Elizabeth Howell, Author at Universe Today

December 4, 2014December 23, 2015 by Elizabeth Howell

Yes, You Can Find Exoplanets With A Simple Camera And Telephoto Lens

Artist’s impression of the deep blue planet HD 189733b, based on observations from the Hubble Space Telescope. Credit: NASA/ESA.

If you think exoplanet detections are only in the realm of professional planet-hunting telescopes such as Kepler, take a look at the video above. David Schneider, a senior editor for IEEE Spectrum, explains that it takes little more than a DSLR camera and a camera lens to catch a glimpse.

Schneider told Universe Today that he’s not an experienced amateur observer, nor should his equipment be expected to detect new exoplanets. But the potential for the future is interesting, he explained.

“I was simply trying to detect the signature of a known exoplanet, one that was discovered years ago with far more sophisticated gear,” he wrote in an e-mail. “I knew exactly which star to look at, when the transit occurs, and what the change in brightness would be. I relied on the expertise of professional astronomers to provide all that information.”

Here’s the setup: a Canon EOS Rebel XS DSLR, a 300-millimeter Nikon telephoto lens, an adapter to get the Nikon talking to the Canon, and a self-built “barn door tracker” that he constructed based on descriptions he found on the web. (His IEEE Spectrum article has more details.)

Schneider chose HD 189733, whose hostile-to-life “deep blue” exoplanet is about 63 light-years away and transits the face of the star every 2.2 days. But often these transits take place at inconvenient times (such as during the day, and the star is low on the horizon). He also faced several cloudy nights, meaning it was several weeks until he could take the imagery.

Once that was finished, Schneider ran the pictures through a piece of astronomical imaging software called Iris. In Schneider’s words, this is how the software helped him pick out the planet:

At the most basic level, Iris allows you to perform the corrections that are customary for really all types of digital astrophotography. In particular, you correct for ‘hot pixels’ in your camera sensor and for variations in the sensitivity of the sensor across the frame. This is standard stuff in astrophotography, requiring that you take images with the lens cap on (so-called “darks”), of a uniformly illuminated background (“flats”), and so forth.

For this project, you also need to use the tools that Iris provides to do what’s called aperture photometry. In a nutshell, you have to adjust the registration of the set of images you collect so that the stars are in the same position in each image. Then you have to set up things in Iris to do photometric measurements of a selected set of stars in one frame. After that, Iris will perform the photometry you want on the whole set of images you have in an automated fashion.

While his equipment isn’t sophisticated enough to account for “false positives” such as a sunspot going across a star — amateurs are more at the stage of confirming professional observations — Schneider pointed out there are many similar projects to his own. Among them are KELT-NORTH (which inspired his search), Evryscope, and this group at the University of Arizona.

“My project merely highlights that you can get your feet wet in this area with some really cheap hardware,” Schneider said. He recommends those that want to do similar work to his read the IEEE Spectrum article, buy the hardware required, read up on astrophotography and Iris, and not be afraid to experiment.

Schneider added he wasn’t trying to do “anything special” — many amateurs have encountered similar success — but he had a lot of fun. “Maybe because I’m a bit of a computer nerd, I found digital astrophotography to be a lot more enjoyable than actually looking through a telescope, which in the few times I’ve done that often involved a lot of squinting and unpleasant vibration.”

December 3, 2014December 23, 2015 by Elizabeth Howell

Mars Needs You! Help Scientists Track Spring Thaw On Red Planet

Carbon dioxide ice begins to feel the heat in the south pole region every spring. In this image of 'Inca City' taken in August 2014, you can see a few fans coming out from channels (araneiforms) that are created when pressurized gas escapes from the melting ice. Picture taken by the Mars Reconnaissance Orbiter's HiRISE camera. Credit: NASA/JPL/University of Arizona

We’ve been watching Mars with spacecraft for about 50 years, but there’s still so little we know about the Red Planet. Take this sequence of images in this post recently taken by a powerful camera on NASA’s Mars Reconnaissance Orbiter. Spring arrives in the southern hemisphere and produces a bunch of mysteries, such as gray-blue streaks you can see in a picture below.

