A forced perspective view of Profokiev crater near Mercury's north pole
It’s always good to get a little change of perspective, and with this image we achieve just that: it’s a view of Mercury’s north pole projected as it might be seen from above a slightly more southerly latitude. Thanks to the MESSENGER spacecraft, with which this image was originally acquired, as well as the Arecibo Observatory here on Earth, scientists now know that these polar craters contain large deposits of water ice – which may seem surprising on an airless and searing-hot planet located so close to the Sun but not when you realize that the interiors of these craters never actually receive sunlight.
The locations of ice deposits are shown in the image in yellow. See below for a full-sized version.
Perspective view of Mercury’s north pole made from MESSENGER MDIS images and Arecibo Observatory data. (NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)
The five largest ice-filled craters in this view are (from front to back) the 112-km-wide Prokofiev and the smaller Kandinsky, Tolkien, Tryggvadottir, and Chesterton craters. A mosaic of many images acquired by MESSENGER’s Mercury Dual Imaging Sustem (MDIS) instrument during its time in orbit, you would never actually see a view of the planet’s pole illuminated like this in real life but orienting it this way helps put things into…well, perspective.
Radar observations from Arecibo showing bright areas on Mercury’s north pole
Radar-bright regions in Mercury’s polar craters have been known about since 1992 when they were first imaged from the Arecibo Observatory in Puerto Rico. Located in areas of permanent shadow where sunlight never reaches (due to the fact that Mercury’s axial tilt is a mere 2.11º, unlike Earth’s much more pronounced 23.4º slant) they have since been confirmed by MESSENGER observations to contain frozen water and other volatile materials.
Similarly-shadowed craters on our Moon’s south pole have also been found to contain water ice, although those deposits appear different in composition, texture, and age. It’s suspected that some of Mercury’s frozen materials may have been delivered later than those found on the Moon, or are being restored via an ongoing process. Read more about these findings here.
In orbit around Mercury since 2011, MESSENGER is now nearing the end of its operational life. Engineers have figured out a way to extend its fuel use for an additional month, possibly delaying its inevitable descent until April, but even if this maneuver goes as planned the spacecraft will be meeting Mercury’s surface very soon.
One of the possible outcomes of today. Falcon 9 sits on the barge, ready to go back home. Image Credit: Reddit user zlsa (zlsa.github.io) CC-BY-SA.
Editor’s note: This guest post was written by Lukas Davia & Marijn Achternaam.
Typing “reusable rockets” into a search engine, you can’t help but be drawn to the allure of SpaceX-related links which fill the screen. In fact, the corporate brainchild of Elon Musk dominates the first few pages of results near-exclusively. The reason for this is understandable: with the death of the Space Shuttle and lack of clear planning for the future by most old players in the spaceflight field, SpaceX’s straightforward, near term plan and previous flight tests make them everyone’s favorite to drastically reduce cost to orbit with rockets which return home – ready to be reused.
And with the upcoming launch of SpaceX’s 14th Falcon 9 rocket on January 6 carrying Dragon to the ISS, the potential for true rocket reusability is certainly within reach for the first time ever in the near 90 years since Goddard launched the world’s first liquid fueled rocket from Massachusetts in 1926. Yet, now is a more important time than ever to temper our wild expectations for the possibility of rockets which fly themselves back to the launch pad. While a rocketry revolution may be among us, it is an iterative, multi-step process that transcends any single mission — and we shouldn’t expect to see regular airline-like reuse and large cost drops anytime soon.
It should be noted that Elon Musk, for all his amazing accomplishments, has never placed a hard and fast timeline on when cheap and accessible rocketry would be available, let alone a solid price. Why? Simply because we are entering territory that remains uncharted.
