Are you ready for another Where In The Universe Challenge? Take a look and see if you can name where in the Universe this image is from. Give yourself extra points if you can name the spacecraft responsible for the image. As usual, we’ll provide the image today, but won’t reveal the answer until tomorrow. This gives you a chance to mull over the image and provide your answer/guess in the comment section. Please, no links or extensive explanations of what you think this is — give everyone the chance to guess.
UPDATE: The answer has now been posted below. Don’t peek before you make your guess.
What you are seeing here is the dark side of Saturn’s moon Titan, with sunlight filtering through the moon’s hazy atmosphere. And obviously, the Cassini spacecraft is responsible for this image.
An airless satellite would appear in this viewing geometry only as a lit crescent. But Titan’s thick atmosphere scatters light around all edges of the planet to create a ring of light.
This view looks toward the Saturn-facing side of Titan. North on Titan is up and rotated 45 degrees to the left. The images were acquired at a distance of approximately 1.8 million kilometers (1.1 million miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 157 degrees. Image scale is 11 kilometers (7 miles) per pixel.
Nice job, everyone! Check back next week for another WITU challenge!
It has been a busy day in space and here are a few jottings about what all has been going on. Above, you can watch the spectacular videos taken by cameras mounted on the shuttle’s solid rocket boosters, taken during the launch of Atlantis on the current Hubble Servicing Mission. It’s a crazy ride, tagging along on the outside of the shuttle going up, and spinning dizzily on the way down until splashing in the ocean. Not for the faint of heart! But seeing the SRB videos means only one thing: Atlantis and the STS-125 crew have been cleared to land. NASA has carefully reviewed the videos and the data from the crew’s scan of the shuttle’s thermal protection system, saying there are absolutely no issues that would preclude the shuttle from landing. Weather, however could be another matter, which is why NASA ordered the shuttle to power down for awhile today to save on consumables. Predicted weather does not look good for landing on Friday, so the crew will make sure they have enough power to stay in orbit for a few more days.
Now about that toast…
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A huge crowd gathered in the space station mission control room at Johnson Space Center today as the ISS crew was given a “go” to drink water that the new recycling system has purified. Everyone joined in at mission control with a toast to the success of the recycling system, giving a nod to everyone who helped create the system, install it on the ISS and work on getting the fussy system to run. This is big news, as it means the station is ready to handle the increased crew size of 6 astronauts.
Also:
The STS-125 crew held a press conference from the shuttle today. The highlight was Mike Massimino talking about how he ripped a handrail off of Hubble in order to proceed with the scheduled repair of the STIS instrument.
“Ripping that thing out of there was quite an experience, and I’m glad it led to a successful repair,” said Massimino, who added that he drew inspiration from his uncle Frank, who once ripped an oil filter out a car. “That was pretty close to what was going on with Hubble.”
Later, during a ship-to-ship call between Atlantis and the ISS, space station crew member Michael Barrett revisited Massimino’s special touch.
“The magic Massimino touch is now legendary, and we’re looking forward to seeing you guys back on the ground,” he said.
If you missed the crew news conference, its available here. Additionally, the discussion between the two crews, can be seen here.
Update: One other piece of news from the shuttle is that President Obama called the STS-125 crew to congratulate them on a job well done. “I wanted to personally tell you how proud I am of all of you and everything that you’ve accomplished,” he said.
“Like a lot of Americans, I’ve been watching with amazement the gorgeous images you’ve been sending back and the incredible repair mission you’ve been making in space,” he said. “I think you’re providing a wonderful example of the kind of dedication and commitment to exploration that represents America and the space program generally. These are traits that have always made this country strong and all of you personify them.”
Obama also said he would be naming a new NASA administrator very soon, but wouldn’t say who it is.
“Just so we’re sure, the new administrator is not any of us on the flight deck right now, is it?” asked Commander Scott Altman (Altman had suggested Hubble fix-it man John Grunsfeld for administrator earlier this week.)
“I’m not going to give you any hints,” Obama said with a laugh.
“Thank you very much, fair enough, sir,” Altman replied.
One other spaceflight news tidbit, Orbital Sciences Corp. finally launched a Minotaur 1 rocket from the Wallops Island Flight Facility with the Tactical Satellite-3 (TacSat-3) satellite. The launch was heavily postponed, with several scrubs relating from the weather to the launch vehicle and facility. Find out more about the launch and the satellite here.
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A volcano caldera is a depression in the ground created by the collapse of land after a volcanic eruption. In some cases, the caldera is created slowly, when the ground sinks down after a magma chamber is emptied. In other situations, the magma explodes violently, and the caldera is the deep pit in the ground that remains after the volcano blows its top off.
