Today’s digital palette cleanser is bought to you courtesy of Cassini and a small icy moon filled with intrigue.
As we constantly check the news sites for updates on the minutia of our daily lives, refresh our social media feeds, and ponder the existential dread that seems to be flooding our immediate future with increasing volume, it’s nice to find little islands of tranquility that appear out of nowhere. Today, I found that island in a beautiful processed image of Saturn’s moon Enceladus by the incredibly talented Kevin Gill, who works at NASA’s Jet Propulsion Laboratory:
In his tweet, Kevin simply describes this view as “solitude” and that’s pretty damn near perfect. In this image, the beautifully back-lit plumes are visible with the tenuous E-ring of Saturn creating an atmospheric backdrop.
Enceladus is a fascinating moon. During the NASA Cassini mission, which ended its glorious 13-year reign in Saturn orbit in 2017, the spacecraft became intimately familiar with the icy moon and its famous geysers. After flying through the plumes of water vapor, it became clear to mission scientists that not only does this 313 mile wide icy marble have an extensive subsurface liquid water ocean, that ocean contains organic molecules that could hint at astrobiological possibilities.
It’s sometimes nice to escape to Saturn orbit every now and again, so be sure to check out Kevin’s awe-inspiring Flickr album for more.
The legendary British rock band has been honored by NASA with a rock that the InSight lander rocket-blasted across the Red Planet’s surface last year.
Those of you who frequently read my articles will know that I have a fascination with rolling rocks on celestial bodies. There’s the numerous boulders on the Moon that have been dislodged and rolled down crater sides, leaving their bouncy imprints in the dirt. There’s also the rolling rocks of Ceres. And the theorized rock tracks that are carved into Phobos. Then there’s Mars, the undisputed king of rolling boulders, imaged to beautiful precision by our orbiting armada of spacecraft.
The most famous rolling rock is no boulder, however; it’s barely larger than a golf ball—but it’s now the most famous pebble in the solar system. It’s a little rock that was minding its own business until a car-sized NASA robot rumbled through the Martian skies on Nov. 26, 2018, retro-rockets firing to slow its descent to the ground, that flipped the innocent ruddy bystander three feet (1 meter) from the landing site. It’s sobering to think that that rock probably hasn’t been disturbed for millions of years until that fateful day.
Behold, the “Rolling Stones Rock,” named after rock legends The Rolling Stones and announced tonight by Avengers actor Robert Downey Jr. to tens of thousands of Stones fans at the Rose Bowl Stadium, just before Mick Jagger, Keith Richards, Charlie Watts, Ronnie Wood, and friends rocked Los Angeles to its core. Space exploration doesn’t get much more Hollywood than this:
And a little animated introduction to the rock itself:
“The name Rolling Stones Rock is a perfect fit,” said Lori Glaze, director of NASA’s Planetary Science Division in Washington, in a statement. “Part of NASA’s charter is to share our work with different audiences. When we found out the Stones would be in Pasadena, honoring them seemed like a fun way to reach fans all over the world.”
While, in the grand scheme of things, naming a little rock after The Rolling Stones may not seem like such a big deal (and, besides, it’s an unofficial designation), as my wife and I stood watching the Stones do a blistering performance of “Sympathy For the Devil”, the family next to us were discussing Mars asking what the InSight lander was doing on the Red Planet.
So, mission success, NASA. Mission success.
“Cross-pollinating science and a legendary rock band is always a good thing…”
The space exploration industry is booming, which is an encouraging sign for our future. But some pundits are arguing that rocket launches will exacerbate global warming.
When so many people, especially those in charge, seem so cavalier about the impact of global warming and climate change on our planet, it’s refreshing to see a perspective that worries about what we’re doing to our environment. Unfortunately, when that perspective focuses on a tiny contributor and seems to lack the understanding of what it criticizes, it needs to be called out. A number of pundits looked at the exploding private space industry and have grown concerned that rocket launches we will inject too much greenhouse gas into the atmosphere, exacerbating global warming and the attendant problems that come with it. And while it’s true that rocket fuel is far from clean, releasing plenty of unwanted chemicals into the atmosphere as it burns, we have to keep the big picture in mind.
