Much to learn about Pluto's surface we have. (Screenshot)
Of course you do! (Who doesn’t?) And so here’s a wonderful tour of our Solar System to provide you with just the type of space you need.
A 3D animation project by Australian video artist Shane Gehlert, I Need Some Space takes us from low-Earth orbit to the Moon and Sun and then through the lineup of planets in the Solar System, using images and models from NASA to accurately depict their unique appearances. Along the way we’ll get some basic info on the planets, select moons, and a few of the various spacecraft that have visited (or are visiting) each world. Set to an intriguing string score by The Zephyr Quartet (of which Shane’s sister Belinda is a member) I Need Some Space is a mesmerizing 6-minute voyage for any space fan — myself very included.
I particularly like the “ghostly” look of Pluto, reminding us that we still have another year and a half before New Horizons reveals its true appearance to us.
Enjoy! (As with most videos, full-screening and HD-ing are strongly suggested.)
A solar halo seen over Klerksdorp, South Africa. Credit:
Daniël Engelbrecht
Fresh off seeing a solar eclipse on Sunday, people across the southern parts of Africa witnessed another solar spectacle today, a sun halo. “It was so beautiful, everyone was taking pictures and sharing them on Facebook,” said Daniël Engelbrecht from Klerksdorp, South Africa, sending in his picture to Universe Today via email.
These halos are quite the sight to see, but unlike an eclipse, they can’t be predicted. Conditions in the atmosphere have to be just right, with moisture or ice crystals creating a “rainbow” effect around the Sun. Sometimes the halos surround the Sun completely, other times, they appear as arcs around the Sun creating what is known as sundogs. Basically, sunlight is reflecting off moisture in the atmosphere.
Ice crystals in Earth’s atmosphere can also cause rings around the Moon, and moondogs(as well as sundogs) and even Venus pillars. News reports indicate sun halos were seen just a few days ago in Africa as well, on Nov. 1, 2013.
A few other people sent in images from their phones, too of today’s sun halo:
Image of a Sun halo seen over Botswana, Southern Africa at 11:08 am local time on Nov, 6, 2013. Taken with an iPhone. Credit: Belleminah K Chitonho.Image of a Sun halo taken at 12:10 on Nov. 6, 2013, in northwest South Africa, in Mmabotho with a blackberry phone. Credit: Vanessa Lucher.
Our Sun isn’t just a terrifying ball of white hot plasma, it’s actually a lot more complex. It’s got layers. And today, we’re going to peel back those layers and learn about the Sun – from the inside out.
We record Astronomy Cast as a live Google+ Hangout on Air every Monday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch here on Universe Today or from the Astronomy Cast Google+ page.
It’s amazing to think that for the majority of human history, we had almost no understanding about the Sun. We didn’t know what it was made of, how it formed, or how it produced energy. We didn’t know how big it was, and we didn’t know how far away it was.
We orbit the Sun at a distance of about 150 million kilometers. This number is actually an average, since we follow an elliptical path. At its closest point, the Earth gets to 147 million km, and at its most distant point, it’s 152 million km.
Distances in the Solar System are so vast that astronomers use this distance as a standard for measurement, and so the average distance from the Earth to the Sun is called an astronomical unit. Instead of saying that Pluto is 5.87 billion kilometers away from the Sun, astronomers say that it’s 39 astronomical units, or AUs.
You might be surprised to know that the distance from the Sun to the Earth was only determined within the last few hundred years. There were just too many variables. If astronomers knew how big it was, they could figure out how far away it was, or vice versa, but both of these numbers were mysteries.
Ancient astronomers, especially the Greeks, tried estimating the distance to the Sun in several different ways: measuring the length of shadows on Earth, or comparing the size of the Moon and its orbit to the Sun. Unfortunately, their estimates were off at least by a factor of 10.
The key to figuring out the distance to the Sun came from observing Venus as it passed directly in front of the Sun. This rare event, known as a Transit of Venus, happens only twice every 108 years. Once devised, the best opportunities for taking this precise measurement came during the Venus transits of 1761 and 1769. Astronomers were dispatched to remote corners of the globe to observe the precise moment when Venus began to move in front of the Sun, and when it had moved completely across the surface.
By comparing these measurements, astronomers could use geometry to calculate exactly how far away the Sun is. Their initial calculations put the distance at 24,000 times the radius of the Earth. Not bad considering our modern measurement of 23,455 times the radius of the Earth.
Modern astronomers can use radar and laser pulses to calculate the distance to objects in the Solar System. For example, they fire an intense beam of radio waves at a distant object, like Mercury, and then calculate how long it takes for the waves to bounce off the planet and return to Earth. Since the speed of light is well known, the return travel time tells you how far away the planet is.
