New Video Celebrates Saturn And The Day The Earth Smiled

The full mosaic from the Cassini imaging team of Saturn on July 19, 2013... the "Day the Earth Smiled"

Just to demonstrate how far-reaching that Saturn snapshot of Earth this year was, the Skopje Astronomical Society (from Macedonia) made a video celebrating “The Day The Earth Smiled”, when the Cassini spacecraft looked at Earth on July 19 and thousands of people made pictures and video showing what they were doing at that time.

Watch the video, then look at some stunning pictures of Saturn below the jump.

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 and its rings, as seen from above the planet by the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute. Assembled by Gordan Ugarkovic.

 

Mosaic of Saturn seen in eclipse in September 2006. Earth is the bright dot just inside the F ring at upper left. (CICLOPS/NASA/JPL-Caltech/SSI)
Mosaic of Saturn seen in eclipse in September 2006. Earth is the bright dot just inside the F ring at upper left. (CICLOPS/NASA/JPL-Caltech/SSI)
A false-color view of Saturn's storm, as seen through Cassini's wide-angle camera. The blue bands at the edge are Saturn's rings. Credit: NASA/JPL-Caltech/SSI
A false-color view of Saturn’s storm, as seen through Cassini’s wide-angle camera. The blue bands at the edge are Saturn’s rings. Credit: NASA/JPL-Caltech/SSI
Saturn, its rings and three moons are visible in this image from Cassini. Credit: NASA/ESA
Saturn, its rings and three moons are visible in this image from Cassini. Credit: NASA/ESA

 

A white storm in Saturn's northern hemisphere, as seen on Dec. 14, 2010. Credit: Anthony Wesley
A white storm in Saturn’s northern hemisphere, as seen on Dec. 14, 2010. Credit: Anthony Wesley

‘Tis the Season to Spot Jupiter: A Guide to the 2014 Opposition

Jupiter+moon imaged recently by Paul Cotton (@paultbird66) of Lincolnshire, England. Used with permission.

Lovers of planetary action rejoice; the king of the planets is returning to the evening skies.

One of the very first notable astronomical events for 2014 occurs on January 5th, when the planet Jupiter reaches opposition. You can already catch site of Jove in late December, rising in the east about an hour after local sunset. And while Venus will be dropping faster than the ball in Times Square on New Year’s Eve to the west in early 2014, Jupiter will begin to dominate the evening planetary action.

Orbiting the Sun once every 11.9 years, oppositions of Jupiter occur about once every 13 months or about 400 days, as the speedy Earth overtakes the gas giant on the inside track. This means that successive oppositions of the planet move roughly one astronomical constellation eastward. In fact, this year’s opposition is it’s northernmost in 12 years, occurring in the constellation Gemini. “Opposition” means that an outer planet is rising “opposite” to the setting Sun. As this opposition of Jupiter occurs just weeks after the southward solstice, Jupiter now lies in the direction that the Sun will occupy six months from now during the June Solstice.

This all means that Jupiter will ride high in the sky for northern hemisphere observers towards local midnight, a boon for astrophotographers looking to catch the planet high in the sky and out of the low horizon murk.

Jupiter will reach its most northern point for 2014 at a declination of +23.3 degrees on March 11th.

Jupiter also “skipped” 2013, in the sense that it was an “oppositionless year” for the giant world, as said 13 month span fell juuusst right, first on December 2nd, 2012 and then on January 5th, 2014. The next opposition of Jupiter will occur on… you guessed it… February 6th, 2015. The last year missing an opposition of Jupiter was 2001.

Jupiter and Io (arrowed) as imaged on the evening of December 22nd, 2013 by the author.
Jupiter and Io (arrowed) as imaged on the evening of December 22nd, 2013 by the author.

The exact timing of Jupiter’s opposition to the Sun in right ascension occurs at 21:00 UT/4:00 PM EST on January 5th. Its closest approach to Earth, however, arrives 27 hours prior, owing to a slight outward curvature of the approach of the two worlds. Jupiter will then lie about 4.21 astronomical units (AUs) or 629 million kilometres distant. This is just about down the middle of how close it can pass; Jupiter was just under 4 AUs distant in September 2010, and can pass almost 4.5 AUs from Earth, as happened in April 2005.

