I’m still struggling to do simple astronometry even on a well-known variable star like RRLyrae. If you could measure its brightness for several nights without any breaks, you should in theory get a light curve like this:
I don’t. I’m still trying to figure out why my light curve for RRLyrae is so flat.
In 2004, during a two-week astronomy summer class at Mount Wilson, with a professional astronomer on hand guiding me at every step of the way over a couple of nights, I got light curves looking like pieces of the good example above. (Why only pieces? Because you can’t image a star in the daytime or when it’s cloudy or if the star is on the other side of our planet!)
A couple of weeks or so ago, inspired by an exoplanet light curve taken by a 9th grader with a Seestar, I had the opportunity to run my tiny automated Seestar S50 for 8 hours outside at Hopewell Observatory, which is a nice, safe location, connected to wall power. The weather was perfect for it. The scope is about the size of a large cookie tin on a tripod. It did nothing but take ten-second photos of a small region around RRLyrae from whenever stars came out until dawn.
Afterwards I then had to start analyzing those 972 images. My first step was to learn how to use YET ANOTHER astro-imaging package, called AstroImageJ. It’s quite impressive, but It pisses me off that every few years I have to learn an entirely new piece of software, and just throw out nearly everything I learned regarding anything software-related over the past 60 years!
I eventually figured out how to get AIJ to verify that the little scope was in fact looking at my chosen star — and it was.
I then asked AIJ to compare the brightness of RRLyrae to the brightness of five or six other stars of similar brightness that happened to be located in the same field of view, for each image. (Today’s computers quickly do all sorts of math on the values of certain pixels in certain rings around certain stars, at lightning speeds, but the human computer of 1899, Williamina Fleming, who discovered this star, had to do it completely manually by comparing the size of the spots on a glass photographic plate. My hat is off to you, Ms Fleming, and all the other unsung female computers!
Here is a screenshot of the very last image in the series I took. The RA and Dec are the coordinates of RRLyrae, which AIJ has circled in green. The stars circled in red are comparison stars. That 20.28′ legend is in arc-minutes, 60 of which equal one degree. So the field of view is a bit over half a degree across and roughly a degree vertically.
To my surprise, my results were totally different from what I expected to find.
The blue dots are RRLyrae’s brightness on some scale that the computer cooked up, and the pink ones are from one of the known comparison stars. The x-axis goes from roughly 0.48 to 0.64, or 0.16, which is 1/6 of a day, or 4 hours.
The cases where both the blue and pink dots drop down below 1.0 are garbage caused by some glitch and should be ignored. But one thing is for sure: there is no sawtooth spike in my data for RRLyrae’s brightness during those 8 or 9 hours!
Four possible reasons are:
I’ve made a great scientific discovery! (probably not correct)
2. Wrong star? (I don’t think so. Checked and re-checked)
3. Perhaps those 8 hours happened to correspond to a flat place in the light curve (Possible — I just noticed that these images end before midnight, but I thought it kept working until dawn! Must re-check!)
4. The pixels all are too saturated, ie were exposed for too long,, which fills up the pixel with too many electrons. (This is possible, I guess, but each of these were merely 10 second-long exposures, which doesn’t sound very long to me, but maybe I’m missing something important).
Saturation is what the following graphic seems to indicate:
If it is indeed saturation that is making all the stars not change brightness, then what do I do?
I don’t think I can control the gain or ISO inside SeeStar, but I can ask for shorter time exposures, I think, by trying a time lapse and asking for shorter exposures, if possible. I just need to have time and a location to let it run all night without anybody disturbing it, making a time lapse of the sky.
We’ve all been brainwashed by years of Star Wars, Star Trek, Marvel Universe, Avatar, etc, to think that space should be teeming with intelligent civilizations, most of them vaguely like ourselves, working with and against each other to carve up the galaxy. As a result, it’s easy to overlook the huge assumptions embedded in your question.
Habitable worlds exist. Do they? It seems overwhelmingly likely, given that there are probably a trillion planets in the Milky Way alone, but for now we don’t know. Perhaps there are many near-miss planets like Venus and Mars, but extremely few true Earth analogs. For instance, life might require a particular rock/ice ratio, a large moon, and a specific style of plate tectonics. That level of specificity seems unlikely to me, but that’s just my random opinion. Until we find another planet with truly Earthlike conditions, we cannot say for sure that this is true.
Alien life exists. Does it? Honestly, we have no idea. There are many strong arguments suggesting that the fundamental biochemistry of self-replication is practically inevitable given the right conditions. But we don’t know how common those conditions are (see above), and even then we don’t know if there is some extremely low-probability gap that hinders the emergence of even simple microbial life.
Intelligent life exists. Does it? This one is a complete unknown. Keep in mind that there was no intelligent, self-aware life on Earth for 99.999% of its existence. Maybe the emergence of intelligence here was a rare fluke, unlikely to be reproduced anywhere else. Rat-level intelligence seems to have existed for at least 200 million years without any indication that higher level intelligence would confer a big evolutionary advantage. (There are all kinds of speculations about why intelligent life could not emerge until now on Earth, but these are just-so stories, trying to paint an explanation on top of a truth that we already know.)
Intelligent species want to “colonize” the galaxy. Do they? Life does have a tendency to explore every available ecological niche, and humans sure do like to spread out. From our example of one Earth, it seems likely that this is a general tendency of life everywhere, but we are doing an awful lot of extrapolating here. Maybe other types of intelligence have other motivations that have nothing to do with expansion.
Intelligent species become technological species. Do they? It’s certainly true for humans, but dolphins have a high level of intelligence and they are not trying to build spaceships. Crows, chimps, and bonobos are also capable of simple tool use, but they don’t appear to have experienced any evolutionary pressure to become true technological species.
