5 questions about Andrew Rader (his work and his activities) will be posted on the blog. 5 quickest answers to each question will earn points – 5 points for the quickest answer, 4 points for second quickest and so on. Person with the most points after fifth question will win Andrew Rader’s book “Mars Rover Rescue” (paperback version if the winner is located in the US, digital version if outside of US).
Nearly 2,500 years ago the Greek philosopher Metrodorus of Chios challenged his students with an analogy. He stated that, because it was unreasonable that in a large field only one shaft of wheat should grow, why then, in an infinite universe, should there be only one living world? Our understanding of how profligate and diverse life is on Earth and recent discoveries in astronomy point to tantalizing possibilities.
When speculating on the nature of advanced extraterrestrial life and a spacefaring extraterrestrial society, some authors go to great lengths to discuss such life forms’ behavior and how they might be disposed toward us, the lifespan of an advanced technological civilization, and so on. At this stage in our understanding, however, all bets are off. If we were to encounter an advanced spacefaring species, we would be confronted with an intelligence that we have never before encountered, one that may not even be possible for us to understand. We cannot assume that an alien species would be motivated as we are, or would share any universal system of values with us, or perhaps even recognize us. At the moment, our understanding of life is confined to its forms, plentiful and varied though they be, found only on our home planet. Assuming that life has arisen elsewhere in our cosmos, it is almost certain to be very different from anything we currently understand, and it would not have the humanoid structure routinely reported in the UFO community or in science fiction.
Biologists define life by four general processes: growth, reproduction, responsiveness, and metabolism. Scientists are in general agreement that if a collection of organic molecules increases in size, if it makes copies of itself, if it somehow responds to its environment, and if it somehow incorporates elements from outside its structure and converts them in a series of controlled internal chemical reactions to compounds needed to grow, reproduce, or physically respond to changes in its environment, it is alive.
In the early 1960s Frank Drake conducted the first search for radio wave signals from potential extraterrestrial civilizations at the National Radio Astronomy Observatory in Green Bank, West Virginia. This began the international effort in astronomy known today as the Search for Extraterrestrial Intelligence, or SETI. In 1961, when the National Academy of Sciences asked him to chair a meeting on the detection of extraterrestrial intelligence, Drake developed his famous equation designed to estimate the number of advanced technical civilizations in our galaxy. In 1980, Carl Sagan popularized this equation in his television series Cosmos to point out to viewers across the world that our own galaxy might well be teeming with not only life but also other advanced technological civilizations. Professor Drake persuaded astronomers and other interested researchers to think seriously about the possibility of other intelligent life in our galaxy, and Sagan persuaded the common man to think about that same possibility, including its implications for our own existence.
We may be assuming too much in thinking that we would be able to recognize an alien intelligence, civilization, or its artifacts. Without a better understanding of how and where life can arise and of what other forms an alien intelligence or civilization can take, any number concerning the Drake Equation is next to meaningless. However, what Professor Drake’s equation has done, even in the absence of hard data, is to stimulate thought and debate about the various factors necessary to predict the likelihood of extraterrestrial civilizations in our galaxy.
It is arguable that any organism possessing spacefaring technology, as we know it, would have had to develop a sophisticated understanding of physics and be able to comprehend mathematical concepts, thereby recognizing a basic order in the universe’s physics and in our symbology. At the same time, of course, symbols such as letters or numerals are normally arbitrary, bearing little resemblance to what they signify, so it is difficult to say whether an alien civilization could make heads or tails of our messages, and vice versa. Still, Drake and Sagan were optimistically banking on the commonalities that we would share with another species. They knew the differences would be vast but thought it better to begin with the traits that we likely share, such as a similar chemistry involving hydrogen, one of the most common elements in the known universe.
For all our cryptographic abilities, however, we again assume much. We assume, for example, that any intelligent recipients generally think the way we do, that they organize information in more or less the same manner we do, and that they are primarily visual creatures. We are limited by our lack of knowledge of how an intelligence from another world might “think.” We must be careful not to assume that life based on a completely different biology would have anything but the most fundamental chemical elements in common with us.