Jupiter also reaches a maximum brightness of magnitude -2.7 at opposition in 2014 and presents a disk 46.8” arc seconds wide. The coming month also provides a great chance to catch Jupiter in the daytime sky just before sunset, when the waxing gibbous Moon passes 4.9 degrees south of the planet on the evening of January 14th.

The Moon and Jupiter on the evening of January 14th shortly before sunset. (Created by the Author using Stellarium).
The Moon and Jupiter on the evening of January 14th shortly before sunset. (Created by the Author using Stellarium).

The very first thing you’ll notice looking at Jupiter, even at low power with binoculars or a telescope, is it retinue of moons. Though the planet has 67 discovered moons and counting, only the four large Galilean moons of Io, Europa, Ganymede and Callisto are readily apparent in a telescope. It’s fun to see orbital mechanics in action and watch them from night to night as they change position, just as Galileo first did over four centuries ago. This provided him with evidence that there is much more to universe than meets the eye, though we can consider ourselves fortunate that his proposal to name them the “Medician Moons” after his Medici benefactors was never widely adopted.

Crank up the magnification, and you’ll notice the large twin stripes of the northern and southern equatorial cloud belts crossing the disk of Jupiter. While the northern belt is stable, the southern belt has been known to submerge and disappear from view about every decade or so, as last happened in 2009-2010. You’ll also notice the Great Red Spot, a massive storm system over three times larger than the Earth that has been tracked by astronomers since it was recorded by Samuel Schwabe in 1831. The planet has the fastest rotation of any world in our solar system at 9.9 hours, and you’ll notice this swift rotation tracking Jupiter over the course of a single evening.

Transits and occultations of Jupiter’s moons are also always interesting to watch. The variation in the timing of these events at differing distances led Danish astronomer Ole Rømer to make the first attempts at measuring the speed of light in 1676.

Europa just beginning to cast a shadow off to one side shortly after opposition on January 8th at 7:30PM EST. (Created by the author using Stellarium).
Europa just beginning to cast a shadow off to one side shortly after opposition on January 8th at 7:30 PM EST. (Created by the author using Starry Night).

It’s interesting to note that Jupiter and its moons cast a shadow nearly straight back from our line of sight around opposition. You can see this change as the planet heads towards quadrature on April 1st, 2014 and Jupiter and its moons cast shadows off to one side. We’re also in the midst of a plane crossing, as the orbits of the Jovian moons appear edge-on to our line of sight in 2014 headed into early 2015. The outermost Jovian moon Callisto began a series of transits in 2013 and will continue to do so through 2014.

This is a great time to begin following all of the Jovian action, as we head into another exciting year of astronomy!

Hubble Looks but Finds No Trace of Comet ISON

Each of the four panels is a combination of two separate exposures made by the Hubble Space Telescope as it tracked Comet ISON's position. Had the comet been in any of these frames, it would have appeared as a small fuzzy glow or stellar point(s) in the center. The stars are trailed because the camera tracked the comet. Credit: NASA/ESA
Each of the four panels is a combination of two separate exposures made by the Hubble Space Telescope as it tracked Comet ISON's position. Had the comet been in any of these frames, it would have appeared as a small fuzzy glow or stellar point(s) in the center. The stars are trailed because the camera tracked the comet. Credit: NASA/ESA

On December 18, the Hubble Space Telescope slewed to Comet ISON’s expected position and found nothing down to the incredibly faint magnitude of 25. According to astronomer Hal Weaver, who planned the ISON search, that limit implies any remaining fragments would have to be smaller than about 500 feet (160 meters) in diameter. 

Composite photo of one of two Comet ISON locations photographed by the Hubble in a way that suppresses features not in the same place. No trace of the comet is visible. Credit: NASA/ESA
Composite photo of one of two Comet ISON locations photographed by the Hubble Space Telescope. No trace of the comet is visible. Credit: NASA/ESA

Nothing is visible in any of the images in the photo panel except trailed stars and galaxies, reflections and the occasional zap of a cosmic ray. After ISON was torn asunder by the sun, there existed the possibility that comet’s remains would follow a slightly different orbit. To make sure he was covered, Weaver photographed two separate comet positions, stacking several exposures together.

