Humans Last Landed On The Moon 42 Years Ago Today

Apollo 17 commander Eugene Cernan with the lunar rover in December 1972, in the moon's Taurus-Littrow valley. Credit: NASA

For a brief period in the 1960s and 1970s, 12 people ventured all the way to the surface of the Moon. The accomplishment at the time was hailed as a political victory over the Soviet Union, but as decades have passed the landings have taken on more symbolic meaning with NASA — a time of optimism, of science and of the American spirit.

The last lunar landing was Apollo 17, which took place on Dec. 11, 1972. Commander Eugene Cernan and lunar module pilot Harrison Schmitt did three moonwalks in the Taurus-Littrow valley, scoping out the highlands to try to get a geologic sense of the area. Among their more memorable findings are orange soil. You can see some pictures from their sojourn below.

Apollo 17's Saturn V rocket poised on the launch pad before its Dec. 7, 1972 takeoff. Credit:
Apollo 17’s Saturn V rocket poised on the launch pad before its Dec. 7, 1972 takeoff. Credit:
Apollo 17's lunar rover, flag and part of the lunar module in this view taken out the module's window. Credit: NASA
Apollo 17’s lunar rover, flag and part of the lunar module in this view taken out the module’s window. Credit: NASA
Apollo 17 commander Gene Cernan with a gravimeter experiment. The lunar rover is at right. Credit; NASA
Apollo 17 commander Gene Cernan with a gravimeter experiment. The lunar rover is at right. Credit; NASA
Orange soil (from volcanic glass beads) is clearly visible in this image from Apollo 17. Credit: NASA
Orange soil (from volcanic glass beads) is clearly visible in this image from Apollo 17. Credit: NASA
The Apollo 17 command module America and its service module, as photographed by the returning lunar module Challenger. Credit: NASA
The Apollo 17 command module America and its service module, as photographed by the returning lunar module Challenger. Credit: NASA

A Martian Blue Snake, Brought To You By Canadians And A Spacecraft

A false-color image of part of Cerberus Fossae on Mars. The view shows two rifts intersecting with each other, with sand (in deep blue) and dust. Credit: NASA/JPL-Caltech/University of Arizona/Western University Planetary Sciences Division

Here’s the awesome thing about space and social media: in some cases, you can often follow along with a mission almost as soon as the images come to Earth. A group of Canadians is taking that to the next level this month as they take control of the 211th imaging cycle of a powerful camera on the Mars Reconnaissance Orbiter.

While some images need to be kept back for science investigations, the team is sharing several pictures a day on Twitter and on Facebook portraying the views they saw coming back from the High Resolution Imaging Science Experiment (HiRISE) camera. The results are astounding, as you can see in the images below.

“It’s mind-blowing to realize that when the team, myself included, first look at the images, we are likely the first people on Earth to lay eyes upon a portion of the Martian surface that may have not been imaged before at such high resolution,” stated research lead Livio Tornabene, who is part of Western University’s center for planetary science and exploration.

The team will capture up to 150 images between Nov. 30 and Dec. 12, and already have released close to two dozen to the public. Some of the best are below.

Mars Landing Recipe: Orion, A Big Rocket And Pretty-On-Paper Spacecraft

A futuristic Mars lander portrayed in a December 2014 video from Boeing called "The Path To Mars." Credit: Boeing / YouTube (screenshot)

Can the just-flown Orion spacecraft truly get us to Mars? NASA has been portraying the mission as part of the roadmap to the Red Planet, but there are observers who say a human landing mission is an unrealistic goal given the budget just isn’t there right now in Congress.

That doesn’t stop Boeing from dreaming, though. In this new video, the prime contractor for the future Space Launch System rocket suggests that going to Mars will take six spacecraft elements. Two are in the works right now — Orion and SLS — while a Mars lander and other bits are just ideas right now, but shown in the video.

According to Boeing, the missing elements include a deep-space tug, a habitat, a lander and a rocket designed to get up out of the Mars gravity well. They also suggest it will take several SLS launches to assemble all the pieces to bring humans to the Red Planet.