When it comes to launching things into space, there aren’t that many alternatives to rockets and their toxic fuel. You can’t use an ion drive or any of the other seemingly sci-fi but realistic propulsion methods for traveling to other worlds and solar systems. Earth’s gravity and atmospheric pressure at sea level are very different from the vacuum of the cosmos where the tiniest push can really add up in the long term. The only way to get tons of supplies and machinery into orbit and beyond is through controlled explosions harnessed by rockets. There is simply no other way currently feasible, and there won’t be until we figure out how to build giant electromagnetic railguns, or how to harness antimatter, although that would come with a high risk of exposure to gamma radiation.
We could conceivably launch human crews in single stage to orbit planes, but their spacecraft are going to have to rely on good old-fashioned rocketry. That said, however, the plan is not to simply keep launching things from earth with no regard to the pollution thousands of rockets launched every year would cause. Launching payloads from Earth is expensive, both financially and energetically, so ideally, we would want to launch them from somewhere else. We would want to take off from the Moon or asteroids, somewhere where the gravity is in a fraction of what it is on our world, and we could use the same engines to propel anywhere between six and a hundred times the cargo. This is what we mean by infrastructure for space exploration. Forget about turning Earth into a giant launchpad. The ideal gateway to the rest of the solar system is the Moon.
Lacking an atmosphere, the Moon doesn’t particularly care how toxic the fuel is or how much greenhouse gas each launch produces. For all intents and purposes, the moon is a harsh and the radioactive wilderness with no environment to conserve. The same goes for asteroids we want to use as refueling stations, which are simply chunks of radiation-battered rock and metal floating through space we could harvest for fuel and building materials by using, of all things, steam powered asteroid-hopping robots. So, while it’s understandable to worry about the carbon footprint of everything that we do, considering the current inaction by so many on pressing climate issues, it’s important to keep things in perspective when doing so. If global warming continues apace, it won’t be thanks to rockets. It will be thanks to stubborn clinging to fossil fuels across the world and pollution from heavy industry and manufacturing.
If we were to push for serious investments in green energy, which is thankfully something that’s already happening, rocket launchers wouldn’t even be a blip on our carbon radar. Before we start asking ourselves how much carbon dioxide a SpaceX Falcon Heavy releases, and how many greenhouse gases it saves by reusing its booster cores, we need to ask ourselves how many coal plants are still powering cities and why, and what it will take to switch them over to clean, renewable sources. Otherwise, we’re doing the equivalent of trying to pay off the national debt by scrimping and saving on how many pencils public school teachers are allowed to get from their school districts. Which would be a funny analogy if it wasn’t true.
The two GRAIL spacecraft flew one in front of the other, precisely measuring the distance of their separation in order to detect very small fluctuations in the Moon’s gravitational field. When the spacecraft passed over a region of higher density, the local gravitational field would become enhanced, slightly accelerating the leading spacecraft (called “Ebb”) before the trailing spacecraft (“Flow”) experienced that acceleration. By mapping these acceleration fluctuations, scientist have gained an invaluable understanding of density fluctuations deep below the Moon’s surface that would have otherwise remained invisible.
During this recent analysis, the researchers discovered a gravitational “anomaly” beneath the South Pole-Aitken basin—a vast depression on the lunar far side spanning 2,000 miles wide and several miles deep. This anomaly represents a huge accumulation of mass hundreds of miles below the basin.
“Imagine taking a pile of metal five times larger than the Big Island of Hawaii and burying it underground. That’s roughly how much unexpected mass we detected,” said Peter B. James, of Baylor University and lead author of the study, in a statement.
How did all that material end up buried inside the Moon’s mantle? The South Pole-Aitken basin was created four billion years ago in the wake of a massive asteroid impact. In fact, the basin is known to be one of the biggest impact craters in the solar system. If this crater was formed by an impact, it stands to reason that the gravitational anomaly is being caused by the dense metallic remains of the massive asteroid that met its demise when the Earth-Moon system was in the throes of formation.
