A tiny rock has been detected in the Kuiper belt, which may not seem like such a big deal, but how it was found is.
[NASA, ESA, and G. Bacon (STScI)]
We think we have a pretty good handle on how planets form. After the birth of a star, big enough clumps of dust and rock in the disk of leftover debris begin to accrete mass until they turn into spheres under the pull of their own gravity, jostling around, pushing smaller protoplanets out of the way and being shoved aside by, or smashing, into larger ones. Whatever planets survive this messy process end up becoming a solar system. We’ve seen this around other stars and aside from a few interesting twists on this model, we think we know what’s going on pretty well by now.
But there was one piece missing. The math says that to start the planet building process, you need a kind of planetary seed between one and ten kilometers wide. Since we happen to live in a solar system, we should be able to look outwards, towards the Kuiper Belt, which we think is made primarily from the leftovers of planetary formation, and see these protoplanetary fossils drifting across the sky. However, the process has proven to be rather tricky. These rocks are very faint and rather small compared to everything else we can usually see, so looking for them is kind of like trying to spot a grain of dust in a room illuminated only by moonlight, which is why we have so much trouble finding them.
Or at least we did until now, when a 1.3 kilometer Kuiper Belt Object, or KBO was spotted by a simple setup and commercially available cameras as it eclipsed background stars. While that might not sound like much right now, it’s actually an extremely important finding. First, it tells us how to find tiny KBOs so we can take a proper survey of protoplanetary leftovers. Secondly, it shows that we’re correct in our solar system formation model and demonstrated that predicted artifacts of baby planets that never quite made it do exist. The next part will be to try and detect more of these little planet seedlings to figure out how efficient the formation process is, and see what we can learn from that.
As noted, these finds don’t just apply to our own solar system, but to pretty much every planet in the universe. Just consider that mighty gas giants with swirling storms that could swallow Earth whole, exotic icy dwarfs with percolating cryovolcanoes and towering peaks dusted with reddish organic molecules, and tropical worlds with deep oceans teeming with life — which might even be home to an alien civilization living through its heyday — all started out as these little rocks lucky enough to clump together for a few hundred million years, find a stable orbit, and cool down enough to become a cosmic petri dish. They might not be impressive or exciting on their own, but that doesn’t mean they aren’t profoundly important.
Reference: Arimatsu, K., et. al., (2019) A kilometre-sized Kuiper belt object discovered by stellar occultation using amateur telescopes, Nature Astronomy Letters, DOI: 10.1038/s41550-018-0685-8
New models trying to infer the geology of potentially habitable moons orbiting Jupiter and Saturn hint at surprisingly cool, geologically inactive worlds, the opposite of what a diverse alien ecosystem would need
[NASA/JPL-Caltech]
Imagine a spaceship finally landing on Europa and slowly drilling into the ice. After weeks of very careful progress, it pierces the moon’s frozen shell and releases a small semi-autonomous submarine connected to the probe with an umbilical to ensure constant communication and a human taking over in case of an emergency. Much of the time, it will chart a course of its own since piloting it with an hour long delay between command and response would be less than ideal. It navigates through the salty ocean, shining its light on structures never before seen by a human eye, making its way deeper and further into the alien environment to find absolutely… nothing at all.
That’s the sad scenario proposed by a team of geologists who crunched the numbers on the four leading contenders to host alien life in our outer solar system: Europa, Ganymede, Titan, and Enceladus. According to their models, looking at gravity, the weight of water and ice on the rocks underneath, and the hardness of the rocks themselves, these moons would be more or less geologically dead. Without volcanoes or sulfur vents, there would be very little in terms of nutrient exchange and therefore, very little food and fuel for an alien ecosystem more complex than microbe colonies.
Of course, these results are a pretty serious departure from the hypotheses commonly held by planetary scientists that the gravity of gas giants cause tidal kneading inside their moons, citing Io as an example. According to the researchers’ model, only Enceladus would be a promising world to look for life, as evidenced by the plumes breaking through its icy crust, spraying organic material into space. The reason why the numbers are different, they say, is because its core is likely to be porous, meaning its ocean would be heated deep inside the moon, fueling geysers and churning organic matter while effectively making the little world a ball of soggy slush.