Technological species can travel a significant fraction of the speed of light. (I assume you mean something like more than 1% of light speed.) Can they? Extrapolating from human technology, that seems extremely likely. Then again, the fastest spacecraft we have ever built would take about 300,000 years to reach the next star. Nobody is going to be colonizing the galaxy at that rate. You have to accept that speculative but unproven technologies are both feasible and practical for more advanced technological civilizations. Maybe intelligent life is out there, but in isolated pockets.
Intelligent, technological, space-faring species survive for a long time. Do they? Oh boy, we have no idea at all if this is true. Earth is 4.5 billion years old. Life has been around 4 billion years. Land species have been around 400 million years. Rat-level intelligence has maybe been around 200 million years. Our species has been around for about 100 thousand years. We have been capable of spaceflight for less than 100 years. It may seem inconceivable that humans could go extinct—but even if we last another 100,000 years, that may not be nearly enough time to spread across the galaxy, even if we develop the means to do it and maintain the will to do it. If intelligent species typically last less than 100,000 years, thousands of them could have come and gone in our galaxy without us ever knowing.
So there’s not one answer, but a whole set of overlapping possible answers why we don’t see evidence of any alien civilizations around us. And that doesn’t even consider more exotic possibilities, such as the idea that they might be here but just undetectable to us or deliberately hidden from our primitive eyes.
Dr Rob Zellem posed this question last night (9-13-2025) to NCA members and visitors at their monthly meeting at the University of Maryland Observatory.
Are we alone in the universe, or are there exoplanets with life of some sort, and even some advanced civilizations out there?
Dr Zellem said the correct answer right now is, maybe. We just don’t have enough data to tell.
He reminded us that Giordano Bruno and Isaac Newton both correctly predicted that other stars would have planets around them. We now know that just about every single star is born with a retinue of planets, asteroids, dust, and comets, so there are at least as many planets as there are stars in our galaxy and all the others as well. Previous speakers to NCA have noted that many of these objects end up getting flung out into the vast frozen emptiness of interstellar space in a giant random game of ‘crack the whip’. No life can exist out there.
My calculations here: It is estimated that there are literally trillions (10^12) of galaxies, each with millions (10^6) or billions (10^9) of stars. Let’s start with our own galaxy, the Milky Way, with maybe 200 billion stars (maybe more). I will assume that life needs a nice, calm, long-lived G class yellow star, which only make up 7.6% of all stars. Roughly 50% to 70% of those stars are in binary systems, which I fear will reduce the chances of having a planet survive in the Goldilocks zone. Perhaps one-third to two-thirds of those G stars have a planet in their habitable zone. We have no idea how likely life is to get started, but after reading Nick Lane’s The Vital Question it sounds pretty complicated to me, so I’ll use a range of estimates: somewhere between 10% and 80% of them develop some form of life. We know that on Earth, the only form of life that existed during the vast majority of the existence of the Earth was unicellular microbes. Four-footed tetrapods like ourselves have only occupied about 1% of the life of our planet, and we humans have only had the telescope for just over 400 years, out of the 400,000,000 years since four-footed animals evolved, which is one in a million. Low estimate:
If my low-end estimates are correct, then there are about five or so exo-planets somewhere in our galaxy with a civilization formed by some sort of animal that can look out into outer space. High estimate:
In that case, there are well over a hundred civilizations in our galaxy — but the Milky Way is huge, hundreds of thousands of light-years across! Most of our exoplanet detections have been within the nearest 100 light years, and we have no way of detecting most exoplanets at all because the planes of their orbits point the wrong way.
NOTE: Jim Kaiser pointed out that I made a dumb mistake: a hundred billion is ten to the 11th power, not ten to the 14th power. Fixed now.
Even so, Zellem pointed out that thanks to incredible advances in sensitivity of telescopes and cameras, we are now closer than ever to being able to answer the title question: Are We Alone.
Plus, any amateur astronomer can take useful measurements of exoplanet transits with any telescope, and any digital camera. Following the directions on NASA’s Planet Watch webpage, you can take your data, in your back yard or from a remote observatory, process it the best you can, send it in, and be credited as a co-author on any papers that are published about that particular exoplanet. Then, later, a massive space telescope can be aimed at the most promising exoplanets during their transits. Astronomers can use their extremely sensitive spectroscopes to detect the atmospheres of those bodies and look for signs of life. They do not want to waste extremely valuable telescope time waiting for a transit that doesn’t recur!
Some day we will be in a situation where scientists will be able to say that based on their measurements, the signal indicates a very good chance of life at least a bit like ours, with similar chemistry on some planet. They will also state what the chances are that they are wrong, and indicate what further steps could be made to disprove or confirm their claim.
Zellem noted that both the Doppler-shift method and the transit methods are quite biased in favor of large exoplanets that are close to their suns.
I asked the speaker how likely it would be for observers from some exoplanet to detect the planet Mercury, but couldn’t do the math in my head and didn’t have paper and pencil to write anything down at the time. But now I do.
The closer Mercury is to the Sun, the larger the possible viewing angle.
Using a calculator to find the arc-tangent of that ratio (865,000 miles solar diameter, divided by the smallest and also by the largest distances between them, namely 28,500,000 and 43,500,000 miles) gave me an angle between 2 and 3 degrees, depending. So there is a circular wedge of our galaxy where observers on some other planet might view a transit of our innermost planet. Where is that wedge in our galaxy?
The following sky diagram has the Ecliptic in pink. Only observers within a degree or so of that curvy line could detect that Sol has planets.
So what fraction of the sky can ever hope to catch a transit of Mercury? Only about 1% or 2% of the sky — not much.