“When we combined [the GRAIL data] with lunar topography data from the Lunar Reconnaissance Orbiter, we discovered the unexpectedly large amount of mass hundreds of miles underneath the South Pole-Aitken basin,” added James. “One of the explanations of this extra mass is that the metal from the asteroid that formed this crater is still embedded in the Moon’s mantle.”
There may be other explanations, one of which focuses on the formation of the Moon itself. As the lunar interior cooled after formation, the large subsurface mass could be an accumulation of “dense oxides associated with the last stage of lunar magma ocean solidification,” the researchers note.
The metallic corpse of an ancient asteroid is the leading candidate, however, and computer simulations carried out by the team indicated that if the conditions are right, the dense iron-nickel core of an asteroid can be dispersed inside the Moon’s mantle where it remains embedded today without sinking into the lunar core.
Although there were certainly larger asteroid impacts throughout the history of our solar system, the Moon’s South Pole-Aitkin basin is the largest preserved impact crater known, making it a prime candidate to study ancient impact sites
“[It’s] one of the best natural laboratories for studying catastrophic impact events, an ancient process that shaped all of the rocky planets and moons we see today,” said James.
It just so happens that we currently have a mission at the basin, exploring this strange and unexplored place. On Jan. 3, the Chinese Chang’e 3 mission achieved the first soft touchdown on the lunar far side, landing inside Von Kármán crater and releasing a robotic rover, Yutu-2, to explore the landscape. At time of writing, the mission is ongoing.
The space telescope has refined the stellar flybys of the Voyager and Pioneer probes—how might it help us chart our way to the stars in the future?
When looking up on a starry night, it can be difficult to comprehend that those stars are not fixed in the sky. Sure, on timescales of a human lifetime, or even the entirety of human history, the stars don’t appear to move too much. But look over longer timescales—tens of thousands, to millions of years—and it becomes clear that the stars in the sky are in motion. This means the constellations we see today will be misshapen (or even non-existent!) in a few hundred thousand years’ time.
This poses an interesting question: If humanity were to send a spacecraft on an interstellar mission—an endeavor that could take thousands of years, depending on how ambitious the target—aiming it directly at a distant star would be a mistake. Depending on how far away that star is, by the time the spacecraft reaches its target, the star could have moved a few light-years away. This is why precision astrometry—the astronomical measurement of a star’s position, speed and direction of motion—will be needed to predict where a target star will be, and not where it currently is, when our future interstellar mission gets there.
To test this, we don’t need to wait until humanity has the means to build a starship, however. We have a bunch of interstellar probes that have already started their epic sojourns into the galaxy.
Earlier this year, NASA’s Voyager 2 spacecraft departed the Sun’s sphere of influence and became humanity’s second interstellar mission, six years after its twin, Voyager 1, made history to become the first human-made object to drift into the space between the stars. Both Voyagers are still transmitting telemetry to this day, over 40 years since their launch. Another two spacecraft, the older Pioneer 10 and 11 missions, are also on their way to interstellar space, but they stopped transmitting decades ago. A newcomer, NASA’s New Horizons mission, will also become an interstellar mission in the future, but it has yet to finish its Kuiper belt explorations and still has fuel to make course corrections, so predictions of its stellar encounters will remain unknown for some time.
Having explored the outer planets in the 1970’s and 80’s, the Voyagers and Pioneers barreled on, revealing stunning science from the outer solar system. In the case of Voyager 1 and 2, when each breached the heliopause (the invisible boundary that demarks the limit of the Sun’s magnetic bubble, between the heliosphere and interstellar medium), they gave us a profound opportunity to experience this distant alien environment, using their dwindling number of instruments to measure particle counts and magnetic orientation.
But where are our intrepid interstellar interlopers going now? With the help of precision astrometry of local stars observed by the European Space Agency’s Gaia space telescope, two researchers have taken a peek into the future, seeing which star systems the spacecraft will drift past in the next few hundred thousand to millions of years.