As we are contemplating extraterrestrial life, one of the more exciting exercises is to imagine what such life might actually look like. If extraterrestrial life is built by DNA, or some equivalent of it, we might hypothesize that such organisms reproduce much as we do. Life evolving on any planet would certainly need to adjust to its gravity, so any sort of alien animal life would have to evolve an anatomy to move through its environment. Such organisms would be very recognizable to us as life forms, but perhaps it is not that simple. British astronomer Martin Rees has posited that there could be organisms and extraterrestrial intelligence in forms we can’t even conceive. We tend to think in terms of “animals” and “plants.” Moreover, the basis of all Earth life appears to be cellular. Whether those cells are eukaryotes, prokaryotes, or archaea, living things on our planet are either single-celled or multicellular organisms. But what if non-Earth life is built of something other than DNA or even an equivalent? We might not recognize it at all. Certainly an intelligence evolved from a profoundly different biology would function very differently than our own. Sagan wrote that extraterrestrial intelligence would be “elegant, complex, internally consistent, and utterly alien.” If we restrict our theorizing to intelligences recognizable to us, however, we could hypothesize that an intelligent extraterrestrial species might have evolved as social life forms. If such a species were also aggressive and highly competitive, as Stephen Hawking recently suggested in an article in the London Sunday Times, we could easily be faced with alien versions of the worst aspects of our human selves. In fact, Hawking cautioned against broadcasting our existence to potential extraterrestrial civilizations, stating that we only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to encounter. Rather than benevolent extraterrestrials as depicted in much science fiction, he posited that intelligent alien life might come to Earth “in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonize whatever planets they can reach.” Humanity would almost certainly be helpless in a confrontation with any species advanced enough to locate our planet and travel here.
In all of our theorizing about extraterrestrial intelligence, we may just as easily suppose that, if such a civilization developed technology sufficiently advanced to explore the stars, they must have harnessed that better nature and progressed beyond base instincts. Such a species might therefore not be bent on conquering the Earth or appropriating its resources. It might ignore us altogether, or it might attempt to contact us, perhaps even engage with us. For the moment, until we have irrefutable evidence of intelligent life beyond Earth, it is impossible to know.
Despite the interesting possibilities raised by Drake’s equation and continuing discoveries of new Earth-sized worlds in our galaxy, physicist Enrico Fermi’s question still nags: “Where are they? Where is everybody?” Could humanity be alone in this vast cosmos? For the moment, it seems that we are far distant from any other life forms that we can recognize in our obscure corner of the Milky Way.
Nancy is a science journalist who writes mainly about space exploration and astronomy and is a Senior Editor for Universe Today. She was a host of the NASA Lunar Science Institute podcast from 2009 to 2014, was a part of production team for Astronomy Cast from 2008 to 2015 and worked with the 365 Days of Astronomy podcast where she was project manager from 2009 to 2011.
Mateusz Macias: Hello Nancy, how are you? Thank you for taking the time to answer my questions. Nancy Atkinson: Thank you very much for your interest in my work and in my book!
Mateusz Macias: How did your adventure with astronomy started? What or who was your inspiration? Nancy Atkinson: I grew up on a farm, in a rural area and so I kind of took for granted that I could always go out and see the stars at night, or see an aurora in the winter skies! So, when I was young, I always enjoyed looking at the stars, but didn’t really have anyone to guide me or teach me, and I didn’t have a telescope. Only when I got older and lived in a city did I realize how much I missed looking at the night sky, and so then got involved with a local space-related group that promoted space exploration, and as a side benefit, some of them had telescopes. I’ll never forget the first time I saw Saturn’s rings through a telescope, it just took my breath away! I was always interested in space exploration, and that helped extend my interest into astronomy too.
Mateusz Macias: How did you met with Fraser Cain? What was the story behind you joining Universe Today team? Nancy Atkinson: I had always wanted to be a writer, but trying to write fiction/novels never really interested me; I loved writing and reading about true events, and with my interest in space, writing about it helped with my wish to share my love of space and tell more people about the wonders of space exploration! I still had a different job, but on the side I started by writing for a few newspapers whenever there was a current space shuttle mission or news from a robotic planetary mission. But then with the rise of the internet, it seemed the best options for writing about space were online. I had been reading Universe Today, and in 2004, Fraser published a note that he was looking for more writers. I sent him an email and he hired me almost immediately!
My first article for UT was a plum assignment. Fraser asked if I’d be interested in interviewing former astronaut Jeffrey Hoffman about his research into using superconducting magnetic technology to protect astronauts from radiation during long-duration spaceflights. Um… let’s see, talk to an astronaut about possibly overcoming one of the biggest hurdles in human spaceflight. Yep, I was all in! While the article generated a lot of interest (and Hoffman ended up using my article in one of his reports for his NASA Institute for Advanced Concepts research) ultimately, after a couple of years, Hoffman and his team realized the technology didn’t pan out.