The only launch vehicle in history that has ever been re-flown several times after achieving orbit was the Space Shuttle. Despite reusing by far the most expensive part of any rocket — the engines and associated systems — the Shuttle cost at least $450 million to launch according to NASA, with a relatively small payload of 24 metric tons to Low Earth Orbit, or almost $19,000 per kilogram. Including development costs, summed and divided up per flight, the price to launch can average as high as $1.5 billion, or thrice NASA’s stated amount. What was supposed to drastically reduce the cost per kilogram of lifting cargo to orbit ended up being one of the most expensive launch vehicles in human history. Why did it become so expensive?
The conception of the Space Shuttle was a result of a marriage between NASA, the Air Force, and other partners. Each wanted their own design specifications, which ended up producing a wieldy vehicle with no well-defined purpose, and it became the “catch all” of the space industry. Mainly, it was that the amount of maintenance required after every mission was greatly underestimated by NASA. After each flight, the entire vehicle had to be essentially rebuilt: tiles replaced, engines inspected, boosters refurbished. In particular, the trio of RS-25 main engines had to be taken apart and checked for every possible defect that could cause a failure, and when things broke, there wasn’t a healthy supply-line that could replace them easily, causing the cost of spare parts to skyrocket, and maintaining a workforce ready and able to refurbish the Shuttle quickly became a money-sink that NASA was never able to recover.
SpaceX isn’t NASA though. They’ve introduced a more agile, responsive development approach to their products which has been overwhelmingly successful. They also have years of prior projects (from multiple sources) to learn from that NASA didn’t. However, these aren’t problems that can be simply waved away. Rather, they are fundamental issues that need addressing: there is no escaping the confines of physics.
A common theme of Musk’s statements is the audacious aspiration to revolutionize the “one use and throw it away” model that has dominated the rocket industry since the beginning, morphing it into something more closely related to a service-based airline model. This is a big task, even by Iron Man’s standards.
Reusable rockets could well become the norm, but when? Image Credit: SpaceX.
Many fans show an under appreciation of the barriers to entry. In fact, in a recent survey conducted on the SpaceX fan community at Reddit.com, when asked to place an educated guess on the price of a Falcon 9 rocket launch in 5 years time, a significant portion of the nearly 600 respondents selected a value beneath $20,000,000. Some even selected prices below $10,000,000. Although COO of SpaceX, Gwynne Shotwell has mentioned in passing that reusable Falcon 9 launches could eventually command a $5-7 million price tag, this is likely far in the future, far past merely the dawn of reusable rockets. For some perspective, five years ago in 2010, SpaceX launched two Falcon 9 rockets. Last year, they launched six, and suddenly, by 2020, the cost of a standard Falcon 9 launch will be three times as cheap? Where has this extra acceleration in development come from? Possibly it comes from the minds of some slightly too-optimistic fans.
In fact, something even as basic as long-term engine maintenance is still relatively unknown. Previously, SpaceX has clarified that each engine has a life of approximately 40 firings, and a casual observer would assume this results in an engine that can be used on 40 missions. However, with three engine test fires prior to each launch, the launch itself, and the three burns required to complete the reentry and re-landing process, the center engine is in fact required to fire 7 times to complete a mission, and with nine engines on every lower stage – even with most only firing a few times, that results in quite a number of parts that can break down after every flight. Checking for these failures and repairing them could become a lot more costly and time consuming than one might hope.
For example, with a diameter of 3.66m, and a height of approximately 42 meters, there is nearly 500 square meters of first stage surface that has been exposed on one side to the frigid temperatures of liquid oxygen and chilled kerosene, and on the other, various temperatures from reentry into the soupy lower atmosphere. In fact, even the ice buildup on the outer skin of the vehicle alone is significant enough to substantially alter the vehicle’s mass! Within that large area, tensile, thermodynamic, and pressure-related fatigue has the potential to accumulate. Striations could nucleate and form hairline cracks. This is a hazard that could lead to a critical failure on an operational mission, and such an event could permanently ingrain an association between the nascent reusable rocket and instability in the minds of satellite operators and the insurance industry. And although Falcon 9 could be considered over-engineered, it is unlikely SpaceX will play rocket roulette.