Previously, astronomers have been able to combine the spacecrafts’ trajectory with stellar data to see which stars they will fly past, but in the wake of the Gaia Data Release 2 (GDR2) last year, an unprecedented trove of information has been made available for millions of stars in the local galaxy, providing the most precise “road map” yet of those stars the Voyagers and Pioneers will encounter.
“[Gaia has measured] the positions and space velocities of nearby stars more precisely than before and so has more precisely characterized the encounters with stars we already knew about,” says astronomer Coryn Bailer-Jones, of the Max Planck Institute for Astronomy in Heidelberg, Germany.
Close Encounters of the Voyager Kind
Bailer-Jones and colleague Davide Farnocchia of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., published their study in Research Notes of the American Astronomical Society, adding another layer of understanding about where our spacecraft, and the stars they’ll encounter, are going. Although their work confirms previous estimates of some stellar close encounters, Bailer-Jones tells Astroengine.com that there have been some surprises in their calculations—including encounters that have not been identified before.
For example, the star Gliese 445 (in the constellation of Camelopardalis, close to Polaris) is often quoted as being the closest encounter for Voyager 1, in approximately 40,000 years. But with the help of Gaia, which is giving an extra layer of precision for stars further afield, the researchers found that the spacecraft will come much closer to another star, called TYC 3135-52-1, in 302,700 years.
“Voyager 1 will pass just 0.30 parsecs [nearly one light-year] from that star and thus may penetrate its Oort cloud, if it has one,” he says.
This is interesting. Keep in mind that the Voyager and Pioneer spacecraft include the famous Golden Records and plaques (respectively), revealing the location, form, and culture of a civilization living on a planet called “Earth.” For an alien intelligence to stumble across one of our long-dead spacecraft in the distant future, the closer the stellar encounter the better (after all, the likelihood of stumbling across a tiny spacecraft in the vast interstellar expanse would be infinitesimally small). Passing within one light-year of TYC 3135-52-1 is still quite distant (for instance, we currently have no way of detecting something as dinky as a Voyager-size probe zooming through the solar system’s Oort Cloud), but who knows what the hypothetical aliens in TYC 3135-52-1 are capable of detecting from their home world?
Another interesting thought is that these Gaia observations can help astronomers find stars that are currently very far away, but now we know their speed and direction of travel, some of those stars will be in our cosmic backyard in the distant future.
“What our study also found, for the first time, is some stars that are currently quite distant from the Sun will nonetheless come very close to one of the spacecraft within the next few million years,” says Bailer-Jones. “For example, the star Gaia DR2 2091429484365218432 is currently 159.5 parsecs [520 light-years] from the Sun (and thus from Voyager 1), but Voyager 1 will pass within 0.39 parsecs [1.3 light-years] of it in 3.4 million years from now.”
In some cases, given unlimited time, you may not have to go to a star, the star will come to you!
Our Interstellar Future?
While pinpointing the various stellar encounters for our first interstellar probes is interesting, the observations being made by Gaia will be important for when humanity develops the technology to make a dedicated effort to travel to the stars.
“It will be essential to have extremely precise astrometry of any target star,” explains Bailer-Jones. “We must also measure its velocity and its acceleration precisely, because these affect where the star will be when the spacecraft arrives.”
Although this scenario may seem a long way off, any precision astrometry we do now will build our knowledge of the local stellar population and boost the “legacy value” of Gaia’s observations, he adds.
“Once a target star has been selected, we would want to make a dedicated campaign to measure its position and velocity even more precisely, but to determine the accelerations we need data measured at many time points over long periods (at least tens of years), so Gaia data will continue to be invaluable in the future,” Bailer-Jones concludes.
“Even now, astrometry from the previous Hipparcos mission—or even from surveys from decades ago or photometric plates 100 years ago!—are important for this.”
Update (May 23): One of the reasons why I focused on the Voyager missions and not the Pioneers is because the latter stopped transmitting a long time ago. Another reason is because we already know Pioneer 10 doesn’t make it very far into interstellar space:
Gather ’round the campfire kids, it’s time to tell the sad story of a brave bat named Brian.