Mateusz Macias: What word best describes Fraser as a boss? Nancy Atkinson: Supportive is the first word that comes to mind. He’s always been supportive of any ideas I’ve had for articles or for doing things with the website, etc. He’s also very creative and resourceful, and very business savvy.
Mateusz Macias: What’s in store for Universe Today in the near and far future? It’s already one of the most popular space and astronomy websites in the world. Nancy Atkinson: Fraser has been doing his award winning video series (he’s won several Parsec Awards) and I think his videos explaining various topics in space and astronomy have been very popular, so he’ll probably continue those. I think things are going very well, so there’s the old adage of “if it’s not broken, don’t fix it!” But also, Fraser does like to change things up every once in a while, and I never know what new idea he has up his sleeve! Maybe he’ll have some surprises! With writing my book, I had to cut back with how much writing and editing I did for Universe Today, so I’m not as involved as much as I was previously. I’m still quite busy with the book, and also have started writing for Seeker.com, too.
Mateusz Macias: December 20th was the day when your book “Incredible Stories From Space” got published. Was it a dream come true, a coronation of so many years as a journalist? Nancy Atkinson: Yes, it certainly was a dream come true! While I’ve always had writing a book in the back of my mind, until about a year and a half ago, I really wasn’t planning to writing a book, at least not in the near future! Life was just too busy. But then I received a call from Page Street Publishing, a subsidiary of Macmillan. They had an idea for a book about NASA’s robotic missions and wondered if I would consider writing it. To say I was honored is an understatement. I’m very thankful for the opportunity.
Mateusz Macias: How hard was the research for the book? What advice would you give to young aspiring authors, especially ones that would like to cover similiar subject? Nancy Atkinson: The fun part was being able to interview 37 NASA scientists and engineers, and have them tell me about their careers, their missions and all the fun, behind-the-scenes things that have gone on with their spacecraft – from building the spacecraft to operating it, sometimes millions of miles from Earth. What I found was that these people bring a lot of dedication, enthusiasm, emotion to what they do, and they are very passionate about their jobs. That part was fun!
The research was done by materials I received from JPL, Goddard Spaceflight Center, the Space Telescope Science Institute, Johns Hopkins University, as well as using NASA’s various websites and the mission websites to get the exact details. That was not quite as fun as interviewing people, and it was a challenge to try and squeeze as much details into the chapters on each mission without making it overly technical, and trying to put as much of the personalities of the people behind the missions into the book. The most challenging was an extremely tight timeline of doing the interviews and research and then writing up my first draft.
But I was able to weave together the stories of these amazing people into the stories of the missions – from what it was like to take the spacecraft they so delicately built and put it on top of an exploding rocket (!), to the challenges of operating a spacecraft millions of miles away from Earth, to how even scientists tend to anthropomorphize our robots, finding their “human” qualities, just like I (and many other space fans) tend to do. As far as advice, when you are interviewing people, let them tell their stories and try to let their personalities shine through your writing. That’s not always easy though! However, all the people I talked with with absolutely wonderful, and I truly hope I was able to capture and convey their passion and dedication.
Mateusz Macias: Which scientist was the most fun to interview and provided the most valuable data? Nancy Atkinson: Marc Rayman from the Dawn mission is an amazing person, and perhaps one of the most passionate persons that I’ve ever met. He’s passionate about both space exploration and life in general. He could go on and on about the virtues of space exploration and how this grand adventure of exploration brings us together. During our interview, he nearly had me teary-eyed, because he spoke so eloquently about his mission. He said, that anyone who has looked at the night sky in wonder, or who has wanted to go over the next horizon and see what is beyond is part of the Dawn mission. “Anyone who has ever felt any of those feelings is a part of our mission,” he said “We are doing this together. And that’s what I think is the most exciting, gratifying, rewarding and profound aspect of exploring the cosmos.” It was also fun to talk with him about the bright regions that have been found on Ceres. When we did the interview, the science team was just beginning to make some conclusions that these were bright salts on the interiors of several craters.
Mateusz Macias: What’s the most interesting fact you learned about space exploration in the process of writing the book that you did not know before? Nancy Atkinson: I knew there was some type of issue with the Huygens spacecraft that went to Titan along with the Cassini mission to Saturn. But I didn’t know how serious the problem was, of how close they came to not having it work at all. And I didn’t know about the international effort it took to make the spacecraft work. Of course, the spacecraft was millions of miles away from Earth when they figured out what the problems was, so how do you fix a spacecraft that far away? And so I learned about how the engineers for the mission were able to compensate for a problem with the radio communication between Huygens and Cassini by just flying the mission differently. It was true ingenuity and that the Huygens spacecraft worked so well is a true testament to the resourcefulness and creativity of the people who operate these spacecraft.