Turning things around, this means that we can ourselves only detect, via transits, a very small portion of all extra-solar planetary systems – those whose planes are pointing almost directly at us, and those with large planets that are very close to their stars. (Any planet so close to a star is not a very good candidate for life, in my opinion.)
The biggest obstacle is the sheer distances between stars. At the speed of our very fastest space craft (the Parker Solar Probe), which only goes 0.064% of the speed of light, it would take about 6250 years to reach our closest stellar neighbors near Proxima Centauri. One way. Which probably explains why, if all these other civilizations do exist, we do not appear so far to have been visited by any other extraterrestrial civilization.
At the meeting, someone in the audience was pretty sure that yes, we have already been visited by aliens. I talked with him outside after the meeting. His main evidence was a 2020 New York Times article concerning the upcoming release of classified data about mysterious flying objects (now called UAPs rather than UFOs). In the article, one Eric Davis claimed (without producing any evidence) that some items have been retrieved from various places by the US military that couldn’t be made here on earth. That is of course true of every single asteroid or meteorite ever discovered, since we can’t reproduce the conditions in which they were formed, so his claim is not very helpful. No technological devices clearly of alien manufacture have ever been publicly produced by him or anybody else for testing.
(It’s pretty obvious that American and other military forces spend a lot of money producing objects that go very fast and are highly maneuverable — and which they want to keep secret.)
There are in fact many, many unsolved mysteries in science (eg, the nature of dark matter and dark energy, and exactly how the nucleus arose in eukaryotes). Many of the unidentified sky or water phenomena that have been witnessed do not have clear explanations so far, but the simplest explanation is usually the correct one. Reputable scientists require a lot more than hearsay evidence before they make bold claims.
Alan Tarica, Pratik Tambe, Tom Crone and I have been pulling our hair out for a couple of years, trying to use cameras and software to measure the ‘figure’ of the telescope mirrors that we and others produce in our telescope-making class.
There has been progress, and there has been frustration.
I think we finally succeeded!
Some of the difficulties have been described in previous posts. In brief, we want our mirrors to be really, really close to a perfect paraboloid. There are many ways of doing those measurements and seeing whether one is close enough, but none of those methods are easy!
(By the way, one needs the entire mirror to be within one-tenth of a wave-length of green light of that ideal paraboloid! That’s extremely tiny, and equivalent to the thickness of a pencil over a ten-mile diameter!)
I think I can finally report a victory. My evidence is this graph that I made just now, using data that Alan and I gathered last night with our setup, which consists of a surveillance camera coupled to an old 35mm SLR film camera lens, which is mounted on a linear actuator screw connected to a stepper motor controlled by an Arduino and a Python app developed by Pratik.
Something seemed to be always a bit — or a lot — ‘off’.
The blue dots just above the x-axis are the measurements for this one particular mirror with a diameter of 8″ and a radius of curvature of 77 inches.
The dotted blue curve in the middle of the image is the best-fit parabola for those dots. Notice that the R-squared value (variance) for that curve is not great: 0.3599.
But that variance isn’t important. What is important is the green and orange blobs and curves above and below the blue ones.
The green and orange curves are the upper and lower allowable limits for the measurements of this particular mirror, using the
Clearly, the blue dots are all well within the green and orange curves.
Which means that this mirror is sufficiently parabolized.
The fact that the blue dots don’t fit the dotted line perfectly, and behave pretty oddly at positive or negative 80 millimeters, both agree with the fact that we can see on the photos that the surface of this mirror is rather rough, as you can see in the images below. Note also that the image labeled ‘Step 6’ found not one, but two null zones on the right, indicated by two vertical blue lines.
So, finally, we have an algorithm that gives good measurements! What I still want to do is to automate all the spreadsheet calculations that I just did today. Perhaps we can upload them to something like FigureXP by Dave Rowe and James Lerch.
Thanks very much to all those who have helped, whom I should look up and name here.
Caveat: This method can give really ridiculous measurements close to the center and close to the edge.
PS: if anybody wants the raw data, just email me at gfbrandenburg at gmail dot com.
Look what this little thing can do that I’ve always failed at myself, even with an entire observatory at my disposal: take decent astrophotos.
Here it is on a home made tripod, taking photos of the sun. Notice the reflective solar filter. Here are two images:
The device woke up, and after less than a minute of self’s-calibration, it pointed very accurately at the sun and focused itself perfectly. It produces a continuous feed; I even did 100 frames of a time-lapse. It’s all stored on my cell phone but I can share the photos or even live views with folks nearby.
And from night time spots here in DC and NOVA:
This can take tolerable astrophotos even when surrounded by streetlights!
When I show people things in the sky with a telescope, I want to help them to realize how lucky we are to live on a nice, warm, wet little planet in a relatively safe part of a medium-large galaxy.
I also want them to realize that if we aren’t careful, we could turn this planet into one of those many varieties of deadly hell that they are viewing in the eyepiece.
We should be very thankful that this planet got formed in a solar system that had sufficient oxygen, silicon, iron, nitrogen, and carbon for life as we know it. We are fortunate that all of those ‘metals’ I just listed (as astronomers call them) got cooked up in cycle after cycle of stars that went boom or whooshed their outer layers into the Milky Way. We are lucky to be alive at the far multicellular side of the timeline of life on Earth*, and that no star has gone supernova in our neighborhood recently or aimed a gamma-ray burst directly at us.
We are exceedingly lucky that a meteorite wiped out the dinosaurs 65 million years and allowed our ancestors, the mammals, to take over. We can rejoice that most of us in the USA can have our physical needs (food, shelter, clean water, clean air, and communication) taken care of by just turning a knob or a key, or pushing a button, instead of hauling the water or firewood on our backs. (There are, obviously, many folks here and abroad who live in tents and who have essentially none of those nice things. We could do something about that, as a society, if we really wanted to.)