On March 15, 2009, Twitter was days away from its third birthday, Ashton Kutcher was one month away from becoming the first tweep to reach one million followers, and a community of space enthusiasts habitually live-tweeted the final space shuttle launches from the comfort of their homes. They were simpler times.
One launch, however, became infamous — nay, historic — not for the fact it was one of the last handful of launches of NASA’s shuttle program, but because there was a tiny stowaway attached to the shuttle’s bulbous orange external fuel tank minutes before ignition.
During the countdown to the launch of STS-119, as we watched in anticipation of the successful start of Space Shuttle Discovery’s International Space Station (ISS) servicing mission, something seemed amiss at Discovery’s launch pad. At the time, the assumption was that a fruit bat (a common species in Florida) had mistakenly thought the orange external fuel tank of the shuttle was a tree to latch itself onto. Follow-up investigations identified the bat as a free-tailed bat and, though its intentions were unclear, zoologists posited that the unfortunate critter may have broken its wing. This would explain why it didn’t fly away when the shuttle’s boosters ignited, carrying the bat to the heavens — literally and metaphorically.
No one really knows how long the bat held on for, but some creative-thinkers hypothesized that the bat remained attached for the duration, making it into space. I don’t think I have to explain why this didn’t happen — it was more likely booted from the fuel tank in the first seconds of launch enduring a fiery death via rocket booster exhaust — but it was a poetic thought. Regardless of the bat’s fate, it’s ultimate sacrifice made this routine launch special. What was “just another” live-tweeted shuttle launch, became a spectacle that rapidly evolved into an international news story. That bat was special.
And that bat’s name was Brian.
Why “Brian”? A bit of background: For some personal reason that I cannot fathom, I like to name things “Brian.” I’ve always done it. The squirrel that lives in my backyard? Brian. An interesting and unnamed rock on the surface of Mars? Brian. My first car? Brian. That gopher that demolished my newly-planted garden of impatiens in 2011? Brian. A random free-tailed bat hanging off the shuttle’s external fuel tank? Brian. There’s no reason and no logic behind this, Brian just seems to fit. It’s a personal mystery.
So, when lightheartedly tweeting about the bat on March 15, 2009, I called the bat Brian and the name stuck. I had no idea about its gender, and it didn’t have a nametag, but that bat was a Brian alright. Suddenly, other space enthusiasts following the launch called him Brian and, for reasons I have yet to understand ten years later, in those minutes before launch, “Brian the Bat” went viral and suddenly everyone was personally invested in that “routine” space launch. Yes, there were billions of dollars of hardware on that launchpad with seven brave astronauts on board, but everyone was talking about Brian who was shivering on the side of the vehicle, a place that no living creature should have been.
Was Brian confused? Was he frozen to the cold tank? Would he fly away in the nick of time? No one knew, but the clock was ticking and the commentator on the NASA live video stream seemed confident that, as the boosters began their ignition sequence, the bat would be scared by the vibrations and fly to safety.
For reasons known only to Brian, he remained attached. And as the boosters roared to life, he held tight. As the plume of smoke and steam enveloped Kennedy Space Center Launch Complex 39, I sat with the computer screen nearly pressed to my nose, seeking out the dark pixels of Brian in the place where he was last seen. But the resolution was too low and Brian’s fate was unknown. (Days later, NASA analysts reviewed infrared imagery from the launch, revealing two very sad facts. 1) Brian was warm while attached to the fuel tank, so he hadn’t frozen to death and was alive up to launch, and 2) he remained in place when Discovery lifted off.)
As the adrenaline ebbed and Space Shuttle Discovery soared into the atmosphere, solid rocket boosters separating and tumbling back to Earth, the sad reality crept in. Brian was, in all likelihood, toast.
But his legacy would live on.
Assuming that little space-launch chapter was over, I wrote a summary about Brian’s adventures for Universe Today and on Astroengine with the assumption that Brian would be soon lost to the annals of shuttle-era history. Little did I know, however, that Norwegian journalist Geir Barstein was paying close attention…
Brian also made appearances in The Sun newspaper (but the article has since disappeared) and other smaller publications, and I participated in a number of radio shows devoted to that now-famous shuttle launch.