“I think we’ll be able to colonize Mars someday,” said Mike Raftery, director of Boeing Space Exploration Systems, in the video. “It’ll take time. It may take hundreds of years. But that’s not unusual for humans. It’s really about establishing a human foothold on the planet. It’s a natural evolution of humanity to take this challenge on.”

That said, the video does hold to the old joke that a Mars landing is always 20 years in the future; the opening sequence suggests that the landing would take place in the 2030s and that those first astronauts are between the ages of 10 to 20 right now. What will it take to make the Mars mission possible? Let us know in the comments.

Edit, 3:39 p.m. EST: Thank you to a reader on Twitter, who pointed out this presentation by Boeing that explains the concepts in more detail.

Swirly Southern Picture Of Jupiter Makes Us Want To Visit Right Now

A view the Cassini spacecraft took during its flyby of Jupiter's southern pole in 2000. Credit: NASA/JPL/Space Science Institute

Gimme a rocketship – we want to see what those bands are made of! This is a strange view of Jupiter, a familiar gas giant that humanity has sent several spacecraft to. This particular view, taken in 2000 and highlighted on the European Space Agency website recently, shows the southern hemisphere of the mighty planet.

The underneath glimpse came from the Cassini spacecraft while it was en route to Saturn. Lucky for researchers, at the time the Galileo Jupiter spacecraft was still in operation. But now that machine is long gone, leaving us to pine for a mission to Jupiter until another spacecraft gets there in 2016.

That spacecraft is called Juno and is a NASA spacecraft the agency sent aloft in August 2011. And here’s the cool thing; once it gets there, Juno is supposed to give us some insights into how the Solar System formed by looking at this particular planet.

Juno will repeatedly dive between the planet and its intense belts of charged particle radiation, coming only 5,000 kilometers (about 3,000 miles) from the cloud tops at closest approach. (NASA/JPL-Caltech)
Juno will repeatedly dive between the planet and its intense belts of charged particle radiation, coming only 5,000 kilometers (about 3,000 miles) from the cloud tops at closest approach. (NASA/JPL-Caltech)

“Underneath its dense cloud cover, Jupiter safeguards secrets to the fundamental processes and conditions that governed our Solar System during its formation. As our primary example of a giant planet, Jupiter can also provide critical knowledge for understanding the planetary systems being discovered around other stars,” NASA wrote on the spacecraft’s web page.

The spacecraft is supposed to look at the amount of water in Jupiter’s atmosphere (an ingredient of planet formation), its magnetic and gravitational fields and also its magnetic environment — including auroras.

Much further in the future (if the spacecraft development is approved all the way) will be a European mission called JUICE, for Jupiter Icy Moon Explorer.

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

The mission will check out the planet and three huge moons, Ganymede, Callisto and Europa, to get a better look at those surfaces. It is strongly believed that these moons could have global oceans that may be suitable for life.

Earlier this month, the European Space Agency approved the implementation phase for JUICE, which means that designers now have approval to come up with plans for the spacecraft. But it’s not going to launch until 2022 and get to Jupiter until 2030, if the schedule holds.

Meanwhile, observations of Jupiter do continue from the ground. One huge finding this year came from the Hubble Space Telescope, which confirmed observations that the Great Red Spot is shrinking for reasons that are yet unknown.

Saturn Smackdown! Icy Moons Burned By Radiation And Ions

This global map of Dione, a moon of Saturn, shows dark red in the trailing hemisphere, which is due to radiation and charged particles from Saturn's intense magnetic environment. Credit: NASA/JPL/Space Science Institute

If you hang out in Saturn’s intense magnetic environment for a while, it’s going to leave a mark. That’s one conclusion from scientists who proudly released new maps yesterday (Dec. 9) of the planet’s icy moons, showing dark blotches on the surfaces of Dione, Rhea, and Tethys.

Cassini has been at Saturn for more than 10 years, and compared to the flyby Voyager mission has given us a greater understanding of what these moons contain. You can see the difference clearly in the maps below; look under the jump and swipe back and forth to see the difference.