That’s where citizen scientists can come in, according to a recent post for the University of Arizona’s High Resolution Imaging Science Experiment (HiRISE) camera that took these pictures. They’re asking people with a little spare time to sign up for Planet Four (a Zooniverse project) to look at mysterious Mars features. With amateurs and professionals working together, maybe we’ll learn more about these strange changes you see below.

On Aug. 20, 2014, Martian dust mounds are on top of the araneiforms in 'Inca City', as well as dark areas on the terrain showing where the ice cap in the southern hemisphere burst and sent gas and dust into the surroundings. Fans in the area are pointing in multiple directions, showing how the wind has changed. Image taken by the Mars Reconnaissance Orbiter's HiRISE camera. Credit: NASA/JPL/University of Arizona — On Aug. 20, 2014, Martian dust mounds are on top of the araneiforms in ‘Inca City’, as well as dark areas on the terrain showing where the ice cap in the southern hemisphere burst and sent gas and dust into the surroundings. Fans in the area are pointing in multiple directions, showing how the wind has changed. Image taken by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of Arizona

On Aug. 25, 2014, more fans and blotches appear on the Martian landscape around "Inca City", a location in the southern polar region, as the ice bursts in the springtime sun. Image obtained by the Mars Reconnaissance Orbiter's HiRISE camera. Credit: NASA/JPL/University of Arizona — On Aug. 25, 2014, more fans and blotches appear on the Martian landscape around “Inca City”, a location in the southern polar region, as the ice bursts in the springtime sun. Image obtained by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of Arizona

As of Sept. 6, 2014, fans in "Inca City" in the Martian southern hemisphere are now blue-gray. Why this color appears in the spring is unknown. It could be because of particles falling into ice underneath, or gas bursting from the ice condensing and falling as frost. It could even be a combination of the two. Image taken by the Mars Reconnaissance Orbiter's HiRISE orbiter. Credit: NASA/JPL/University of Arizona — As of Sept. 6, 2014, fans in “Inca City” in the Martian southern hemisphere are now blue-gray. Why this color appears in the spring is unknown. It could be because of particles falling into ice underneath, or gas bursting from the ice condensing and falling as frost. It could even be a combination of the two. Image taken by the Mars Reconnaissance Orbiter’s HiRISE orbiter. Credit: NASA/JPL/University of Arizona

As spring takes hold in the southern polar region of Mars on Sept. 27, 2014, cracks are now developing in the ice at "Inca City" with multiple new dust fans appearing. Cracks develop when the ice does not have a path to easily rupture and release gas. Picture taken by the Mars Reconnaissance Orbiter's HiRISE camera. Credit: NASA/JPL/University of Arizona — As spring takes hold in the southern polar region of Mars on Sept. 27, 2014, cracks are now developing in the ice at “Inca City” with multiple new dust fans appearing. Cracks develop when the ice does not have a path to easily rupture and release gas. Picture taken by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of Arizona

December 3, 2014December 23, 2015 by Elizabeth Howell

Europa Life: Could ‘Extreme Shrimp’ Point To Microbes On That Moon?

This is a type of shrimp that lives in hydrothermal vents (areas of hot water) in the Caribbean. NASA is studying Rimicaris hybisae and other "extreme shrimp" to learn more about lifeforms that could survive on other worlds. Credit: Chris German, WHOI/NSF, NASA/ROV Jason C: 2012 Woods

For all of the talk about aliens that we see in science fiction, the reality is in our Solar System, any extraterrestrial life is likely to be microbial. The lucky thing for us is there are an abundance of places that we can search for them — not least Europa, an icy moon of Jupiter believed to harbor a global ocean and that NASA wants to visit fairly soon. What lurks in those waters?

To gain a better understanding of the extremes of life, scientists regularly look at bacteria and other lifeforms here on Earth that can make their living in hazardous spots. One recent line of research involves shrimp that live in almost the same area as bacteria that survive in vents of up to 750 degrees Fahrenheit (400 degrees Celsius) — way beyond the boiling point, but still hospitable to life.

