Dr. Kevin Grazier was a planetary scientist with the Cassini mission for over 15 years, studying Saturn and its icy rings. He was also the science advisor for Battlestar Galactica, Eureka and the movie Gravity.
Mike Brown is a professor of planetary astronomy at Caltech. He’s best known as the man who killed Pluto, thanks to his team’s discovery of Eris and other Kuiper Belt Objects.
We recently asked them about many things – here’s what they shared with us about the rings of Saturn.
Saturn’s majestic, iconic rings define the planet, but where did they come from?
Kevin Grazier: “Saturn’s rings, good question. And the answer is different depending on which ring we’re discussing.”
That’s Dr. Kevin Grazier, a planetary scientist who worked on NASA’s Cassini mission or over 15 years, studying Saturn’s rings extensively.
Mike Brown: “Saturn’s rings – the strange things about Saturn’s rings is that they shouldn’t be there, really, in the sense that they don’t last for very long. So, if they are just left over from when Saturn was formed, they’d be gone by now. They would slowly work their way into Saturn and burn up and be gone. And yet they’re there. So they are either relatively new or somehow continuously regenerated. ‘Continuously regenerated’ seems strange and ‘relatively new’ seems also kind of strange. Something broke up – a large moon broke up, or a comet broke up – something had to have happened relatively recently. And by relatively recently, that means hundreds of millions of years ago for someone like me.”
And that’s Mike Brown, professor of planetary geology at Caltech, who studies many of the icy objects in the Solar System.
Saturn and its rings, as seen from above the planet by the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute. Assembled by Gordan Ugarkovic.
Saturn’s rings start just 7,000 km above the surface of the planet, and extend out to an altitude of 80,000 km. But they’re gossamer thin, just 10 km across at some points.
We’ve known about Saturn’s rings since 1610, when Galileo was the first person to turn a telescope on them. The resolution was primitive, and he thought he saw “handles” attached to Saturn, or perhaps what were big moons on either side.
In 1659, using a better telescope, the Dutch astronomer Christiaan Huygens figured out that these “handles” were actually rings. And finally in the 1670s, the Italian astronomer Giovanni Cassini was able to resolve the rings in more detail, even observed the biggest gap in the rings.
The Cassini mission, named after Giovanni, has been with Saturn for almost a decade, allowing us to view the rings in incredible detail. Determining the origin and evolution of Saturn’s rings has been one of its objectives.
Saturn’s rings. Credit: NASA/JPL/Space Science Institute.
So far, the argument continues:
Kevin Grazier: “There’s an age-old debate about whether the rings are old or new. And that goes back and forth – it’s been going back and forth for ages and it still goes back and forth. Are they old, or have they been there a long period of time? Are they new? I don’t know what to think, to be quite honest. I’m not being wishy-washy, I just don’t know what to think anymore.”
Evidence from NASA’s Voyager spacecraft indicated that the material in Saturn’s rings was young. Perhaps a comet shattered one of Saturn’s moons within the last few hundred million years, creating the rings we see today. If that was the case case, what incredible luck that we’re here to see the rings in their current form.
But when Cassini arrived, it showed evidence that Saturn’s rings are being refreshed, which could explain why they appear so young. Perhaps they are ancient after all.
Kevin Grazier: “If Saturn’s rings are old, a moon could have gotten too close to Saturn and been pulled apart by tidal stresses. There could have been a collision of moons. It could have been a pass by a nearby object, since in the early days of planetary formation, there were many objects zooming past Saturn. Saturn probably had a halo of material in it’s early days that was loosely bound to the moon.”
Enceladus, backdropped by Saturn’s rings. Credit: NASA/JPL/ Space Science Institute.
There is one ring that we know for certain is being refreshed…
Kevin Grazier: “The E-Ring, certainly a new ring, because the E-Ring consists of roughly micron-sized ice particles. And micron-sized ice particles don’t last in space. They sputter and sublimate – they go away in very short time periods, and we knew that. And so when we went to Saturn with Cassini, we knew to look for a source of materiel because we knew that the individual components of the E-Ring don’t last, so it has to be replenished. So the E-Ring stands alone from the established system, and the E-Ring is absolutely new.”
In 2005, scientist discovered that Saturn’s E-Ring is being constantly replenished by the moon Enceladus. Cryovolcanoes spew water ice into space from a series of fissures at its south pole.
