The southern hemisphere of Neptune's moon Triton, at a resolution of 600 meters (1,969 feet) per pixel. Credit: Paul Schenk (LPI, Houston) from Voyager 2 images acquired August 1989
Talk about recycling! Twenty-five years after Voyager 2 zinged past Neptune’s moon Triton, scientists have put together a new map of the icy moon’s surface using the old data. The information has special relevance right now because the New Horizons spacecraft is approaching Pluto fast, getting to the dwarf planet in less than a year. And it’s quite possible that Pluto and Triton will look similar.
Triton has an exciting history. Scientists believed it used to be a lone wanderer until Neptune captured it, causing tidal heating that in turn created fractures, volcanoes and other features on the surface. While Triton and Pluto aren’t twins — this certainly didn’t happen to Pluto — Pluto also has frozen volatiles on its surface such as carbon monoxide, methane and nitrogen.
What you see in the map is a slightly enhanced version of Triton’s natural colors, bearing in mind that Voyager’s sensors are a little different from the human eye. Voyager 2 only did a brief flyby, so only about half the planet has been imaged. Nonetheless, the encounter was an exciting time for Paul Schenk, a planetary scientist at the Lunar and Planetary Institute in Houston. He led the creation of the new Triton map, and wrote about the experience of Voyager 2 in a blog post.
“Triton is a near twin of Pluto,” wrote Schenk. “Triton and Pluto are both slightly smaller than Earth’s Moon, have very thin nitrogen atmospheres, frozen ices on the surface (carbon monoxide, carbon dioxide, methane and nitrogen), and similar bulk composition (a mixture of ices, including water ice, and rock. Triton however was captured by Neptune long time ago and has been wracked by intense heating ever since. This has remade its surface into a tortured landscape of overturned layers, volcanism, and erupting geysers.”
He also added speculation about what will be seen at Pluto. Will it be a dead planet, or will geology still be affecting its surface? How close will Triton be to Pluto, particularly regarding its volcanoes? Only a year until we know for sure.
Holger Sierks, OSIRIS principal investigator, discusses spectacular hi res comet images returned so far by Rosetta during the Aug. 6 ESA webcast from mission control at ESOC, Darmstadt, Germany. Credit: Roland Keller
Animation Caption: Possible landing sites on Comet 67P/Churyumov-Gerasimenko. The model shows the illumination of the comets surface and regions under landing site consideration for the Philae lander on board ESA’s Rosetta spececraft . Credit: CNES
“The race is on” to find a safe and scientifically interesting landing site for the Philae lander piggybacked on ESA’s Rosetta spacecraft as it swoops in ever closer to the heavily cratered Comet 67P/Churyumov-Gerasimenko since arriving two weeks ago after a decade long chase of 6.4 billion kilometers (4 Billion miles).
Rosetta made history by becoming the first ever probe from Earth to orbit a comet upon arrival on Aug. 6, 2014.
The probe discovered an utterly alien and bizarre icy wanderer that science team member Mark McCaughrean, of ESA’s Science Directorate, delightedly calls a ‘Scientific Disneyland.’
“It’s just astonishing,” he said during a live ESA webcast of the Aug. 6 arrival event.
Now, another audacious and history making event is on tap – Landing on the comet!
To enable a safe landing, Rosetta is moving in closer to the comet to gather higher resolution imaging and spectroscopic data. When Rosetta arrived on Aug. 6, it was initially orbiting at a distance of about 100 km (62 miles). As of today, carefully timed thruster firings have brought it to within about 80 km distance. And it will get far closer.
Right now a top priority task for the science and engineering team leading Rosetta is “Finding a landing strip” for the Philae comet lander.
Philae’s landing on comet 67P is currently scheduled for Nov. 11, 2014. The 100 kg lander is equipped with 10 science instruments
“The challenge ahead is to map the surface and find a landing strip,” said Andrea Accomazzo, ESA Rosetta Spacecraft Operations Manager, at the Aug. 6 ESA webcast.
The team responsibility for choosing the candidate sites comprises “the Landing Site Selection Group (LSSG), which comprises engineers and scientists from Philae’s Science, Operations and Navigation Centre (SONC) at CNES, the Lander Control Centre (LCC) at DLR, scientists representing the Philae Lander instruments, and supported by the ESA Rosetta team, which includes representatives from science, operations and flight dynamics,” according to an ESA statement.
This week the team is intensively combing through a preliminary list of 10 potential landing sites.
Over the weekend they will whittle the list down to five candidate landing sites for continued detailed analysis.
ESA will announce the Top 5 landing site candidates on Monday, Aug. 25.
