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The Earth’s mantle, just a few dozen kilometers beneath your feet is incredibly hot. The high temperatures cause rocks to melt and form magma that collects in vast chambers beneath the Earth’s surface. Since it’s lighter than the surrounding rock, this magma makes its way up through weaknesses in the rock until it reaches the Earth’s surface erupting as a volcano. The spot where it erupts is known as a volcanic vent.
A volcanic vent is that spot in the Earth’s crust where gases, molten rock, lava and rocks erupt.
Volcanic vents can be at the top of some of the largest volcanoes on Earth, like Hawaii’s Mauna Kea, or they can be openings in the Earth’s crust down at the bottom of the ocean. The shape of the volcanic vent can sometimes define whether the volcano is explosive or not. A fissure vent can be a few meters wide and many kilometers long. Lava pours out of fissure vents, creating lava channels, but they don’t usually explode.
The tall familiar cone shaped stratovolcano (like Mount Fuji) can have one volcanic vent at the top of the mountain, but also have many smaller volcanic vents across the flanks of the volcano where smaller eruptions occur. These large volcanoes can erupt explosively, posing a great danger to people living nearby.
In the case of very viscous (or thick) lava, you can get a slow buildup of material into a lava dome. The lava is so thick that it doesn’t move very far from the volcanic vent. Instead it just plugs it up, forming a bulging dome of material. These can also explode violently.
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What if there were a device that could provide an interactive experience for city dwellers to be able to gaze at the wonders of our night sky, while also providing a beautiful sculpture for landscapes, parks and gardens? Two inventors who specialize in digital interactive design are working on just such a device, and they call it the Humble Telescope. “We like to bring new experiences to people by finding innovative ways to use technologies,” said Steven Mieszelewicz president of a company called ENESS, based in Melbourne, Australia. “I think everyone at some stage in their lives loves to learn about space, but there’s the problem that many people can’t see the night sky without traveling an hour outside the city. We want to help people be able to marvel at the universe around them.”
ENESS is designing the Humble Telescope as an interactive civic sculpture that not only brings the wonders of space down to earth, but also encourages people to learn more about the universe and perhaps appreciate our own world a little more. The telescope works by using 3-D simulation software that incorporates actual images of space from NASA, along with GPS technology. When the user points the telescope in any direction, no matter what location the telescope if located on Earth, the Humble Telescope will show what exists in that area of the sky. It works during the day or night, cloudy or clear.
Watch the video below to see how it might work:
Mieszelewicz and his partner Nimrod Weis design 3D software applications and animations such as interactive maps, as well as creating interactive public art installations and environmental design concepts.
“We’ve been living and breathing interactivity, creating new experiences, and dealing with technology,” said Meiszelewicz, “We love the idea of enhancing active environments and we also feel that artwork should be accessible and relevant to everyone. And we wanted to combine all that to create something to make space and astronomy relevant to everyone.”
They also wanted to do something for the International Year of Astronomy, and hope to have the Humble Telescope ready by October 2009.
Mieszelewicz noted that they came up with the name before they heard about the “Humble Space Telescope,” the small Canadian telescope that was launched into space in 2003. (The official name of the telescope is MOST or Microvariability and Oscillations of STars, but it’s affectionately known as the Humble, a takeoff on the larger Hubble space telescope.) “We liked the name “Humble” because we wanted to do something that makes us more humble and more conscious about what we’re doing to our planet and how small we really are. We saw the name as being a good message for people.” How the Humble Telescope might look in an urban setting. Credit: ENESS
The company is fairly far along with the design of the interior workings of the telescope. “We have put a considerable amount of time into how everything will be achieved,” said Mieszelewicz. “We already have written software on how to map out the solar system, so it’s not a massive hurdle for us.” But they are also looking at teaming up with a technology institute in Japan who has developed some open source software that will be helpful in the design.
The exterior structure however, is still being considered. “We’re discussing different ideas and the considerations for the design, to make it foolproof in a way, so it’s safe for public use, where people can’t hurt themselves while using it.” Mieszelewicz said. “We wanted it to be a city sculpture because it’s a very positive sort of image, being able to look up at the stars. We like the idea that people can get their hands on it and move its position – but it won’t be able to be wildly swung around, and people will need to take a patient role in using it.” Mieszelewicz said they want to emphasize the observation part rather than that you can swing around on it like a toy.
Mieszelewicz thinks the Humble Telescope will likely look like the promo images seen here, but they are still looking at how people will be able to move it. “We want to give it a very mechanical feel, maybe with a wheel or something that will give it rotation and another wheel will to move the angle,” he said.