Since these findings are so different from what’s implied by observations, the researchers aren’t in a rush to publish them are are soliciting other scientists’ opinions to make sure they have a complete picture, and lead investigator Paul Byrne grumbled about his disappointment with what the models indicate. That said, while he’s hoping to be proven wrong, we shouldn’t forget that these are alien worlds and while we’ve spent decades studying them, our knowledge came in bursts. Simply put, we might know a fair bit but far from everything and disappointing surprises may lurk under their icy surfaces and subterranean oceans.
The binary system observed by ALMA isn’t wonky, it’s the first example of a polar protoplanetary disk
Artwork of the system HD 98000. This is a binary star comprising two sun-like components, surrounded by a thick disk of material. What’s different about this system is that the plane of the stars’ orbits is inclined at almost 90 degrees to the plane of the disk. Here is a view from the surface of an imagined planet orbiting in the inner edge of the disk [University of Warwick/Mark Garlick].
Some star systems simply don’t like conforming to cosmic norms. Take HD 98000, for example: It’s a binary system consisting of two sun-like stars and it also sports a beautiful protoplanetary disk of gas and dust. So far, so good; sounds pretty “normal” to me. But that’s only part of the story.
When a star is born, it will form a disk of dust and gas — basically the leftovers of the molecular cloud the star itself formed in — creating an environment in which planets can accrete and evolve. Around a single star (like our solar system) the protoplanetary disk is fairly well behaved and will create a relatively flat disk around the star’s spin axis. For the solar system, this flat disk would have formed close to the plane of the ecliptic, an imaginary flat surface that projects out from the sun’s equator where all the planets, more or less, occupy. There are “wonky” exceptions to this rule (as, let’s face it, cosmic rules are there to be broken), but the textbook descriptions of a star system in its infancy will usually include a single star and a flat, boring disk of swirling material primed to build planets.
Cue HD 98000, a star system that has flipped this textbook description on its head, literally. As a binary, this is very different to what we’re used to with our single, lonely star. Binary stars are very common throughout the galaxy, but HD 98000 has a little something extra that made astronomers take special note. As observed by the Atacama Large Millimeter/sub-millimeter Array (ALMA), its protoplanetary disk doesn’t occupy the same plane as the binary orbit; it’s been flipped by 90 degrees over the orbital plane of the binary pair. Although such systems have been long believed to be theoretically possible, this is the first example that has been found.
“Discs rich in gas and dust are seen around nearly all young stars, and we know that at least a third of the ones orbiting single stars form planets,” said Grant M. Kennedy, of the University of Warwick and lead author of the study published today in the journal Nature Astronomy, in a statement. “Some of these planets end up being misaligned with the spin of the star, so we’ve been wondering whether a similar thing might be possible for circumbinary planets. A quirk of the dynamics means that a so-called polar misalignment should be possible, but until now we had no evidence of misaligned discs in which these planets might form.”
Artwork of the system HD 98000. This is a binary star comprising two sun-like components, surrounded by a thick disc of material [University of Warwick/Mark Garlick]
This star system makes for some rather interesting visuals, as shown in the artist’s impression at the top of the page. Should there be a planetary body orbiting the stars on the inner edge of the disk, an observer would be met with a dramatic pillar of gas and dust towering into space with the two stars either side of it in the distance. As they orbit one another, the planetary observer would see them switch positions to either side of the pillar. It goes without saying that any planet orbiting two stars would have very different seasons than Earth. It will even have two different shadows cast across the surface.
“We used to think other solar systems would form just like ours, with the planets all orbiting in the same direction around a single sun,” added co-author Daniel Price of Monash University. “But with the new images we see a swirling disc of gas and dust orbiting around two stars. It was quite surprising to also find that that disc orbits at right angles to the orbit of the two stars.”
Interestingly, the researchers note that there are another two stars orbiting beyond the disk, meaning that our hypothetical observer would have four suns of different brightnesses in the sky.
The most exciting thing to come out of this study, however, is that ALMA has detected signatures that hint at dust growth in the disk, meaning that material is in the process of clumping together. Planetary formation theories suggest that accreting dust will go on to form small asteroids and planetoids, creating a fertile enviornment in which planets can evolve.
“We take this to mean planet formation can at least get started in these polar circumbinary discs,” said Kennedy. “If the rest of the planet formation process can happen, there might be a whole population of misaligned circumbinary planets that we have yet to discover, and things like weird seasonal variations to consider.”
What was that I was saying about “cosmic norms”? When it comes to star system formation, there doesn’t appear to be any.