So where did Saturn’s rings come from? We don’t know. Are the new or old? We don’t know. It just another great mystery of the Solar System.
Earth eclipses the sun from Chang'e 3's location in the Sea of Rains on April 15, 2014. At the same time, we'll see a total lunar eclipse from the ground. Stellarium
Last night I used my telescope to eye-hike the volcanic plains of the Sea of Rains (Mare Imbrium) where the Yutu rover and lander sit beneath a blistering sun. With no atmosphere to speak of and days that last two weeks, noontime temperatures can hit 250 degrees Fahrenheit (122 C) . That’s hot enough that mission control at the Beijing Aerospace Command and Control Centerhas decided to draw the shades and give the rover a nap from science duties until December 23 when things cool down a bit.
While studying the subtle gray hues of the Imbrium lava flows I got to wondering what the sky might look like if I could don a spacesuit and visit the landing site “where the skies are not cloudy all day” (to quote a famous song). With no atmosphere to speak of, stargazing can be done both day and night on the moon though I suspect it’s better at night when there’s less glare from your surroundings. Night, defined as the time from sunset to sunrise (no twilights here), lasts about 14.5 Earth days. Days are equally long.
Lunar landscape photographed by the Chang’e 3 lander on Dec. 15, 2013. Credit: CCTV
From Yutu’s point of view, it’s very nearly lunar noon today (Dec. 19) with the sun halfway up in the southern sky. Looking at the map of the sky from the lander’s location, you’ll see a few familiar constellations and one very familiar planet – Earth!
Phases of the moon and Earth are complementary. When the moon is full, Earth’s a crescent. This map shows the Earth in Capricornus on Dec. 20 as thin blue crescent. Stellarium
Today Earth appears as a very thin crescent a short distance to the left or east of the sun. Because the moon takes just as long to rotate on its axis as it does to revolve around the Earth, the same face of the moon always faces our planet. Because the two are in synchrony, astronomers call it synchronous rotation.
From the perspective of someone standing on the moon, Earth stands still in one spot of sky throughout the 29.5 day lunar day-night cycle. Well, not perfectly still. Because the moon’s orbit is inclined about 5 degrees to Earth’s orbit and its speed varies along its non-circular orbit, Earth describes a little circle in the lunar sky about 10 degrees in diameter every four weeks.
As the sun slowly moves off to the west, our blue planet remains nearly stationary from Yutu’s perspective and undergoes all the familiar phases we see the moon experience back here on Earth: an evening crescent to start followed by a first quarter Earth, Full Earth last quarter and finally, New Earth. I like the ring of that last one.
The lunar landscape at the rover’s location is bathed in pale blue light on Dec. 31, 2013 during a Full Earth. Stellarium
Yutu and the lander will see the sun drift to the west while Earth moves east, rises higher in the lunar sky and putting on the pounds phase-wise. Today Earth’s glides across the border of Sagittarius into Capricornus. The next Full Earth happens on New Year’s Eve when the sun is directly opposite the Earth in the lunar sky.
Full Earth always happens around local midnight or about one week before sunrise during the long lunar day. On the moon the sun is up for about two weeks and then disappears below the horizon for another two weeks before rising again. At Full Earth time, the sun remains hidden around the lunar backside. When the nights are blackest, the bright ball of Earth spreads a welcome blue glow over the desolate landscape.
Simulated eclipse of the sun by the Earth just before totality on April 15 and Oct. 8 next year. On both dates, we’ll see a total lunar eclipse from the ground. Stellarium
Things really get interesting during lunar eclipses when the moon moves behind the Earth into the planet’s shadow. The next one’s on April 15, 2014. Here on the ground we’ll see the moon gradually munched into by Earth’s shadow until totality, when sunlight from all the sunrises and sunsets around the rim of the planet are refracted by the atmosphere into the shadow, coloring the moon a coppery red.
Two pictures of the ring of sunset-sunrise fire around the Earth as it totally eclipsed the sun from the moon. Credit: NASA
Yutu will see just the opposite. Looking back toward the Earth from inside its shadow, the rover will witness a total eclipse of the sun by the Earth. If by some wonder the Chinese are able to photograph the event, we’ll see photos of the black ball of Earth rimmed in red fire from sunset and sunrise light refracted by our atmosphere. My interpretation using sky mapping software only hints at the wonder of the scene. Beijing Aerospace, if you’re reading this, please make it happen.