Far from sunlight, the bacteria receive their energy from chemical combinations (specifically, hydrogen sulfide). While the shrimp certainly don’t live in these hostile areas, they perch just at the edge — about an inch away. The shrimp feed on the bacteria, which in turn feed on the hydrogen sulfide (which is toxic to larger organisms if there is enough of it.) Oh, and by the way, some of the shrimps are likely cannibals!

One species called Rimicaris hybisae, according to the evidence, likely feeds on each other. This happens in areas where the bacteria are not as abundant and the organisms need to find some food to survive. To be sure, nobody saw the shrimps munching on each other, but scientists did find small crustaceans inside them — and there are few other types of crustaceans in the area.

But how likely, really, are these organisms on Europa? Bacteria might be plausible, but something larger and more complicated? The researchers say this all depends on how much energy the ecosystems have to offer. And in order to see up close, we’d have to get underwater somehow and do some exploring.

In a recent Universe Today interview with Mike Brown, a professor of planetary science at the California Institute of Technology, the renowned dwarf-planet hunter talked about how a submarine could do some neat work.

“In the proposed missions that I’ve heard, and in the only one that seems semi-viable, you land on the surface with basically a big nuclear pile, and you melt your way down through the ice and eventually you get down into the water,” he said. “Then you set your robotic submarine free and it goes around and swims with the big Europa whales.” You can see the rest of that interview here.

Source: Jet Propulsion Laboratory

The puzzling, fascinating surface of Jupiter's icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. Image credit: NASA/JPL-Caltech/SETI Institute — The puzzling, fascinating surface of Jupiter’s icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA’s Galileo spacecraft in the late 1990s. Image credit: NASA/JPL-Caltech/SETI Institute

December 3, 2014December 23, 2015 by Elizabeth Howell

DNA Won’t Be Killed Dead By A Rocket Ride To Space, Study Suggests

Launch of the TEXUS-51 sounding rocket that included plasmid DNA on the exterior of the rocket. A November 2014 study based on the flight suggests DNA could survive a suborbital spaceflight. Credit: Adrian Mettauer

So how ’bout those planetary protection agreements? Turns out that plasmid DNA — the kind that exists in bacterial cells — may be able to survive a rocket trip to space, based on research with an engineered version. And if life’s building blocks can get there, perhaps they can even go beyond. The International Space Station? Mars?

This information comes from a single peer-reviewed study based on a sounding rocket that went into suborbital space in March 2011. Called TEXUS-49, its payload included artificial plasmid DNA that had both a fluorescent marker and an antibiotic resistance gene.

Even in the 13-minute flight, temperatures on the rocket exterior soared to 1,000 degrees Celsius (1,832 degrees Fahrenheit.) And remarkably, the DNA survived.

While we talk about Earth having carbon-based life forms, the coding parts of DNA are nucleotides - with a carbon content of zero. Credit: NASA (adapted image). — While we talk about Earth having carbon-based life forms, the coding parts of DNA are nucleotides – with a carbon content of zero. Credit: NASA (adapted image).

Not all of the DNA was working properly, though. Up to 35% of it had its “full biological function”, researchers stated, specifically in terms of helping bacteria with antibiotic resistance and encouraging the fluorescent marker to express itself in eukaryotic cells, the cell type found in animals and plants.

The next step, naturally, would be to test this theory with more flights, the authors suggest. But interestingly enough, DNA survival wasn’t even the intended goal of the original study, even though there are stories of simple life surviving for a time in space, such as spores on the exterior of the International Space Station shown in the image below.

Images of Bacillus pumilus SAFR-032 spores (seen in an electron micrograph) on aluminum before and after being exposed to space on an International Space Station experiment. Credit: P. Vaishampayan, et al./Astrobiology

“We were totally surprised. Originally, we designed this experiment as a technology test for biomarker stability during spaceflight and re-entry,” the authors wrote in a statement for PLOS.