A nearby baby star has been discovered with a warped protoplanetary disk — a feature that may reveal the true nature of the solar system’s planetary misalignments
[RIKEN]
Textbook descriptions of our solar system often give the impression that all the planets orbit the sun in well-behaved near-circular orbits. Sure, there’s a few anomalies, but, in general, we’re led to believe that everything in our interplanetary neighborhood travels around the sun around a flat orbital plane. This, however, isn’t exactly accurate.
Pluto, for example, has an orbit around the sun that is tilted by over 17 degrees out of the plane of the ecliptic (an imaginary flat plane around which the Earth orbits the sun). Mercury has an inclination of seven degrees. Even Venus likes to misbehave and has an orbital inclination of over three degrees. If all the material that built the planets originated from the same protoplanetary disk that was — as all the artist’s impressions would have us believe — flat, what knocked all the planet’s out of alignment with the ecliptic?
Until now, it was assumed that, during the early epoch of our solar system’s planet-forming days, dynamic chaos ruled. Planets jostled for gravitational dominance, Jupiter bullied smaller worlds into other orbits (possibly chucking one or two unfortunates into deep space), and gravitational instabilities threw the rest into disorderly orbital paths. Other star systems also exhibit this orbital disorder, so perhaps it’s just an orbital consequence of a star system’s growing pains.
But there might be another contribution to the chaos: perhaps wonky star systems were just born that way.
Cue a recent observation campaign of the nearby baby star L1527. Located 450 light-years away in the direction of the Taurus Molecular Cloud, L1527 is a protostar embedded in a thick protoplanetry disk. Using the Atacama Large Millimeter/submillimeter Array (ALMA), in Chile, astronomers of the RIKEN Cluster for Pioneering Research (CPR) and Chiba University in Japan discovered that the L1527 disk is actually two disks morphed into one — both of which are out of alignment with one another. Imagine a vinyl record that has been left on a heater and you wouldn’t be far off visualizing what this baby star system looks like.
The RIKEN study, published on Jan. 1 in Nature, suggests that this warping may have been caused by jets of material emanating from the star’s birth, kicking planet-forming material into this warped configuration and, should this configuration remain stable, could result in planets with orbital planes that are significantly out of alignment.
“This observation shows that it is conceivable that the misalignment of planetary orbits can be caused by a warp structure formed in the earliest stages of planetary formation,” said team leader Nami Sakai in a RIKEN press release. “We will have to investigate more systems to find out if this is a common phenomenon or not.”
It’s interesting to think that if this protoplanetary disk warping is due to the mechanics behind the formation of the star itself, we might be able to look at mature star systems to see the ancient fingerprint of a star’s earliest outbursts or, possibly, its initial magnetic environment.
It’s possible “that irregularities in the flow of gas and dust in the protostellar cloud are still preserved and manifest themselves as the warped disk,” added Sakai. “A second possibility is that the magnetic field of the protostar is in a different plane from the rotational plane of the disk, and that the inner disk is being pulled into a different plane from the rest of the disk by the magnetic field.”
Though orbital chaos undoubtedly contributed to how our solar system looks today, with help of this research, we may be also getting a glimpse of how warped our sun’s protoplanetry disk may have been before the planets even formed.
Creating the conditions of interstellar space in the lab has led to a sweet discovery
The Egg Nebula, as imaged by Hubble, is a protoplanetary nebula with a young star in its core [NASA/ESA]
What do you get if you combine water with methanol and then bombard the mix with radiation? It turns out that the resulting cocktail is where the building blocks for life are found. But these chemicals aren’t bubbling out of the puddles of primordial goo pooling on some alien planet; the cocktail shaker is the frigid depths of interstellar space and the mixologist is the universe.
As described in a new study published on Tuesday in Nature Communications, a team of NASA scientists took what they knew of interstellar space and recreated it in a laboratory experiment. Interstellar space may not seem like a place where the chemistry of life could gain a foothold, but given enough time and the right ingredients, chemical reactions do happen — albeit very slowly. And if there’s one thing the universe has it’s time, and we’re beginning to understand that the cosmos we reside in could be a vast organic experiment.
“The universe is an organic chemist,” said Scott Sandford, a senior scientist in the NASA Ames Astrophysics and Astrochemistry Laboratory and co-investigator of the study. “It has big beakers and lots of time — and the result is a lot of organic material, some of which is useful to life.”