Mateusz Macias: Book is getting great reviews. Did you expected such a great reception? Nancy Atkinson: A writer can only hope! When you pour your heart and soul into a project, you hope that people enjoy the finished product, and that your writing resonates with people. I’ve been especially gratified by the comments from the people I wrote about, with some of them saying I really captured the essence of their mission, or that the book really represents well both the spacecraft and the people behind it. That really means a lot to me!
Mateusz Macias: Now, looking back, would you change something in the book, something you think you might have done better? Nancy Atkinson: Oh yes. A writer is never done editing and making changes! There was a rather tight timeline in writing the book, so I wished there had been more time in making the final edits. I actually haven’t read much of the book since it was published. It was just part of me for the year it took to write and edit it, and want to be able to look at it with fresh eyes at some point!
Mateusz Macias: Did you enjoy attending book signings events? How important is meeting with the readers face to face? Nancy Atkinson: I really do. Of course its very gratifying to have people show such an interest your book that they actually take time out of their busy lives to come to an event! And of course, I’ll talk anyone’s ear off about space and astronomy! But its also fun to hear the stories from people about how they got interested in space or astronomy. And I love to hear what parts of the book they liked or even that they didn’t like. Feedback is always good! The fun events I do where I get to share pictures from the missions are the best, because the images from space are so intriguing and engaging.
Mateusz Macias: Are there any events planned that our readers would like to know about? Where could we see you? Nancy Atkinson: I’ll be at a Barnes & Noble in St. Cloud, Minnesota on April 8 (this Saturday) and giving talks at a few schools in the Minneapolis area in April, and also at various libraries in Minnesota and Illinois. My big event this year was attending the Tucson (Arizona) Festival of Books, which was really wonderful! I hope to do more events, too, in case anyone is looking for a speaker!
Mateusz Macias: I know it’s too early but have you wondered what your next book could be about? Nancy Atkinson: Well, I’ll break the news here with you that my publisher has offered the opportunity for me to write another book! However, this time, they don’t have an idea for me, so I have to find a topic on my own. So, I have been giving it some thought, bouncing ideas around, and have contacted a few people about potential ideas. Some of the ideas have not panned out, other ideas I found out are already in the works by other writers, and so I’m still working on figuring out what the topic might be. I’ll take any suggestions!
Mateusz Macias: Nancy, thank you again for your time. I wish you all the best with your book and with your work at Universe Today! Nancy Atkinson: Thanks Mateusz! It was really fun to chat with you!
Earth is quite a lovely little rock in space. While there is no doubt that at least most of our planet supports ideal conditions for human life, and Earth is the most “habitable” world we know of, this doesn’t necessarily mean that Earth is a member of an exclusive a club. It’s not that we magically dropped down out of the sky onto a planet that happened to be perfect. The reality is that our line of organisms has been shaped by billions of years of evolution on this planet. Earth seems so amazingly habitable to us not by happenstance, but precisely because we evolved to thrive in its environment.
Lots of types of worlds may support many types of life, but not necessarily life as we know it. There are of course certain bounds and limits. So far as we know, there must be a temperature range capable of supporting chemical reactions of stable organic molecules, and (we think) some sort of liquid. Water is ideal, but may not be the only liquid capable of serving this purpose. For example, the surface of Saturn’s moon Titan is covered in liquid hydrocarbons at a chilly -180°C (colder than liquid nitrogen). We can’t rule out the possibility of microorganisms or even sizable animals living in this environment, albeit with very un-Earthlike chemistry, relying on a methane cycle not so different from our planet’s water cycle. Perhaps small crystalline “sea snakes” glide through the freezing waters of Titan.
Life on Earth thrives across an extremely wide array of conditions, and this would be no different from other worlds. Bacteria on Earth live essentially everywhere from the upper atmosphere to the depths of Earth’s crust. They survive extremes of radiation exposure, high and low pressures and temperatures, abundance or lack of light, and utter deprivation of water and nutrients. The live in the thermal pools of Yellowstone National Park at temperatures up to 80°C, dining on a rich array of chemicals leaking from volcanic vents. Microorganisms have been found deep underground in oil wells, and suspended in lakes of liquid water trapped miles under the Antarctic ice sheet. In fact, there’s more life underneath our planet than on top of it. Bacteria live miles underground, never seeing light and consuming nothing but chemicals stored in rocks. There might be as many as a hundred trillion tons of bacteria living beneath our feet. Pile up all the underground bacteria, and it would cover our planet’s surface to a depth of over five feet.