Earth eclipses the sun filmed by Japan’s Kaguya lunar orbiter. There are really two eclipses here – the Earth eclipsed by the limb of the moon at the video’s start followed by the solar eclipse.
On two other occasions, our robotic emissaries have photographed solar eclipses from Luna. NASA’s Surveyor 3 snapped a couple crude pictures of the April 24, 1967 eclipse from inside a crater in Mare Cognitium, the Sea that has Become Known. Japan’s orbiting Kaguya probe did the job much more eloquently on video during the February 9, 2009 penumbral lunar eclipse. In a penumbral eclipse (seen from Earth) the moon misses Earth’s dark inner shadow called the umbra, passing only through the outer penumbra, but because the Earth is three times larger than the sun (seen from the moon), it easily covered the sun completely in the complementary total solar eclipse.
And the best thing about watching eclipses from the moon? Guaranteed clear skies!
The night sky over Pyramid Lake in Jasper National Park in Alberta, Canada. Credit and copyright: Jack Fusco.
One of our favorite photographers, Jack Fusco, recently visited Jasper National Park in Alberta, Canada, one of the worlds largest dark sky preserves. He went there on behalf of Travel Alberta, during the annual Night Sky Festival. “I was lucky enough to have two clear nights to explore and shoot as many photos as possible to create a short timelapse while there,” Jack told us via email. “In the end, I took over 2,000 photos at locations such as Lake Annette, Athabasca Glacier, Pyramid Lake, and many others. Out of all the places I’ve traveled in search for dark skies, Jasper definitely offered some of the best views I’ve ever seen. The sky in the Columbia Icefield area was unlike any I had witnessed before.”
Jack added that it was great to be around so many people that were excited about astronomy and preserving the night sky, and he’s already looking forward to going again in 2014, and astronaut Chris Hadfield is already lined up as a guest.
If you’re rushing about for the holidays, take a few minutes to enjoy a brief respite with this lovely timelapse. You can see more images and videos at Jack’s website.
Star trails above the European Space Observatory's Paranal Observatory in Chile, showing three of the four auxiliary telescopes of the Very Large Telescope Interferometer (VLTI). Credit: ESO/B. Tafreshi
There are so many colorful streaks in that image above that you’d be forgiven for thinking somebody is shooting lasers around the European Southern Observatory (ESO) in Chile. Actually, though, this demonstrates a common technique for astronomy photo-taking where you do a time lapse to watch the stars moving as the Earth makes its daily rotation.
The image of auxiliary telescopes of Very Large Telescope Interferometer is not only pretty, but does have some scientific interest as well, ESO said.
“This technique … enhances the natural colours of the stars, which gives an indication of their temperature, ranging from about 1000 degrees Celsius [1,832 Fahrenheit] for the reddest stars to a few tens of thousands of degrees Celsius [or Fahrenheit] for the hottest, which appear blue. The sky in this remote and high location in Chile is extremely clear and there is no light pollution, offering us this amazing light show,” stated the European Southern Observatory.
According to ESO, these supplementary telescopes working together allow astronomers to “see details up to 25 times finer than with the individual telescopes.” You can read more about the VLTI at this ESO link, which includes some interesting facts — such as why the interferometers are named Antu, Kueyen, Melipal and Yepun.
Chris Hadfield in the Cupola of the ISS. Credit: NASA
And we have liftoff … for a social media sensation! Canadian astronaut Chris Hadfield rocketed into orbit a year ago today (Dec. 19, 2012) accompanied by NASA astronaut Tom Marshburn and Russian cosmonaut Roman Romanenko.
Hadfield was a part of the Expedition 34 crew, then took command of the station during Expedition 35 in early 2013. While running an extremely productive science mission, he did tons of public outreach, ranging from singing to humorous space-y how-to videos to chatting with numerous celebrities before landing in May.
The Canadian Space Agency invited folks on Twitter to share their reflections under the hashtag #hadfield1yr, which is already producing a lot of thoughtful responses (a few of which you can see below the jump). What was your favorite part of the mission? Feel free to share in the comments.
While Hadfield is retired as an astronaut, he remains very busy. He’s in the middle of a multi-country book tour and will begin teaching at the University of Waterloo in Ontario, Canada in fall 2014.