To see what chemistry might be going on in the void between the stars, the researchers simulated this extreme environment inside a vacuum chamber at Ames that was cooled to near-absolute zero. Inside, they placed an aluminum substance and then added the gaseous mixture of water vapor and methanol, a very common carbon-based molecule that is known to exist throughout our galaxy. Holding the aluminum at such low temperatures caused a frosty layer to form upon it. Then, they irradiated the substance with ultraviolet light — a form of radiation that is abundant in stellar nurseries, for example — and found that some interesting chemical reactions had occurred.
They discovered that a variety of sugar derivatives had formed on the substance — and one of those sugars was 2-deoxyribose. Yes, the same stuff you’d find in deoxyribonucleic acid. That’s the “D” in our DNA.
But this isn’t the first time an essential ingredient for life has been created in the lab while simulating the conditions of interstellar space. In 2009, the same team announced the discovery of uracil in their laboratory experiments — a key component of ribonucleic acid (RNA), which is central to protein synthesis in living systems. Also, in 2016, a French group discovered the formation of ribose, the sugar found in RNA.
“For more than two decades we’ve asked ourselves if the chemistry we find in space can make the kinds of compounds essential to life. So far, we haven’t picked a single broad set of molecules that can’t be produced,” said Sandford in a NASA statement.
Although these are significant discoveries that provide new insights to how and where the most basic ingredients for life may form, it’s a long way from helping us understand whether or not life is common throughout the universe. But it turns out that some of the coldest spaces in the cosmos could also be the most fertile environments for the formation of a range of chemicals that are essential for life on Earth. It’s not such a reach, then, to realize that the protoplanetary disks surrounding young stars will also contain these chemicals and, as planets form, these chemicals become an intrinsic ingredient in young planets, asteroids and comets. Over four billion years ago, when the planets condensed from our baby Sun’s nebulous surroundings, Earth may have formed with just the right abundance of molecules that form the backbone of DNA and RNA to kick-start the genesis of life on our planet. Or those ingredients were delivered here later in the frozen cores of ancient comets and asteroids.
The building blocks of life are probably everywhere, but what “spark” binds these chemicals in such a way that allows life to evolve? This question is probably well beyond our understanding for now, but it seems that if you give our Cosmic Mixologist enough time to concoct all the chemicals for life, life will eventually emerge from the cocktail.
InSight’s recording of Martian winds isn’t what you’d hear if you were on the planet yourself
Artist’s impression of the European Huygens lander that descended through Titan’s atmosphere and landed on the Saturn moon’s surface [ESA]
We live in a world where spacecraft are now routinely landing on other worlds and recording their sounds. Soviet probes aimed at Venus captured the thunder and howling winds on the volcanic world, giving us the first ever audio recording captured beyond Earth. We’ve been able to reconstruct the sound of alien rain on Saturn’s moon Titan. And now, for the first time, we get to hear the low hum of Martian winds sweeping down the planes. Except not exactly. You see, while InSight did in fact record a 10 to 15 mile per hour draft on Martian, the recording’s pitch had to be dialed up and its frequency sped up roughly 100 times for the human ear to make any real sense of it. But why is it so hard to hear them otherwise?
Unlike Venus or Titan, Mars has an extremely thin, barely there atmosphere stripped away by solar winds and with virtually no protection from its weak magnetosphere. It’s so thin and fragile that it might actually make the planet impossible to terraform if we ever wanted to try to make it even a little more like our world. Even hurricane force winds would feel like a gentle breeze because there’s just not enough air to impart any meaningful kinetic energy. So, if you were able to stand on the surface of Mars without a spacesuit, you’d probably hear and feel nothing, hence NASA had to help us out so we could get some appreciation of what they were able to record, which is still exquisitely haunting and beautiful in the end.
What about winds on other planets and moons?
With extremely thick atmospheres, you’d have absolutely no problem hearing and feeling the full force of the wind on worlds like Venus, Jupiter and the other gas giants, and of course, Titan. In the turbulent clouds of gas giants, the winds would never stop and without anything solid to act as a brake, gusts can howl at astonishing speeds. Neptune boasts the fastest winds in the solar system at 1,200 miles per hour, with Saturn not far behind as 1,118 mile per hour gales whip around its equator, making Jupiter seem almost inert by comparison with peak wind speeds of 384 miles per hour around its Great Red Spot.
