To Explore Space, Earth’s Environment Will Take One for the Team

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.

A time-lapse photograph of a SpaceX launch at night [SpaceX]

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.

[This article originally appeared on World of Weird Things]

Coolest White Dwarf Is a Glimpse of What Happens Long After Our Sun Dies

All good things come to a cold and dusty end.

[NASA’s Goddard Space Flight Center/Scott Wiessinger]

“So, what do you think happens after you die?”

The question was more of an accusation. The lady asking was sitting across from me at a Christmas dinner a friend of mine was hosting and the previous query was one about my religion. She wasn’t impressed by my response.

Granted, it probably wasn’t the ideal setting to say that I was an atheist, but I wasn’t going to lie either.

“Um, well…” I remember feeling vulnerable when I responded, especially as I’d only just met half the dozen people in the room, including the lady opposite, but I remember thinking: stick with what you know, Ian. So, I continued: “When I’m dead, all the elements from my body will remain on Earth,” — I didn’t want to go into much detail about my real plan of having my remains blended up into a jar and then launched into space (more on that in a future post, possibly) — “and those elements will get cycled through the biosphere through various biological, chemical and physical processes for billions of years. Eventually, however, all good things must come to an end and the sun will run out of fuel, ballooning into a huge red giant star, leaving what is known as a white dwarf in its wake.” (By her glazed look, I could tell she regretted asking, but I continued.) “If, and it’s a big IF, the Earth survives this phase of stellar death, our planet might be hurled out of the solar system. Or, and this is my favorite scenario,” — I’d hit my stride and everyone else seemed to be entertained — “it might careen inward, toward the now tiny white dwarf sun, where Earth will be ripped to sheds under powerful tidal forces, sending all the rocks, dust, and the elements that used to be my body, raining down onto the white dwarf.”

This is an abridged version. I also went into some white dwarf science, why planetary nebulae are cool, and how our sun as a white dwarf would stand as a monument to the once great solar system that will be gone five billion years from now. The recycled elements from my long-gone body could eventually rain down onto the atmosphere of a newborn white dwarf star — pretty cool if you ask me. This might be more of a cautionary tail about inviting an atheist astrophysicist to religious celebrations, but I feel my tabletop TED talk was good value for money. And besides, by turning that inevitable “what religion are you?” question into a scientific one, I hadn’t gotten bogged down with justifying why I’m an atheist — a conversation that, in my experience, never works out well over dinner.

So, why am I remembering that fun evening many years ago? Well, today, there’s some cool white dwarf news. And I love white dwarf news, especially if it’s about dusty white dwarfs. Because dusty white dwarfs are a reminder that nothing lasts forever, not even our beautiful 5-billion-year-old solar system.

One Cool Dwarf

A citizen scientist working on the NASA-led “Backyard Worlds: Planet 9” project has discovered the coldest and oldest white dwarf ever found. The project’s aim is to seek out as-yet-to-be-discovered worlds beyond the orbit of Neptune (re: “Planet Nine” and beyond). Through the analysis of infrared data collected by NASA’s Wide-field Infrared Survey Explorer, or WISE (inspired by data from the European Gaia mission), Melina Thévenot was looking for local brown dwarfs — failed stars that lack the mass to sustain nuclear fusion in their cores, but pump out enough infrared radiation to be detected. In the observations, Thévenot spied what she thought was bad data, but with the help of WISE, she found not a nearby brown dwarf, but a white dwarf that was brighter and further away. After sharing her discovery with the Backyard Worlds team, astronomers at the W. M. Keck Observatory confirmed that not only was that white dwarf lowest temperature specimen yet found, it was also very dusty. In fact, it’s thought that the white dwarf, designated LSPM J0207+3331, has multiple dusty rings. Its discovery, however, is something of a conundrum and the researchers think it may challenge planetary models.