Not only was the whole event a poignant one, it also made me realize something about the power of social media. In all my years covering space stories, particularly when I was a producer at Discovery News (now called “Seeker”), shuttle launches would receive very little attention. Apart from a few outliers, such as the final shuttle launch, the articles I’d publish about one of NASA’s most significant programs would receive very little readership. The routine nature of these launches meant that, unless you were at Cape Canaveral, interest in seeing shuttles launch into space was lukewarm at best. As a space enthusiast, I was frustrated. Every launch in my eyes was special and certainly not “routine.”
Brian, however, made me realize by accident that you have to seek out the unique thing about that one launch that will hook readers to that story. Granted, not all launches have a “Brian the Bat” moment, but that doesn’t mean they’re not special.
I like to think that the cosmos is doing Brian a solid by commemorating that brave little bat’s ultimate sacrifice.
The event may have been a footnote in humanity’s quest to explore our universe, but I truly believe that the viral social media (and then mainstream media) attention Brian whipped up created a buzz around a launch that may not have otherwise made an impact.
As a science communicator, I’m always on the lookout for interesting hooks to stories that wouldn’t otherwise be of interest, and on March 15, 2009, Brian was that hook — who knows what kind of impact that little free-tailed bat had on viewers who wouldn’t have otherwise been paying attention to one of the biggest endeavors in human exploration history.
So, tomorrow, on March 15, 2019, raise a drink to Brian’s legacy. He will live on in the spirit he inspired when he left our planet attached to the space shuttle’s external fuel tank.
The private spaceflight company SpaceX has done it again, and this latest achievement is an important one.
We space writers are very familiar with Elon Musk’s human spaceflight dreams that can be encapsulated in his well-known goal to “make humanity multi-planetary,” starting with a Mars settlement. And today, that goal took another step closer to reality.
I’ve been following Musk’s rocket adventures ever since his early days of exploding single-engine rockets in the South Pacific. Back then, Musk was a “dreamer” and more than a little eccentric. His eccentricities are well documented, but the world’s best known billionaire-entrepreneur is a dreamer no more. The first successful flight of a Falcon 1 happened on Sept. 28, 2008. (You can read my 2008 Space Lifestyle Magazine article on that topic, page 36) A little over a decade later, the Falcon 1 has rapidly evolved into the reusable Falcon 9 workhorse and the Falcon Heavy and, with key partnerships with NASA and companies that need to get stuff into orbit cheaply, SpaceX has developed the human-rated Dragon spacecraft to ultimately get astronauts to the space station, and beyond.
After proving itself in the cargo-delivery arena, the Dragon has now won its human-spaceflight wings: an (uncrewed) Crew Dragon is now attached to the International Space Station’s Harmony module and the outpost’s astronauts have entered the vehicle.
Building a commercially-viable space infrastructure is paramount if humanity is to truly become multi-planetary, and through partnerships between private business and government contracts, today’s achievement is proof that this model can work.
Too often, governments lack the long-term vision for human space exploration, instead plowing money into bloated, politically motivated, and ultimately doomed federally-funded projects. SpaceX may be an exhausting company to work for, but its ultimate mission is crystal clear. It’s not a satellite-launching company, it’s just doing that to build funds to do the Next Big Thing. Dragon’s autonomous berthing with the space station is That Big Thing that will drive more investment into getting stuff beyond Earth orbit.
Musk’s interim target — before getting humans to Mars — is the moon, to create a permanently-crewed lunar base. How that will shape up remains to be seen, but if there’s one thing I’ve learnt from following his dreams of getting into space on a reusable spaceflight infrastructure, it’s don’t bet against SpaceX and Elon Musk’s “eccentricities.”
The NASA mission looks like it’s getting comfortable in Elysium Planitia.
Like any self-respecting social media influencer, Mars’s latest resident is hard at work snapping photos of its new digs. The robot has even thrown in a beautiful selfie for good measure.