A caldera forms when the magma chamber beneath a volcano is emptied in a large eruption. If the eruption happens quickly enough, the empty chamber beneath isn’t strong enough to support the weight of the volcano and it collapses down. This can happen in a single cataclysmic event, or over the course of several eruptions. Volcano calderas can be hundreds and even thousands of square kilometers in area.
There are many famous examples of volcano calderas. Crater Lake in Oregon was created when a volcano detonated around 10,000 years ago. Over time water filled up the nearly 597 meter deep caldera, making it the deepest lake in the United States, and the second deepest lake in North America (Great Slave Lake is the deepest). Another example of a volcanic caldera is the Yellowstone Caldera, which last erupted 640,000 years ago. It released 1,000 cubic kilometers of rock, covering much of North America in two meters of debris.
There are other examples of non-explosive volcano calderas. For example, the volcano Kilauea on the Big Island of Hawaii has a magma chamber that’s emptied by large lava flows, and not explosive eruptions. This causes the ground to collapse down after the lava eruptions, sinking many meters into the ground.
Volcano calderas have been seen on many other places in the Solar System. Although there aren’t active volcanoes on Mars today, regions of Mars were active billions of years ago, and there are many regions with large calderas. Jupiter’s moon Io is an example of a place with active calderas being created right now.
We have written many articles about volcanoes for Universe Today. Here’s an article about types of eruptions, and here’s an article about volcanic craters (not to be confused with calderas).
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Some craters are formed by a meteor impact, when a space rock strikes the Earth. And other craters are volcanic in origin. A volcano crater is a circular depression around a volcanic vent. This is where the lava, ash and rock erupt out of a volcano. In most situations, the volcano crater is located at the top of the volcano.
Think of a classic cone-shaped volcano, with steep sides and a slightly flattened top. If you could climb up to the top of the volcano and peer over the edge, you would look down into the volcano crater. And when the volcano does erupt, the material comes out of this volcano crater.
But not all volcano craters are found at the top of the volcano. They can also appear on the flanks of large volcanoes, when side vents reach the surface and erupt. These are known as flank craters, while the crater on top is called a summit crater. The volcano crater will often fill up with water and create a crater lake.
One kind of eruption creates a crater without a volcanic cinder cone at all: a phreatic eruption. This is a situation where magma rises through water-saturated rocks and causes steam to build up under the surface. The pressure from all the steam causes the rock to explode outward and create a volcanic crater. These can be strange to discover as they often appear in plains, far away from any other obvious volcanoes.
When the ground depresses down because a volcano’s magma chamber has been emptied, this is actually known as a caldera, and not a volcano crater.
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The Pacific Ring of Fire is a region that surrounds the Earth’s Pacific Ocean, and is known for its volcanoes and earthquake activity. The Ring of Fire has a total of 452 volcanoes, and has 75% of the Earth’s active and dormant volcanoes. The whole Ring of Fire stretches for 40,000 km in length.
The Ring of Fire is created by the Earth’s plate tectonics. The Earth’s crust is broken up into plates which float on top of the mantle. When these plates come together, you can get volcanoes and earthquakes. The eastern side of the Ring of Fire has the Nazca Plate and the Cocos Plate being subducted (going underneath) the South American Plate. And in the North, the Pacific Plate and the Juan de Fuca Plate are being subducted underneath the North American Plate. The Pacific plate is also subducting underneath the Kamchatka Peninsula and Japan.
Because of all this subduction, there are many cracks in the Earth’s crust where magma can reach the surface and erupt as volcanoes. There are volcanoes in Chile, Mexico, the United States, Canada, Russia, Japan, the Philippines, Indonesia, New Zealand and Antarctica.
Some of the most famous volcanoes on Earth are in the Ring of Fire. A famous volcano, Mount St. Helens, which erupted in 1980 is a good example, or Mount Rainier in Washington State, or Mount Shasta in California. The recent eruption of Mount Redoubt in Alaska is part of the Ring of Fire. And so are Mount Pinatubo in the Philippines and Mount Fuji in Japan.
The Ring of Fire has produced more than just volcanoes. It has also created islands and mountain chains around the Pacific Ocean. The Aleutian Islands in Alaska are all volcanic, and Japan is part of the subduction of the Pacific Plate going underneath the Eurasian Plate.
I personally live in the Ring of Fire, so I’m aware that there are dangers to living in this part of the world. There can be powerful earthquakes, huge tsunami, and new volcanic eruptions. Every year the Ring of Fire volcanoes demonstrate just how active they still are.
Redoubt volcano crater showing rapidly melting glacier and enlarged "ice piston" feature. Picture Date: March 21, 2009 Image Creator: Cyrus Read, Image courtesy of AVO/USGS.