I am often asked whether there is life elsewhere. My answer is that I am almost positive that there are lots of planets with some form of life in every single galaxy visible in an amateur telescope. But there is no possible way for us humans to ever visit such a planet. Nor can aliens from any exoplanet ever visit us, whether they be single-celled organisms or something you would see in a Sci-Fi movie.
Yes, it is possible to send a handful of people to Mars, if we are willing to spend enormous sums of money doing so, and if the voyagers are willing to face loss of bone and muscle mass, and the dangers of lethal radiation, meteorites, accidental explosions, and freezing to death. If they do survive the voyage, then by all means, let them pick up some rocks and bring them back for analysis before they die.
But wait: we already have robots that can do that! Plus, robots won’t leave nearly as many germs behind as would a group of human beings. And we already know a lot about how Mars looks, because of all the great photos sent back by ESA, JAXA, NASA and others for some decades now. You can see photos taken by NASA at JMARS, which I highly recommend. (https://jmars.asu.edu/ )
While one can justify sending a few brave folks to Mars for a little while, it is completely insane to think that we can avoid our terrestrial problems by sending large populations there. Mars is often colder than Antarctica, is close to waterless, has poisonous perchlorates in its soil, no vegetation whatsoever, and no atmosphere to speak of. How would millions or billions of exiles from Earth possibly live there? Do you seriously think they can gather enough solar energy to find and melt sufficient water to drink and cook and bathe and grow plants and livestock in the huge, pressurized, aluminum cans they would need to live in? No way.
I wish there was some way to get around the laws of physics, and that we could actually visit other exoplanets. But there isn’t, and we can’t. I’ve seen estimates that accelerating a medium-sized spaceship to a mere 1% of the speed of light would require the entire energy budget of the entire human population of the planet for quite some time. (For example, see https://physics.stackexchange.com/questions/447246/energy-requirements-for-relativistic-acceleration )
Let us assume, for the sake of argument, that you could actually generate enough energy to accelerate that spaceship with nuclear fusion or something else that doesn’t violate the laws of physics as far as we know.
The next problem is the distance. It’s a bit over 4 light years to the nearest known exoplanet in a straight line, (compared with under 2 light-seconds for the Moon or about 35 light minutes for Jupiter). The table below gives the number of planets lying each extra solar system that are thought to be terrestrial (as opposed to gas giants) and to be within their stars’ habitable zones. Nobody knows if there is any life on any of those planets right not, but it is possible that astronomers may one day figure out a very effective way to test for extra-solar life. Let us suppose that a few of the ones in this list do have breathable atmospheres and are neither too cold nor too hot, have a fair amount of liquid water, and are protected from nasty radiation by magnetic fields and belts.
Unfortunately, a one-way trip to Proxima or Alpha Centauri for any possible spaceship, at one percent of the speed of light, (3,000 km per second), in a straight line, and pretending that you don’t need years and years to both accelerate and decelerate, would take over four centuries. And that’s for the very closest one! All the other planetary systems are many multiples of that distance! See this or this table:
Our fastest spacecraft so far, the Parker Solar Probe, reaches the insanely fast speed of 190 km/sec, but that’s still fifteen times slower than my hypothetical 1% of c. At the speed of Parker, it would take around six thousand years to reach the Proxima Cen planetary system! If all goes well!
Do you seriously think that a score or so generations of humans would all agree, century after century, that they, and their descendants — born and raised in a big metal box rushing through space — for the entire 400 years, would consent to live in a large metal box with no gravity to speak of, subject to who knows how many blasts of gamma rays, x-rays, and super-high-energy cosmic particles? What are the chances that each single generation would agree to stay the course and that not a single meteorite going the other direction, over a course of four centuries, would happen to smash into the space ship and instantly disable all the life support systems and kill all the passengers, quickly or slowly?
And how do you keep alive all the animals we would need to feed us upon arrival? I guess you compost all the poop from all the cattle, chickens, and so on. But do you also bring zillions of insects and tons of plant seeds as well, knowing full well that if you do so, then you lose the vast majority of the information you could have learned about an actual, functioning, extra-solar ecosystem like nothing we can possibly imagine.
The argument is made that perhaps the travelers would be put into suspended life. If that were possible, and nothing went wrong, upon arrival, they could take a triumphant group selfie and put it into a radio message back to Earth saying, “Hi, we made it, wish you were here…” That reply will of course take four years to reach Earth. Would people back on Earth still remember the handful of people who began the trip out, made over four centuries earlier? What will the humans back on earth remember about the absolutely prodigious effort expense that their ancestors had made to build and power that rocket, 20 generations or so earlier?
Let us suppose they have the tremendous luck to find, after 4 to 10 centuries of travel, a nice warm exoplanet with water, oxygen-producing life, and air that we can breathe.
Unfortunately, there is an overwhelming chance that there would be no humanoids or any other Sci-Fi characters. The chances are that creatures that look like insects, crustaceans, fish and salamanders are the most highly-organized life forms – at best; after all, for most of the existence of life on earth, it was single-celled organisms! Our travelers would have to have to build an entire urban and agricultural infrastructure *from scratch*, with no help. They could only do that if the plants and animals they brought from Earth are able to flourish.
The return trip, if desired, would of course take another four or more centuries, if the handful of travelers can find a proper power source and if they can figure out how to create, completely from scratch, an entire agricultural and industrial instructure. They would have to figure out where the natural resources of that planet (wood? minerals? energy sources?) are located, and how they can make use of them, to build something like the incredibly precise absolutely enormous rocket-building industries we have here, on a hypothetical planet that has never even had any mammals living on it.
