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So, you are out one night and you see an object in the sky that you can’t quite explain. You have never seen anything quite like it in your life before. Could it be an alien spacecraft? Have you had a Close Encounter of the Third Kind?
An alien visitation would be a truly outstanding occurrence if it were validated scientifically. It would possibly rank as the greatest discovery ever since science began. For centuries however, astronomers, both professional and amateur, have been looking into the skies without ever finding good evidence for the existence of extraterrestrial beings. Given our knowledge of the Universe, this is not surprising. Although there are many billions of stars around us, the distances involved are stupendously large. The practical difficulties involved for alien spacecraft traveling to Earth beggar belief. This is not to say it is impossible; just very unlikely. When you see a strange light in the sky, you should not jump to the conclusion that you have seen a UFO. Other, more mundane explanations are possible in the majority of cases.
Here’s a quick guide to some strange lights in the night sky, and what they might be.
- Steady moving lights, flashing each second, possibly green or red; sometimes very bright white lights.
It’s likely to be an aircraft. This is probably a trivial case as most people are aware of what planes look like at night. Near airports, planes can have very bright landing lights turned on that can drown out any flashing beacons.
- Steady moving light with no flashing. Moving slowly. Seen after sunset or before sunrise. Can be very bright, but usually quite dim objects. May disappear almost instantaneously.
You may have seen an artificial satellite. There are hundreds of satellites in the sky, normally only visible in the night sky after sun-down, when the light is still shining on them. The sudden disappearance happens when it moves into the Earth’s shadow. If the light is very bright, it is likely that you have just seen the International Space Station, quite a common sight in our skies these days.
- Orange flickering light, floating around 50 to 100 metres above the ground. May dim slowly after a few minutes.
You have possibly seen a Chinese Lantern, a small, inexpensive hot-air balloon made out of paper and wire. Chinese Lanterns have become very common around the country at celebrations, Halloween and New Year’s Eve.
- Steady bright light. No apparent movement. May be close to horizon or visible in the southern sky. Much brighter than surrounding stars.
It’s possible you have seen Jupiter or Venus, two surprisingly bright planets at certain times of the year. After the Moon, these two objects are the brightest objects in the night sky.
- A very bright point of light in the sky. It lasts momentarily, then disappears again. Object may move slowly. So bright you might even see it during the day.
You may have seen an Iridium Flare, essentially the reflection of a low-orbit Iridium satellite, originally used to provide satellite mobile communications. The reflections can be surprisingly bright.
- Very bright green or red light in the sky, about 200 metres above ground. Appears to move slowly.
You may have seen an emergency flare. This is a very bright firework, shot up in the sky as a distress signal to nearby shipping. In Ireland, flares are often sent up during celebrations like the New Year.
- Fast moving bright object. May travel a large distance across the sky in a split second. Possibly a greenish colour associated with the event.
You may have seen a fireball. This is a rocky object from space that has collided with the Earth’s atmosphere, heating up and exploding on impact. It may also be a satellite re-entering the Earth’s atmosphere. Such an event is worth noting! You should make a note of your observation with the International Meteor Organisation.
- Strange diffuse lights, illuminating clouds. Moving rapidly, possibly rhythmically. There may be more than one light in the sky.
You may have seen the effect of searchlights shining up on clouds. Local festivals and event organisers sometimes use searchlights to attract attention to their shows at night.
Other sightings may have arisen from light reflections, optical illusions or mistaken identity. It may be that the witnesses were very tired at the time or under the influence of drugs or medication, or they may have been the subject or originator of a deliberate hoax. The key thing is to always discount the more mundane answers before ever jumping to improbable conclusions.
Tonight I am performing cutting-edge science. I am searching for planets revolving around stars some quadrillions of kilometres from here. My equipment? A laptop and an Internet connection. The cost? Just a bit of my time. The possible benefit? Contributing to discovery of entirely new worlds.
On December 16th, a new project – Planet Hunters – was put online. The aim is simple. You are given a whole series of light curves (graphs) from different stars, and your mission – should you choose to accept it – is to identify anything that might indicate a planet crossing in front of its parent star. It’s easy to learn. In a few minutes you can be searching for far-away planets like an expert.
Planet Hunters uses data from a satellite known as Kepler, whose job it is to study hundreds of thousands of stars over an extended period, looking for signs of planets crossing in front of their parent stars. Planets are very dim compared to stars, so they are almost impossible to detect visually. However if they happen to cross in front of a star, the light from that star decreases momentarily. This decrease can be picked up by powerful telescopes and it is these occurrences that Kepler is keeping a lookout for.