Although the rocket’s chief engineer estimated a coin toss’s probability of success, upon the hopeful propulsive landing of CRS-5 on the recently christened “autonomous drone landing ship,” the empty first stage will likely be shipped back to SpaceX’s Hawthorne, California headquarters and inspected with various methods of destructive and non-destructive analysis to quantify how the rigors of accelerating to a velocity of nearly 2 kilometers per second in less than three minutes and then decelerating enough, reentering through the atmosphere, to land in close proximity to sea and salt, affect the vehicle.
Another example of a potential refurbishment cost lies in SpaceX’s fuel of choice, kerosene. It burns relatively dirty, as evidenced by the translucent pillar of brown-black soot that Falcon 9 ascends on, a throwback to the days of early aircraft. This leads to an effect predominantly associated with kerolox engines known as “coking” – where incompletely combusted soot adheres to the near-molten engine and nozzle, reducing its ability to radiate away heat. Clean it off, you say? Congratulations, you’ve just introduced refurbishment into the equation, something that SpaceX is striving to avoid. It’s not just rockets that are expensive. There are other costs too… Image Credit: SpaceX.
Even ignoring the vehicle itself, launches and the chemicals needed are expensive! There’s the exorbitantly-priced helium which is required to keep the tanks pressurized, and the pyrophoric TEA-TEB ignition fluid used to begin the explosive marriage between the RP-1 & LOX. It’s not just chemicals either. There’s ground launch operation costs too, ranging from employee wages, to the dull process of permit applications, to the slightly more interesting ablative paint that coats the Transporter-Erector structure which holds Falcon 9 vertical, to transportation and relocation costs. In all likelihood, the current capital expenses of a single launch alone, ignoring the obvious value of the rocket itself, total in the region of $3 million plus.
Fundamentally, we must decouple re-landing, refurbishment, reusability, and financially viable and rapid reuse from each other. It can be a difficult concept to grasp that all four are distinct, and the success of one does not imply the next step is guaranteed. Because of this, question marks still remain over the cost, time, and complexity of the final steps necessary for SpaceX to complete its reusable rocket master plan. For example: re-landing a rocket does not necessarily make refurbishment nonexistent. This is the take home story of the Space Shuttle.
A landing alone doesn’t revolutionize rocketry; rather, we may only realize the revolution of refining rocketry into an airline-like model has occurred well only by looking back in the rear view mirror.
We live in hope that SpaceX achieves what it originally set out to do nearly 13 years ago. SpaceX has come far, far closer than anyone else to this goal, but as Musk himself has said, “Rockets are hard”. Good luck to the team at SpaceX for their upcoming CRS-5 launch and landing attempt, it’s the beginning of something far bigger.
Written by Lukas Davia & Marijn Achternaam
Bios: When not juggling being a software engineering student & full time web developer in New Zealand, Lukas Davia is a self professed SpaceX-addict, and can be found contributing to Reddit community /r/SpaceX, adding to his website SpaceXStats.com, and creating infographics. Believe it or not he does find time to go outside and hike in his spare time too!
Marijn Achternaam is a Dutch student, self proclaimed armchair engineer and spaceflight fanatic who can frequently be found contributing to the /r/space and /r/SpaceX Reddit communities.
Artist's depiction of a waterworld. A new study suggests that Earth is in a minority when it comes to planets, and that most habitable planets may be greater than 90% ocean. Credit: David A. Aguilar (CfA)
Astronomers from around the world gathered in Seattle today for the 225th meeting of the American Astronomical Society. Although it’s just past noon on the West Coast, the discoveries are already beginning to unfurl. Here are some of the highlights from this morning’s exoplanet session. And the keyword seems to be “water.”
A Recipe for Earth-like Planets?
There’s no doubt that the term “Earth-like” is a bit of a misnomer. It requires only that a planet is both Earth-size and circles its host star within the habitable zone. It says nothing about the composition of that planet.