“We never expected to recover so many intact and functional active DNA. But it is not only an issue from space to Earth, it is also an issue from Earth to space and to other planets: Our findings made us a little bit worried about the probability of contaminating spacecrafts, landers and landing sites with DNA from Earth.”

You can read more about the study in the journal PLOS One. The research was led by the University of Zurich’s Cora Thiel.

Source: PLOS

December 2, 2014December 23, 2015 by Elizabeth Howell

Famous Hubble Star Explosion Is Expanding, New Animation Reveals

Eta Carinae from Hubble's STIS instrument. Credit: NASA, ESA, and the Hubble SM4 ERO Team

Wow! One of the most famous star explosions captured by the Hubble Space Telescope — several times — shows clear evidence of expansion in this new animation. You can see here the Homunculus Nebula getting bigger and bigger between 1995 and 2008, when Hubble took pictures of the Eta Carinae star system. More details from one of the animation authors below.

“I had the idea to check the Hubble image of Eta Carinae because I know this star rather well,” wrote Philippe Henarejos, one of the authors of the animation, in an e-mail to Universe Today. Henarejos has written several times about the star for the magazine he edits, Ciel et espace (Sky and Space) and also published a French-language book on star histories.

“Telling this story, I realized that astronomers knew for a long time that the Homunculus Nebula was expanding. Also, I knew that the HST had taken many photos of this object since 1995. So I thought that thanks to the very high resolution of the HST images, it could be possible to see the expansion.”

Along with colleague Jean-Luc Dauvergne, Henarejos tracked down two images in the archives and searched for a fixed object that wouldn’t be moving as the expansion occurred, which they decided would be two stars close to the border of the field of view. Then Dauvergne found a third image that clearly showed the expansion happening.

The two gentlemen then verified their findings with astronomer John Martin from the University of Illinois, who maintains a page on Eta Carinae. “He told me that the expansion is real,” Henarejos said.

And the animation is already getting attention. After being published in the new magazine First Light, it was featured today on the Astronomy Picture of the Day website.

Eta Carinae mysteriously brightened about 170 years ago, becoming the second-most luminous object in Earth’s night sky. Then it faded 150 years ago. Astronomers are still examining the system to see what might have caused this.

December 2, 2014December 23, 2015 by Elizabeth Howell

Philae’s Wild Comet Landing: Crater Grazing, Spinning And Landing In Parts Unknown

Philae landed nearly vertically on its side with one leg up in outer space. Here we see it in relation to the panoramic photos taken with the CIVA cameras. Credit: ESA

No, scientists haven’t found Philae yet. But as they churn through the scientific data on the comet lander, more information is emerging about the crazy landing last month that included three touchdowns and an incredible two hours of drifting before Philae came to rest in a relatively shady spot on the surface.

Among the latest: the tumbling spacecraft “collided with a surface feature” shortly after its first landing, perhaps grazing a crater rim with one of its legs. This information comes from an instrument called ROMAP (Rosetta Lander Magnetometer and Plasma Monitor) that monitors magnetic fields. The instrument is now being used to track down the spacecraft.

ROMAP’s usual role is to look at the comet’s magnetic field as it interacts with the solar wind, but the challenge is the orbiter (Rosetta) and lander both create tiny ones of their own due to the magnetic circuitry. Usually this data is removed to see what the comet’s environment is like. But during the landing, ROMAP was used to track Philae’s descent.

Four images of Comet 67P/Churyumov–Gerasimenko taken on Nov. 30, 2014 by the orbiting Rosetta spacecraft. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

Philae was supposed to fire harpoons to secure itself to the surface when it touched down at 3:34 p.m. UTC (10:34 a.m. EST) Nov. 12, but the mechanism failed. ROMAP’s data then shows the spin rate increasing, with the lander turning at one rotation every 13 seconds.