NASA’s InSight lander touched down on the Red Planet on Nov. 26 and since then its mission controllers have been hard at work checking out the instrumentation and surroundings. Using its Instrument Deployment Camera, or IDC, InSight has been giving us a tour of its permanent home. Fans on social media have even been nominating names for the rocks that can be seen embedded in the dusty regolith — the only rocks we’ll see close up for the duration of the mission.
Very early on, NASA scientists knew they’d landed in the right place. The beautifully-flat plain of Elysium Planitia has a landscape that is in stark contrast to Curiosity’s Mount Sharp environment; instead of seeing a smorgasbord of geological features — created by ancient water action and ongoing aeolian (wind-blown) processes — Elysium is flat, dusty and appears to only have small-ish rocks strewn over its surface. You see, InSight cares little for what’s on the surface; the science it’s after lies below the stationary lander, all the way to the planet’s core.
“The near-absence of rocks, hills and holes means it’ll be extremely safe for our instruments,” said InSight’s Principal Investigator Bruce Banerdt of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., in a statement. “This might seem like a pretty plain piece of ground if it weren’t on Mars, but we’re glad to see that.”
Now that InSight’s raw image archive is churning out new pictures daily, mission scientists are scoping out its “work space” directly in front of the lander’s robotic arm. Over the coming weeks, optimal positions for InSight’s two main experiments — the Seismic Experiment for Interior Structure (SEIS) andHeat Flow and Physical Properties Package (HP3) —will be decided on and then commands will be sent to the lander to begin the painstaking task of retrieving them from its deck and setting them down on the ground. The main task will be to determine exact locations that are smooth, flat and contain small rocks that are no bigger than half an inch. This will ensure stable contact with the ground so seismic and heat flow measurements can be continuously carried out. InSight is basically going to give Mars an internal examination 24/7, listening to the slightest seismic waves like a doctor would listen to your heartbeat. And it looks like InSight has landed inside a depression, likely created by an ancient crater that has been filled with loose material over time — this is great news for HP3 that has a self-digging probe (called the “mole”) that will now have an easier task of burrowing meters underground.
But what about that selfie? Well, here you go:
This photo is a mosaic composed of 11 different images snapped by the lander’s robotic arm-mounted camera. You can see the lander’s open solar panels and stowed instrumentation on the deck, including SEIS and HP3. And no, the selfie isn’t a fake; by sticking a bunch of individual photos together, they’ve overlapped to edit out any trace of the arm itself. Curiosity does the same thing; so did Opportunity and Spirit. InSight’s older sibling, Phoenix also did it. Selfies are as much the rage on Mars as they are on Earth. Not only do they look cool, they are also useful for mission controllers to monitor the build-up of dust on solar panels, for example.
The NASA probe was launched in 1977 and has now joined its twin, Voyager 1, to begin a new chapter of interstellar discovery
Carolyn Porco, planetary scientist and lead of the NASA Cassini mission imaging team, probably said it best:
Voyager 1 made us an interstellar species; 6 yrs later, Voyager 2 makes it look easy. While these are historic, soul-stirring achievements, I am most happy right now that Ed Stone, the best Project Scientist who ever lived, lived to see this moment.
It can be easy to lump today’s announcement about Voyager 2 entering interstellar space as “simply” another magnificent science achievement for NASA — but that would be too narrow; the Voyager spacecraft have become so much more. They represent humanity at our best; our will to explore, our need to push boundaries, our excitement for expanding the human experience far beyond terrestrial shores. They also act as a means to understand the sheer scale of our solar system. And what better way to measure that scale than with a human life.
Ed Stone started working on the Voyager Program in 1972 as a project scientist. Now, at 82 years old, he’s still working on the Voyagers nearly half a century later as they continue to send back data from the frontier beyond our solar system. When we start measuring space missions in half-centuries, or missions that have lasted entire careers, it becomes clear how far we’ve come. Not only does NASA build really tough space robots that surpass expectations routinely, returning new discoveries and revelations about the universe that surrounds us, the Voyagers have become a monument to the essence of being human, something with which Stone would probably agree.