That’s where we citizen scientists come in. Many of these small drops in brightness are not easily detectable by computers. Humans are good pattern recognisers, so we can often see anomalies that a computer might not recognise. Searching through the light curves for transiting planets is a bit like finding a needle in a haystack. The planet, the star and the Earth need to line up exactly, so only a small percentage of stars are likely to show anything of interest, even if they have planets revolving around them. If enough stars are sampled however, new planets will certainly be discovered. Some scientists reckon that Kepler will quadruple the number of exoplanets known to us. We currently know of 700 planets revolving around stars other than our sun.
What hit me about searching were the many different types of light curves available. Many stars are relatively uniform, but others show complex variations and rapid fluctuations. The picture below gives you an indication of some of the star patterns I came across today.
So far in my searches I have come across a few patterns that may indicate a planetary transit. The software permits you to tag and highlight possible candidates. The same pattern is shown simultaneously to other users, so that comparisons can be made and observation errors reduced. If many people are tagging the same feature, then it is likely that something interesting is going on. Having us “citizen scientists” involved is of huge benefit to the real scientists,who would otherwise need to sort through a deluge of data.
Here are my 4 best candidates from my searches so far. They may turn out to be nothing of importance, but in any case for a few hours searching it’s been a fascinating introduction to the world of planetary discovery.
What a tremendous and wholly unexpected reaction to my “Five Reasons” post last Friday. To everyone who commented, “Liked” or shared my entry I would like to thank you all.
The entry had been in the works over several weeks due a renewed interest in astronomy caused in no small part by a recent visit to some huge meteorite craters in Germany. I had refrained from posting it earlier because of some problems with wording. I certainly didn’t expect it to get much of a reaction because my posting has been quite sporadic lately and comments tended to be few and far between.
How wrong I was. The entry was placed in a prominent position on WordPress’ Freshly Pressed page, and the numbers began to shoot up immediately. My initial reaction was that I was the victim of a spam attack, but after reading the comments I was delighted to discover that something entirely different was happening. My site got thousands of hits over the weekend with over 120 comments to the entry at the time of writing, many of them very positive and supportive.
Some of the commenters were exceptionally kind. Many of you share my love of the stars and planets and the sense of wonder it creates. A few of you lamented the lack of light available in urban areas – a concern I share too. Here is a small selection of comments from you that I thought I would respond to.
Nothing is more fascinating than that which we cannot obtain.
Very true. But who knows what awaits us in the future? Arthur C. Clarke once said that when a distinguished but elderly scientist declares that something is impossible, he is probably wrong. I think we have a lot to learn yet, but yes, it seems there will always be an “unobtainable” when it comes to the vastness of the Universe.
CommentatorandPoet said some particularly nice things about my use of the English language, and I would like to thank him for this. If only I could always be so fluent, as it often takes quite a bit of work for me to come up with the right words.
Nora Weston said
“Every time I venture into virtual space to find information and photographs…I’m left in awe”
A great point Nora. Astronomy is not just about what we can see, but what these amazing instruments such as Hubble can perceive. We can experience so much just sitting at our desktops now.
Pduan quoted Carl Sagan, one of the foremost science communicators of the last century.
“every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.”
This piece of writing should be on the desk of every politician and religious leader in the world.
“I was laying on my back on the grass during the night and looking at the stars and thinking that if a civilization advanced enough to see details on Earth’s surface will look this way from Andromeda in 2 million years, they will see me, laying on the grass, looking towards them.”
You never know. Keep having weird thoughts, RV.
Chemical Marriage said
“Plus, IT IS HUGE! Space is a never ending hill to look over.”
Spot on and well said. I just quoted five reasons. I’m sure there are hundreds.
“The universe is indeed filled with wonders and the more we learn about it the more wondrous it becomes.”
So true. We are only now beginning to learn about planets around nearby stars, and their strange and wonderful ways. What next? Life?
Last but not least, Tom Baker said
“I think my favorite heavenly body is my wife, but next to her is the Horsehead Nebula.”
Thanks Tom! That brought a smile to my face.
These are just a selection of the comments. I will try to visit as many of your blogs as possible over the coming days to see what I can find.
Thanks again for all your kind words.
If you go out on a dark moonless night, you will immediately know what I mean. The Milky Way, stretching its jagged course across the heavens, is quite a sight to behold. The constellations, particularly the winter constellations, have an elegance and familiarity to them. The Moon is also an appealing object, with its ever changing phases and frequent conjunctions with other planets in the sky. Through a small telescope, planetary disks, galaxies, nebulae and open clusters come into view, often startling in their majesty.