Comet ISON photographed at a second location. Again, nothing detected. Credit: NASA/ESA
Comet ISON photographed at a second location. Again, nothing detected. Credit: NASA/ESA

“The images have been combined so that features not at the same place in the various images are suppressed. Any comet fragments would show up more clearly in this composite, though stars still show up as faint streaks”, writes Zolt Lavay, author of the ISONblog at the Hubble site.

Again, nothing shows up in these either. While no one can say that ISON has completely disappeared, we now know that at the very least it’s broken into pieces too small for even Hubble to see. What was once a beautiful sight in binoculars has expanded into a vast cloud of gas and dust thinner than Ebenezer Scrooge’s gruel.

Rare White Dwarf Systems Do A Doubletake

For those of us who remain forever fascinated by astronomy, nothing could spark our imaginations more than a cosmic curiosity. In this case, the unusual object is a star cataloged as AM Canum Venaticorum (AM CVn) located in the constellation of Canes Venatici. What makes this dual star system of interest? Try the fact that the pair revolve completely around each other in a brief 18 minutes. What’s more, they are the stuff of which Einstein dreamed… creators of ripples in space-time known as gravitational waves.

Like other astronomical anomalies, AM CVn became the forerunner of a new class of stellar objects. It is a white dwarf, a sun-like star which has exhausted its fuel and collapsed to around the size of Earth. Yet it also has a white dwarf companion – a very compact orb which is delivering matter to its neighbor. AM Canum Venaticorum is not alone, however. There are similar systems where the stellar pairs complete their rotations in about an hour and even as rapidly as five minutes! Can you imagine the crackling amount of energy a system like this produces?!

Even though we have been aware of systems like AM CVn for almost five decades, no one is quite sure how they originate. Now, through the use of X-ray and optical observations, astronomers are taking a look at newly evolved double stars systems which one day might become a dueling duo dwarf. Heading their list are two binary systems, J0751 and J1741. These candidates were observed in the X-ray part of the electromagnetic spectrum by NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton telescope. In addition, observations at optical wavelengths were made using the McDonald Observatory’s 2.1-meter telescope in Texas, and the Mt. John Observatory 1.0-meter telescope in New Zealand.

dual_dwarf“The artist’s illustration depicts what these systems are like now and what may happen to them in the future. The top panel shows the current state of the binary that contains one white dwarf (on the right) with about one-fifth the mass of the Sun and another much heavier and more compact white dwarf about five or more times as massive (unlike Sun-like stars, heavier white dwarfs are smaller).” says the Chandra X-ray Observatory news release.

What’s happening here? As the pair of white dwarf stars whip around each other, they are releasing gravitational waves which constrict the orbit. In time, the heavier, diminutive dwarf will begin stripping material from its lighter, larger companion (as seen in the middle panel). This material consumption will continue for perhaps a 100 million years, or until the collected matter reaches a critical mass and releases a thermonuclear explosion.

Another scenario is the thermonuclear explosion could annihilate the larger white dwarf completely in what astronomers call a Type Ia supernova. An event like this is well-known and gives a measurement in standard candles for cosmic distance. However, chances are better the explosion will happen on the surface of the star – an event known as .Ia supernovae. While .Ia supernovae events have been recorded in other galaxies, J0751 and J1741 are the first binary stars which have the potential to erupt in .Ia supernovae.

“The optical observations were critical in identifying the two white dwarfs in these systems and ascertaining their masses. The X-ray observations were needed to rule out the possibility that J0751 and J1741 contained neutron stars.” says the Chandra team. “A neutron star – which would disqualify it from being a possible parent to an AM CVn system – would give off strong X-ray emission due to its magnetic field and rapid rotation. Neither Chandra nor XMM-Newton detected any X-rays from these systems.”

Are AM CVn systems riding the gravitational wave? While astronomers haven’t been able to detect them yet, these new observations are highly important because equipment to verify their presences is currently being developed. It won’t be long until we can see the wave and have a whole new way of looking at the Universe!

Original Story Source: Chandra Observatory News Release.

Celestial Laser Show? Nope, These Are Trails Showing Off Star Colors

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.