Astronomy has truly helped us find our place in the Universe. It nice to be living in a time when many of these big mysteries have been solved. I don’t know about you, but I can’t wait to see what’s around the corner of the next discovery.
So much space news, so little time. We had a great Weekly Space Hangout with several of our familiar space journalist friends. No huge stories, but lots of interesting tidbits, about asteroid protection, balloon trips to the edge of space, and the discovery of the furthest galaxy.
Host: Fraser Cain
Panel: Alan Boyle, Amy Shira Teitel, David Dickinson, Nancy Atkinson, Elizabeth Howell
We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page.
Here’s your amazing oh-my-gosh-space-is-so-cool video of the day — a “canyon of fire” forming on the Sun after the liftoff and detachment of an enormous filament on September 29-30. A new video, created from images captured by the Solar Dynamics Observatory (SDO) and assembled by NASA’s Goddard Space Flight Center, shows the entire dramatic event unfolding in all its mesmerizing magnetic glory.
Watch it below:
Solarrific! (And I highly suggest full-screening it in HD.) That filament was 200,000 miles long, and the rift that formed afterwards was well over a dozen Earths wide!
Captured in various wavelengths of light by SDO’s Atmospheric Imaging Assembly (AIA) the video shows the solar schism in different layers of the Sun’s corona, which varies greatly in temperature at different altitudes.
According to the description from Karen Fox at GSFC:
“The red images shown in the movie help highlight plasma at temperatures of 90,000° F and are good for observing filaments as they form and erupt. The yellow images, showing temperatures at 1,000,000° F, are useful for observing material coursing along the sun’s magnetic field lines, seen in the movie as an arcade of loops across the area of the eruption. The browner images at the beginning of the movie show material at temperatures of 1,800,000° F, and it is here where the canyon of fire imagery is most obvious.”
Now, there’s not really any “fire” on the Sun — that’s just an illustrative term. What we’re actually seeing here is plasma contained by powerful magnetic fields that constantly twist and churn across the Sun’s surface and well up from its interior. The Sun is boiling with magnetic fields, and when particularly large ones erupt from deep below its surface we get the features we see as sunspots, filaments, and prominences.
When those fields break, the plasma they contained gets blasted out into space as coronal mass ejections… and this is what typically happens when one hits Earth. (But it could be much worse.)
This question comes from Andrew Bumford and Steven Stormont.
In a previous episode I’ve talked about how the entire Solar System collapsed down from a cloud of hydrogen and helium left over from the Big Bang. And yet, we stand here on planet Earth, with all its water. So, how did that H20 get to our planet? The hydrogen came from the solar nebula, but where did the oxygen come from?
Here’s the amazing part.
The oxygen came from stars that lived and died before our Sun was even born. When those stars puffed out their final breaths of oxygen, carbon and other “metals”, they seeded new nebulae with the raw material for new worlds. We owe our very existence to the dead stars that came before.
When our Sun dies, it’ll give up some of its heavier elements to the next generation of stars. So, mix hydrogen together with this donated oxygen, and you’ll get H20. It doesn’t take any special process or encouragement, when those two elements come together, water is the result.
But how did it get from being spread across the early Solar System to concentrating here on Earth, and filling up our oceans, lakes and rivers? The exact mechanism is a mystery. Astronomers don’t know for sure, but there are a few theories:
Idea #1: impacts. Take a look at the craters on the Moon and you’ll see that the Solar System was a busy place, long ago. Approximately 3.8 to 4.1 billion years ago was the Late Heavy Bombardment period, when the entire inner Solar System was pummeled by asteroids. The surfaces of the planets and their moons were heated to molten slag because of the non-stop impacts. These impactors could have been comets or asteroids.
Comets are 80% water, and would deliver vast amounts of water to Earth, but they’re also volatile, and would have a difficult time surviving the harsh radiation of the young Sun. Asteroids have a lower ratio of water, but they could protect that water a little better, delivering less with each catastrophic impact.
A false-color, visible-light image of Comet ISON taken with Hubble’s Wide Field Camera 3. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
Astronomers have also found many hybrid objects which contain large amounts of both rock and water. It’s hard to classify them either way.
Idea #2 is that large amounts of water just came directly from the solar nebula. As we orbited around the young Sun, it passed through the water-rich material in the nebula and scooped it up. Gravitational interactions between the planets would have transferred material around the Solar System, and it would have added to the Earth’s volume of water over hundreds of millions of years.
Of course, it’s entirely possible that the answer is “all of the above”. Asteroids and comets and the early solar nebula all delivered water to the Earth. Where did the Earth’s water come from? Astronomers don’t know for sure. But I’m sure glad the water is here; life here wouldn’t exist without it.