So what do these maps yield? Radiation-burned hemispheres in Dione, Tethys, and Rhea. Icy deposits building up on Enceladus from eruptions, which you can see in yellow and magenta, as well as fractures in blue. Dust from Saturn’s E-ring covering several of the moons, except for Iapetus and Tethys.

"Tiger stripes" -- sources of ice spewing -- in this image of Saturn's Enceladus taken by the Cassini spacecraft in 2009. Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
“Tiger stripes” — sources of ice spewing — in this image of Saturn’s Enceladus taken by the Cassini spacecraft in 2009. Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Could these be used by future explorers seeking life in some of these moons? In the meantime, enjoy the difference between Voyager’s view in the 1980s, and Cassini’s view for the past decade, in the comparison maps below.

A caution about the maps: they are a little more enhanced than human vision, showing some features in infrared and ultraviolet wavelengths. “Differences in color across the moons’ surfaces that are subtle in natural-color views become much easier to study in these enhanced colors,” NASA stated.

Dione

Enceladus

Iapetus

Mimas

Rhea

Tethys

Fear Not: Quarter-Mile Asteroid Is No Threat To Earth, NASA Says

Illustration of small asteroids passing near Earth. Credit: ESA / P. Carril

Before assuming an asteroid is going to kill us all, take a deep breath and open up the NASA’s Near Earth Object (NEO) program website to check your information, the agency suggests in a statement regarding a so-called threatening asteroid making the rounds in media reports.

Data from the Minor Planet Center shows that the quarter-mile-wide asteroid 2014 UR116 won’t pose a threat to Earth or any other planet in the next 150 years or more, the agency said.

“Some recent press reports have suggested that an asteroid designated 2014 UR116, found on October 27, 2014, at the MASTER-II observatory in Kislovodsk, Russia, represents an impact threat to the Earth,” NASA wrote, assumedly referring to publications such as this one in Russia.

“While this approximately 400-meter sized asteroid has a three-year orbital period around the sun and returns to the Earth’s neighborhood periodically, it does not represent a threat because its orbital path does not pass sufficiently close to the Earth’s orbit … Any statements about risk for impact of discovered asteroids and comets should be verified by scientists and the media by accessing NASA’s Near Earth Object (NEO) program web site.”

Three classes of asteroids that pass near Earth or cross its orbit are named for the first member discovered — Apollo, Aten and Amor. Apollo asteroids like 2014 SC324 routinely cross Earth’s orbit, Atens also cross but have different orbital characteristics and Amors cross Mars’ orbit but miss Earth’s. Credit: ESA
Three classes of asteroids that pass near Earth or cross its orbit are named for the first member discovered — Apollo, Aten and Amor. Apollo asteroids like 2014 SC324 routinely cross Earth’s orbit, Atens also cross but have different orbital characteristics and Amors cross Mars’ orbit but miss Earth’s. Credit: ESA

The threat from comets and asteroids hit a fever pitch last year after the Chelyabinsk meteoroid exploded over Russia, injuring thousands and causing property damage (such as blown-out windows). The incident caused NASA, the European Space Agency and others to express a renewed commitment in watching these interluders from Earth.

In the months after the incident, the European Space Agency established an asteroid monitoring center that is intended to be a co-ordination hub for asteroid threats detected in Europe and elsewhere. NASA administrator Charles Bolden also talked about the threat in a Congressional hearing, suggesting measures such as crowdsourcing, co-ordination with other agencies and more telescopic feeds to supplement the monitoring program NASA has right now.

Years ago, Congress directed NASA to find 90% of asteroids 140 meters or larger by 2020, which the agency says is well within reach. Chelyabinsk was only a fraction of that size.

Bizarre Mars: Did Lava Bubbles Wrinkle This Giant Circle?

The Mars Reconnaissance Orbiter took this image of a "circular feature" estimated to be 1.2 miles (2 kilometers) in diameter. Picture released in December 2014. Credit: NASA/JPL-Caltech/University of Arizona

NASA is puzzled by this “enigmatic landform” caught on camera by one of its Mars orbiters, but looking around the region provides some possible clues. This 1.2-mile (2-kilometer) feature is surrounded by relatively young lava flows, so they suspect that it could be some kind of volcanism in the Athabasca area that created this rippled surface.