Of course, the beauty of the universe is not limited to what is immediately visible to our eyes. Deep space objects, seen through the largest of telescopes, are candidates for some of the most beautiful things ever seen by human eyes. Who could not fail to be impressed by the wonderful Hubble photos of the Crab and Eagle nebulas, or the views of the outer planets and moons from space probes such as Voyager and Cassini? To see for yourself, each day NASA publishes it’s Astronomy Picture of the Day. Few images ever fail to impress.
Nothing can be taken for granted about space. Most of it is unimaginably cold, interspersed occasionally by blisteringly hot stars with coronal temperatures of millions of degrees. Almost everything is racing around at breakneck speed: barreling through space at velocities of hundreds or thousands of kilometers a second relative to us. That’s enough to cause quite an impact if we were to get in their way. All around us catastrophic convulsions are taking place, with vast explosions and unconscionably high energies. This is a Universe of supernovas, neutron stars, magnetars, pulsars and Gamma Ray Bursts – beams of high energy radiation that would eliminate all life on our planet in an instant were our Earth unfortunate enough to stray too close. Black holes exist that can compress the mass of whole stars into volumes a few kilometers wide, creating gravitational fields that nothing, not even light itself, can escape from.
This is the stuff of childhood fantasies. Superpowers. Forcefields. Instantaneous death. The destruction of worlds. It is no wonder that space features so prominently in the minds of the young.
It ignites our curiosity.
Astronomy confronts us with some of the biggest and most challenging problems about the nature of ourselves and the fabric of reality. As a science, it has lead the way in overturning ancient notions of how nature should behave. At one time we believed ourselves to be at the centre of the Universe, with all objects, including the Sun, revolving around the Earth. Astronomers through the ages slowly revealed a different truth. Our star and our home planet are among countless billions in a very ancient Universe. Everything we do ultimately only affects an infinitesimally small piece of real-estate in the cosmos. This discovery, while deeply humbling, is enlightening. It tells us that we will never know everything. Our quest for knowledge is unlimited. We are ants in a cathedral, and what a cathedral it is.
The study of the stars and planets has pushed out the frontiers of knowledge in every direction. It’s contribution to science and mathematics cannot be underestimated. Without astronomy, the modern world as we know it would not exist. Astronomy continues to confound us and guide us right to this day. Gigantic accelerators are busy smashing sub-atomic particles into smithereens to gain greater insights into the nature of matter because objects in space do not always behave the way our current scientific models expect them to. Astronomy has revolutionised our understanding of nature and it will continue to do so.
It tells us about our past.
When you look into space, at any star you care to mention, you are looking into history. You are not seeing the star as it is now, but as it was when the photons of light left its photosphere many years ago. If you can find the Andromeda Galaxy in the sky, you are getting a picture of how it looked two million years ago, long before humans ever roamed our planet. The largest telescopes can see back billions of years ago, to galaxies in their infancy, still in the process of being formed.
History is about ourselves, how we got here, why things are how they are. Astronomy opens history even further by explaining the origins of our planet, our sun, our galaxy – even providing insights into our Universe and how it all started some 13 odd billion years ago.
Astronomy is fascinating even when applied to our own modest human story. We have had an intense relationship with the stars and planets for thousands of years. It guided the ancient cycles of sowing and harvesting. It provided the raw material for belief systems, rituals and religions. It contributed to our language. It assisted with navigation and discovery. In living memory, we have witnessed men walking on the Moon and robot probes being flung out of the solar system – events likely to be celebrated for millennia to come. Our relationship with the stars has shaped the culture of today.
It’s our future.
Astronomy is important to our future, from the short term to the distant long term. Over the coming decades, private companies will take over much of the heavy lifting formerly associated with government agencies such as NASA and ESA. This will create new jobs and new wealth. Bigger telescopes and better equipment will provide insights into reality that will stretch our technological capabilities. Over the coming centuries perhaps we will explore and colonise deep space for ourselves, using technologies yet undreamt of. In the end, billions of years from now, our sun will expand, frying everything on this planet before diminishing in size itself, its fuel spent, its job done.
Perhaps there is a large asteroid or comet out there in space with our name on it. Perhaps our planet will eventually turn against us, forcing us to find a new home. Perhaps we will find a way to cross the enormous gulfs separating us from other stars in our galaxy. All of these possibilities lead us to the conclusion that the stars will feature prominently in the future of the human race.
Astronomy is available to all, from the small child with his toy rocketship, to the octogenarian peering through her telescope at a crater on the Moon. Few endeavours are so wide in scope, so rich in detail, or so marvelous in implication. I invite you to join in.