Where will Philae land?
This image of comet 67P/Churyumov-Gerasimenko shows the diversity of surface structures on the comet’s nucleus. It was taken by the Rosetta spacecraft’s OSIRIS narrow-angle camera on August 7, 2014. At the time, the spacecraft was 65 miles (104 kilometers) away from the 2.5 mile (4 kilometer) wide nucleus. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA/Enhanced processing Marco Di Lorenzo/Ken Kremer
The decision rests on the results of Rosetta’s ongoing global mapping campaign, including high resolution imaging from the OSIRIS and NAVCAM cameras and further observations from the other science instruments, especially MIRO, VIRTIS, ALICE, GIADA and ROSINA.
The surface criteria for a suitable landing site include day time landing illumination, a balance between day and night to allow the solar panels to recharge the batteries, avoiding steep slopes, large boulders and deep crevasses so it doesn’t topple over.
Of course the team also must consider the comet’s rotation period (12.4 hours) and axis of rotation (see animation at top). Sites near the equator offering roughly equal periods of day and night may be preferred.
The selection of the primary landing site is slated for mid-October after consultation between ESA and the lander team on a “Go/No Go” decision.
The three-legged lander will fire two harpoons and use ice screws to anchor itself to the 4 kilometer (2.5 mile) wide comet’s surface. Philae will collect stereo and panoramic images and also drill 23 centimeters into and sample its incredibly varied surface.
Artist impression of Philae on the surface of comet 67P/Churyumov-Gerasimenko. Credit: ESA/ATG medialab
Read an Italian language version of this story by my imaging partner Marco Di Lorenzo – here
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Sunlight and shadow combine in this photo of Saturn and its rings taken Aug. 19, 2014. Credit: NASA/JPL/Space Science Institute
When Saturn is at its closest to Earth, it’s three-quarters of a billion miles away — or more than a billion kilometers! That makes these raw images from the ringed planet all the more remarkable.
Nearly every day, the Cassini spacecraft beams back what it sees at Saturn and the images are put up on this NASA website. This week, for example, it was checking out Saturn’s rings. We have a few of the pictures below, plus an older picture of the entire planet for reference.
Saturn’s rings are believed to be about 4.4 billion years old — that’s close to the age of the Solar System itself. Astronomers, however, have only known about them since the 1600s, when Galileo Galilei was trying to make sense of some funny-looking shapes on either side of the planet in his telescope.
According to NASA, the particles in the rings range from dust-sized to mountain-sized. Some of Saturn’s dozens of moons act as shepherds to the rings, keeping gaps open. You can read more about what we know about their origins here.
The Cassini spacecraft looks to the side of Saturn’s rings in this picture from Aug. 19, 2014. Credit: NASA/JPL/Space Science InstituteBands prominently feature in this raw picture of Saturn taken by the Cassini spacecraft Aug. 17, 2014. Credit: NASA/JPL/Space Science InstituteDifferent shades shine in this raw image of Saturn’s rings taken by the Cassini spacecraft taken Aug. 19, 2014. Credit: NASA/JPL/Space Science InstituteSaturn and its rings, as seen from above the planet by the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute. Assembled by Gordan Ugarkovic.
NASA's Jet Propulsion Laboratory is working on a solar array that would fold up like an origami shape, to make it easier to unfurl. Credit: BYU
From paper cranes to solar sails, looks like the Japanese art of origami is making its way into the space world. As you can see in the video above, origami serves a great purpose for launching sails into space — it makes them easy to fold. And this makes it easier to pack into a rocket for the crucial launch phase, before unfurling in orbit.
“This is a unique crossover of art and culture and technology,” stated Brian Trease, a mechanical engineer at NASA’s Jet Propulsion Laboratory who co-created the concept with Shannon Zirbel, a Ph.D. student in mechanical engineering at Brigham Young University in Utah.
Origami and solar arrays have been explored before, particularly with a type of fold named after Koryo Mirua (a Japanese astrophysicist). This allows structures to unfold with a single tug; in fact, there’s only one way to open or close the structure. This was tested in space on a Japanese satellite called the Space Flyer Unit in 1995.
This new solar array, by contrast, uses several kinds of folds that makes it look “like a blooming flower that expands into a large, flat circular surface,” NASA stated. While the technology is in the early stages, it’s possible these could be used on CubeSats (small satellites) in the future.
Is there any place in the Universe where there’s truly nothing? Consider the gaps between stars and galaxies? Or the gaps between atoms? What are the properties of nothing?