Where would you be able to find a Humble Telescope? Mieszelewicz said they are still deciding whether to have the telescopes at permanent locations, or if they would travel city to city, like a traveling exhibition.
They’ve received inquiries about the telescope sculptures from several cities around the world, and also from the Space Telescope Science Institute in Baltimore, home of the Hubble Space Telescope, which might be interested in having one in the gardens on the Institute’s property.
Mieszelewicz said they haven’t yet determined the cost of the telescopes, and costs would be dependent on whether the sculpture was permanent or was a touring model that might stay a a location for 3-12 months before moving to another city. He said they received considerable interest in the touring idea, so that would change the way they would market and price the telescopes.
See ENESS’s website for more information on the company and the Humble Telescope.
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Here on the surface of the Earth, the ground is relatively cool. But as you descend into the Earth, things get hotter and hotter, eventually reaching hundreds or even thousands of degrees C. The hot temperatures inside the Earth’s mantle can melt rock; this is magma.
Magma collects in large pools underneath the surface of the Earth in vast magma chambers. Because it’s lighter than the surrounding rock, it makes its way upwards through weaknesses in the Earth’s crust until it reaches the surface. When the magma reaches the surface, it can extrude as lava, or even erupt violently throwing up ash and even rocks.
The temperature of magma can range between 700 and 1300 degrees Celsius depending on the chemical composition of the rocks. You might be surprised to know that the interior of the Earth is a solid, not liquid. The magma only forms in regions where the temperatures are high and the pressures are low; typically within a few kilometers of the surface of the Earth.
The melted magma comes from rocks under huge temperatures and pressures. Most rocks are a collection of different minerals, which can have different melting points. When one part of the rock starts to melt, the rest remains solid. This causes the melted material to squeeze out in small globules. These globules collect together to fill up the magma chamber underneath a volcano.
All igneous rock found on the Earth was originally formed as magma.
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All lava isn’t the same. There can be tremendous differences in the viscosity (thickness), temperature and chemical composition of lava. The least viscous (least syrupy) lava is known as pahoehoe, and it can flow for many kilometers away from the source of a volcanic eruption. One of the longest flows ever recorded was an eruption from Mauna Loa that was 47 km long.
In fact, when you think of an erupting volcano, with vast rivers of lava flowing out, that’s pahoehoe – it’s a Hawaiian term. It’s a basaltic lava that once hardened has a smooth, ropy surface. In fact, it can have such beautiful shapes that people call it lava sculptures. The strange shapes happen because the front of the lava flow forms a thin shell, and then blobs continually break out from the crust. These cool and then more lava breaks out from that.
Once the pahoehoe lava flows finally cool, the resulting rock is incredibly smooth; they’re smooth down to a scale of just a few millimeters. This is very different to aa lava flows, which feel like jagged glass once they harden. Pahoehoe is smooth and nice to walk across, while a’a lava will ravage your shoes and give you a nasty cut if you happen to fall on it.
We have written many articles about the Earth for Universe Today. Here’s an article about all the different types of lava, and here’s an article about a’a lava.
Thurston Lava Tube on the Big Island of Hawaii. Credit: P. Mouginis-Mark, LPI
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If you’ve ever visited the Big Island of Hawaii, you’ll get a chance to see one of nature’s most amazing formations: a lava tube. Lava tubes are natural tunnels where lava flows underneath the ground, sometimes for many kilometers. After the eruption is over, you can be left with a long empty tunnel that seems almost man made.
A lava tube happens when low viscosity lava forms a continuous hard crust that gets thicker and thicker, while lava is flowing inside it. Eventually the lava forms a thick hard crust above, but low viscosity lava continues to flow inside. In fact, the thick sides act like insulation to keep the inner lava hot and molten. When the eruption finally ends, the lava flows out of the tube, emptying it out.
Lava tubes can be many meters wide, and typically run several meters below the surface. One tube on Mauna Loa starts at the eruption point and then flows about 50 km to the ocean. Inside the tube there can be various formations, like lava stalactites known as lavacicles (named after icicles). You can also get pillars that stretch from the top to the bottom of the lava tube.
Some of the most well known lava tubes are Thurston Lava Tube in Hawaii Volcanoes National Park, and Lava Beds National Monument in Northern California.
We have written many articles about the Earth for Universe Today. Here’s an article about different types of lava. And here’s an article about lava flows in general.