“This white dwarf is so old that whatever process is feeding material into its rings must operate on billion-year timescales,” said astronomer John Debes, at the Space Telescope Science Institute in Baltimore, in a NASA statement. “Most of the models scientists have created to explain rings around white dwarfs only work well up to around 100 million years, so this star is really challenging our assumptions of how planetary systems evolve.”

Interesting side note: It was Debes who first got me excited about dusty white dwarfs when I met him at the 2009 American Astronomical Society (AAS) meeting in Long Beach, Calif. You can read my enthusiastic Universe Today article I wrote on the topic here.

After deducing the tiny Earth-sized star’s cool temperature — 10,500 degrees Fahrenheit (5,800 degrees Celsius) — the researchers estimate that the white dwarf is approximately 3-billion years old. The infrared signal suggests a copious quantity of dust is present, which is a bit weird. As I alluded to in my tabletop TED talk, after a sun-like star runs out of fuel and puffs up into a red giant, it will leave a shiny white dwarf surrounded by a planetary nebula in its wake. Should any mangled planet, asteroid or comet that survived the red giant phase stray too close to that white dwarf, it’ll get shredded. So, it’s poignant when astronomers find dusty white dwarfs; it means those star systems used to have some kind of planetary system, but the white dwarf is in the process of destroying it. That is the inevitable demise of our solar system in 5 billion years time. But to find a 3-billion-year-old specimen with a ring system doesn’t make a whole lot of sense — the white dwarf had plenty of time to consume all that dusty debris by now, a process, according to Debes, that should only take 100 million years to complete.

Debes, who led the study published in The Astrophysical Journal on Feb. 19, and his team, including discoverer and co-author Thévenot, has some idea as to what might be going on, but more research is needed. One hypothesis is that J0207’s dusty ring is composed of multiple rings with two distinct components, one thin ring just at the edge of where the star is breaking up a belt of asteroids and a wider ring closer to the white dwarf. It’s hoped that follow-up observations by the next generation of space telescopes, such as NASA’s James Webb Space Telescope (JWST), will be able to deduce what those rings are made of, thus helping astronomers understand the evolution of these ancient star systems.

Besides being the ultimate way to gain perspective on our tiny existence (and an excellent topic for an awkward dinner conversation), this research underpins a powerful way in which citizen scientists are shaping space science, particularly projects that require many human brains to process vast datasets.

“That is a really motivating aspect of the search,” said Thévenot, who is one of more than 150,000 volunteers who works on Backyard Worlds. “The researchers will move their telescopes to look at worlds you have discovered. What I especially enjoy, though, is the interaction with the awesome research team. Everyone is very kind, and they are always trying to make the best out of our discoveries.”

Home Is Where the Mars Rover Is

Now that Opportunity’s mission is complete, many wistfully lament about “bringing our robot home.” There’s just one problem: it’s already home.

A rendering of Opportunity on Mars [NASA/JPL-Caltech]

I am fascinated with how we anthropomorphize robots, particularly space robots. We call them “brave,” “pioneers” and even give them genders — usually a “she.” We get emotional when they reach the end of their missions, saying they’ve “died” or, as I like to say, “gone to Silicon Heaven.” But these robots are, for all intents and purposes, tools. Sure, they expand the reach of our senses, allowing us to see strange new worlds and parts of the universe where humans fear to tread, but they’re an assembly of electronics, metal, plastic, sensors, transmitters, wheels and solar panels. They don’t have emotions. They don’t breathe. They don’t philosophize about the incredible feats of exploration they are undertaking. They don’t have genders.

Still, we fall in love. When watching Curiosity land on Mars from NASA’s Jet Propulsion Laboratory, I teared up, full of joy that the six-wheeled hulk of a rover — that I’d met personally in JPL’s clean room a couple of years before — had safely landed on the Red Planet. After watching NASA’s InSight lander touch down on Elysium Planitia, again via JPL’s media room last year, there it was again, I was in love. I’m already anthropomorphizing the heck out of that mission, seeing InSight’s landing as another “heartbeat” on Mars. When the European Rosetta mission found Philae lying on its side like a discarded child’s toy on the surface of comet 67P/Churyumov–Gerasimenko, I jumped up from my desk with joy. When Cassini’s mission at Saturn ended in 2017, I was miserable. When the Chinese rover Yutu rolled off its lander in 2014, I realized I was cheering the robot on. When Spirit got stuck in a sand trap in Gusev Crater, I set up a Google alert for any and all news on the recovery efforts.