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It sounds like such a simple question: how many volcanoes are there on the Earth. But it’s actually very complicated, and the true answer is that scientists just don’t know. Some volcanoes are completely unknown, hidden beneath the ocean. Other volcanoes haven’t erupted in a long time, and so scientists don’t know if they’re still active. It also depends on whether you consider a single volcanic vent a volcano, or count an entire volcanic field of volcanoes that connect to a single magma chamber. See how’s it’s complicated to count the number of volcanoes?
The Smithsonian National Museum of Natural History calculates that there are currently about 20 volcanoes actively erupting when you’re reading these words. About 50-70 volcanoes have erupted over the course of the last year, and 160 erupt during a single decade. There are 550 volcanoes that have been active in all recorded history, and geologists have located an additional 1300 volcanoes that have erupted in the last 10,000 years.
So if you add these numbers up, you get about 1500 volcanoes that have erupted in the last 10,000 years.
But most of the actively erupting volcanoes are on the deep sea floor, where nobody was there to measure it. If you assume that 3/4 of all eruptions were underwater volcanoes, you get a total of about 6,000 volcanoes that have erupted worldwide in the last 10,000 years.
So that’s the best estimate of how many many volcanoes there are.
We have written many articles about volcanoes for Universe Today. Here’s an article about different types of volcanoes, and here’s an article about different types of lava.
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The ground beneath your feet feels cool, but you’re actually standing on a thin shell of crust around the much hotter mantle of the Earth. The mantle is under such pressure and temperature that rock squeezes out as a liquid and makes its way to the surface. When the magma reaches the surface, it’s called a volcanic eruption, and can spew out as lava, ash and even large volcanic rocks.
There are actually different kinds of volcanic eruptions, depending on the chemical nature of the magma itself.
The most powerful volcanic eruptions are known as Plinian eruptions, and they involved the explosion ejection of viscous (very thick) lava. A well known example of this is the eruption of Mount Saint Helens in 1980, or Pinatubo in the Philippines.
In a Strombolian eruption, clots of lava blast out of volcano caldera and make arcs through the sky before raining down around the volcano. The lava can continue to stream down the sides of the volcano like tiny rivers causing more damage.
In a Vulcanian eruption, a dense cloud of ash blasts out of the volcano and rises dozens of kilometers into the atmosphere above the peak.
In a Vesuvian eruption, the ash cloud doesn’t rise as high, and forms more of a cauliflower-shaped plume above the volcano peak. This type of volcanic eruption was named after Mount Vesuvius, which destroyed two Roman towns in 79 AD.
During a Pelean eruption, large quantities of ash, rock and dust are blasted out of a central crater and then travel down the slopes of the volcano and hundreds of kilometers per hour. These are one of the most dangerous kinds of volcanic eruptions, as they can lead to a tremendous loss of life to towns and villages near the volcano.
A Hawaiian eruption is when lava comes out of linear vents, and joins together to form streams and rivers of lava. The lava can even come out of the ground at such speed that it creates fountains that erupt for dozens of meters into the air.
Phreatic eruptions are also known as steam blast eruptions, and are caused by expanding steam beneath the ground created when water comes in contact with hot rock or magma.
Even if an early Mars never got above freezing, the brine on its surface could have stayed liquid and supported life, a new study says.
Lead author Alberto G. Fairen, of NASA Ames Research Center in Moffett Field, California, and his colleagues have analyzed the behavior of Martian chemical concentrations found at various mission landing sites, and revealed that warm temperatures wouldn’t have been necessary to support salt-loving life forms.
The authors point out that many features on the Martian surface are believed to have been formed by flowing water and related mineral activity on the surface. Water is a key ingredient for life, but models were having a hard time envisioning a Mars warm enough to support it.
Much evidence has indicated surface temperatures well below freezing.
According to the new study, life may have fared all right anyway.
“Solutes could depress the melting point of water in a frozen Martian environment, providing a plausible solution to the early Mars climate paradox,” the authors write.
Fairen and his colleagues modeled the freezing and evaporation processes of Martian fluids with a composition resulting from the weathering of basalts, as reflected in the chemical compositions at Mars landing sites of Viking 1, Mars Pathfinder, and the rovers Spirit and Opportunity.
“Our results show that a significant fraction of weathering fluids loaded with Si, Fe, S, Mg, Ca, Cl, Na, K and Al remain in the liquid state at temperatures well below 273 K,” or nearly 32 degrees Fahrenheit (zero C), they write.
“This stability against freezing of Martian fluids can explain saline liquid water activity on the surface of Mars at mean global temperatures well below 273 K.”