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Volcanoes can erupt with ash and rocks, but one of the most common images are great rivers of molten lava streaming from the volcano’s vent. This molten lava is made of rock, heated to more than 700 degrees C inside the Earth. Inside the Earth, it’s called magma, but when it reaches the surface, scientists call it molten lava.
You might be surprised to know that there are many different kinds of molten lava, depending on the chemical structure of the rock itself. This structure defines how viscous the lava is; how easily it flows. Think of the difference between water and syrup. Syrup is very viscous. Molten lava can be 100,000 times as viscous as water.
The least viscous lava can flow great distances from a volcano during an eruption, sometimes traveling many kilometers, destroying everything in its path. Volcanoes with this kind of molten lava are called shield volcanoes and they take on a very wide, low appearance, since the lava can flow so far. Other types of lava are thicker, or more viscous. It only travels a short distance in thick, crumbling flows. And some molten lava is so thick that it doesn’t really flow at all. It just piles up around the volcanic vent.
When it first erupts from the volcanic vent, molten lava can be anywhere from 700 to 1200 degrees Celsius. The thickness (or viscosity) defines how the lava behaves as it leaves the vent, and how far it can flow downhill before cooling and solidifying. Even though it looks solid, a lava flow can remain hot for weeks and even years before it finally cools.
As scary as it looks, molten lava really isn’t that dangerous for people. You can easily outrun a lava flow. Of course, buildings and trees aren’t so lucky since they’re attached to the ground.
Professor Stephen Hawking in 2006. Credit: Wikipedia
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Physicist/mathematician Stephen Hawking has improved after spending the night at a hospital near his home in Cambridge, England, and the 67-year-old’s condition was described as “comfortable.” Hawking’s first wife, Jane, was quoted that she believed his illness was no longer life-threatening. A spokesperson for Cambridge University, where Prof Hawking holds the post of Lucasian Professor of Mathematics, said that he would be kept in hospital for observation. “He is comfortable and his family is looking forward to him making a full recovery,” said Gregory Hayman. “He has had a good night but will be kept in at Addenbrooke’s Hospital for observation. He is showing signs of improvement.”
Hawking, best known as the author of the best-selling science book A Brief History of Time, was taken to hospital two days after returning from a tour of engagements in the United States. Cambridge University took the unprecedented step of commenting on Hawking’s condition, describing him as “very ill”.
Hawking suffers from ALS (amyotrophic lateral sclerosis), an incurable degenerative disorder also known as Lou Gehrig’s disease. He is wheelchair bound and only able to speak with the help of a voice synthesiser.
He was diagnosed with the muscle-wasting disease at the age of 21, which has gradually robbed him of his voice and movement in his limbs.
At the time of being diagnosed with the disease, he was told that he could expect to live for two years but has become one of the oldest-known survivors of the disease, after more than 40 years.
To commemorate the Hubble Space Telescope’s 19 years in space, the ESA and NASA have released an image of a celestial celebration.
Two members in this trio of galaxies are apparently engaged in a gravitational tug-o-war, giving rise to a bright streamer of newborn blue stars that stretches 100,000 light years across.
Constellation region near ARP 194. Credit: NASA, ESA Z. Levay and A. Fujii
Resembling a pair of owl’s eyes, the two nuclei of the colliding galaxies can be seen in the process of merging at the upper left. The bizarre blue bridge of material extending out from the northern component looks as if it connects to a third galaxy but in reality this galaxy is in the background, and not connected at all.
Hubble’s sharp view allows astronomers to try and sort out visually which are the foreground and background objects when galaxies, superficially, appear to overlap.
The blue “fountain” is the most striking feature of this galaxy troupe and it contains complexes of super star clusters that may have as many as dozens of individual young star clusters in them. It formed as a result of the interactions among the galaxies in the northern component of Arp 194. The gravitational forces involved in a galaxy interaction can enhance the star formation rate and give rise to brilliant bursts of star formation in merging systems.
The stream of material lies in front of the southern component of Arp 194, as shown by the dust that is silhouetted around the star cluster complexes.
The details of the interactions among the multiple galaxies that make up Arp 194 are complex. The system was most likely disrupted by a previous collision or close encounter. The shapes of all the galaxies involved have been distorted by their gravitational interactions with one another.
Arp 194, located in the constellation of Cepheus, resides approximately 600 million light-years away from Earth. Arp 194 is one of thousands of interacting and merging galaxies known in our nearby Universe.