A powerful X-class solar flare erupting on the sun on July 6, 2012 photographed by the Solar Dynamics Observers. Credit: NASA
Life has existed on Earth for billions of years, appearing shortly after the planet had cooled and liquid water became available.
From the first bacteria to the amazingly complex animals we see today, life has colonized every corner of our planet.
As you know, our Sun has a limited lifespan.
Over the next 5 billion years, it will burn the last of its hydrogen, bloat up as a red giant and consume Mercury and Venus.
This would be totally disastrous for local flora and fauna, but all life on the surface of the Earth will already be long gone.
In fact, we have less than a billion years to enjoy the surface of our planet before it becomes inhospitable.
Because our Sun… is heating up.
You can’t feel it over the course of a human lifetime, but over hundreds of millions of years, the amount of radiation pouring out of the Sun will grow.
This will heat the surface of our planet to the point that the oceans boil.
At the core of the Sun, the high temperatures and pressures convert hydrogen into helium. For every tonne of material the Sun converts, it shrinks a bit making the Sun denser, and a little hotter.
Over the course of the next billion years or so, the amount of energy the Earth receives from the Sun will increase by about 10%. Which doesn’t sound like much, but it means a greenhouse effect of epic proportions.
A TerraSAR-X stripmap image of icebergs.Whatever is left of the ice caps will melt, and the water itself will boil away, leaving the planet dry and parched. Water vapor is a powerful greenhouse gas, this will drive the temperatures even hotter.
Plate tectonics will shut down, and all the carbon will be stripped from the atmosphere.
It’ll be bad.
As temperatures rise, complex lifeforms will find life on Earth less hospitable. It will seem as if evolution is running in reverse, as plants and animals die off, leaving the invertebrates and eventually just microbial life.
This rise in temperature will be the end of life on the surface of Earth as we know it.
Still, there are reserves of water deep underground which will continue to protect microbial life for billions of years.
Perhaps they’ll experience that final baking when the Sun does reach the end of its life.
Even a few hundred million years is an incomprehensible amount of time compared to the age of our civilization.
If humanity does survive well into the future, is there anything we could do about this problem?
As the Sun heats up, making Earth inhospitable, it heats up the rest of the Solar System too. Frozen worlds in the Solar System will melt, becoming more habitable.
Encaladus, a moon of Saturn, as shown in this Voyager 1 image. Credit: NASAIt’s possible that future civilizations could relocate to the asteroid belt, or the moons of Saturn. We could try something even more radical: move the Earth.
By carefully steering asteroids so they barely miss us, an advanced civilization could distort the Earth’s orbit, relocating our planet further from the Sun.
As the Sun heats up, our planet would be continuously repositioned so the surface temperature stays roughly the same. Of course, this would be tricky business. Make the wrong move, and you’re facing the frigid cold of the outer Solar System.
So there’s no need to panic. Life here has a few hundred million years left; a billion, tops. But if we want to continue on for billions of years, we’ll want to add solar heating to our growing list of big problems.
A detailed image of the Sun's photosphere taken near Paris, France, with an added detail: at 747 airplane. Credit and copyright: Sebastien Lebrigand.
Watch out! That plane is heading straight for a sunspot! Astrophotographer Sebastien Lebrigand was taking some detailed images of the Sun and when something zoomed into his field of view, a 737 airplane. He was about 70 km outside of Paris France when he took this image, using a CANON EOS 500D camera and a 114 mm refractor telescope with a 1200mm focal length. Exposure: 1 / 3200s in 100 iso. The image was taken on September 5, 2013.
Nice catch!
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The Solar System: it’s our home in space, the neighborhood that we all grew up in and where — unless we figure out a way to get somewhere else — all of our kids and grandkids and great-great-great-great-times-infinity-great-grandkids will grow up too. That is, of course, until the Sun swells up and roasts Earth and all the other inner planets to a dry crunchy crisp before going into a multi-billion year retirement as a white dwarf.
But until then it’s a pretty nice place to call home, if I may say so myself.
Edu-film designer Philipp Dettmer and his team have put together a wonderful little animation explaining the basic structure of the Solar System using bright, colorful graphics and simple shapes to illustrate the key points of our cosmic neighborhood. It won’t teach you everything you’ll ever need to know about the planets and it’s not advisable to use it as a navigation guide, but it is fun to watch and well-constructed, with nice animation by Stephan Rether and narration by Steve Taylor.
Check out the full video below:
“Through information design, concepts can be made easy and accessible when presented in a short, understandable edu-film or perhaps an infographic. Whether explaining the vastness of the universe or the tiniest building blocks of life – all information can be presented in a way that everyone understands. Regardless of prior knowledge.”
– Philipp Dettmer
(And come on, admit it… you learned something new from this!)