Source: European Southern Observatory

Is the Solar System Really a Vortex?

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.

Reposted with permission from Rhys Taylor’s blog, Physicists (Formerly) of the Caribbean:

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)
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:

Credit : Science Minus Details
Credit : Science Minus Details

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)
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.

What Is The Big Rip?

What Is The Big Rip?

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.

‘You Cannot Press Pause While You’re Flying A Jet’: Why Planes Help Astronauts Prepare For Space

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).

For more information on the T-38s used for astronaut training, check out this NASA link.

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.
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.

When Science is Art: a New Map of Wind Patterns

Blah.

A new map of wind patterns is so visually stunning it’s easily mistaken for art.

This interactive visualization of wind patterns — modeled from the U.S. National Weather Service’s Global Forecast System database — provides nearly current weather conditions on the global scale. And it’s beautiful.

In an interactive form, this data set allows the user to move the globe around (simply drag with your mouse) and zoom in and out (use your scroll wheel). After a few seconds the colors appear in snaking lines, depicting wind patterns at varying speeds. Gentle breezes are thin lines of green, strong winds are light streaks of yellow, and the strongest current are thick lines of red and purple.

A screenshot of the Earth's north pole at 5,500 meters.
A screen capture of the Earth’s north pole at 5,500 meters. The thick purple line is the polar jet stream.

Adjustable parameters also allow the user to view the wind patterns at various heights in the atmosphere, from 100 meters (noted as 1000 hPa in the program) to 26,500 meters (10 hPa) above the Earth’s surface. Simply click on the word “earth” in the lower left-hand corner of the web browser.

At the surface the map is a mirage of blue and green — with fairly gentle wind patterns in green. Circling patterns over the oceans are cyclones. They rotate clockwise over the southern Indian ocean and counter-clockwise over the northern Pacific ocean. If you turn your eyes toward land, you can compare the light summer winds across Australia with the swirling gusts off the northeast coast of Japan.

But you can also graze the jet streams, where thick bands of purple and red dance among the less violent green and yellow streaks. The wavy polar jet stream is entering the U.S. near Seattle, dropping southward near the Rocky Mountains, and then turning northward again just beyond the Great Lakes.  It creates a temperature boundary, where south of the jet stream is warm and north of the jet stream is cold.

Users can view seven different altitudes using eight different map projections. This surprising new look at our own world is stunning in its artistic and educative beauty.

Comet Tourism Flight Trades ISON For Lovejoy

Bright, brighter, brightest: these views of Comet ISON after its closest approach to the sun Nov. 28 show that a small part of the nucleus may have survived the comet's close encounter with the sun. Images from the Solar and Heliospheric Observatory. Credit: ESA/NASA/SOHO/GSFC

When Comet ISON entered its zombie stage a few weeks ago, the effects were not only felt in the astronomical community, but also on astronomy tourists as the comet faded from the view of amateurs.

German company “Eclipse-Reisen” (Eclipse Travel) had to make a last-minute change in plans for a Dec. 8 flight for some 75 tourists planning to observe ISON, which morphed into a travelling dust blob after skimming too close to the sun in late November. Fortunately, Comet Lovejoy is still a strong astronomical object, providing an alternate thing to watch.

“Most of the passengers weren’t disappointed. They were more excited to see something new. Only a few journalists cancelled the flight. All photographers and experts fully understood the situation,” a statement from Air Partner to Universe Today said. (The spokespeople were German-speaking, requiring a translation by another party.)

Negative image taken Nov. 14 of Lovejoy's nucleus and dust fan. Credit: Dr. P. Clay Sherrod
Negative image taken Nov. 14 of Lovejoy’s nucleus and dust fan. Credit: Dr. P. Clay Sherrod

“Comet Lovejoy is no less spectacular and still very exciting like ISON and they were pleased to see it, actually. Although Lovejoy is less bright than ISON, it is weaker by four size classes, its tail is smaller and pale and Lovejoy flies farther past the Earth and the Sun.”

The company had to ask for permission to alter its flight path, and inform the passengers of the last-minute change, all in a few days, but officials added that the flight went off without a hitch.

You can read more information about the company (in German) on its website. In 2014, it plans to run a flight to observe auroras over Iceland, among others.