One of the high points of my stay in Germany recently was a visit I made to Nördlingen on the border between the provinces of Bavaria and Baden-Württemberg in southern Germany. It’s a beautiful place. It is enclosed by a defensive wall that dates back to the 14th Century – there are only three towns in Germany with this claim to fame. All the buildings are full of character. The town was the site of two battles during the Thirty Years War and were it not for the cars and the shops, you could easily imagine yourself in another time, another era.
But beautiful and all though the town is, this is not the reason I went there. It’s Nordlingen’s surroundings that interested me the most. The town is located in a region known as the Ries: a round, flat plain with an approximate diameter of around 23 km (15 miles). This area is quite different to the surrounding countryside as the following scale model clearly indicates.
For many centuries, the prevailing idea about how this geological feature came to be was that it was an ancient volcanic caldera. The trouble was that much of the boulders and debris surrounding the region were of non-volcanic origin. Many ideas were presented as to how this material got there, but it’s didn’t fully add up. The origins of the Ries remained controversial until fifty years ago.
Enter Eugene “Gene” Shoemaker. Gene was an astronomer and he had a few questions. When he looked at the Moon he saw a landscape quite different to the Earth. Everywhere on the Moon he saw craters. Big craters, small craters, enormous craters. Why then was the Earth practically devoid of them? Was it credible that the Moon could be subject to the slings and arrows of outrageous impacts while its larger sister, our planetary home, missed them all? He was convinced that the evidence for impact craters must exist on Earth, but where were they all? Gene had a good idea what kind of material would be created when a large object hit the Earth. It was just a matter of finding it.
Rieskrater MuseumHintere Gerbergasse 3
86720 Nördlingen, Deutschland
MeteorkratermuseumHochfeldweg 589555 Steinheim, Deutschland
Next Sunday, September 5th, The 365 Days of Astronomy website will be broadcasting my second podcast.
It’s all about two gigantic meteor craters in the heart of Europe. I talk about how they were created, what they look like today and how their discovery has changed the way we look at our planet. I will be backing up the podcast with pictures and further details here on this blog.
Please take a listen in and let me know what you think.
It’s a common story with astronomy enthusiasts. You are at a party or with friends when a friend introduces you as a person having an interest in astrology. You smile politely and gently correct them, but in the back of your mind you realise that they didn’t really get it. After all your explaining, you still expect to be called “the horoscope guy” later on. To many people, astrology and astronomy are different sides of the same coin.
Indeed, on a very superficial level, astronomy and astrology are quite similar. They are both concerned with the stars and planets, they both have very ancient pedigrees and are accompanied by a vast body of literature. Both astrology and astronomy are highly prominent in modern culture as any newspaper or magazine will attest. They both deal with future predictions and people involved in a professional level take their expertise very seriously.
However the astronomical and astrological camps are very, very different, and it is very rare to find an astronomer who has any regard for astrology whatsoever. (The opposie is probably not the case, but astrologers don’t particularly like astronomers so much). So what is wrong? Is it a case of snobbishness from the astronomical community? Professional rivalry perhaps? Or a conspiracy theory against the hard-working astrologers?
The answer is somewhat different. Fundamentally, astronomy and astrology are quite different philosophically.
Astronomy is a scientific philosophy. Astronomy is based primarily on the evidence, the facts. Beliefs about what these facts mean come second. All beliefs are tested and if they fail the tests, they are rejected. If they pass all the tests they are accepted as true, or at least provisionally true until new evidence becomes available. In this way, astronomy has been very successful in changing what were once strongly cherished beliefs – the belief that the sun and the planets revolved around the Earth, for instance, or the belief that the universe was timeless, even that time itself was somehow outside of the universe; all these ideas have perished as better data and better knowledge came on the scene.
Not so with astrology. With astrology, the beliefs themselves come first, with facts and evidence coming a poor second place. One of the strongest beliefs in astrology is that the stars and planets affect us in all sorts of ways. They guide our personalities, our moods and our fortunes in life. Now, this is a testable proposition and yet no evidence has ever been found to back up these claims. Furthermore, it is not a particularly plausible proposition given the enormous distances between astronomical bodies and ourselves on Earth and the lack of any coherent mechanism that would link the position and movement of the planets with the human psyche. The basic beliefs behind astrology therefore are magical, miraculous – somehow outside the realm of normal experience and scientific understanding.
Yet the beliefs persist. Plenty of people will tell you that astrology works. As proof they will often claim direct personal experience. The charts indicated that something would happen, and it did – exactly as described. The horoscopes gave a reading of their personalities with breathtaking accuracy. How could this happen?