Titan’s hazy atmosphere – the most Earthlike in our solar system Based on recent estimates from the Kepler Space Telescope, there are billions of Earthlike planets in our galaxy alone – around one per star, on average. With billions of galaxies in the Universe, we now think that there are more Earthlike planets than grains of sand on all the beaches of Earth. That’s a lot of potential life as we know it, but if we include life in more exotic environments like icy moons, the conditions for life are ten time more common than that. Even in our own solar system, there are a dozen worlds that support liquid water and could, by that definition, be considered habitable.
Of these, Jupiter’s moon Europa is perhaps the best prospect for life, with a liquid water ocean heated by regular tidal flexing in mighty Jupiter’s gravitational field. Almost entirely isolated from the outside world (there is evidence that liquid water occasionally rises and bursts through the icy surface), Europa’s ocean floor is in direct contact with the bedrock beneath, where there should be thermal vents spewing out energy and nutrients. On Earth, these ocean floor thermal vents are cradles of life, and similar to the primitive ecosystems that nurtured the origin of life itself.
Europa has a lot more water than even our blue planet Thus arises a question: since the conditions for life are ubiquitous, is life common in our Universe, or are there challenges to the origin that make life a relative rarity? Although intelligent beings may exist elsewhere in our galaxy, they obviously aren’t exceedingly common or else we would have extraterrestrials roaming around our solar system or perhaps a nearby star. Yet, this tells us nothing about simpler life which may indeed be common, possibly even to be found on another world orbiting our Sun. Beyond, there could be billions of worlds covered in microorganisms or even simple plants and animals, just waiting to be found. Either we’re alone or we aren’t: both prospects are equally terrifying. Our curiosity drives us to search for answers, as living beings connected to the Universe.
Imagine yourself walking out of a lunar module “Eagle” on July, 21st 1969 and stepping on the surface of the Moon. What would be your first words? What would you like to do while performing EVA?
Andrew Rader (SpaceX engineer, MIT PhD, author)
Neil had 3 full days to think about what to say on his trip to the Moon, probably months before that, and a potentially a NASA PR team working on the problem. I’d be hard pressed to come up with something better. Something like: “Hello Moon, greetings from planet Earth. Thanks for all you’ve done for us, from inspiring our dreams when we look up a night, to stabilizing our planet’s spin, to driving our ocean tides. We’re glad you’re here, and now we are too.”
Paul Carr (Space Systems engineer at NASA, podcaster, blogger, investigator)
I was 11 years old when Neil Armstrong walked out onto the moon, and I remember being deeply envious of him. I had no idea of the depth and duration of training required of astronauts, or the complexity of their equipment, and I even had a silly fantasy about stowing away on a the rocket.
If it had been me, I think I would have resisted delivering a scripted line, and instead would have blurted out something like “look at me! I’m on the moon!”. I’m sure it would have been nothing quotable. If I were free to do whatever I wanted on the EVA, my priorities would be running, jumping, and throwing things (I was 11!). I would have wanted to scale the nearest hill, thinking it would be easy to exploit the low gravity of the moon. Of course, I would have also put all kinds of rocks in my pockets.
Ciro Villa (technologist, application developer, STEM communicator)
After the Apollo era, men haven’t returned to the Moon in now almost 45 years. Humans are long overdue for a return to the lunar surface, which could provide tremendous opportunities to act as a “launchpad” to the rest of space. If I had the unique and historical opportunity to be that first man stepping out on the surface of the Moon, I would probably be speechless and have no words at all.
During my EVA I’d like to satisfy spirit, body, and mind. The human spirit will be in awe at the incredible sight of an “alien” landscape and scenery and the realization that I am on a rock located about 384,000 km from our home, the Earth. The body would be experiencing the lower gravity and have fun hopping around. The mind would be involved in any science possible and work on the mission at hand, hoping that whatever advancement is made will benefit the rest of humanity.
Robert Novella (co-founder and vice-president of New England Skeptical Society, co-host of Skeptics’ Guide to the Universe)
If I were the first to set foot on the moon It would be hard to beat the iconic words of Neal Armstrong, except by having them heard as was actually intended of course…”One small step for “A” man, One giant leap for mankind.”
I’ve often thought that it would have been cool if both Neal Armstrong and that other dude (what was his name? ;)) both jumped and took that first step together.