If these voyagers should run into any technical problem while doing trying to build a modern civilization from nothing, fat chance of getting a prompt reply from Earth, since the question would take years to reach its home base back here!
Yes, the very closest exoplanets are a mere 4 LY away, but the others are all much, much farther away, so one-way trips for ones within 10 parsecs, i.e., in our tiny corner of our galaxy, at one percent of the speed of light, would require a thousand to three thousand years to reach. Each way.
Forget it. Just send a radio message, and see if we get a reply. Oh, wait – we’ve been doing that for several decades so far. No reply so far.
Speaking of radio – it’s only 120 years since Marconi first sent a very crude radio message from a ship to a station on land, and now we routinely use enormous parts of the entire electromagnetic spectrum for all sorts of private and public purposes, including sending messages like this one. Astronomers are able to gather amazing amounts of information via the longest radio waves to the very shortest gamma rays and make all sorts of inferences about worlds we have never seen at optical wavelengths. In addition, we have begun detecting gravity waves from extremely distant and powerful events with devices whose accuracy is quite literally unbelievable.
There is no planet B. We must, absolutely must, take care of this one, lest we turn into one of those freezing or burning variations of hell that we see through our eyepieces. Think I’m being alarmist? We now know this nice little planet Earth is more fragile than we once believed. It has been discovered that life was almost completely wiped out on this planet several times. The Chixculub impact I mentioned earlier, the Permian extinction and Snowball Earth are just three such events.
More recently, folks thought it was impossible for people to cause the extinction or near-extinction of the unbelievably huge flocks and herds and schools that once roamed the earth: passenger pigeons, buffaloes, cod, salmon, redwoods, elms, chestnuts, elephants, rhinos, tropical birds, rainforests, and so on, but we did, and continue to do so. The quantities of insects measured at site after site around the world have plummeted by 30 to 70% and more, over just a few decades, and so have the numbers of migratory birds observed on radar feeds. Light pollution, the bane of us amateur and professional astronomers, seems to be partly responsible for both the insect and bird population declines. The rise in the levels of atmospheric carbon dioxide and global temperatures are very scary.
In addition, we are dumping incredible amounts of plastic into the oceans, and rising water temperatures are causing coral reefs around the world to bleach themselves and die, while melting glaciers are causing average sea levels rise and threaten more and more low-lying cities.
What’s more, only a very tiny fraction of our planet’s mass is even habitable by humans: the deepest mine only goes down a few miles, and people die of altitude sickness when they climb just a few miles above sea level. Most of the planet is covered by ocean, deserts, and ice cap. By volume, the livable part of this planet is infinitesimal, and the temperatures on it are rising at an alarming rate.
Will we be able to curb the burning and leaking of fossil fuels sufficiently so as to turn around the parts of global warming caused by increases in carbon dioxide and methane? I am not optimistic, given that the main emitters have kept essentially none of the promises that they have been making to those various international gatherings on climate, and graphs like this one, taken from: https://ourworldindata.org/fossil-fuels
I have been wondering whether we may need to reduce temperatures more directly, by putting enough sulfur compounds into the stratosphere. We have excellent evidence that very violent volcanic eruptions have the power to lower global temperatures with the sulfates they put into the stratosphere. It would not be great for ground-based astronomy if such compounds were artificially lofted high into the atmosphere to lower global temperatures, and we won’t know for sure exactly which areas of the planet would benefit and which would be harmed, but at least it’s an experiment that can be stopped pretty easily, since the high-altitude sulfates would dissipate in a few years. High-altitude sulfur compounds do not seem to cause the obvious harm that SO2 does at the typical altitude of a terrestrial coal-burning power plant.
Adding iron to the oceans to increase the growth of phytoplankton, which then consumes CO2, dies, and settles to the bottom of the ocean, has been tried a number of times, but doesn’t seem to have a very large effect.
I agree that large-scale injection of sulfates into the stratosphere is scary. I also agree that there is a whole lot of unknown unknowns out there and inside of us, and we are being very short-sighted, as usual.
We have mapped the far side of the moon better than we have mapped the floors of Earth’s oceans – yet permits are being filed right now to begin deep-ocean dredging for manganese nodules, which will enrich some folks greatly. Unfortunately, that dredging is bound to utterly destroy those slow-growing ecosystems, before we even know what’s down there in the first place!
We continue to dump unbelievable amounts of plain old trash, fish nets, fishing lines, live ammunition, modern warships and hazardous chemicals into the oceans.
While the waters and atmosphere of the USA are much, much cleaner now than they were when I was a kid in the 50s and 60s, places like Delhi or Beijing are so polluted that folks can barely see the sun on a clear day.
If dark matter and dark energy really do exist, that means that scientists have absolutely no idea what 96% of the universe is made of!
If dark matter and dark energy don’t exist, then that means that astrophysicists don’t understand long-distance gravity and physics nearly as well as they thought. The late Vera Rubin (a past NCA member who should have won a Nobel for her careful measurements of the rotational measurements of galaxies that led to the Dark Matter hypothesis) once told me when we were co-chaperoning a field trip to the Smithsonian for the Carnegie Institution for Science’s Saturday program for middle-schoolers, that she thought that the entire question is perfectly open. I think she’s still correct.
If the Big Bang is real, then how come the Webb is seeing fully-formed galaxies as far back in time as it can see?
Do the alternative theories to the Big Bang (eg, Burbridge’s hypothesis that matter is being created in the centers of active galactic nuclei) make any sense?
But — does anybody have better solutions?
Can we engineer our way out of the mess we are making on this planet – the only home that humans will ever have?