Now, Courtney Dressing from the Harvard-Smithsonian Center for Astrophysics (CfA) and her colleagues have taken detailed observations of small exoplanets in order to nail down a digestible recipe.
Dressing and her colleagues focused on only a handful of exoplanets because they had to take painstakingly long, but accurate measurements. They used the HARPS-N instrument on the 3.6-meter Telescope in the Canary Islands to precisely determine the planets’ densities.
Most recently the team targeted Kepler-93b, a planet 1.5 times the size of Earth and 4.01 times the mass of Earth. Kepler 93-b, as well as all other exoplanets with sizes less than 1.6 times Earth’s size and six times Earth’s mass, show a tight relationship between size and mass. In other words, when plotted by size vs. mass, they fit onto the same line as Venus and the Earth, suggesting they’re all rocky planets.
Larger and more massive exoplanets do not follow the same trend. Nature simply doesn’t want to make rocky planets that are more massive than six Earth masses. Instead, their densities are significantly lower, meaning their recipes include a large fraction of water or hydrogen and helium.
“Today if you’re not too worn out from all the holiday baking, when you get back home, I’d encourage you to check out this new recipe for rocky planets” said Dressing at the AAS press conference. The playful recipe requires one cup of magnesium, one cup of silicon, two cups of iron, two cups of oxygen, ½ teaspoon aluminum, ½ teaspoon nickel, ½ teaspoon calcium, and ¼ teaspoon sulfur.
Now you have to be patient. “Bake this for a couple million years until you start to see a thin, light brown crust form on the surface of the planet,” said Dressing. Then season it with a dash of water. “If you check back in a couple million years, maybe you’ll see some intelligent life on your planet.”
Super-Earths Have Long Lasting Oceans
Another team of astronomers took a closer look at that dash of water. There’s no doubt that life, as we know it, needs liquid water. The Earth’s oceans cover about 70 percent of the surface and have for nearly the entire history of our world. So the next logical step suggests that for life to develop on other planets, those planets would also need oceans.
Water, however, isn’t just on Earth’s surface. Studies have shown that Earth’s mantle holds several oceans’ worth of water that was dragged underground. If water weren’t able to return to the surface via volcanism, it would disappear entirely.
Laura Schaefer, also from the CfA, used computer simulations to see if this so-called deep water cycle could take place on Earth-like planets and super-Earths.
She found that small Earth-like planets outgas their water quickly, while larger super-Earths form their oceans later on. The sweet spot seems to be for planets between two and four times the mass of Earth, which are even better at establishing and maintaining oceans than our Earth. Once started, these oceans could persist for at least 10 billion years.
“If you want to look for life, you should look at older super-Earths,” said Schaefer. It’s a statement that applies to both realms of research presented today.
The AAS will continue throughout the week. So stay tuned because Universe Today will continue bringing you the highlights.
The debris of Long March 3A rocket carrier is falling above southwest China's Guizhou province on December 31, 2014. Photo: Chinanews.com
Amazing images of falling rocket debris from a spent Chinese booster were captured in the final moments of its plummet back to Earth outside a remote village located in southwest China.
The images were taken by a photo journalist during the final seconds of the descent of the first stage of the Long March 3A rocket carrier as it was crashing to the ground by the village of Gaopingsi in southwest China’s Guizhou province on December 31, 2014.
Local villagers soon gathered around the rocket crash debris.
The rocket incident and images were featured online by the state-run China New Service (CNS) website. Checkout the photo gallery herein.
First stage debris of Long March 3A rocket carrier crashes outside Gaopingsi village of southwest China’s Guizhou province on December 31, 2014. Photo: Chinanews.com
“A journalist captured the moment the debris was falling across the sky,” according to CNS.
No injuries or damage to the local village was reported.
“The landing did not influence the local villagers or bring any damages.”
The Long March 3A rocket debris stems from the successful launch of a Chinese meteorological satellite, some minutes earlier at 9:02 am local time on Wednesday, December 31, 2014.