My first words would probably be “holy crap”. If I were able to rein in my emotions, perhaps I’d say something like “This first ever human footprint on the moon….brought to you by SCIENCE”
During the EVA I would thoroughly enjoy the sensation of moon gravity. I’d lift the biggest boulders I could manage and leap as far as possible. I’d throw small rocks and hands-full of regolith and watch their trajectory and descent. I’d look at the camera and say “See that? You can’t fake physics like that on a stupid set on earth”
I have a little training in astronomy, although I can hardly call myself a professional. Becoming a professional at anything is a long, hard road, one I haven’t traveled far down in astronomy. No, I’m decidedly an amateur, and not a highly accomplished amateur at that.
Sadly, the word “amateur” has been cheapened a bit by modern use. It doesn’t really mean inexpert dabbler (although I will cop to that), but “lover.” An amateur does what they do for the love of it, and there are many highly knowledgeable and skilled amateur astronomers who do real science. Far from earning a living at astronomy, amateurs spend considerable sums of their own money – for love. If you are reading this, you probably understand why. The night sky and the cosmos at large combines natural beauty and profound fascination as few other things we can all experience.
In our time, nearly any object – save perhaps the odd undiscovered comet or asteroid – that is accessible to amateur equipment has already been imaged at multiple wavelengths using professional instruments. Sensitive astronomical surveys have been performed and are being performed on a regular basis, and have been for many generations, going back for more than two thousand years to the great Greek astronomer Hipparchus, who since had a major modern catalog named after him.
Since ancient times, the proliferation of astronomical catalogs and atlases has accelerated – from John Flamsteed’s sky atlas, to the 19th century Bonner Durchmusterung, to the Henry Draper catalog, to the US Naval Observatory’s catalog based upon the Palomar Observatory’s photographic sky survey, to the Hubble Guide Star catalog, up until the present, with the Gaia Source List containing more than a billion objects. What is remarkable about this accelerating growth is not only the number of catalogs and the broader coverage of the electromagnetic spectrum, but also the fact that they are now accessible to anyone, and you can also access images from many of these surveys. You no longer need a good university library and stacks of bound volumes to find the information you want.
I should point out that you can do meaningful citizen science at sites like Cosmoquest or Galaxy Zoo, but this does not mean that you can’t poke around at random in the vast library of astronomical knowledge and try to answer your own questions. I do this – and I return from my wanderings with more questions, and so far, no answers.
In 2015, when the paper describing Boyajian’s Star and its bizarre lightcurve was first made public on Arxiv, I was curious about what was known about the immediate neighborhood in that patch of sky in the constellation Cygnus. To investigate this, I used a free tool called the Aladin Sky Atlas, provided by the University of Strasbourg in France. Aladin, with a modest learning curve, allows you to overlay many of the most widely used catalogs and image libraries. For example, if you just open up Aladin and enter “Boyajian’s Star” in to the Location field, you will get this window:
That’s Boyajian’s Star, aka KIC 8462852, centered in the purple reticle. You can zoom in from there and explore to your heart’s content. What I wanted to investigate was what was known about the other stars right around the target, so I zoomed in and overlaid one of the biggest catalogs, 2MASS (2 Micron All Sky Survey). The 2MASS has over 470 million objects in it, so chances are if you can see it in an image, it’s in 2MASS, as shown in Figure 2:
Beyond the images though, I was interested in any measurements of the distance to any of these objects, and their proper motions – how fast they appear to be moving against the background of more distant objects. Objects with a distance similar to Boyajian’s Star or with similar proper motions are candidate neighbors, or even companions. The proper motion of Boyajian’s Star has been fairly well known (about 13 thousandths of an arcsecond per year West) for a while now, but it’s distance (a bit under 1500 light years) has only been inferred from its spectral type and apparent brightness.The little red squares in Figure 2 indicate an object in the 2MASS catalog. As you can see, all but some tiny faint smudges are cataloged by 2MASS. Most of these objects are in other catalogs, like the infrared ALLWISE catalog, or the Gaia Source List. If you are interested, you may also want to look up the PanSTARRS images, which don’t seem to be available via Aladin.
It turns out that directly measuring the distance to such a star using subtle variations in its apparent movement, or parallax, as the Earth moves around the Sun is very tricky, and only in recent times have we known more than a handful of these distances. So, we’re still not sure which of those stars are actual neighbors to Boyajian’s Star The only real measurement of its parallax was released only a few months ago by the Gaia team, and still carries a fair bit of uncertainty. We hope that with future Gaia data releases (perhaps one as soon as late 2017), we will have better information, not only about Boyajian’s star, but its neighbors as well.