Although most of the instruments aboard the Voyagers are no longer functional, both missions are still returning data from the shores of the interstellar ocean and, on Nov. 5, mission controllers noticed that one of Voyager 2’s instruments, the Plasma Science Experiment (PSE), had detected a rapid change in its surrounding environment. Used to being immersed the comparatively warm and tenuous solar wind flowing past it, its plasma measurements detected a change. The spacecraft had passed into a region of space where the plasma was now denser and cooler. Three other particle experiments also detected a dramatic change; solar wind particle counts were down, but cosmic ray counts precipitously increased. Voyager 1’s PSE failed in 1980, so couldn’t measure this boundary when it entered interstellar space in 2012, so Voyager 2 is adding more detail about what we can expect happens when a spacecraft travels from the heliosphere, through the heliopause and into interstellar space.
“There is still a lot to learn about the region of interstellar space immediately beyond the heliopause,” said Stone in a NASA statement.
The heliosphere can be imagined as a vast magnetized bubble that is generated by the Sun. This bubble is inflated by the solar wind, a persistent stream of solar particles that ebb and flow with the Sun’s 11-year cycle. When the Sun is at its most active, the bubble expands; at its least active, it contracts. This dynamic solar sphere of influence affects the flux of high-energy cosmic rays entering the inner solar system, but the physics at this enigmatic boundary is poorly understood. With the help of the Voyagers, however, we’re getting an in-situ feel for the plasma environment at the boundary of where the Sun’s magnetism hits the interstellar medium.
To achieve this, however, we had to rely on two spacecraft that were launched before I was born, in 1977. Voyager 2 is now 11 billion miles away (Voyager 1 is further away, at nearly 14 billion miles) and it took the probe 41 years just to reach our interstellar doorstep. Neither Voyagers have “left” the solar system, not by a long shot. The gravitational boundary of the solar system is thought to lie some 100,000 AU (astronomical units, where one AU is the average distance from the Earth to the Sun), the outermost limit to the Oort Cloud — a region surrounding the solar system that contains countless billions of icy objects, some of which become the long-period comets that intermittently careen through the inner solar system. Voyager 2 is barely 120 AU from Earth, so as you can see, it has a long way to go (probably another 30,000 years) before it really leaves the solar system — despite what the BBC tells us.
So, tonight, as we ponder our existence on this tiny pale blue dot, look up and think of the two space robot pioneers that are still returning valuable data despite being in deep space for over four decades. I hope their legacy lives on well beyond the life of their radioactive generators, and that the next interstellar spacecraft (no pressure, New Horizons) lives as long, if not longer, than the Voyagers.
It’s always fun to browse through the raw image archive for any Mars mission. You see rocks, dust, more rocks and more dust, but then you see something strange, sitting atop the dirt that is like nothing you’ve seen before.
Once, there was a piece of plastic on the ground in front of Curiosity. Plastic! Not alien plastic though, it was likely something that fell off the rover. Mars rover Opportunity even found strange “blueberries” scattered over Meridiani Planum that turned out to be spherical hematite inclusions, basically little balls of mineral that were formed via water action in Mars’ ancient past.
Now there’s a shiny rock just sitting there, in front of Curiosity.
Mars isn’t known for its shiny objects. Everything is a ruddy color (because of the iron-oxide-laced dust that covers everything) and dull. So, when mission controllers saw this small shiny object, it became a focus of interest. They’ve even named it “Little Colonsay.” Don’t get too excited for an explanation that’s too outlandish, but it will be an interesting find if it turns out to be what scientists think it is.
“The planning team thinks it might be a meteorite because it is so shiny,” writes Susanne Schwenzer, Curiosity mission team member.
Meteorites have been discovered on Mars before by the Mars rovers — and Curiosity is no stranger to finding space rocks strewn on the ground — though it would still be a rare find by Curiosity if it does turn out to be a (likely) metallic chunk of space rock. As pointed out by Schwenzer, the team intend to carry out further analysis of the sample, as well as some other interesting rocks, with Curiosity’s ChemCam instrument to decipher what it’s made of.
So as we welcome the InSight mission to the Red Planet to begin its unprecedented study of Mars’ interior, always remember there’s still plenty of gems sitting on the surface waiting to be found.