There is cause for optimism:
Our NCA speaker this month, Deborah Shapley, will tell how, almost exactly a century ago, astronomers finally figured out that the Milky Way was just one of many billions of other galaxies. Since that time, the amount of astronomical information gathered has been staggering, as has the efficacy of the instruments!
After scientists figured out what was causing the ozone hole, every single agency and government in the entire world passed and enforced regulations that banned those chlorofluorocarbons that were used in almost everything from air conditioners to hair spray. Since that time, there has been almost complete compliance and agreement, and the ozone hole continues to shrink, as you can see here.
I have vivid memories about how smoggy and stinky the air used to be on a typical summer day in almost any American city of my youth. A fat-rendering plant right here in Georgetown (DC) stank worse than a hundred skunks, and is now gone. I know a paper mill in West Virginia whose fumes had long killed almost all the vegetation downwind of the factory. Nearby, acid drainage from an abandoned coal mine turned a stream so acidic that the rocks (and water) were amazing shades of orange, reds, and yellow. The rivers of this national often flowed with raw sewage, trash, and mine waste. Some, like the Cuyahoga, even caught fire, repeatedly (see https://www.smithsonianmag.com/history/cuyahoga-river-caught-fire-least-dozen-times-no-one-cared-until-1969-180972444/ ). The passage and actual enforcement of the Clean Air and the Clean Water Acts have cleaned up the air and water in this country to an amazing degree in my lifetime (I’m over 70). The cleanup of the Potomac and Anacostia Rivers in that period has also been tremendous. However, my friends who grew up in India and China tell me that the air and water pollution over there is worse than I can possibly imagine and is not improving at all.
When I was young, it appeared that nearly every adult I knew chain-smoked cigarettes and drank a lot of alcohol, and the bars, restaurants, dormitories, private houses, classrooms, buses and airplanes everywhere were filled with tobacco smoke. Despite the lies and obfuscation of the tobacco industry, not only legislation but also public opinion is such that today, I seldom encounter the nasty smell of tobacco smoke anywhere, even on people’s clothing on the bus or subway, and the number of drunk-driving fatalities is way down as well.
During my youth, the various nuclear powers exploded literally hundreds of nuclear weapons in the open air and underwater, spewing Strontium-90 and other radionucleides into things like cow or human milk, and doing untold destruction to the oceans nearby. While the number of world-wide nuclear explosions per year has dropped tremendously since then, they still continue, and may start up again on a larger scale.
Some noteworthy experiments re stopping global warming are listed in this month’s National Geographic. One of them, which has promise but also obvious drawbacks, involves dumping large quantities of finely ground-up alkaline rocks and minerals like olivine counteract the increasing acidification of the seas being caused by the absorption of so much carbon dioxide. Will these experiments work? I don’t know.
But let us not turn this planet – the only home we will ever know – into one of the barren, freezing or boiling versions of hell we see in the eyepieces of a telescope.
I have raised pigs, and I noticed that they never foul their own beds, if they are given any room to move around. Let’s be better than pigs and stop trying to extract riches in the short run while destroying the lovely planet we all love in the long run!
Heaven is not somewhere else.
It’s right here, if we can keep it that way and fix the damage we have done.
* For five-sixths of the roughly 3.7-billion-year time line of life on earth, all living things were single-celled microbes (or microbes living together in colonies). We mammals have only been important for the last 1.7% of that time, (ie since the dinosaurs died out 66 million years ago), the first known writing system was invented a few millennia ago, and Marconi only sent the first ship-to-shore radio message 130 years ago, which is an infinitesimally small fraction of 3.7 billion. Home radios only became popular 100 years ago.
Assuming that planets and stars are created at random times in the history of the universe, and assuming that a certain amount of enrichment of the interstellar medium by many generations of dead stars is necessary before life can begin at all, then it looks to me like the odds are not at all good for intelligent life of any sort to exist right now on any random planet we may study. And, unfortunately, if they do exist, we will never meet them. If there is an incredibly advanced civilization somewhere within 100 light years that can actually detect those first radio signals, then they just received our first messages. If they do respond, we won’t get the answer for another century or two!
For example, take a look at this time line of life on earth at a linear scale. If a hypothetical space traveler should somehow arrive on the 3rd rock from our Sun at a random moment in time over the past 4.5 billion years, then that’s like tossing a dart at this graph while blindfolded, and seeing where it lands. Notice the kind of organisms dominating during most of the past 4 billion years! The chances that they would happen to arrive here in the past few centuries or so, when we humans began to really understand science, are vanishingly small!
My original title began with “Space Travel is Impossible” — which is obviously false, because it is an incontrovertible fact of history that a handful of American astronauts, at enormous expense, did in fact land on the Moon and return. I remember the event well; I was working in a factory in Waltham, Mass that summer as part of the SDS Summer Work-In.
I should have written, “Space Travel to Exoplanets Is Impossible”.
But you could make the case that traveling to the Moon is barely even space travel! The distance to the moon is less than the total mileage on my last two automobiles (a Subaru Forester and a Toyota Prius) added together. Or, at the speed of light, the Moon is about 1.5 light-seconds away, the Sun about 8 light-minutes, Jupiter 34 light-minutes, and Saturn is about 85 light minutes this month. But the very nearest star-planet system to us is over four YEARS away, and the distances to the vast majority of exoplanets are measured in light-decades, light-centuries, or light-millennia.
I remember the Space Race! Both the USA and the Soviets poured incredible sums of cash, labor, raw materials, and brain power into that race, while, frankly, millions of people around the world starved or were killed in proxy wars between those two powers, representing two ideological and political opposing blocks. The incredibly expensive and dangerous race to win global prestige by being the first power bloc to reach the various goals has, so far, at its apogee, carted a handful of men to the near side of our Moon, less than two light-seconds away! And some people think we can easily travel to exoplanets that are light-decades or light-centuries away!