The grazing collision happened at 4:20 pm. UTC (11:20 a.m. EST), making the rotation decrease to once every 24 seconds. Then the final two touchdowns happened around 5:25 p.m. UTC (12:25 p.m. EST) and 5:31 p.m. UTC (12:31 p.m. EST). Controllers hope they can figure out exactly where Philae arrived once they look at data from ROMAP, CONSERT and other instruments on the lander.

Philae is now hibernating because there isn’t enough sunlight in its landing spot to recharge its battery through the solar panels. Rosetta, meanwhile, continues orbiting 67P and sending back pictures of the comet as it draws closer to the Sun, including the image you see further up in this blog post, released today (Dec. 2) a few days after it was taken in space.

Source: European Space Agency

December 2, 2014December 23, 2015 by Elizabeth Howell

Pluto’s Closeup Will Be Awesome Based On Jupiter Pics From New Horizons Spacecraft

A montage of images taken of Jupiter and its moon Io (foreground) by the New Horizons mission in 2007. Jupiter is shown in infrared wavelengths while Io is close to true-color. On top of Io is an eruption from the volcano Tvashtar. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

New Horizons, you gotta wake up this weekend. There’s so much work ahead of you when you reach Pluto next year! The spacecraft has been sleeping quietly for weeks in its last great hibernation before the dwarf planet close encounter in July. On Saturday (Dec. 6), the NASA craft will open its eyes and begin preparations for that flyby.

How cool will those closeups of Pluto and its moons look? A hint comes from a swing New Horizons took by Jupiter in 2007 en route. It caught a huge volcanic plume erupting off of the moon Io, picked up new details in Jupiter’s atmosphere and gave scientists a close-up of a mysterious “Little Red Spot.” Get a taste of the fun seven years ago in the gallery below.

An eruption from the Tvashtar volcano on Io, Jupiter's moon, in several different wavelength images taken by the New Horizons spacecraft in 2007. The left image from the Long Range Reconnaissance Imager (LORRI) shows lava glowing in the night. At top right, the Multispectral Visible Imaging Camera (MVIC) spotted sulfur and sulfor dioxide deposits on the sunny side of Io. The remaining image from the Linear Etalon Imaging Spectral Array (LEISA) shows volcanic hotspots on Io's surface. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute — An eruption from the Tvashtar volcano on Io, Jupiter’s moon, in several different wavelength images taken by the New Horizons spacecraft in 2007. The left image from the Long Range Reconnaissance Imager (LORRI) shows lava glowing in the night. At top right, the Multispectral Visible Imaging Camera (MVIC) spotted sulfur and sulfor dioxide deposits on the sunny side of Io. The remaining image from the Linear Etalon Imaging Spectral Array (LEISA) shows volcanic hotspots on Io’s surface. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Jupiter's "Little Red Spot" seen by the New Horizons spacecraft in 2007. The spot turned red in 2005 for reasons scientists were then unsure of, but speculated it could be due to stuff from inside the atmosphere being stirred up by a storm surge. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute — Jupiter’s “Little Red Spot” seen by the New Horizons spacecraft in 2007. The spot turned red in 2005 for reasons scientists were then unsure of, but speculated it could be due to stuff from inside the atmosphere being stirred up by a storm surge. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

A "family portrait" of the four Galilean satellites around Jupiter taken by the New Horizons spacecraft and released in 2007. From left, the montage includes Io, Europa, Ganymede and Callisto. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute — A “family portrait” of the four Galilean satellites around Jupiter taken by the New Horizons spacecraft and released in 2007. From left, the montage includes Io, Europa, Ganymede and Callisto. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

A composite of Jupiter's bands (and atmospheric structures) taken in several images by the New Horizons Multispectral Visual Imaging Camera, showing differences due to sunlight and wind. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute — A composite of Jupiter’s bands (and atmospheric structures) taken in several images by the New Horizons Multispectral Visual Imaging Camera, showing differences due to sunlight and wind. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