NASA astronaut Rick Mastracchio during a spacewalk on STS-118. Credit: NASA
When NASA astronaut Mike Hopkins steps into space for the first time this week, he will wear a spacesuit that previously sprung a water leak and forced Italian astronaut Luca Parmitano back to station in July, NASA officials said Wednesday (Dec. 18).
While at first glance this sounds like an extra bit of drama as Hopkins and Rick Mastracchio make contingency spacewalks Dec. 21, 23 and 25 to kickstart a shut-down cooling loop, NASA officials say the suit is ready to go for another trip outside because astronauts (under NASA’s direction) have made a bunch of changes to the unit.
Repurposing spacesuit parts, a new pad will be added to the back of all NASA spacesuit helmets to soak up water, should one leak again. Astronauts also velcroed a pipe into each suit — a sort of snorkel — that in the worst case, would give an astronaut with a water leak an alternate route for drawing in air.
Also, the Expedition 38 crew swapped out a fan pump separator that likely malfunctioned and caused the spacesuit leak. The cause is still under investigation, but NASA believes that a problem in the water chemistry caused contamination that plugged a tiny hole inside the water separation part of the unit. This allowed the water to escape, enter the air loop and get into the helmet.
Finally, there are new procedures in place for the astronauts themselves. They will monitor the helmet pad for fluid. NASA additionally plotted out its spacewalk procedures — which include the use of a Canadian robotic arm on station — to make sure the astronauts are always within reasonable reach of an airlock.
NASA astronauts Rick Mastracchio and Mike Hopkins will do spacewalks in December 2013 to swap out a cooling pump on the International Space Station. Credit: NASA
So here’s why the spacewalks are happening: a week ago (Dec. 11), a flow control valve inside of a pump — the pump is located outside of the station — stopped regulating ammonia temperatures inside of an external cooling loop. The loop is required to, as the name implies, cool down space station electronics. The loop got too cold, it shut down automatically, and NASA took science experiments and redundant systems offline to deal with the problem. (The main problem is NASA can’t run a heat exchanger on Node 2, which affects experiments in the U.S. Columbus laboratory and Japanese Experiment Module. No completed research has been lost to date, however.)
After figuring out that it couldn’t control the valve again, NASA shifted its attention to an isolation valve upstream. That valve is only designed to be in two positions — opened or closed — but the hardware vendor said it could be used at spots in between to regulate the ammonia flow. So software engineers created a patch to make this happen, and uploaded it to station.
Throw in another element, however: the station is about to enter what’s called an annual “high beta” period, when orbital dynamics mean the sun will be shining on it for longer periods of time than usual. (Read more technical details here.) When the angle exceeds 60 degrees, for safety reasons NASA suspends all cargo flights to station as well as spacewalks. This year, it will happen between about Dec. 30, 2013 and Jan. 9, 2014.
The International Space Station in 2010. Credit: NASA
So if NASA spent time playing with the valve and found out it couldn’t work in the long run, a couple of problems could happen. First, it would be harder to do a spacewalk to fix it.
Here’s a diagram of the pump that Mastracchio and Hopkins plan to replace:
A view of a pump module aboard the International Space Station that is used to maintain ammonia at the correct temperature in an external cooling loop. Credit: NASA
The “nominal” plan is for three spacewalks, but it could range anywhere from two to four depending on how things go. To put things simply, here’s how the spacewalks would go:
EVA 1: The pump with the broken valve would be disconnected and a spare pump (which is some distance away, but reachable using Canadarm2) would be prepped for the swap.
EVA 2: The pump with the broken valve would be removed and set aside while the spare pump is partially installed (meaning, only the bolts and electrical connections would be put in.)
EVA 3: The spare pump’s installation would be finished, and the pump with the broken valve would be stowed more permanently outside. NASA thinks that eventually, it could use that first pump again if astronauts installed a new valve on it, but that isn’t a need for the time being.
Flying Canadarm2 would be Japanese astronaut Koichi Wakata, who has operated every type of robotics currently in orbit. Mastracchio has six spacewalks under his belt already, while Hopkins will be on his first go.
If all goes to plan, NASA will not only swap out the pump, but also preserve the option for the Russians to proceed with a planned Dec. 27 spacewalk that is less urgent. In that case, the cosmonauts plan to swap out experiments, put in a foot restraint and install some cameras.