“Perhaps lava has intruded underneath this mound and pushed it up from beneath. It looks as if material is missing from the mound, so it is also possible that there was a significant amount of ice in the mound that was driven out by the heat of the lava,” NASA wrote in an update on Thursday (Dec. 4).

“There are an array of features like this in the region that continue to puzzle scientists. We hope that close inspection of this … image, and others around it, will provide some clues regarding its formation.”

The picture was captured by the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE), a University of Arizona payload which has released a whole slew of intriguing pictures lately. We’ve collected a sample of them below.

These transverse aeolian ridges seen by the Mars Reconnaissance Orbiter are caused by wind, but scientists are unsure why this image (released in December 2014) shows two wavelengths of ripples. Credit: NASA/JPL-Caltech/University of Arizona
These transverse aeolian ridges seen by the Mars Reconnaissance Orbiter are caused by wind, but scientists are unsure why this image (released in December 2014) shows two wavelengths of ripples. Credit: NASA/JPL-Caltech/University of Arizona
This area south of Coprates Chasma is an example of sulfate and clay deposits on Mars, showing water once flowed readily in this region. Why the water evaporated from the Red Planet is one question scientists are hoping to answer with missions such as the Mars Reconnaissance Orbiter, which took this image (released in December 2014). Credit: NASA/JPL-Caltech/University of Arizona
This area south of Coprates Chasma is an example of sulfate and clay deposits on Mars, showing water once flowed readily in this region. Why the water evaporated from the Red Planet is one question scientists are hoping to answer with missions such as the Mars Reconnaissance Orbiter, which took this image (released in December 2014). Credit: NASA/JPL-Caltech/University of Arizona
Arabia Terra, one of the dustiest regions on Mars, is filled with dunes such as this one captured by the Mars Reconnaissance Orbiter and released in December 2014. Credit: NASA/JPL/University of Arizona
Arabia Terra, one of the dustiest regions on Mars, is filled with dunes such as this one captured by the Mars Reconnaissance Orbiter and released in December 2014. Credit: NASA/JPL/University of Arizona

Why NASA’s Orion Spacecraft Flew Old, Slow Computers Into Orbit

The Orion spacecraft floats in the Pacific Ocean after an uncrewed orbital flight test Dec. 5, 2014. In the background is the recovery ship, the USS Anchorage. Credit: NASA

It’s funny to think that your smartphone might be faster than a new spaceship, but that’s what one report is saying about the Orion spacecraft. The computers are less-than-cutting-edge, the processors are 12 years old, and the speed at which it “thinks” is … slow, at least compared to a typical laptop today.

But according to NASA, there’s good reasoning behind using older equipment. In fact, it’s common for the agency to use this philosophy when designing missions — even one such as Orion, which saw the spacecraft soar 3,600 miles (roughly 5,800 kilometers) above Earth in an uncrewed test last week and make the speediest re-entry for a human spacecraft since the Apollo years.

The reason, according to a Computer World report, is to design the spacecraft for reliability and being rugged. Orion — which soared into the radiation-laden Van Allen belts above Earth — needs to withstand that environment and protect humans on board. The computer is therefore based on a well-tested Honeywell system used in 787 jetliners. And Orion in fact carries three computers to provide redundancy if radiation causes a reset.

Up close view of Orion inside the mobile service tower pad 37 at Cape Canaveral Air Force Station in Florida one day prior to launch.   Credit: Ken Kremer - kenkremer.com
Up close view of Orion inside the mobile service tower pad 37 at Cape Canaveral Air Force Station in Florida one day prior to launch. Credit: Ken Kremer – kenkremer.com

“The one thing we really like about this computer is that it doesn’t get destroyed by radiation,” said Matt Lemke, NASA’s deputy manager for Orion’s avionics, power and software team, in the report. “It can be upset, but it won’t fail. We’ve done a lot of testing on the different parts of the computer. When it sees radiation, it might have to reset, but it will come back up and work again.”