So, lesson learned – many more objects have been cataloged than have been closely studied. We only know the spectral type and other information about Boyajian’s Star because it’s weird light curve as observed by the Kepler Space Telescope triggered a number of follow-up observations. As I poke around in these catalogs, I notice more and more, and with some guidance from professionals, I am able to start making sense of things, and also learning how to be more cautious.
Did a Star Go into Hiding?
In 2016, three Swedish astronomy students published their finding about a clever new approach to SETI – looking for stars that had vanished between surveys. In the sample of objects they studied, they found one faint object that appeared to be in a US Naval Observatory Catalog, but had vanished from subsequent, more sensitive surveys. I interviewed the lead author, Beatriiz Villarroel for my podcast, the Wow! Signal. Villarroel’s team weren’t sure this object was even a star, but I was intrigued by the possibility of a SETI discovery.
Using Aladin and the Vizier server, I found an image from the Sloan Digital Sky Survey and overlaid the USNO B1 catalog (Figure 3), represented by the red crosses. Right in the center is where the missing object, poetically named 1084-0241525 was, but as you can see, there is nothing there now. It’s also missing from all the other major catalogs, but keep in mind we don’t really know its proper motion. It may have moved a little over the decades, since the Palomar survey images upon which the northern part of USNO catalog is based were mostly taken in the 1950s. In 50 years, this object could have potentially moved a few arcseconds, depending on how close to us it is.
The conjecture is that if someone out there was building something around this star (if it is a star) that was hiding it from our cameras, it might be heating up enough to be visible in the infrared. Villaroel’s team looked for this, but didn’t see anything. However, if we overlay the infrared ALLWISE survey catalog (the little blue circles), and look just outside their 5 arcsecond search radius:
You can probably guess what I was thinking. Some object moving fairly fast against the sky – a bit more than a tenth of an arcsecond per year – had reddened so much that it had once been visible, but was now only visible in the infrared. And yes, that is a bit odd. For that to be a SETI detection is still not a slam dunk, but is much closer than we usually get.There is nothing visible under the reticle, but just to the north, about 6 arcseconds away, is an infrared object spotted by WISE, J145736.52+182507.8, that doesn’t appear to have any corresponding optical counterpart.
The WISE space telescope, back when it was able to keep its focal plane extremely cold, took measurements in 4 bands from in the infrared. These bands are called W1, W2, W3, and W4, and run from W1 centered at 3.35 microns wavelength to about 22 microns for W4. For comparison, the light you can see with your eyes is the neighborhood of half a micron in wavelength. Normally, the infrared bands for a star are on what is called the Rayleigh-Jeans tail – that is, the infrared spectrum is fairly flat, and the brightness wouldn’t vary that much from band to band.
Sadly, what we know from WISE isn’t enough. W1 and W2 are fairly close in brightness, as you would expect, but the signal to noise is too low, and the best you can say is that the source is no brighter than a certain magnitude in W3 and W4 – it could be much dimmer. Maybe someday we’ll have a survey that nails down the infrared spectrum of this object, but WFIRST may not be enough, since it will only survey out to about 2 microns wavelength. So, I haven’t found the missing star – yet.
The Mysterious Gaia Dipper
I hope you know I’m using the word “mysterious” here ironically. This word used to mean something, but now I’m afraid it’s just cheap clickbait.
ESA’s Gaia mission is doing some really interesting things right at the cutting edge of what is possible. One of the things it does as it scans the sky is measure the brightness of stars in both a blue and red band. The Gaia team keeps track of the brightness measurements for individual objects and publishes an alert when it detects that the brightness has changed by a significant amount. It has spotted quite a few supernovae this way, for example.
A small fraction of the Gaia alerts note when the brightness of the object drops considerably. I started tracking these dippers because I wanted to see if Gaia might possibly spot something that behaves like Boyajian’s Star. No doubt many of the dippers are what are called Young Stellar Objects, stars that have just formed and are still surrounded by a large disk of gas and dust.
One of the first ones of these I noted was Gaia 16bnj. Here’s what its Gaia light curve looked like (Figure 5):
Here’s the colorized WISE image:Those are very sharp dips shown in Figure 5 – quite a bit deeper than Boyajian’s Star, and the two dips are roughly the same size as best as we can tell. Using Aladin, I was able to quickly see that this relatively faint object is also in the ALLWISE catalog, as J200207.30+174649.7.
Ah, but you guessed it, wet blanket time. WISE astronomer and SETI researcher Jason Wright pointed out that there were problems with these measurements:The object of interest is at the center of Figure 6, with a little blue circle around it. When I looked at the WISE magnitude data at first, I got pretty excited – it is much brighter in the longer W4 wavelength than in the shorter W1 and W2, and this time these were not limiting magnitudes, as they were for J145736.52+182507.8. A big infrared excess could mean one of our favorite classes of conjecture – a megastructure.