In February and March 2007, a huge plume erupted from the Tvashtar volcano on Jupiter's moon Io. The image sequence taken by New Horizons showed the largest such explosion then viewed by a spacecraft -- even accounting for the Galileo spacecraft that examined Io between 1996 and 2001. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute — In February and March 2007, a huge plume erupted from the Tvashtar volcano on Jupiter’s moon Io. The image sequence taken by New Horizons showed the largest such explosion then viewed by a spacecraft — even accounting for the Galileo spacecraft that examined Io between 1996 and 2001. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

The New Horizons flyby of Io in 2007 (right) revealed a changing feature on the surface of the Jupiter moon since Galileo's image of 1999 (left.) Inside the circle, a new volcanic eruption spewed material; other pictures showed this region was still active. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute — The New Horizons flyby of Io in 2007 (right) revealed a changing feature on the surface of the Jupiter moon since Galileo’s image of 1999 (left.) Inside the circle, a new volcanic eruption spewed material; other pictures showed this region was still active. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

December 2, 2014December 23, 2015 by Elizabeth Howell

Orion’s ‘Glass Cockpit’ Will Steer Astronauts Through The Solar System

Screenshot of ground testing of the Orion spacecrafts "glass cockpit." Credit: NASA/YouTube (screenshot)

If it’s good enough for a Boeing 787, it’s gotta be good enough for space, right? NASA’s Orion spacecraft — poised for its first uncrewed flight on Thursday (Dec. 4) — will eventually include a “glass cockpit” that will make it easier for astronauts to step across the Solar System, based on the passenger jet avionics.

Why go for glass over switches? The huge benefit is weight (which means less fuel expended to heft the spacecraft), according to the NASA video above.

“One big benefit is the weight savings because you don’t need to have a physical switch,” said astronaut Lee Morin, who was involved in the design, in the video. “With a physical switch, not only is there the weight of the switch, but you also have the weight of the wire to the switch, and you have to have the weight of the circuity that takes that wire and feeds it into the vehicle computers.”

This means that the new spacecraft will sport only 60 physical switches for the astronauts to control (the video did not specify what they would do), which could also be simpler in terms of usability.

The cockpit, however, is not quite ready for prime-time. Although Exploration Test Flight-1 (ETF-1) will have most of the Orion systems included in the crew portion, the glass cockpit will not be among them, according to the flight’s press kit. “The only crew module systems that will not fly on this vehicle are the environmental control and life support system; and the crew support systems such as displays, seats and crew-operable hatches,” it reads.

But there will be more testing ahead. Orion is slated to run its next flight in about 2017 or 2018, which could include a more complete spacecraft at that time. Meanwhile, people are already starting to gather for the test flight, which will see the deepest space exploration by a crew capsule since the Apollo era. Orion will roar into space and return for a high-speed re-entry to make sure that heat shield works when NASA sticks people inside.

The goal, eventually, is to bring astronauts all over the solar system — to an asteroid, the Moon or even Mars. Check out this recent step-by-step animation of how this test flight is going to go forward. Universe Today’s Ken Kremer will be on site for the historic day.

December 1, 2014December 23, 2015 by Elizabeth Howell

Jupiter-Bound Spacecraft Takes A Small Step To Seek Habitable Worlds

Artist's impression of the Jupiter Icy Moons Explorer (JUICE) near Jupiter and one of its moons, Europa. Credit: ESA/AOES

It takes years of painstaking work to get a spacecraft off the ground. So when you have a spacecraft like JUICE (the Jupiter Icy Moons Explorer) set to launch in 2022, you need to back up about a decade to get things figured out. How will the spacecraft get there? What science instruments will it carry? What will the spacecraft look like and what systems will support its work?

JUICE just hit another milestone in its development a few days ago, when the European Space Agency gave the go-ahead for the “implementation phase” — the part where the spacecraft design begins to take shape. The major goal of the mission will be to better understand those moons around Jupiter that could be host to life.

The spacecraft will reach Jupiter’s system in 2030 and begin with observations of the mighty planet — the biggest in our Solar System — to learn more about the gas giant’s atmosphere, faint rings and magnetic environment. It also will be responsible for teaching us more about Europa (an icy world that could host a global ocean) and Callisto (a moon pockmarked with the most craters of anything in the Solar System.)