Celestial impacts can bring life as well as wipe it out, say the authors of a new study out of the University of Colorado at Boulder.
A case in point: the bombardment of Earth nearly 4 billion years ago by asteroids as large as Kansas would not have had the firepower to extinguish potential early life on the planet and may even have given it a boost.
In a new paper in the journal Nature, Oleg Abramov and Stephen Mojzsis report on their study of impact evidence from lunar samples, meteorites and the pockmarked surfaces of the inner planets. The evidence paints a picture of a violent environment in the solar system during the Hadean Eon 4.5 to 3.8 billion years ago, particularly through a cataclysmic event known as the Late Heavy Bombardment about 3.9 billion years ago.
Although many believe the bombardment would have sterilized Earth, the new study shows it would have melted only a fraction of Earth’s crust, and that microbes could well have survived in subsurface habitats, insulated from the destruction.
“These new results push back the possible beginnings of life on Earth to well before the bombardment period 3.9 billion years ago,” Abramov said. “It opens up the possibility that life emerged as far back as 4.4 billion years ago, about the time the first oceans are thought to have formed.”
Because physical evidence of Earth’s early bombardment has been erased by weathering and plate tectonics over the eons, the researchers used data from Apollo moon rocks, impact records from the moon, Mars and Mercury, and previous theoretical studies to build three-dimensional computer models that replicate the bombardment. Abramov and Mojzsis plugged in asteroid size, frequency and distribution estimates into their simulations to chart the damage to the Earth during the Late Heavy Bombardment, which is thought to have lasted for 20 million to 200 million years.
The 3-D models allowed Abramov and Mojzsis to monitor temperatures beneath individual craters to assess heating and cooling of the crust following large impacts in order to evaluate habitability. The study indicated that less than 25 percent of Earth’s crust would have melted during such a bombardment.
The CU-Boulder researchers even cranked up the intensity of the asteroid barrage in their simulations by 10-fold — an event that could have vaporized Earth’s oceans. “Even under the most extreme conditions we imposed, Earth would not have been completely sterilized by the bombardment,” said Abramov.
Instead, hydrothermal vents may have provided sanctuaries for extreme, heat-loving microbes known as “hyperthermophilic bacteria” following bombardments, said Mojzsis. Even if life had not emerged by 3.9 billion years ago, such underground havens could still have provided a “crucible” for life’s origin on Earth, Mojzsis said.
Geologic evidence suggests that life on Earth was present at least 3.83 billion years ago, said Mojzsis. “So it is not unreasonable to suggest there was life on Earth before 3.9 billion years ago. We know from the geochemical record that our planet was eminently habitable by that time, and this new study sews up a major problem in origins of life studies by sweeping away the necessity for multiple origins of life on Earth.”
The results also support the potential for microbial life on other planets like Mars and perhaps even rocky, Earth-like planets in other solar systems that may have been resurfaced by impacts, said Abramov.
On a recent trip to Canada in the great province of Ontario, I found a quiet corner on Lundy’s Lane. I had been enjoying the scenic beauty of Niagara Falls and to break away for the tourist aspect seemed like a welcome respite. How could someone who lives, eats and breathes space 24/7 pass up an opportunity to visit a place like this? The answer was… I couldn’t.
For any one old enough to remember and still too young to resist, the retro-styling and drive-in atmosphere of this super clean diner was enough to make you smile the moment you stopped in the parking lot. Glittering multi-colored lights and a welcoming glow was all I needed to take a chance. Once inside I was transported back to all of my childhood fantasies, and despite having a well stocked refreshment area – all you really wanted was a cold soda or a milk shake. Why spoil the fun?
When the menu came, my grin got even wider. There’s nothing that delights me more than a sense of humor… and to combine it with good food makes the experience even more extraordinary. Needless to say, I didn’t just stop by this place on a whim. I’d researched my restaurants in advance and every sample around the family table proved to be just as tasty and well prepared as the reviews promised. The “Jupiter Burgers” were absolutely among the finest I’ve ever eaten and the clam chowder didn’t come out of can, my friends. Even though the hour was late, I had a delightful time talking to the “natives” who were patient with my questions and seemed to enjoy the company as much as we enjoyed theirs!
Right down to the little stuffed aliens…
So what’s a less than serious piece about finding a flying saucer restaurant doing in a serious astronomical webpage like Universe Today? It’s to remind you to take a chance on what you love. If you love astronomy and having dinner in a restaurant shaped like a flying saucer looks like fun? Do it! You may end up in some remote corner of Iowa having the worst cup of coffee you’ve ever tasted… Or you might end up in a quiet corner of Niagara Falls surrounded by your laughing family enjoying diner food at it’s best.