We’ll cover the spacewalks as they happen. They’re scheduled for Dec. 21, 23 and 25 at 7:10 a.m. EST (12:10 p.m. UTC) and should run about 6.5 hours each. Broadcasts will run live on NASA Television.
By the way, the pump with the problem is just three years old — astronauts had to make three spacewalks in 2010 to install it after a more severe failure. NASA characterized this situation as a more unusual failure and said this is not a symptom of an aging station at all.
Overview of the tasks that Rick Mastracchio and Mike Hopkins will perform during three spacewalks in December 2013 to remove and replace a pump with a faulty valve inside of it. The pump is required to maintain the external cooling system at the right temperature. Credit: NASA
Is this really how the Solar System works? (Rendering by DjSadhu)
The short answer? No. Not in the way that a popular animated gif insinuates, at least.
If you’re even a casual space fan you may have seen a viral gif animation showing our solar system traveling through space, the motions of the planets tracing corkscrew “vortex” paths around a line-driving Sun. While it’s definitely intriguing to watch (in that mesmerizingly-repetitive gif fashion) and rendered with a talented flair for design, there are two fundamental problems with it. One: it’s not entirely correct, scientifically, and two: its creator’s intention is to illustrate a decidedly un-scientific point of view about the Solar System and the Universe as a whole.
For the long answer, I now offer up the stage to astrophysicist Rhys Taylor, who recently posted an in-depth article describing why the planets do yet move… just not like that.
There’s this annoying space GIF roaming the internet causing trouble. Perhaps you’ve seen it. No ? Well, here it is.
Solar system “vortex” gif (by DjSadhu)
What it purports to show is the motion of the Solar System through space. But the accuracy of this has been utterly derided as an affront to scientific dignity. Which is a shame, because the video version is really quite nicely done, with good camera movement and a catchy soundtrack. The principle antagonist is notorious “Bad Astronomer” Phil Plait, who wrote a convincing and virulent attack on the video. I decided to investigate for myself.
Like many people, I was at first glance really quite impressed with the video, and didn’t have any major objections to it. Obviously the orbits and size of the planets are not to scale (and I think their orbital speeds have be altered too), but that’s just to make them visible. Fair enough. But then I read Phil Plait’s analysis, and it seems that things are much, much worse than that. Says Plait :
“Sadhu shows the Sun leading the planets, ahead of them as it goes around the galaxy… This is not just misleading, it’s completely wrong.”
He clarifies :
“Sometimes the planets really are ahead of the Sun as we orbit in the Milky Way, and sometimes trail behind it (depending on where they are in their orbit around the Sun).” [my italics]
The orbits of the major planets of the solar system all lie in a narrow plane (like being in economy class! hahaha… sorry), which is tilted at about 60 degrees to the disc of stars that forms the Milky Way. Like this:
We’ll return to the tilt in a moment. But first, if the Sun was really leading the planets, then the thing is completely ludicrous (and this is quite a major part of Plait’s argument). Yet I’m not so sure the viral gif does show the Sun leading the planets. Having read through the author’s website, I can’t find any evidence that he suggests this. In fact, some of other videos on his website clearly show that this isn’t the case:
It seems to me that the appearance of the Sun leading the planets in the gif is just the result of a projection effect – i.e. that things can look different from different angles. On the other hand, Plait read the source material for Sadhu’s model, so maybe there’s something in there that’s more explicit. I’ve glanced at it, but couldn’t find anything stating this precisely. Actually I couldn’t find a whole lot that was even vaguely coherent, but we’ll return to this later. For now, just keep in mind that Sadhu is using an alternative model, even though that may not always be evident.
What the gif definitely does not show is the fact that the orbits of the planets are tilted at about 60 degrees to the direction of the Sun’s motion. Says Plait :
“In the helical model, he shows the planets as orbiting around the Sun perpendicular to the motion of the Sun around the galaxy; “face-on”, if you like.This is wrong. Because the orbits of the planets are tipped by 60°, not 90°, they can sometimes be ahead and sometimes behind the Sun. That right there, and all by itself, shows this helical depiction is incorrect.”
There can be no mistaking that Sadhu’s video shows the orbits with the wrong tilt. But is that so critical? Well actually no, not really. Fact is that if you include the tilt, you still see the planets making a “spiral” pattern (technically it’s a helix) as they move through space. The overall appearance just isn’t that massively different compared to a 90-degree tilt.