Villagers gather around the debris of Long March 3A rocket carrier on December 31, 2014. Photo: Chinanews.com
The photographer and local villagers made their way to the crash site and captured spectacular up close photos of the first stage rocket, engine and related debris that had fallen in a heavily forested area.
Chinese security officials eventually arrived, evacuated the villagers and cordoned off the area.
Soldiers and police arrive at Gaopingsi village of southwest China’s Guizhou province on December 31, 2014, to carry the debris of Long March 3A rocket carrier away. Photo: Chinanews.com
The rocket and Fengyun-II 08 satellite lifted off from the Xichang Satellite Launch Center in southwest China’s Sichuan province.
Photo: Chinanews.com
Fengyun-II 08 successfully achieved orbit. It will collect meteorological, maritime and hydrological data and transmit information that will be used for weather forecasting and environmental monitoring according to a CCTV report.
Since the Long March rockets blast off from China’s interior in Sichuan province, they flies over long swathes of land area and near some populated areas and occasional fall nearby and can occasionally cause damage.
Photo: Chinanews.com
The situation is similar with Russian rockets launching from Baikonur in Kazahzstan.
By contrast, US and European rockets take off from coastal areas towards oceans. They avoid most populated areas, but not all. The flight termination system is required to protect nearby coastal towns in case of wayward rockets like the Oct. 28 failure of the Orbital Sciences Antares rocket which exploded seconds after blastoff.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
Sierra Nevada Corp.'s Dream Chaser just before tow tests at NASA's Dryden Flight Research Center on Aug. 2, 2013. Credit: NASA/Ken Ulbrich
Update, 4 p.m. EST: Sierra Nevada’s statement, which was posted after the story was first published, is now mentioned below.
Sierra Nevada’s protest concerning NASA’s commercial crew program was turned down today (Jan. 5), according to a statement from the U.S. Government Accountability Office.
The company is developing a spacecraft called the Dream Chaser, which was in competition for NASA funding along with Boeing’s CST-100 and SpaceX’s Dragon to bring crews to the International Space Station. A few months ago, NASA awarded further development money to Boeing and SpaceX, prompting a protest from Sierra Nevada.
At the time, Sierra Nevada both protested the decision and requested a stop-work order on all commercial crew work. The stop-work order was lifted fairly quickly, but the protest remained under review. From today, this was the crux of the GAO statement, which you can read in full here:
In making its selection decision, NASA concluded that the proposals submitted by Boeing and SpaceX represented the best value to the government. Specifically, NASA recognized Boeing’s higher price, but also considered Boeing’s proposal to be the strongest of all three proposals in terms of technical approach, management approach, and past performance, and to offer the crew transportation system with most utility and highest value to the government. NASA also recognized several favorable features in the Sierra Nevada and SpaceX proposals, but ultimately concluded that SpaceX’s lower price made it a better value than the proposal submitted by Sierra Nevada.
In making its selection decision, NASA concluded that the proposals submitted by Boeing and SpaceX represented the best value to the government. Specifically, NASA recognized Boeing’s higher price, but also considered Boeing’s proposal to be the strongest of all three proposals in terms of technical approach, management approach, and past performance, and to offer the crew transportation system with most utility and highest value to the government. NASA also recognized several favorable features in the Sierra Nevada and SpaceX proposals, but ultimately concluded that SpaceX’s lower price made it a better value than the proposal submitted by Sierra Nevada.
Other key points:
The prices for each proposal were as follows: Sierra Nevada was $2.55 billion, Boeing’s was $3.01 billion and SpaceX’s $1.75 billion.
NASA, the GAO said, had “no undue emphasis” on any proposal’s schedule or the chances of a particular system making it to orbit by 2017. Also, the agency did say in its request for proposals that the 2017 certification goal would be a part of the process — a different point than what Sierra Nevada argued, who said the agency had added that stipulation while the process was underway.