The observations were taken in January 2009 with the Wide Field Planetary Camera 2. Blue, green and red filters were composited together to form the galaxy interaction image.
This picture was issued to celebrate the 19th anniversary of the launch of the Hubble Space Telescope aboard the space shuttle Discovery in 1990. In the past 19 years, Hubble has made more than 880,000 observations and snapped over 570,000 images of 29,000 celestial objects.
Image credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA)
Astronomers are announcing a newly discovered exoplanet in the habitable zone of its star, and another one — in the same system — that’s just twice the size of Earth.
The Gliese 581 planetary system now has four known planets, with masses of about 1.9 (planet e, left in the foreground), 16 (planet b, nearest to the star), 5 (planet c, center), and 7 Earth-masses (planet d, with the bluish colour).
This diagram shows the distances of the planets in the Solar System (upper row) and in the Gliese 581 system (lower row), from their respective stars (left). The habitable zone is indicated as the blue area, showing that Gliese 581 d is located inside the habitable zone around its low-mass red star. Based on a diagram by Franck Selsis, Univ. of Bordeaux.
Michel Mayor, a well-known exoplanet researcher from the Geneva Observatory, announced the find today. The planet, “e,” in the famous system Gliese 581, is only about twice the mass of our Earth. The team also refined the orbit of the planet Gliese 581 d, first discovered in 2007, placing it well within the habitable zone, where liquid water oceans could exist.
Both planets were discovered by the so-called “wobble method,” using the HARPS spectrograph attached to the 3.6-meter (11.8-foot) ESO telescope at La Silla, Chile.
The gentle pull of an exoplanet as it orbits the host star introduces a tiny wobble in the star’s motion that can just be detected on Earth with today’s most sophisticated technology. Low-mass red dwarf stars such as Gliese 581 are potentially fruitful hunting grounds for low-mass exoplanets in the habitable zone. Such cool stars are relatively faint and their habitable zones lie close in, where the gravitational tug of any orbiting planet found there would be stronger, making the telltale wobble more pronounced.
Many more exoplanets have been discovered using the transit method being employed by NASA’s Kepler mission: as planets pass between their host stars and Earth, they cause an observable, periodic dimming.
Planet Gliese 581 e orbits its host star – located only 20.5 light-years away in the constellation Libra (“the Scales”) — in just 3.15 days.
“With only 1.9 Earth-masses, it is the least massive exoplanet ever detected and is, very likely, a rocky planet,” says co-author Xavier Bonfils from Grenoble Observatory. Being so close to its host star, the planet e is not in the habitable zone. But another planet in this system appears to be.
“Gliese 581 d is probably too massive to be made only of rocky material, but we can speculate that it is an icy planet that has migrated closer to the star,” added team member Stephane Udry. The new observations have revealed that this planet is in the habitable zone, where liquid water could exist. “‘d’ could even be covered by a large and deep ocean — it is the first serious ‘water world’ candidate,” he said.
Mayor said it’s “amazing to see how far we have come since we discovered the first exoplanet around a normal star in 1995 — the one around 51 Pegasi. The mass of Gliese 581 e is 80 times less than that of 51 Pegasi b. This is tremendous progress in just 14 years.”
But the astronomers aren’t finished yet. “With similar observing conditions an Earth-like planet located in the middle of the habitable zone of a red dwarf star could be detectable,” says Bonfils. “The hunt continues.”
The findings were presented this week at the European Week of Astronomy & Space Science, which is taking place at the University of Hertfordshire in the UK. The results have also been submitted for publication in the research journal Astronomy & Astrophysics. A preprint is available here.
Source: ESO. (The site also offers numerous videos about the find.)
The design etched to the Pioneer probes. The first interstellar pornography? (NASA)
[/caption]So, you have a radio transmitter and you’ve been tasked to send a message into space to try to communicate with a hypothetical alien civilization. Where do you begin? Probably high on your list is to seek out the best candidate stars to send a signal to. As we only have experience of life on Earth, it’s a pretty good idea to look for Sun-like stars, as for all you know, that is the only place where Life As We Know It™ could exist.
So now you have found the potential location of an alien civilization, what message should you send? Firstly you’d probably want to make a good impression; perhaps sending directions to Earth, a universal map with an arrow pointing at the Solar System. Secondly you might want to identify what/who you are (insert some human physiology here). And third? Perhaps you’d consider sending information about our culture, civilization, history, science; all the good stuff that makes us human.