Exactly how hard that wind would hit you will depend on your altitude in the gas giants’ vast atmospheres but analogies with the impacts of anything between a tornado and a freight train come to mind. At this point, we would consider the kinetic energy of winds on Venus and Titan because they have solid surfaces and very thick atmospheres, but on both worlds, a very odd and interesting thing happens as you descend through the clouds. That atmospheric thickness means that gasses are compressed as you get close and closer to the surface and winds very quickly die down under the mass of the air through which they have to move.
On Titan, winds reach maybe 2 miles per hour at ground level at their strongest. On Venus, they peak at 3 miles per hour. Still, because there’s so much mass in motion, they would feel like a stiff breeze of 20 to 25 miles per hour if we note that the gusts in question are strong enough to scatter small rocks and use the Beaufort scale to translate that into comparable conditions right here on Earth. You would certainly hear it as well, deeper and more ominous than you’d expect, with absolutely no need to increase the pitch or speed up frequency for your ear to know what’s happening.
So, in case you ever look at the night sky and wonder about how different other planets are from the one on which you’re standing, consider that something seemingly as simple as the sound of moving air can be vastly different from world to world, what you’d consider a gentle breeze could be imperceptible on one planet and blow an umbrella out of your hand on another, and that sometimes, to appreciate what our robotic probes are detecting, we need to specially process the data they’ve gathered so you can even start making sense of it.
The NASA mission looks like it’s getting comfortable in Elysium Planitia.
The view from InSight’s Instrument Deployment Camera (IDC), which is attached to the lander’s robotic arm, looking over the flat and rock-strewn plane of Elysium Planetia, on sol 14 of its mission. The lens flare is caused by the Sun that is just out of shot [NASA/JPL-Caltech]
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.
Dusty with a dash of small rocks, perfect ground for InSight’s work [NASA/JPL-Caltech]
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.”
One of InSight’s three legs can be seen here slightly sunken into the Martian regolith, showing us how soft and powdery the uppermost layers of the mission’s landing zone is. Oh, and that rock to the right? Luckily InSight missed it [NASA/JPL-Caltech]
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:
InSight says hi! [NASA/JPL-Caltech]
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.
For now, as we await the science to start flowing in (well, there’s been some early science before the robot has even gotten started), enjoy checking back on InSight’s raw photos, it won’t be long until we’ll be browsing through potentially thousands of snaps from Elysium Planitia. Oh, and don’t forget about Curiosity that’s still going strong on the slopes of Mount Sharp!
The NASA probe was launched in 1977 and has now joined its twin, Voyager 1, to begin a new chapter of interstellar discovery
Both Voyager 1 and 2 are sampling particles from the interstellar medium, becoming humanity’s furthest-flung missions into deep space [NASA/JPL-Caltech]
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.
[NASA/JPL-Caltech]
“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.
This image was taken by Curiosity’s ChemCam: Remote Micro-Imager (CHEMCAM_RMI) on Sol 2242 (Nov. 26) [NASA/JPL-Caltech/LANL]
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.
After following InSight’s journey and dramatic landing on Mars, I’m now emotionally attached to the space robot.
The view from InSight’s Instrument Deployment Camera (IDC) that is attached to its robotic arm [NASA/JPL-Caltech]
It’s funny how our perception of the robots we send into space changes with the experiences we have with them. Take NASA’s InSight lander, for example.
I was thrilled to be able to see the mission launch on May 5 from my backyard. I was following the launch feed from my office in the early hours of the morning — lift-off was just after 4 a.m., so I was particularly proud that I hadn’t fallen asleep in my home office. Going outside, I looked to the northwest in hopes of glimpsing the light of the Atlas V-401 rocket as it rose into the dark pre-dawn skies. After I’d seen confirmation via the live-stream video of launch from Vandenburg Air Force Base (130 miles to the northwest of my home in Woodland Hills), I stood precariously on a patio chair to get a better view over my roof and… there it was! A bright plume rising and moving very fast toward the south. And then it was gone; the first ever mission to Mars launched from California was on its way into interplanetary space.
Needless to say, I quickly became invested in this space robot, but before I witnessed its launch from afar, it was another anonymous piece of cold space hardware. As soon as I saw its rocket plume, the mission became “real” and InSight was warmly embedded in my emotions.