NASA’s review of SpaceX’s price and “financial resources” was adequate, along with its evaluation of the competing proposals in terms of mission suitability and past performance. This was in contrast to Sierra Nevada’s argument.
This is part of what Sierra Nevada had to say about the decision. The company also said it plans to maintain ties with NASA. The full statement is here.
While the outcome was not what SNC expected, we maintain our belief that the Dream Chaser spacecraft is technically very capable, reliable and was qualified to win based on NASA’s high ratings of the space system. We appreciate the time and effort contributed to this process by the GAO and NASA to fully evaluate such a critical decision for the United States …
SNC also plans to further the development and testing of the Dream Chaser and is making significant progress in its vehicle design and test program. In addition, SNC is continuing to expand its existing, while developing new, partnerships domestically and abroad in order to expand the multi-mission flexibility of the system, reduce overall long-term costs of the vehicle and ensure long-term affordability and sustainability for the Dream Chaser.
A public record of the decision is expected in a few weeks. Right now, due to the proprietary nature of the information, only NASA personnel and a few “outside counsel” are able to view it, the GAO added.
Have you ever wondered how much water it would take to put out the Sun? It turns out, the Sun isn’t on fire. So what would happen if you did try to hit the Sun with a tremendous amount of water?
How much water would it take to extinguish the Sun? I recently saw this great question on Reddit, and I couldn’t resist taking a crack at it: We know that the question doesn’t make a lot of sense.
A fire is a chemical reaction, where material releases heat as it oxidizes. If you take away oxygen from a fire, it goes out. But.. there’s no oxygen in space, it’s a vacuum. So, there’s not a whole lot of room for regular flavor water-extinguishable fire in space. You know this. How many times have we had to seal off the living quarters and open the bay doors to vent all the oxygen in the space because there was a fire in the cargo bay? We have to do that, like, all the time.
Our wonderful Sun is something quite different. It’s a nuclear fusion reaction, converting hydrogen atoms into helium under the immense temperatures and pressures at its core. It doesn’t need oxygen to keep producing energy. It’s already got its fuel baked in. All the Sun needs is our adoration, quiet, and yet ever present fear. Only if we constantly pray will it be happy and perhaps we’ll go another day where it doesn’t hurl a giant chunk of itself at our smug little faces because it’s tired of our shenanigans.
So, I’m still going to take a swing at this question… so let’s talk about what would happen if you did pour a tremendous amount of water on the Sun? Let’s say another Sun’s worth of H20. Conveniently, Hydrogen is what the Sun uses for fuel, so if you give the Sun more hydrogen, it should just get larger and hotter.
Oxygen is one of the byproducts of fusion. Right now, our Sun is turning hydrogen into helium using the proton-proton fusion reaction. But there’s another type of reaction that happens in there called the carbon-nitrogen-oxygen reaction. As of right now, only 0.8% of the Sun’s fusion reactions proceed along this path.
So if you fed the Sun more oxygen as part of the water, it would allow it to perform more of these fusion reactions too. For stars which are 1.3 times the mass of the Sun, this CNO reaction is the main way fusion is taking place. So, if we did dump a giant pile of water onto the Sun, we’d just be making Sun bigger and hotter.
Cutaway to the Interior of the Sun. Credit: NASA
Conveniently, larger hotter stars burn for a shorter amount of time before they die. The largest, most massive stars only last a few million years and then they explode as supernovae. So, if you’re out to destroy the Sun, and you’re playing a really, really long game, this might actually be a viable route.
I’m pretty sure that wasn’t the intent though. Let’s say we just want to snuff out the Sun. Vsauce provides a strategy for this. If you could somehow blast your water at the Sun at high enough velocity, you might be able to tear it apart. If you can reduce the Sun’s mass, you can decrease the temperature and pressure in its core so that it can no longer support fusion reactions.