The answer lies, not so much with the effectiveness of astrology, but with how our brains work. Most of us realise our brains are not perfect, but far less people understand how deep those imperfections extend. We are subject to all sorts of biases. We tend to assign undue significance to ideas we agree with while ignoring contrary ideas. We seek purpose and causality where it does not exist. We forget quickly and what we remember may often be very different from what actually happened. We are highly prone to suggestion. Professional magicians use such weaknesses against us to good (and profitable) use.
It’s not just astrology that is subject to such biases. Bias is commonplace throughout all human experience – politics, business, management, relationships, you name it. Science too. What makes the sciences different however are the extensive set of techniques that are used to eliminate bias. Controls, randomisation, blinding, sampling and peer review are examples. Such techniques, while seemingly arcane, are quite rational and logical in reality. They tend to make the process less subjective and any results tend to have greater weight, particularly if they can be repeated in a number of different settings.
The difference between astronomy and astrology highlights an important difference between science and pseudoscience. One area is founded on facts and evidence, the other is founded on beliefs. There are many fields of endeavour that are based on a set of implausible or untestable beliefs. Homeopathy, for instance, uses a belief that a tiny amount of material can cure chronic complaints and that the more dilute you make the solution, the more powerful the remedy will be. It’s over 200 years since Homeopathy originated, yet homeopaths have never properly challenged these founding beliefs. They assume them to be true and move on from there. In any field of study, when the founding beliefs are deemed to be too precious to be properly challenged, you should be very wary indeed.
My first ever podcast, “A series of spectacular events” has been posted on the 365 Days of Astronomy blog today. It recounts a number of memorable experiences that I had while looking upwards at the skies over the past few years: a meteor storm, an aurora and a space shuttle launch. Hopefully it will convey the power of astronomy to recreate that sense of wonder that we had in abundance as children.
I’d love to hear your feedback on this. It was a lot of fun to put together and I have a few other ideas in the pipe-works that I would love to turn into finished podcasts some time in the future.
The Falcon 1 lifted off the Kwajalein Atoll in the Pacific on Sunday, lifting a 165 km dummy payload into an elliptical orbit around the planet. This is the fourth attempt after a number of high-profile failed launches.
Although putting an object in space is no big deal nowadays, it’s still a big milestone because it heralds in a much more competitive, cheaper, efficient and fast-moving era in space exploitation.
The possibilities? Space tourism, space mining, zero-g manufacturing, and faster travel from one location to another on Earth. The downsides? More space junk and advertising. When will the McDonald’s Golden Arches or a big Coke bottle grace our evening and morning skies, I wonder? Sooner than we might think, I expect. The day when billions of LEDs are implanted on the Moon, creating the largest dynamic TV display in history is on it’s way..
Later today (or early tomorrow morning depending on your current time zone), the Phoenix probe lands on Mars to investigate if life, or traces of ancient life, exists in Mars’ polar wastes. There is a fascinating video on APOD today showing the probe entering Mars’ atmosphere and unfurling its instruments.
It is possible that today may mark one of the greatest discoveries in human history – finding life on another planet. But what are the repercussions, really?
From a religious perspective, there appears to be two possibilities: many of the moderate religions would be relatively open to the idea that the universe is teeming with life, a view bolstered by the Vatican astronomer recently. The fundamentalist religions would appear to have a problem, having accepted that the Earth is the ultimate focus of God’s work. It’s unlikely though that any of them will collapse, inoculated as they are against logic and evidence-based thinking. A bit of word-smithing will usually suffice for most of their congregations and to hell with those throwing stones from the outside. In other words: business as usual.
From a scientific perspective, the discovery on life should not come as a surprise. Over the last 400 years, a stong body of evidence has been built up that we are not so important, or unique, in the greater scheme of things. Given the vastness of the universe, and the ability of life forms to survive even in the most inhospitable of conditions on Earth, the discovery of extraterrestrial life would only bolster this viewpoint. Philosophically, the existence of life would be uncontroversial enough. What’s far more interesting would be the questions that this discovery would pose. What is the composition of the DNA? Would the chemical composition be different? What are the origins of life on Mars? Where else might we look for life? What would the implications be were we to bring samples back to earth? What would this tell us about the creation of artificial life in the lab? To put it mildly, the discovery would have the effect of reshaping and redirecting the research agenda in the 21st Century.
From a man-in-the-street perspective, it would be enlightening, a topic of conversation. I’m not sure if it would change anyone’s life irreperably, as we have now become so used to the announcement of impressive scientific discoveries in our lives. It would be a flitting moment of celebrity, until the media find something else to absorb their attention.
Maybe I’m wrong. Maybe this is moot and the more probable event of life not being found will be the result. In any case I’d welcome any views you might have.