NASA likes to play up the dangers of sending missions to Mars — and I can’t blame them; more Mars missions have failed than have succeeded. But in recent years, NASA has beaten the odds and landed all of their surface missions and inserted a bunch of satellites into orbit successfully. The last failed NASA mission to Mars was nearly 20 years ago (the Mars Polar Lander in 1999), everything else since — Mars Odyssey, the two Mars Exploration Rovers, Mars Reconnaissance Orbiter, Phoenix lander (InSight’s twin), Curiosity, MAVEN — have all been resounding successes.
JPL’s “lucky peanuts” at mission control obviously paid off.
Then, on Monday (Nov. 26), after nearly seven months since I saw it fly over my roof, InSight landed on the dusty surface of Mars.
I was fortunate to be at NASA’s Jet Propulsion Laboratory (JPL) on that day, covering the event for Scientific American and HowStuffWorks, and it was a thrill to be in the hub of all the festivities and spend time with my fellow science communicators. JPL always puts together a great event — whether that be the landing of Curiosity over six years ago, or the sad farewell of Cassini last year — and this was no different. The air was thick with anticipation, and all of the mission scientists, managers and engineers were more than willing to share their stories with the dozens of journalists, reporters, social media peeps and TV crews who were in attendance.
Then it was time for landing.
Sending a mission to Mars is risky and, as already pointed out, in the earlier days of humanity throwing stuff at Mars the majority of the missions failed. So, understandably, everyone had a healthy level of nervousness that there was always a chance that InSight might just make another (expensive) crater in the Martian dirt. But that wasn’t to be. And by all accounts, the landing couldn’t have gone better.
InSight and MarCO mission controllers celebrate the landing with NASA Administrator Jim Bridenstine (far left) at NASA JPL
The two Mars Cube One (MarCO) spacecraft that were flying with InSight during its time cruising from Earth became the undisputed silicon heroes of the day. Their purpose was to relay telemetry data from InSight as the lander slammed into the Martian atmosphere to commence its hair-raising entry, descent and landing (EDL) on Mars — a.k.a. the Seven Minutes or Six and a Half Minutes Of Terror, depending on who you talk to. As InSight would be landing in a region where there wouldn’t be a satellite overpass for several hours after landing, MarCO became the relay that, in real time (minus the several minute lag-time that it takes for any signal to travel at the speed of light between Mars and Earth) prevented too many chewed fingernails and passed the message to mission control that the lander had landed safely and everything was, well, just perfect.
In the media area, with a live feed streaming from just next door on the JPL campus, any nervousness evaporated when we all cheered with the mission controllers who were celebrating on the screen. Memories of Curiosity’s landing came flooding back. NASA has done it again, we’re on Mars!
And then, despite warnings that it might be some time before we see the first view of Elysium Planitia from InSight’s camera, we became aware that the mood had changed in mission control. Managers were now huddled around a computer terminal. They were receiving the first image only a few minutes after touch down!
The first image from NASA’s Mars InSight mission was a dusty one — the black specks are dusty debris kicked up from the surface during landing. When NASA pops the lens cover, the fish-eye lens will have a clear view of its new, permanent home [NASA/JPL-Caltech]
Keep in mind that relaying this image would have been impossible without InSight’s MarCO travel buddies. The success of the mission didn’t depend on MarCO, but they sure made the landing event a more lively celebration, rather than a “yes we’re on Mars, but no pictures until tomorrow!” anticlimax. I asked a couple of the MarCO managers what was next for their robotic heroes, and they said that their mission was complete and that they were a proof of concept “that was now proven.” Apparently, managers for other robotic space missions are planning MarCO-like payloads for future missions. Justifiably so.
Monday was a blur, but I remember walking away from JPL feeling emotional and humbled. Humanity is capable of doing incredible, bold things, I thought to myself. Why can’t we be more like this? Discussing the nature of humanity and our contradictory ways can be saved for another day, however.
Now that we’ve lived InSight’s dramatic journey to Mars, the lander has become more than a robot, it’s a bona fide Mars explorer that, like Curiosity and all the landers and rovers that have come before it, is an extension of the human experience. Designed to live in the Martian environment, InSight has arrived home. Hopes are high for some incredible scientific discoveries about Mars’ interior and its evolution, but I’m also hopeful that the mission will inspire people to embrace our natural urge to explore and discover new things about our universe. This time exploration will be done through the eyes of the newest space robot to join its Martian family, but some time in the next couple of decades, it will be human eyes exploring Elysium Planitia.
For more about the science behind InSight, read my articles for Scientific American and HowStuffWorks.com:
astroengine.com 