variety of techniques and produces a map with well-defined geological units, with in-laid topography (on digital versions,) and with a guide of sorts for moon watchers on Earth.  The red sections in the map above are the basalt lava flows that have the fewest craters from asteroid hits and so are the youngest surfaces.  They are also the darker sections of the moon that we see when we look into the night sky at a full moon.

The maps are not at a detail to allow NASA mission planners to assess a landing site, but they do tell what the geological environs are going to be and so are a guide to what might be found.

 

Orthographic projections (presenting three-dimensional objects in two-dimensions)  of the new “Unified Geologic Map of the Moon” showing the geology of the moon’s near side (left) and far side (right) with shaded topography from the Lunar Orbiter Laser Altimeter (LOLA). This geologic map is a synthesis of six Apollo-era regional geologic maps, updated based on data from recent satellite missions. It will serve as a reference for lunar science and future human missions to the Moon.  (NASA/GSFC/USGS.)

The chief purpose of the map — in which 5 kilometers of distance are represented by 1 millimeter on the map — is to summarize the current state of lunar geologic knowledge.… Read more

Theorized Northern Ocean of Mars; now long gone.  (NASA)

Change is the one constant in our world– moving in ways tiny and enormous,  constructive and destructive.

We’re living now in a time when a rampaging pandemic circles the globe and when the climate is changing in so many worrisome and potentially devastating ways.

With these ominous  changes as a backdrop, it is perhaps useful to spend a moment with change as it happens in a natural world without humans.  And just how complete that change can be:

For years now, planetary scientists have debated whether Mars once had a large ocean across its northern hemisphere.

There certainly isn’t one now — the north of Mars is parched, frigid and largely featureless.  The hemisphere was largely covered over in a later epoch by a deep bed of lava, hiding signs of its past.

The northern lowlands of Mars, as photographed by the Viking 2 lander. The spacecraft landed in the Utopia Planitia section of northern Mars in 1976. (NASA/JPL)

Because our sun sent out significantly less warmth at the time of early Mars (4.2-3.5  billion years ago,) climate modelers have long struggled to come up with an explanation for how the planet — on average, 137 million miles further out than Earth — could have been anything but profoundly colder than today. And if that world was so unrelentingly frigid, how could there be a surface ocean of liquid water?

But discoveries in the 21st century have strongly supported the long-ago presence of water on a Mars in the form of river valleys, lakes and a water cycle to feed them.  The work done by the Curiosity rover and Mars-orbiting satellites has made this abundantly clear.

An ocean in the northern lowlands is one proposal made to explain how the water cycle was fed.

And now, In a new paper in Journal of Geophysical Research: Planets,  scientists from Japan and the United States have presented modelling and analysis describing how and why Mars had to have a large ocean early in its history to produce the geological landscape that is being found.

Lead author Ramses Ramirez, a planetary scientist with the Earth-Life Science Institute in Tokyo, said it was not possible to determine how long the ocean persisted, but their team concluded that it had to be present  in that early period around 4 billion to 3.5 billion years ago.  That is roughly when what are now known to be river valleys were cut in the planet’s southern highlands.… Read more

Exploring Our Sun Will Help Us Understand Habitability

The surface of the sun, with each “kernel” or “cell” roughly the size of Texas. The movie is made up of images produced by the Daniel Inouye SolarTelescope in Hawaii.  Novel and even revolutionary data and images are also expected from the Parker Solar Probe (which will travel into the sun’s atmosphere, or corona) and the just launched Solar Orbiter, which will study (among many other things) the sun’s polar regions. (NSO/NSF/AURA)

 

Scientists have been  studying our sun for centuries, and at this point know an awful lot about it — the millions of degrees Fahrenheit heat that it radiates out from the corona, the tangled and essential magnetic fields that it creates, the million-miles-per-hour solar wind and the charged high-energy solar particles that can be so damaging to anything alive.

But we have now entered a time when solar science is taking a major leap forward with the deployment of three pioneering instruments that will explore the sun and its surroundings as never before.  One is a space telescopes that will get closer to the sun (by far) than any probe before, another is a probe that will make the first observations of the sun’s poles, and the third is a ground-based solar telescope that can resolve the sun in radically new ways — as seen in the image above, released last month.

Together, NASA’s Parker Solar Probe, the joint European Space Agency-NASA Solar Orbiter mission and the National Science Foundation’s Inouye Solar Telescope on Hawai’i will provide pathways to understand some of the mysteries of the sun.  They include resolving practical issues involving the dynamics  of “space weather” that can harm astronauts and telecommunications systems, and larger theoretical unknowns related to all the material that stars scatter into space and onto planets.

Some of those unresolved questions include determining how and why heat and energy flow from the sun’s inner core to the outer corona and make it so much hotter, determining the structure and dynamics of the plasma and magnetic fields at the sources of the solar wind, the make-up and effects of solar flares and coronal mass ejections, and how and why the sun is able to create and control the heliosphere — the vast bubble of charged particles blown by the solar wind into interstellar space.

 

An illustration of Kepler2-33b, , one of the youngest exoplanets detected to date using NASA Kepler Space Telescope.

Read more

Exactly How Like Our Earth is an Earth-like Planet?

Explainer video for Earth-Like. (Vimeo edition with subtitles here)

Are we alone? The question hangs over each discovery of an Earth-sized planet as we speculate on its habitability. But how different and varied could these worlds really be? Perhaps the best way to get a flavor of this potential diversity is to build a few planets.

This is the idea behind Earth-Like: a website and twitter bot that lets you build your own Earth-like world. Earth-Like begins with a planet that resembles our Earth today, with oceans flowing over the surface and an atmosphere that maintains the global average temperature at a comfortable 15°C (59°F) on our orbit within the habitable zone. By making changes to the fraction of exposed land, the volcanic rate and position within the habitable zone, you can change the conditions on our planet into wildly different environments from desert to snowball.

Earth-Like can create a visualisation of what your planet might look like. This one is 91% covered with land, sitting in the middle of the habitable zone with 5 x the volcanic rate of Earth today! Its average temperature is about 9°C (48°F).

The concept for Earth-Like began during a workshop on planet diversity held at the Earth-Life Sciences Institute (ELSI) in Tokyo. The discussions highlighted that the potential for variation between rocky worlds is vast. A planet rich in carbon could have a mantle of diamond. A stagnant surface rather than mobile continental plates could throttle volcanism. The gravity on a large rocky planet might flatten the topology to allow shallow seas to cover all the land.

At the moment, observations can only tell us the physical size (either radius or mass) and the orbit of the majority of extrasolar planets. As we do not know what the surface of these worlds is like, we dub new discoveries Earth-like or potentially habitable if their size and the amount of radiation they receive from the star is similar to Earth. But this fails to convey how incredibly alien these worlds could be.

Earth-Like was spearheaded by undergraduate student, Kana Ishimaru, at the University of Tokyo (now a graduate student at the University of Arizona), working with myself, Julien Foriel (now a researcher at Harvard University) and Nicholas Guttenberg at ELSI. We wanted to build a model that would give a feel of the diversity of potentially habitable worlds and which could be run easily on a web browser.… Read more

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