A 2013 NASA presentation points out that the agency is a common user of commercial off-the-shelf (COTS) electronics. This usually happens for three reasons: officials can’t find military or aerospace alternatives, unknown risks are a part of the mission, or a mission has “a short lifetime or benign space environment exposure”. NASA makes sure to test the electronics beyond design limits and will often make accommodations to make it even safer. Ideally, the use of proven hardware overall reduces risk and cost for a mission, if used properly.

“The more understanding you have of a device’s failure modes and causes, the higher the confidence level that it will perform under mission environments and lifetime,” the presentation says. “Qualification processes are statistical beasts
designed to understand/remove known reliability risks and uncover unknown risks inherent in a part.”

Artist's conception of NASA's Space Launch System. Credit: NASA
Artist’s conception of NASA’s Space Launch System. Credit: NASA

In fact, the rocket that is eventually supposed to pair up with Orion will also use flight-tested systems for at least the first few flights. The Space Launch System, which NASA hopes will heft Orion on the next test flight in 2017 or 2018, will use solid rocket boosters based on those used with the shuttle. But NASA adds that upgrades are planned to the technology, which flew on shuttle missions in space starting in 1981.

“Although similar to the solid rocket boosters that helped power the space shuttle to orbit, the five-segment SLS boosters include several upgrades and improvements implemented by NASA and ATK engineers,” NASA wrote in a 2012 press release. “In addition, the SLS boosters will be built more affordably and efficiently than shuttle boosters, incorporating new and innovative processes and technologies.”

A handful of other prominent space recycling uses in space exploration:

Crazy Space Christmases: Moon Readings, Food Cans And Emergency Repairs

"AstroButch [Butch Wilmore] has set up our Xmas tree in the lab and hung socks for us," tweeted astronaut Samantha Cristoforetti from the International Space Station Dec. 7, 2014. Credit: Samantha Cristoforetti/Twitter

If you think the upside-down Christmas tree above is bizarre — that’s one of the latest activities of Expedition 42 astronauts in space right now — think back to the history of other holidays in orbit.

We’ve seen a vital telescope undergo repairs, an emergency replacement of part of a space station’s cooling system, and even a tree made of food cans. Learn more about these fun holiday times below.

Reading from above the moon (Apollo 8, 1969)

In this famous reading from the Bible, astronauts Frank Borman, Jim Lovell and Bill Anders shared their experience looking at the Moon on Dec. 24, 1968. The Apollo 8 crew was the first to venture to lunar orbit, just seven months before the Apollo 11 crew made it all the way to the surface.

Food can “Christmas tree” (Skylab 4, 1973)

A "Christmas tree" created out of food cans by the Skylab 4 crew in 1973. Credit: NASA
A “Christmas tree” created out of food cans by the Skylab 4 crew in 1973. Credit: NASA

Living on the Skylab station taught astronauts the value of improvisation, such as when the first crew (under NASA’s instructions) repaired a sunshield to stop electronics and people from roasting inside. Skylab 4 took the creativity to Christmas when they created a tree out of food cans.

Hubble Space Telescope repair (STS-103, 1999)

The Hubble Space Telescope during a 1999 repair mission with STS-103 crew members Mike Foale (left, for NASA) and Claude Nicollier (European Space Agency). Credit: NASA
The Hubble Space Telescope during a 1999 repair mission with STS-103 crew members Mike Foale (left, for NASA) and Claude Nicollier (European Space Agency). Credit: NASA

When the Hubble Space Telescope was in hibernation due to a failed gyroscope, the STS-103 crew made repairs in December 1999 that culminated with the final spacewalk on Christmas Day. The telescope remains in great shape to this day, following another repair mission in 2009.

First Christmas on the International Space Station (Expedition 1, 2000)

The Expedition 1 crew with fresh oranges on the International Space Station in December 2000. From left, Yuri Gidzenko (Roscosmos), Bill Shepherd (NASA) and Sergei Krikalev (Roscosmos). Credit: NASA
The Expedition 1 crew with fresh oranges on the International Space Station in December 2000. From left, Yuri Gidzenko (Roscosmos), Bill Shepherd (NASA) and Sergei Krikalev (Roscosmos). Credit: NASA

The Expedition 1 crew was the first on the International Space Station to spend Christmas in orbit. “On this night, we would like to share with all-our good fortune on this space adventure; our wonder and excitement as we gaze on the Earth’s splendor; and our strong sense — that the human spirit to do, to explore, to discover — has no limit,” the crew said in a statement on Christmas Eve, in part.