These emotions aren’t just for the exciting science and engineering strides humanity makes, there’s a certain inspirational character that each robot brings. Undoubtedly, this character naturally emerges from the wonderful scientists and engineers who design and build these amazing machines, and the social media managers who often “speak” for their robots in first person. But if you strip away the science, the technology and the people who build them, we still personalize our beloved robots, giving them their own character and creating a cartoon personality. I believe that’s a beautiful trait in the human condition (except a few flawed cultural and stereotypical missteps) and can be used to great effect to captivate the general public with the science that these robots do.

Opportunity’s landing site inside Eagle crater [NASA/JPL-Caltech]

So there’s no great surprise about the outpouring of emotion for last week’s announcement that NASA called off the communications efforts with Mars Exploration Rover Opportunity. This kick-ass robot traveled 28 miles and lasted nearly 15 years, until a global dust storm in early 2018 starved it of sunlight. It landed on Mars way back in 2004, with its twin, Spirit, beginning its Martian reign with a hole-in-one, literally — after bouncing and rolling across the regolith after its entry and descent, encased inside a genius airbag system, it plopped inside the tiny Eagle crater. We’ve collectively lived through Opportunity’s adventures and the groundbreaking science it has done. There’s a huge number of terrific robot obituaries out there, so I won’t duplicate those efforts here. There is, however, a recurring sentiment that is somewhat misplaced, though entirely innocent.

Opportunity — like Spirit and all the Mars rovers and landers that have come and gone — died at home.

This may sound like an odd statement, but there seems to be this fascination with “returning” our space robots to Earth. I’ve seen cartoons of the Dr Who traveling through time to “rescue” Opportunity. People have argued for the case of future Mars astronauts returning these artifacts to terrestrial museums. There’s that touching XKCD cartoon of Spirit being “stranded” on Mars after NASA declared it lost in 2010, that is being resurfaced for Opportunity. We want our dusty Mars rover back!

Dusty rover [NASA/JPL-Caltech]

It’s understandable, that rover has been continuously exploring Mars for a decade and a half, many of its fans, including myself, could check in on Opportunity’s adventures daily, browsing the latest batch of raw images that were uploaded to the NASA servers. We love that thing. In the tradition of military service members who die abroad, we go to great efforts to bring their bodies home so they can repatriated; we want to repatriate our science service member back to Earth.

But Opportunity is a robot that was designed for Mars. Every single design consideration took the Martian environment into account. The Red Planet’s gravity is roughly 1/3rd that of Earth, so the weight on its actuators and chassis are 2/3rds less than what they’d experience on our planet. Its motors are too under powered to reliably drive the robot forward on Earth. On Mars, they’re perfect. Granted, the mass of the Mars Exploration Rovers (approximately 185 kg) are a lot less than their supersized cousin, Curiosity (899 kg), but if Opportunity and Spirit had a 90-day mission exploring the dunes of the Californian Mojave Desert, I’m betting they wouldn’t get very far; they would be under-powered and grind to a halt. They’d also likely overheat as they were designed to withstand the incredibly low temperatures on the Martian surface.

The robots we send to Mars are undeniably Martian. If we’re going to anthropomorphize these beautiful machines, let’s think about what they’d want. I’m guessing they’d want to stay on that dusty terrain and not return to the alien place where they were constructed. And, in doing so, they become the first generation of archaeological sites on the Red Planet that, one day, the first biological Martians will visit.

A Martian’s shadow [NASA/JPL-Caltech]