Look at the quality control flags:
One character per band (W1/W2/W3/W4) that indicates that the photometry and/or position measurements of a source may be contaminated or biased due to proximity to an image artifact:
P,p = Persistence. Source may be a spurious detection of or contaminated by a latent image left by a bright star.
So, no reason to think this thing has any excess IR emission.
So, it could easily be an imaging artifact and there is no way to tell. You know – the old extraordinary claims/extraordinary evidence thing. We’ll keep looking for more dips, and perhaps we’ll see something interesting in the future, but for now, we’ve got nothing much. However, I’m not overly discouraged. Boyajian’s star doesn’t exhibit an infrared excess, and there’s still lots of interest attached to it.
Are We Any Wiser, Then?
The first lesson from all this is that amateur attempts to mine the astronomical databases for little nuggets of holy cow are likely to be frustrated. We have cataloged billions of objects but only really studied a relative handful. Also, some of the data we do have available for exploration has problems. There might in fact be a star that goes missing from a catalog, but trying to figure out what happened to it will be frustrated by the lack of follow up observations.
For now, most of the people who get credit even for minor astronomical discoveries will overwhelmingly be the ones who make an intelligent choice of targets and point their telescopes at them for years of painstaking observations, followed by sophisticated and careful analysis. As far as I can tell, they are also the ones who deserve the credit.
However, this is not by itself a sufficient reason to give up, since after all, it’s quite pleasing to take a magic carpet ride among the stars looking for rarities. It’s your universe as much as anyone else’s, and we know orders of magnitude more about than our grandfathers did. So, feel free to download Aladin or similar tools and poke around the deep sky in whatever direction you like. Please, just let us know if you find anything.
It’s been 13 years since NASA’s Opportunity rover is exploring Mars. In your oppinion what is it’s most important discovery to date? Is it our most succesful Mars rover? Will the next Mars rover (planned for touchdown on Mars surface in 2020) have to chance to achieve even more? What would you personally like to see as it’s scientific payload?
Andrew Rader (SpaceX engineer, MIT PhD, author)
Perhaps the greatest discovery of the Spirit and Opportunity rovers has been to study the water cycle on Mars and yield clues as to how ice and frost moves about the planet with seasons and weather, although it would be hard to argue that Opportunity’s greatest achievement isn’t its marathon longevity. Curiosity and the 2020 Rover are much more capable than Opportunity so should interact more with the planet and (presuming a long mission) may even eventually travel farther. I think the most important experiments going forward are related to the search for water and life on Mars, and starting to conduct experiments on use and conversion of local resources like the production of methane, oxygen, and liquid water.
Nancy Atkinson (Senior Editor for Universe Today, Host of the NASA Lunar Science Institute podcast & a NASA/JPL Solar System Ambassador)
I think its interesting that basically everywhere Curiosity has traveled, it is finding evidence of past water. From the rounded pebbles that were worn by flowing water to the mudstone and sandstone features, to the layered rock formations that could only be laid down in large amounts of water, it appears that Gale Crater was at one time filled with water. And that’s intriguing because we know on Earth, everywhere there is water, there is life. Curiosity has been finding these features and potentially habitable environments almost since it landed, so the choice of Gale Crater as the landing site appears to have been the perfect place to explore!
I’m really looking forward to the Mars 2020 rover, especially how it should be able to test ways for future human explorers to use the resources available on Mars to ‘live off the land.’ Also, it should help us understand the hazards posed by Martian dust and demonstrating technologies to process carbon dioxide from the atmosphere to produce oxygen, which could be used for the production of fuel.
Antonio Paris (Astronaut Candidate, Astronomy Professor, Planetary Scientist, Space Science Author)
The Mars rover Opportunity has made many groundbreaking achievements in the exploration on Mars. Its greatest achievement, in my opinion, does categorically fall into science or technology. I believe that Opportunity’s greatest achievement is that it served as an “extension” to the human eye, thus allowing us to explore a far distant world where humans are still decades away from making landfall. Additionally, none of the rovers on Mars are more successfully than the other. Each robotic mission to Mars had a specific purpose and it was their cumulative discoveries that have made the exploration of Mars a success thus far. Moving forward, there is an assortment of Mars rovers that will one day take the helm for Opportunity. As technology continues to improve, I sure hope a HD live cam makes it way into the next rover’s payload!