Ammonia tank replacement (Expedition 38, 2013)

Just last year, an ammonia tank failure crippled a bunch of systems on the International Space Station and forced spacewalkers outside to fix the problem, in the middle of a leaky suit investigation. The astronauts made the final repairs ahead of schedule, on Christmas Eve.

Did Philae Land In That Comet Crater? One Month Later, The Search Continues

A mosaic of Comet 67P/Churyumov-Gerasimenko taken Dec. 2 with the Rosetta spacecraft. The shadowed area is a crater in which Philae is expected to be. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

Don’t forget about Philae! The comet lander made a touchdown a month ago this week on its target, marking the first time we’ve ever made a soft landing on such a body. Celebrations were quickly mixed with confusion, however, as controllers realized the spacecraft drifted quite a ways off target. In fact, we still don’t know exactly where it is.

The parent Rosetta spacecraft is working well in orbit and still transmitting images of the comet while Philae hibernates in a shady spot below. This latest image here shows a clear view of where the European Space Agency thinks the lander arrived — somewhere in the rim of that shadowy crater you see up front.

“The internal walls are seen in quite some detail. It is thought that Philae’s final touchdown site might be located close to the rim of this depression, but further high-resolution imaging is still being obtained and analyzed to confirm this,” the agency wrote in a statement concerning the image of Comet 67P/Churyumov-Gerasimenko.

This is based on data collected from Philae in a brief science surge on the surface. Recently, information based on measured magnetic fields showed the spacecraft likely hit an object — perhaps a crater rim — as it drifted for two hours on the surface, unsecured by the harpoons that were supposed to fire to hold it in place.

The distortion at bottom of this mosaic of Comet 67P/Churyumov-Gerasimenko occured as imagers made image joining adjustments for the comet's rotation and the movements of the Rosetta spacecraft. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
The distortion at bottom of this Dec. 1, 2014 mosaic of Comet 67P/Churyumov-Gerasimenko occured as imagers made image joining adjustments for the comet’s rotation and the movements of the Rosetta spacecraft. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

Searches for the lander are ongoing, but it’s hard to pick it out on such a boulder-strewn landscape. Yet the agency is doing its mightiest, and has made some progress on the problem since the landing took place. Rosetta caught several glimpses of the lander during its journey across the surface. And they have data from an experiment that communicated between Rosetta and Philae which could help pinpoint the location.

Rosetta science results have been quiet in the past week, although ESA has released several images of the comet. This comes as the agency has been criticized for its data release policy regarding the mission. It’s a vigorous debate, with there being examples of more open missions (such as Curiosity) and more closed missions (such as the Hubble Space Telescope) to compare Rosetta’s releases with.

As these activities continue, however, Rosetta will remain transmitting information from 67P through at least part of 2015, watching the comet increase in activity as both draw closer to the Sun. Jets and gas are visible already in some of the recent images of the comet, which you can see below.

Comet 67P/Churyumov-Gerasimenko viewed by the Rosetta spacecraft on Nov. 30, 2014 showing off layered material in the "neck" of the comet. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Comet 67P/Churyumov-Gerasimenko viewed by the Rosetta spacecraft on Nov. 30, 2014 showing off layered material in the “neck” of the comet. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Erupting gas and dust is just visible in the "neck" region of Comet 67P/Churyumov-Gerasimenko in this montage taken Nov. 26, 2014 by the Rosetta spacecraft. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Erupting gas and dust is just visible in the “neck” region of Comet 67P/Churyumov-Gerasimenko in this montage taken Nov. 26, 2014 by the Rosetta spacecraft. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Gas and dust stream from Comet 67P/Churyumov–Gerasimenko in this mosaic from the Rosetta spacecraft taken Nov. 20, 2014. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Gas and dust stream from Comet 67P/Churyumov–Gerasimenko in this mosaic from the Rosetta spacecraft taken Nov. 20, 2014. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0