I’m going to sum up. The Sun isn’t on fire. There’s no amount of water you could add that would quench it, you’d just make it explode, but if you used firehoses that could spray water at nearly the speed of light, you could probably shut the thing off and eventually freeze us all, which is what I think you were hoping for in the first place.
What do you think? What else could we do to snuff out the Sun?
An example of some of the tasks Robonaut 2 can perform. Credit: NASA
We’re all a little scared (in the impressed-with-technology sense!) of Robonaut, that robot on the International Space Station that is expected to start using legs to move around in the next few months. Eventually, it could even do repairs on the outside — saving astronauts time and keeping them safer.
This fun timelapse video shows Expedition 42 astronaut Terry Virts taking the robot out from what looks like a suitcase on the wall. After he set up Robonaut, however, the machine ran into a few problems.
“The ground teams deployed software and received telemetry from Robonaut. However, [they] were unable to obtain the commanded leg movement that was planned for the day. Ground teams are assessing a forward plan,” NASA wrote in the last ISS update concerning the robot, in mid-December.
While the astronauts patiently wait, they have been posting a few fun tweets about the robot in recent days. Check out what they’ve been saying below.
Missing Venus? The third brightest natural object in the heavens returns to prime time dusk skies in 2015 after being absent and lingering in the dawn for most of 2014. But there’s another reason to hunt down the Cytherean world this week, as elusive Mercury chases after it low in the dusk. If you’ve never seen Mercury for yourself, now is a great time to try, using brilliant Venus as a guide.
The circumstances surrounding this pairing are intriguing. We have to admit, we missed this close conjunction whilst filtering through research for the Top 101 Astronomical Events for 2015 due to those very same unique attributes until an astute reader of Universe Today pointed it out.
Venus and Mercury setting over the Duluth, Minnesota skyline on December 31st. Credit and copyright: Bob King.
On the evening of January 5th, Venus shines at magnitude -3.3 and sits about 18 degrees east of the Sun in dusk skies. You’ll have a narrow window of opportunity to nab Venus, as it’ll sit only 10 degrees above the southwestern horizon as seen from latitude 40 degrees north about an hour after sunset. Make sure you have a clear, uncluttered horizon, and start sweeping the field with binoculars about half an hour after sunset.
Do you see a tiny point of light about a degree and a half to Venus’s lower right? That’s Mercury, just beginning its first dusk apparition of seven for 2015, the most possible in a calendar year. Shining at -0.7 magnitude, Mercury is currently about 8 times fainter than Venus, and drops to +1.4 magnitude by late January.
If you watch the pair on successive evenings, you’ll see Mercury — aptly named after the fleet-footed Roman god — racing to rapidly close the gap. Mercury crosses the one degree separation threshold from January 8th through January 12th, and sits just 39’ — slightly larger than the apparent size of the Full Moon — right around 7:00 PM EST/Midnight Universal Time on January 10th, favoring dusk along eastern North America just a few hours prior.
Venus and Mercury as seen from Venezuela on January 2nd. Credit and copyright: Jose Rozada.
This also means that you’ll be able to squeeze both Mercury and Venus into the same low power telescopic field of view. They’ll both even show the same approximate gibbous phase, with Venus presenting a 10.5” sized 95% illuminated disk, and Mercury subtending 6” in apparent diameter with a 74% illuminated visage. Venus will seem to be doing its very own mocking impersonation of the Earth, appearing to have a single large moon… Neith, the spurious pseudo-moon of Venus lives!
One curious facet of this week’s conjunction is the fact that Venus and Mercury approach, but never quite meet each other in right ascension. We call such a near miss a “quasi-conjunction.” This is the closest pairing of Venus and Mercury since 2012, though you have to go all the way back to 2005 for one that was easily observable, and the last true quasi-conjunction was in October 2001. Miss this week’s event, and you’ll have to wait until May 13th 2016 to catch Mercury — fresh off of transiting the Sun a week earlier — passing just 26’ from Venus only 6.5 degrees west of the Sun. This is unobservable from your backyard, but SOHO’s LASCO C3 camera’s 15 degree wide field of view will have a front row cyber-seat.