Solar system model by Rhys Taylor (Click to play)
So what’s the big deal? What does the author claim in this internet sensation that’s so outrageous? Well, not much. That particular video/gif are actually fairly inoffensive, to my mind. The most basic notion that the planets trace helical paths through space is perfectly correct. What honestly surprises me is that this is so incredibly popular on the internet. If you weren’t aware that the Sun orbits the center of the galaxy — which, since the planets orbit it, necessitates that they trace out helical paths — then the education system has seriously failed. But do not despair! This can be remedied very, very easily.
But we’re not done yet. There’s a sting in the tail, and it’s a big one. The gif doesn’t show it, but the video version ends with the worrying remarks that:
“Rotational motion and vortex motion are completely different things.”*
“Life spirals.” [Picture of leaves]
“Life is vortex, not just rotation.” [Picture of developing ferns, then a flower, the Milky Way, the DNA double helix, etc.]
“The Solar System is part of life. Think about this while racing through space.”
*Yes, they are. Plait notes: “They’re different in more than just name; they’re actually very different physical motions with different properties—you can get helical motion without the particles in it interacting, like in the solar system, but in a vortex the particles interact through drag and friction.” Basically, claiming that the Solar System is a vortex is simply wrong. Sadhu appears not to have checked the word “vortex” in a dictionary.
I could forgive even these rather hippyish sentiments, if they were no more than that. Alas, they’re symptomatic of a much larger problem. Plait’s merciless attack is full of sound and fury, but it’s also signifying something. Reading more of the author’s website, it turns out he is actively promoting quackery. It’s on a par with the excellent Space Mirror Mystery* (the idea that everything further away than about 150 million km is just a reflection in a giant mirror), but less funny.
*I was delighted to find that this website is back online. Seriously, read it. It’s epic.
From Sadhu’s website:
“In this diagram it seems the Solar System travel to the left. When the Earth is also traveling[sic] to the left (for half a year) it must go faster than the Sun. Then in the second half of the year, it travels in a ‘relative opposite direction’ so it must go slower than the Sun. Then, after completing one orbit, it must increase speed to overtake the Sun in half a year. And this would go for all the planets. Just like any point you draw on a frisbee will not have a constant speed, neither will any planet.”
Apparently he thinks this is a problem. Worryingly, it suggests that he didn’t show the 60-degree orbital tilt not for mere simplicity, but because he doesn’t believe it’s possible. Which — if true — is utter madness, pure and simple. There’s absolutely no reason the planetary speeds have to be constant as they move around the galaxy — the massive gravitational pull of the Sun is keeping them firmly in its orbit, regardless of how those orbits are inclined.
“Secondly, most planets are visible throughout the entire year. In a ‘flat’ model, every single planet would hide behind the Sun at least once a year. They don’t. Now the heliocentric model isn’t entirely flat, but mostly.”
Fine. The heliocentric model isn’t flat, which perfectly explains why planets aren’t eclipsed by the Sun once per year. What need to state this ? Is he really saying that this is a problem in a heliocentric model…? SERIOUSLY?
“Fact of the matter is that if the helical model is correct and our Solar System is a traveling[sic] vortex, it will change how we feel about our journey. For me personally the heliocentric model feels like a useless marry[sic]-go-round: after one year we are back to square one. The helical model feels much more like progress, growth, a journey through space in which we never ever come back to our starting point. We are NOT in a big marry[sic]-go-round. We are on a journey.”
Planets trace a helical path in space because our Solar System is orbiting the center of the galaxy. Big bloody deal. It’s that simple. You don’t need a wacky alternative model of the Solar System for this – it’s happening anyway! As for going on a journey though – well no, not really. Every other star is also orbiting the center of the galaxy, so no, we’re not actually getting anywhere relative to other star systems.
Then there are some pointless ravings about the Mayan calendar.
He also links the following video. Skip to about 2 minutes in:
This has the bizarre quote that :
“The planets do not come back on to their [own] path[s]. They don’t. If they did, we most likely would have the same set of information over and over and over… like a broken record. And we’d probably get bored. It would be like Groundhog Year.”
Then he links a video claiming that the Fibonacci sequence is the fingerprint of God.
None of which changes the fact that his first video/gif has only minor inaccuracies, but at this point I can’t help feeling that this was more by luck than judgement.