A decade or so ago, I bought a brand-new Personal Solar Telescope from Hands On Optics. It was great! Not only could you see sunspots safely, but you could also make out prominences around the circumference of the sun, and if sky conditions were OK, you could make out plages, striations, and all sorts of other features on the Sun’s surface. If you were patient, you could tune the filters so that with the Doppler effect and the fact that many of the filaments and prominences are moving very quickly, you could make them appear and disappear as you changed the H-alpha frequency ever so slightly to one end of the spectrum to the other.
However, as the years went on, the Sun’s image got harder and harder to see. Finally I couldn’t see anything at all. And the Sun got quiet, so my PST just sat in its case, unused, for over a year. I was hoping it wasn’t my eyes!
I later found some information at Starry Nights on fixing the problem: one of the several filters (a ‘blocking’ or ‘ITF’ filter) not far in front of the eyepiece tends to get oxidized, and hence, opaque. I ordered a replacement from Meier at about $80, but was frankly rather apprehensive about figuring out how to do the actual deed. (Unfortunately they are now out of stock: https://maierphotonics.com/656bandpassfilter-1.aspx )
I finally found some threads on Starry Nights that explained more clearly what one was supposed to do ( https://www.cloudynights.com/topic/530890-newbie-trouble-with-coronado-pst/page-4 ) and with a pair of taped-up channel lock pliers and an old 3/4″ chisel that I ground down so that it would turn the threads on the retaining ring, I was able to remove the old filter and put in the new one. Here is a photo of the old filter (to the right, yellowish – blue) and the new one, which is so reflective you can see my red-and-blue cell phone with a fuzzy shiny Apple logo in the middle.
This afternoon, since for a change it wasn’t raining, I got to take it out and use it.
At long last, we have finally got the venerable, massive Ealing telescope mount at Hopewell Observatory working again, after nearly 9 months, with a totally different, modern, electronic stepper motor drive based on Arduino.
My first post to the OnStep group ( https://onstep.groups.io/g/main/message/37699 ) was on October 21, 2021, over eight months ago. In it, I wrote that I had decided to give up trying to fix the electro-mechanical synchronous drive and clutches on our Ealing-Byers mount at Hopewell Observatory, and asked the folks on the OnStep message boards for help in choosing the best OnStep combination to drive such a mount.
Since then, it’s been a very long and steep learning curve. We only fried a couple of little slip-stick drivers and maybe one MaxESP board. We got LOTS of help from the OnStep list (not that the posters all agreed with each other on everything)! We ran into a lot of mysteries, especially when we found, repeatedly, that configurations that worked just fine on our workbench wouldn’t work at all when the components were put into the mount!
But now it works.
Let me thank again in particular:
* Prasad Agrahar for giving me the OnStep idea in the first place by showing me a conversion he had done;
* Alan Tarica, a fellow ATMer, for cheerfully partnering and persevering with me in working on this project for the past 8 months in many, many ways;
* Ken Hunter for providing tons of basic and advanced advice and a lot of hardware, all for free;
* Robert Benward for extremely helpful advice and drawings;
* George Cushing for providing some of the original boards we used;
* Khalid Bahayeldin for lots and lots of OnStep design features;
* Howard Dutton for designing, implementing, and supporting this whole project in the first place; and
* Arlen Raasch for bringing his wealth of trouble-shooting experience and a lot of nice equipment up to Hopewell, spending full days up there, and saving our asses in figuring out the final mysteries. Among other things, he kluged (by the way, “kluge” is German for “clever”, not clumsy) a level shifter to make it so that the 3.3 volt signals from our MaxESP3 board would actually and reliably communicate with the higher-voltage external DM542T stepper drivers that controlled the very-high-torque NEMA23 steppers, rewiring some of the jumpers on our already-modified MaxESP boards, and making the wiring look professional, and other stuff as well, thus essentially pushing us over the finish line.
* All of the Hopewell members for supporting this project
* Bill Rohrer and Michael Chesnes who physically helped out with soldering and wiring work at the observatory.
I plan to write up a coherent narrative with a list of lessons learned, and perhaps I can help make some of the step-by-step directions in the OnStep wiki a bit clearer to the uninitiated. Obviously I’ll need to write a user guide for this mount for the other Hopewell members.
If Alan and I had gone straight to our final configuration, this project would have been quite a bit cheaper. In addition to what’s inside the mount and control box at the observatory, we now have on hand something like this list of surplus items:
* four MaxESP boards in various stages of construction and functionality;
* a dozen or more different slip stick stepper drivers we aren’t using;
* four or more external stepper drivers, mostly TB6600;
* five or more stepper motors of different sizes;
* a hand-held digital oscilloscope;
* lots and lots of wires of many types;
* lots of metal and plastic project boxes of various sizes;
* lots of tiny motherboards; and
* lots and lots of sets of various mechanical electrical connectors (many were used, later cut off, and then ended up in the trash).
Yes, one does need spares, and yes, lots of this stuff has multiple uses, but this has not been a ‘green’ project. On the third hand, it has been extremely interesting and fun to learn all these new skills.
The final substantive changes that got the Ealing mount up and running were made during the Fourth of July fireworks down in the valleys on each side of the ridge that our observatory sits on. What were the changes? (1) switching the black and white leads from the mains power leads (they original, scavenged, cord had the white lead as Hot!) and (2) reversing the Declination motor direction. It also helped that I was not zoned-out and punchy from lack of sleep, as we had been when Arlen and I had last worked on it.