I want you to take a second and think about nothing. Close your eyes. Picture it in your mind. Focus. Fooooocus. On nothing….It’s pretty hard, isn’t it? Especially when I keep nattering at you.
Instead, let’s just consider the vast spaces between stars and galaxies, or the gaps between atoms and other microscopic particles. When we talk about nothing in the vast reaches between of space, it’s not actually, technically nothing. Got that? It’s not nothing. There’s… something there.
Even in the gulfs of intergalactic space, there are hundreds or thousands of particles in every cubic meter. But even if you could rent MegaMaid from a Dark Helmet surplus store, and vacuum up those particles, there would still be wavelengths of radiation, stretching across vast distances of space.
There’s the inevitable reach of gravity stretching across the entire Universe. There’s the weak magnetic field from a distant quasar. It’s infinitesimally weak, but it’s not nothing. It’s still something.
Philosophers, and some physicists, argue that *that* nothing isn’t the same as “real” nothing. Different physicists see different things as nothing, from nothing is classical vacuum, to the idea of nothing as undifferentiated potential.
Even if you could remove all the particles, shield against all electric and magnetic fields, your box would still contain gravity, because gravity can never be shielded or cancelled out. Gravity doesn’t go away, and it’s always attractive, so you can’t do anything to block it. In Newton’s physics that’s because it is a force, but in general relativity space and time *are* gravity.
Quantum theory includes strange particles like these quarks, seen here in a three-dimensional computer-generated simulation. PASIEKA/SPL
So, imagine if you could remove all particles, energy, gravity… everything from a system. You’d be left with a true vacuum. Even at its lowest energy level, there are fluctuations in the quantum vacuum of the Universe. There are quantum particles popping into and out of existence throughout the Universe. There’s nothing, then pop, something, and then the particles collide and you’re left with nothing again. And so, even if you could remove everything from the Universe, you’d still be left with these quantum fluctuations embedded in spacetime.
There are physicists like Lawrence Krauss that argue the “universe from nothing”, really meaning “the universe from a potentiality”. Which comes down to if you add all the mass and energy in the universe, all the gravitational curvature, everything… it looks like it all sums up to zero. So it is possible that the universe really did come from nothing. And if that’s the case, then “nothing” is everything we see around us, and “everything” is nothing.
What do you think? How do you wrap your head around the idea of nothing? Tell us in the comments below. And if you like what you see, come check out our Patreon page and find out how you can get these videos early while helping us bring you more great content!
The ozone hole over Antarctica on Aug. 18, 2014. Purple and blue represent zones with the least ozone, while yellow and red show thicker areas. Data sources come from multiple NASA, European Space Agency and National Oceanic and Atmospheric Administration satellites. Credit: NASA
Some bad news in the fight to protect Earth’s ozone — one of the banned compounds that attacks this protective atmospheric layer is still being produced, somehow.
That compound is called carbon tetrachloride, which used to be common in fire extinguishers and dry cleaning. But those who have signed the Montreal Protocol in 1987 reported no new emissions between 2007 and 2012.
So how is it that new research found atmospheric emissions are persisting at 30% of peak production, even with no new emissions being reported?
“We are not supposed to be seeing this at all,” stated lead author Qing Liang, an atmospheric scientist at NASA’s Goddard Space Flight Center in Maryland. “It is now apparent there are either unidentified industrial leakages, large emissions from contaminated sites, or unknown CCl4 sources.”
The concentrations are still declining, but only by 1% a year instead of the expected 4%. Liang’s team used several sources to piece together data from their new study, including ground-based observation and NASA’s 3-D GEOS Chemistry Climate Model.
Their work found that CC14 is still being produced, somehow, and also stays in the atmosphere for about 40% longer than thought. They estimate worldwide emissions of about 39 kilotons per year.
Screenshot of a simulation of how the universe's dark matter and gas grew in its first 13 billion years. Credit: Harvard-Smithsonian Center for Astrophysics / YouTube
How do you show off 13 billion years of cosmic growth? One way that astronomers can figure that out is through visualizations — such as this one from the Harvard-Smithsonian Center for Astrophysics, called Illustris.
Billed as the most detailed computer simulation ever of the universe (done on a fast supercomputer), you can slowly see how galaxies come alight and the structure of the universe grows. While the pictures are pretty to look at, the Kavli Foundation also argues this is good for science.
In a recent roundtable discussion, the foundation polled experts to talk about the simulation (and in particular how the gas evolves), and how watching these interaction play out before their eyes helps them come to new understandings. But like any dataset, part of the understanding comes from knowing what to focus on and why.