The dusk path of Venus through early 2015. Credit: Starry Night Education software.
In 2015, Venus will become ever more prominent in the dusk sky before reaching greatest elongation 45.4 degrees east of the Sun on June 6th, 2015. The angle of the January ecliptic at dusk is currently shoving Mercury and Venus southward for northern hemisphere observers, though that’ll change dramatically as we head towards the March equinox. Venus reaches solar conjunction sans transit (which last occurred in 2012 and won’t happen again til 2117 A.D.) on August 15th before heading towards its second elongation of 2015 on October 26th in the dawn sky. And don’t forget, it’s possible to see Venus in the daytime as it approaches greatest elongation. Venus is also occulted by the Moon 4 times in 2015, including a fine daytime occultation on December 7th for North America.
The path of Mercury through January 2015. Credit: Starry Night Education software.
This month, Mercury reaches greatest eastern elongation on January 14th at 18.9 degrees east of the Sun. Mercury begins retrograde movement later this month — one of the prime reasons this week’s conjunction is quasi — before resuming direct (eastward) motion as seen from our terrestrial vantage point. Though it may seem convenient to blame your earthly woes on Mercury in retrograde as astrologers will have you believe, this is just an illusion of planetary orbital motion. And speaking of motion, Mercury transits the Sun next year on May 9th.
Venus and Mercury as seen from Tucson, Arizona on January 3rd. Credit and copyright: John Barentine (@JohnBarentine)
Mercury and Venus factor in to space exploration in 2015 as well. NASA’s MESSENGER spacecraft wraps up its successful mission in orbit around Mercury in a few months, and the Japanese Space Agency takes another crack at putting its Akatsuki spacecraft in orbit around Venus this coming November.
So don’t fear the bone-chilling January temps (or Mercury in retrograde) but do get out there these coming evenings and check out the fine celestial waltz being performed by the solar system’s two innermost worlds.
Artist's conception of the futuristic Hypersonic Inflatable Aerodynamic Decelerator (HIAD) entering the atmosphere of Mars. Credit: NASA
Assuming we can get humans all the way to Mars, how the heck do we land them on the Red Planet? The challenge is the atmosphere of Mars is very thin, making parachutes tricky. Heavier payloads require unique ideas to get them on the surface, such as the wild ride we saw for the Curiosity rover.
Since humans and their cargo would have much more mass, one of the ideas NASA is exploring is something called the Hypersonic Inflatable Aerodynamic Decelerator (HIAD). And here’s the surprising thing — it looks a little like those donut toys that small children play with.
“In a real spacecraft, a connected stack of donut rings would be inflated before entering a planet’s atmosphere to slow the vehicle for landing,” NASA wrote in an update last June. “The spaceship would look a lot like a giant cone with the space donuts assembled, similar to a child’s stacking ring toy. The stacked-cone concept would allow NASA to land heavier payloads to the surface of the planet than is currently possible, and could eventually be used to deliver crews.”
The concept has been heavily highlighted in the media this week, but what is less spoken about is the uncertainty of the project. The June update came after NASA performed structural testing on a prototype in NASA Armstrong’s Flight Loads Laboratory for seven months in 2013 and 2014. And that was the end of a three-year project under NASA’s Game-Changing Technology program.
What project officials hope for is that they will win a proposal to do more work in 2016. If that works out, they’ll perform more testing on the project. NASA says the technology could be available for use as soon as 2020, but we’ll have to see how things work out.
The principal investigator for its materials and structure is Anthony Calomino, who is with NASA Langley. You can find more information on HIAD on this website.
The Hypersonic Inflatable Aerodynamic Decelerator prototype undergoes structural tests at NASA Armstrong’s Flight Loads Laboratory in this undated photo. Tests took place in 2013 and 2014. Credit: NASA