Would it cross your mind to mention there are 23 bloody conflicts going on right now amongst our own kind? Would you think about telling our potential alien neighbours about what you just had for dinner? Would it be a good idea to tell them about the political corruption in your country, the vast poverty worldwide or the ecological damage we are doing to our own home?
In a recent article written by the director of interstellar message composition at the SETI Institute, the question about communicating honestly with ET, without sanitizing the truth, is asked. Should we really tell an alien civilization about our problems?
Communication with potential alien races is a tricky business (Ian O'Neill)For five decades, the Search for Extraterrestrial Intelligence (SETI) has been scouring the skies for any signal from an intelligent alien civilization. This is a painstaking task that requires much patience and lots of ingenuity. After all, what are we looking for? Assuming extraterrestrial civilizations have worked out how to transmit radio, perhaps we could listen out for that. Unfortunately, apart from the 72 second Wow! signal in 1977, it all seems very quiet out there. If the Drake Equation is to be taken literally, the Milky Way should be teeming with life, some of which should be transmitting their greatest hits right now. There are problems with this theory, as some believe that although aliens might be transmitting, radio signals might not reach us. Perhaps then a sufficiently advanced alien race might be using powerful laser beacons or moving stars to communicate with us. Alas, nothing. Yet.
OK, so let’s turn this around. Perhaps we’ll have more luck if we start transmitting radio signals to Sun-like stars in the hope of an alien race as advanced as ourselves receiving it. This program is known as Messaging Extraterrestrial Intelligence (METI) or “Active-SETI.” But what do we say? One of the earliest messaging attempts was the plaque bolted to the side of the Pioneer spacecraft (pictured top), even though the naked human figures representing male and female caused a stir (some groups considered the naked human form interstellar pornography). Despite a few disputes about what we should be sending into space, generally the messages have been very positive, trying to portray the human race in a very positive light.
Douglas Vakoch, from the SETI Institute in Mountain View, California, disagrees with the policy of sending only positive messages into space via radio transmissions or metal plaques strapped to the sides of spaceships.
“An acknowledgment of our flaws and frailties seems a more honest approach than sending a sanitised, one-sided story,” Vakoch said in a recent New Scientist column. “Honesty is a good starting point for a conversation that could last for generations.”
As the director of interstellar message composition, Vakoch obviously knows a thing or two about sending messages to our potential alien neighbours. However, the question as to whether or not we should sanitize our communications seems a little strange. Of course we should transmit the best mankind has to offer! I don’t believe sending messages of culture, science, mathematics, art and music would be setting us up for a fall. If we are indeed the new kids on the block of extraterrestrial civilizations, I think we’d need to make a great impression (depending on whether ET understands what we are trying to communicate in the first place).
The 1977 Wow! signal (SETI)Vakoch is keen to point out that a sufficiently advanced alien civilization is going to be savvy as to what it takes to be a a galactic race (it’s not all roses after all). If they receive a message from mankind full of positive messages, perhaps they won’t trust us. Worse still, as they get to know us, they think we were hiding our human flaws, misleading them in some way. Therefore, we need to be honest up-front. We need to send the views and opinions of as many people as possible, for good or bad, so extraterrestrial civilizations know what they are dealing with; a talented, yet flawed race.
Unfortunately, that goes against human nature. What’s the first thing you do when moving into a new neighbourhood? You might throw a house-warming party, as a way to introduce yourself to the new neighbours. You probably wouldn’t tell your neighbours about your family/money/alcohol/drug/criminal problems at the party. If you did, you might find the room emptying very quickly. It’s not that you are being dishonest, you’re trying to gain their first-impression trust and interest. This principal holds true for companies trying to sell a product (I have yet to have a doorstep sales person telling me his encyclopaedia collection is actually useless when the world has Wikipedia) and to countries forming new diplomatic ties. We know there’s more to the story than just first impressions, but first impressions are the bonds that help develop the relationship in the future.
Assimilation could be ET's solution to human problemsSo going back to being honest with messaging alien civilizations, if we send “the truth” about our race, we would actually be doing ourselves a disservice. What if the receiving alien civilization doesn’t want to be associated with us as we are considered too aggressive, cruel, greedy or weird?
We can’t second-guess how an extraterrestrial civilization is going to respond to us, there is no precedent of alien communications, so perhaps we should take the “sanitized” approach. Positive information is probably enough information; too much information could turn us into interstellar outcasts before we’ve even had a chance to receive a message from another star. (I thought it was a little too quiet out there, perhaps they received our commercial TV signals.)