Then there’s his second video. This one is more objectively just plain wrong. He shows the Sun tracing out a corkscrew pattern as it orbits the galaxy, which makes no sense. The Sun simply goes around the center of the galaxy (and up and down a little bit) — nothing else. It’s not orbiting anything else at the same time. For it to trace a helix is just nonsense. He seems to have an almost unique case of helix madness.
What of the source material — the alternative model Sadhu uses? Garbage. Utter garbage. I find it difficult to read more than a sentence or two, because it’s verging on incomprehensible. As in almost at the level of TimeCube.
“Three types of time may be recognized: – An absolute time that is universal and has neither a known starting point nor an end point; not even limited to a measurable parameter. – For living organisms there is a time for birth and a moment for death. The interval is the life span. This time may be measured with parameters like seconds, minutes, days and so on. Mechanical devices may measure fractions and to some extant reliable. In every case some kind of energy source or gear system is involved. -–When one is engaged with some work involvement in another activity may be impossible or result to be unnatural. In such cases personal values decide what course to take up and say “no time” to the other work, however important that may be. This time is highly subjective.”
Later: “The constellations at the background are sufficient evidence to deny the heliocentric orbits for planets. The Sun at 500 light seconds distance, when visible within a cone of 30° maintaining a background of one constellation, say for example Aries, (Hamel at 68ly) the SOLSTICES and EQUINOXES through Zodiac Earth maintains in the opposite constellation at midnight, namely Libra. After six months to maintain heliocentric orbit, the mid day of today should become midnight and the midnight should become midday. This has not taken place!“
Well of course it hasn’t — it’s complete gibberish ! Plait may well be right that somewhere in this mess is a model wherein the Sun leads the planets, but I don’t have the time or sheer mental fortitude to read the whole thing. I will note, though, that there’s a paragraph where the author rubbishes the conventional explanation for the ozone hole — and God help us all if that goes viral. That, not petty disputes about whether the orbits of planets are tilted by 60 or 90 degrees, is why such quackery deserves to be shot down without mercy.
“My feeling is that if your take-home message was only that the Solar System moves through space, and the planets trace out pretty spirally paths, then all is well and no harm done. But if it’s leading you to question the heliocentric model, then we’re all buggered.”
–Rhys Taylor, astrophysicist
In conclusion then, the first video and gif of the Solar System as a “vortex” are not really all that bad. Unfortunately, the inaccuracies are not due to some minor over-simplifications, but are symptoms of a some very deep-seated misunderstandings. My feeling is that if your take-home message was only that the Solar System moves through space, and the planets trace out pretty spirally paths, then all is well and no harm done. But if it’s leading you to question the heliocentric model, then we’re all buggered.
___________________
Thanks to Rhys Taylor for the guest post of his entertaining and informative article — at the very least, you got to watch “The Galaxy Song” again! Read more from Rhys (and check out some really nice infographics too) on his blog here.
An artist's conception of the European Space Agency's ExoMars rover, scheduled to launch in 2018. Credit: ESA
Scientists, start your engines. The next few weeks will see a flurry of proposals come for the European Space Agency’s first rover mission on the Red Planet in 2018.
The ExoMars mission will see a lander and rover touch Mars, and what’s neat about this particular mission is the rover has a drill on board that can burrow as far down as 6 feet (2 meters) — a first on that planet. This means the mission would be well-suited to look for organic molecules, especially in light of the stunning findings Mars Curiosity scientists recently presented about a possibly life-friendly ancient lake on Mars.
Here, in ESA’s words, are what the site must accomplish:
The site must be ancient (older than 3.6 Ga)—from Mars’ early, habitable period: Pre- to late-Noachian (Phyllosian), possibly extending into the Hesperian;
The site must show abundant morphological and mineralogical evidence for long-duration, or frequently reoccurring, aqueous activity;
The site must include numerous sedimentary rock outcrops;
The outcrops must be distributed over the landing ellipse to ensure that the rover can get to some of them (typical rover traverse range is a few km);
The site must have little dust coverage.
If you’re well-versed in Red Planet geology, we’d love to hear your idea for possible sites. Feel free to leave your thoughts in the comments. For more information about the mission requirements, you can check out the ESA page, which details what proposals must contain.