Its major departure from past missions, though, will come when JUICE enters orbit around Ganymede. This will the first time any spacecraft has circled an icy moon repeatedly; past views of the moon have only come through flybys by the passing-through spacecraft (such as Pioneer and Voyager) and the Galileo mission, which stuck around Jupiter’s system in the 1990s and early 2000s.

With Ganymede, another moon thought to host a global ocean, JUICE will examine its surface and insides. What makes the moon unique in our neighborhood is its ability to create its own magnetic field, which creates interesting effects when it interacts with Jupiter’s intense magnetic environment.

“Jupiter’s diverse Galilean moons – volcanic Io, icy Europa and rock-ice Ganymede and Callisto – make the Jovian system a miniature Solar System in its own right,” the European Space Agency stated when the mission was selected in 2012.

“With Europa, Ganymede and Callisto all thought to host internal oceans, the mission will study the moons as potential habitats for life, addressing two key themes of cosmic vision: what are the conditions for planet formation and the emergence of life, and how does the Solar System work?”

JUICE is one of several major spacecraft ESA plans to launch in the next couple of decades. You can read more about the other Cosmic Vision candidates at this ESA website.

Source: European Space Agency

December 1, 2014December 23, 2015 by Elizabeth Howell

Dawn Spacecraft Will Take Pictures Of Its Target Dwarf Planet Today

Artist's conception of the Dawn spacecraft approaching the asteroid Ceres. Credit: NASA/JPL-Caltech

The year 2015 is going to be a big one for far-off spacecraft. Among them is the long-running Dawn mission, which is on its way to the dwarf planet Ceres (by way of Vesta) and should settle into orbit in April after a radiation blast delayed the original flight plan.

And today (Dec. 1) comes a special day for Dawn — when it turns its cameras to Ceres to capture the world, which will appear about nine pixels across. The reason? Besides scientific curiosity, it turns out to be a perfect calibration target, according to NASA.

“One final calibration of the science camera is needed before arrival at Ceres,” wrote Marc Rayman, the mission director at the Jet Propulsion Laboratory, in a recent blog post.

“To accomplish it, the camera needs to take pictures of a target that appears just a few pixels across. The endless sky that surrounds our interplanetary traveler is full of stars, but those beautiful pinpoints of light, while easily detectable, are too small for this specialized measurement. But there is an object that just happens to be the right size. On Dec. 1, Ceres will be about nine pixels in diameter, nearly perfect for this calibration.”

The Dawn spacecraft's first image of Ceres, taken July 20, 2010. Credit: NASA/JPL-Caltech/MPS/DLR/IDA — The Dawn spacecraft’s first image of Ceres, taken July 20, 2010. Credit: NASA/JPL-Caltech/MPS/DLR/IDA

This isn’t the first picture of Ceres by Dawn — not by a long-shot — but it sure will loom bigger than you see in the image at left, which was taken in 2010. Dawn hadn’t even arrived at Vesta at the time, the blog post points out, and the spacecraft was about 1,300 times further from Ceres then as it is now. Translating that into visual magnitude, the new pictures of Ceres will show an appearance about as bright as Venus, from Earth’s perspective.

In October, the Dawn blog said that more pictures of Ceres are planned on Jan. 13, when Ceres will appear 25 pixels across. This won’t be quite the best view ever — that was taken by the Hubble Space Telescope, which you can see below, — but just wait a couple of weeks. The mission planners say that by Jan. 26, the images will be slightly better. On Feb. 4, they will be twice as good and by Feb. 20, seven times as good.

As with the calibration photo taken today, these photos in 2015 will have a double purpose: optical navigation. It’s to help the spacecraft figure out where to go, because our pictures of Ceres are so fuzzy that mission planners will need more exact information as the mission proceeds.

You can read more information about the picture-taking, and Dawn’s planned approach to Ceres, in the Nov. 28 entry of the Dawn blog.