On July 4th, it at long last worked properly!
This Ealing mount’s original, labeled, built-in manual RA and DEC setting circles make it quite easy to put the scope into Home position before you turn on the power. One just loosens the clutches and moves the axes to 6:00 hours exactly in Right Ascension and 90 degrees exactly in Declination. From there, I found the OnStep system behaves very nicely. It accurately slewed to a number of bright, obvious targets of various sorts on both sides of the meridian. However, when I tried to get it to aim that night at M13, it refused, sending an error message that it was too close to the zenith for safety. And it was (altitude 87 degrees)! Very impressive – a safety feature I hadn’t even known about!
None of the objects that I slewed to was far from the center of the field of view, even when the scope slewed across the meridian. I was using an old, 2-inch diameter 50 mm Kellner eyepiece on an f/12 six-inch aperture D&G refractor.
I found that the Android app to be **much** better for initial setup than the SHC. Arlen, Alan and I all found that setting the correct latitude, longitude, UTC offset and so on from the SHC was a real brain-twister because of its unfortunately not-very-friendly user interface. Using the OnStep app on a cheap, old Android tablet made the whole initialization process very much easier and faster, especially after I let the tablet discover what time it really was from my iPhone’s wireless HotSpot.
However, I found that the hand paddle is much better for fine-tuning of pointing and so on, because the bright display on an Android, no matter how dim one makes it, will destroy one’s night vision, and one cannot reliably feel where the directional buttons are on a flat screen while staring through an eyepiece. Obviously, one can feel the buttons on the SHC quite well, maybe even with gloves. A joy stick would be even better…
Alan and I and the other Hopewell members still have many more OnStep features to learn.
However: if I had known this project would take over eight months of hard work, I think I might have tried fiddling with the original Ealing clutches some more.
Oh well, we have a mount that has much more capabilities than it ever had, and Alan and I have learned quite a bit of electronics! I’m proud of what we did!
The Hopewell Observatory had available a finely-machined antique, brass-tube 6″ f./14 achromatic refractor.
The mount and drive were apparently made by John Brashear, but we don’t know for sure who made the tube, lens, focuser or optics.
We removed a lot of accumulated green or black grunge on the outside of the tube, but found no identifying markings of any sort anywhere, except for the degrees and such on the setting circles and some very subtle marks on the sides of the lens elements indicating the proper alignment.
The son of the original owner told me that the scope and mount were built a bit over a century ago for the American professional astronomer Carl Kiess. The latter worked mostly on stellar and solar spectra for the National Bureau of Standards, was for many years on the faculty of Georgetown University, and passed away in 1967. A few decades later, his son later donated this scope and mount to National Capital Astronomers (of DC), who were unable to use it. NCA then later sold it to us (Hopewell Observatory), who cleaned and tested it.
The attribution of the mount to Brashear was by Bart Fried of the Antique Telescope Society, who said that quite often Brashear didn’t initial or stamp his products. Looking at known examples of Brashear’s mounts, I think Fried is probably correct. Kiess’s son said he thought that the optics were made by an optician in California, but he didn’t remember any other details. His father got his PhD at UC Berkeley in 1913, and later worked at the Lick Observatory before settling in the DC area. The company that Brashear became doesn’t have any records going back that far.
When we first looked through the scope, we thought the views were terrible, which surprised us. However, as we were cleaning the lens cell, someone noticed subtle pencil marks on the edges of the two lens elements, indicating how they were supposed to be aligned with each other. Once we fixed that, and replaced the 8 or so paper tabs with three blue tape tabs, we found it produced very nice views indeed!
The focuser accepts standard 1.25″ eyepieces, and the focuser slides very smoothly (once we got the nasty, flaky corrosion off as delicately as possible and sprayed the metal with several coats of clear polyurethane). The workmanship is beautiful!
Top: tiller for hand control of right ascension. Middle: counterweight bar (machined by me to screw into the mount) with clamps to hold weights in place. Bottom: detail of 1.25″ rack-and-pinion focuser.
We have not cleaned the mechanical mount, or tried it out, but it does appear to operate: the user turns a miniature boat tiller at the end of a long lever to keep up with the motions of the stars.
The mount and cradle (with size 12 feet for scale)
The counterweight rod was missing, so I machined a replacement, which has weight holder clamps like you see in gymnasiums. Normal Barbell-type weights with 1 inch holes fit well and can be adjusted with the clamps.
Unfortunately, the whole device is rather heavy, and we already own a nice 6″ f/15 refractor made by Jaegers, as well as some Schmidt-Cassegrain telescopes that also have long focal lengths. Putting this scope on its own pedestal, outside our roll-off roof, with adequate protection from both the elements and from vandals, or figuring out a way to mount it and remove it when needed, are efforts that we don’t see as being wise for us.
Did I mention that it’s heavy? The OTA and the mount together weigh roughly 100 pounds.
However, it’s really a beautiful, historic piece with great optics. Perhaps a collector might be interested in putting this in a dome atop their home or in their office? Or perhaps someone might be interested in trading this towards a nice Ritchey Chretien or Corrected Dal-Kirkham telescope of moderate aperture?
Anybody know what might be a fair price for this?
Guy Brandenburg
President
The Hopewell Observatory
Some more photos of the process and to three previous posts on this telescope.
Partway through cleaning the greenish, peeling, grimy layer and old duct tape residue with a fine wire brush at low speed to reveal the beautiful brass OTA.This shows the universal joint that attaches to the ’tiller’ and drives the RA axisDo you see the secret mark, not aligned with anything?Aluminum lens cover and cell before cleaningLens cell and cover, with adjustment screws highlighted, after cleaningIt works!
Guy's Math & Astro Blog 