“I think we should look at visualization like mapmakers look at map making. A good mapmaker will be deliberate in what gets included in the map, but also in what gets left out,” said Stuart Levy, a research programmer at the National Center for Supercomputing Applications’ advanced visualization lab, in a statement.
“Visualizers think about their audience … and the specific story they want to tell. And so even with the same audience in mind, you might set up the visualization very differently to tell different stories. For example, for one story you might want to show only what it’s possible for the human eye to see, and in others you might want to show the presence of something that wouldn’t be visible in any sort of radiation at all. That can help to get a point across.”
The Meteorite of Serooskerken (Source: Sterrenwacht Sonnenborgh)
Calling all meteorite collectors and enthusiasts! There’s a hot space rock at large and, as Indiana Jones would say, it belongs in a museum. Perhaps you can help put it back in one.
Mosaic of the asteroid Vesta made from images acquired by NASA’s Dawn spacecraft. Credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA
On Aug. 19 a burglary was reported at the Sonnenborgh Museum and Observatory in Utrecht, Netherlands, and one of the items missing is a meteorite that is thought to have originated from the asteroid Vesta.
Seen above in a photo from the museum’s collection, the Meteorite of Serooskerken was recovered from a rare fall in 1925 in the province of Zeeland. Only five meteorites have ever been found in the Netherlands, making the Serooskerken specimen somewhat of a national treasure – not to mention a valuable piece of our Solar System’s history!
About 5–6% of all the meteorites found on Earth are thought to be from Vesta, the second-largest world in the main asteroid belt. (Source)
It doesn’t sound like the meteorite was the target of the burglary, but rather it just happened to be included with other things taken from the museum’s safe.
Chris Hadfield all dressed up for another day in space. Credit: Chris Hadfield (Twitter)
It’s possible that Chris Hadfield’s best-selling book will become a sitcom! The astronaut who quickly became the world’s most-wanted Canadian last year, based on his amusing YouTube videos and stunning space pictures, is involved in production of a sitcom based on An Astronaut’s Guide To Life On Earth, Deadline reports.
“The TV series is described as a family comedy about an astronaut who is back from space and finds that re-entering domestic life might be the hardest mission he’s ever faced,” wrote Deadline. Hadfield is slated to be the consulting producer on the show, which has been approved for pilot production.
Hadfield made headlines during his third and final spaceflight in 2012-13, part of which saw him was commander of the International Space Station’s Expedition 35. His five-month flight in space saw his Twitter numbers soar as he virtually hobnobbed with celebrities and worked social media every day, with the help of his son Evan. (This was done in between running one of the most scientifically productive missions on the station ever.)
Chris Hadfield in the Cupola of the ISS. Credit: NASA
Weeks after returning to Earth, Hadfield retired from the Canadian Space Agency. His second book, You Are Here: Around the World in 92 Minutes, is expected to be released in October.
Space is a serious business, but there are some comedies associated with it. Former NASA astronaut Mike Massimino has been a repeat guest on The Big Bang Theory, particularly when one of the main characters went into space. NBC is also working on a sitcom called Mission Control, which describes the challenges of a female aerospace engineer trying to make her way in the male-dominated field of the 1960s.
ABC also is taking space to a more serious side, as it is expected to make a miniseries based on the Lily Koppel bestseller The Astronaut Wives Club — a look at the wives of the first astronauts in the 1960s.
Space Station robotic arm releases Cygnus after detachment from the ISS Harmony node. Credit: NASA TV
What does it look like when a cargo ship goes flying away from the International Space Station? This timelapse gives you a sense of what to expect. Here, you can see the handiwork of the (off-camera) Expedition 40 crew as they use the robotic Canadarm2 to let go of the Cygnus spacecraft.
“Great feeling to release a captured swan back into the wild last week,” wrote Alexander Gerst, an astronaut with the European Space Agency, on Twitter with the video.
Cygnus (Latin for “swan”, and a northern constellation) is a commercial spacecraft manufactured by Orbital Sciences Corp., and is one of two regular private visitors to the space station. The other one is Dragon, which is manufactured by SpaceX. Both companies have agreements with NASA to run periodic cargo flights to the station so that the astronauts can receive fresh equipment, food and personal items.
Both spacecraft are designed to be captured and released by Canadarm2, which the astronauts operate. When the Canadarm2 captures the spacecraft, it is referred to as a “berthing” (as opposed to a docking, when a spacecraft directly latches on to the station.)
Cygnus made a (planned) fiery re-entry Sunday that the astronauts captured on camera from their orbiting perch. Besides the inherent spectacular value of looking at the pictures, they could also be useful to help plan the eventual de-orbiting of the space station.