Dr. Thad Szabo is a professor of physics and astronomy at Cerritos College. He’s also a regular contributor to many of our projects, like the Virtual Star Party and the Weekly Space Hangout. Thad has an encyclopedic knowledge of all things space, so we got him to explain a few fascinating concepts.
In this video, Thad explains the strange mystery of dark energy, and the even stranger idea of the Big Rip.
What is the ‘Big Rip?’
If we look at the expansion of the universe, at first it was thought that, as things are expanding while objects have mass, the mass is going to be attracted to other mass, and that should slow the expansion. Then, in the late 1990’s, you have the supernova surveys that are looking deeper into space than we’ve ever looked before, and measuring distances accurately to greater distances than we’ve ever seen before. Something really surprising came out, and that was what we’ll now use “dark energy” now to explain, and that is that the acceleration is not actually slowing down – it’s not even stopped. It’s actually getting faster, and if you look at the most distant objects, they’re actually moving away from us and the acceleration is increasing the acceleration of expansion. This is actually a huge result.
One of the ideas of trying to explain it is to use the “cosmological constant,” which is something that Einstein actually introduced to his field equations to try to keep the universe the same size. He didn’t like the idea of a universe changing, so he just kind of cooked up this term and threw it into the equations to say, alright, well if it isn’t supposed to expand or contract, if I make this little mathematical adjustment, it stays the same size.
Hubble comes along about ten years later, and is observing galaxies and measuring their red shifts and their distances, and says wait a minute – no the universe is expanding. And actually we should really credit that to Georges Lemaître, who was able to interpret Hubble’s data to come up with the idea of what we now call the Big Bang.
So, the expansion’s happening – wait, it’s getting faster. And now the attempt is to try to understand how dark energy works. Right now, most of the evidence points to this idea that the expansion will continue in the space between galaxies. That the forces of gravity, and especially magnetism and the strong nuclear force that holds protons and neutrons together in the center of an atom, would be strong enough that dark energy is never going to be able to pull those objects apart.
However, there’s a possibility that it doesn’t work like that. There’s actually a little bit of experimental evidence right now that, although it’s not well-established, that there’s a little bit of a bias with certain experiments that dark energy may get stronger over time. And, if it does so, the distances won’t matter – that any object will be pulled apart. So first, you will see all galaxies recede from each other, as space starts to grow bigger and bigger, faster and faster. Then the galaxies will start to be pulled apart. Then star systems, then planets from their stars, then stars themselves, and then other objects that would typically be held together by the much stronger forces, the electromagnetic force objects held by that will be pulled apart, and then eventually, nuclei in atoms.
So if dark energy behaves so that it gets stronger and stronger over time, it will eventually overcome everything, and you’ll have a universe with nothing left. That’s the ‘Big Rip’ – if dark energy gets stronger and stronger over time, it will eventually overcome any forces of attraction, and then everything is torn apart.
You can find more information from Dr. Thad Szabo at his YouTube channel.
Astronauts use planes to prepare psychologically for the rigors of spaceflight, since they must constantly filter out information to proceed safely. Credit: Canadian Space Agency/Youtube (screenshot)
In between these sweet, sweet video shots of jets in the video above, you’ll find some wisdom about why it’s so important that astronauts climb into these planes for training. Turns out that flying has a lot to do with preparing for very quick-changing situations in spaceflight — whether it’s in a cockpit or in a spacesuit.
“Psychologically, being in an aircraft is very similar to being in a rocket because you are dependent on this machinery,” says astronaut David Saint-Jacques in this new Canadian Space Agency video.
“You are in an uncomfortable cockpit. You’re wearing a helmet, oxygen mask. There’s tens of dials in front of you. You have to monitor all that data; the radio, on many channels talking at the same time. You have to constantly filter out what is important and to make decisions that could have big impacts. You cannot press pause while you’re flying a jet.”
Saint-Jacques and fellow Canadian Jeremy Hansen took part in this video to mark the 110th anniversary of the Wright brothers’ first powered flight, which took place Dec. 17, 1903.
And there’s more to this video than jets — you can see astronauts participating in spacewalks and also the ongoing European Space Agency CAVES expedition series in Sardinia, Italy. There’s even a quick glimpse of the Snowbirds, a famous military flying demonstration team in Canada (which Hansen flew with earlier this year).
A T-38 plane parked in front of space shuttle Discovery in this undated photo taken by NASA astronaut Story Musgrave, who flew six times in space in the 1980s and 1990s.
