When we see an auroral arc - and associated rays - we really seeing a small section of the much larger, permanent aurora called the auroral oval. The northern oval is centered over the geomagnetic north pole located in northern Canada. Credit: NASA
Or perhaps I should say “eine grosse Aurora!” ESA astronaut Alexander Gerst made this time-lapse of a “massive aurora” as seen from the Space Station on August 24. The entire video is beautiful, showing not just a view of the ghostly green aurora but also plenty of stars, airglow, the graceful rotation of the ISS’ solar arrays, and finally the blooming light of dawn – one of sixteen the crew of the Station get to witness every day.
Then again, I’m now wondering: what is the mass of an aurora? Hmm…
Noctilucent clouds over Sweden on July 27, 2014. Credit and copyright: Göran Strand
This year, the noctilucent cloud season has been especially eventful, and this new timelapse from Swedish astrophotographer Göran Strand shows these “night-shining” clouds covering the entire sky over the course of 2 hours.
“On the 27th of July 2014 I saw some of the most beautiful Noctilucent Clouds I’ve ever seen,” Göran said via email. “They emerged shortly after sunset and after a while they covered the entire sky.”
In the movie you can see an all-sky timelapse view that shows how these clouds changed during the evening.
See some gorgeous still photos from that night, below:
Noctilucent clouds are wispy, glowing tendrils of high-altitude ice crystals that shine long after the Sun has set. They appear in upper latitudes only and form about 83 km (51 miles) up in the atmosphere. The icy clouds are illuminated by the Sun when it is just below the horizon, giving the clouds their “night-shining” properties.
Also called polar mesospheric clouds, these are the highest cloud formations in the atmosphere. They’ve been associated with rocket launches and space shuttle re-entries, and another theory is that they might also be associated with meteor activity.
Noctilucent clouds over Sweden on July 27, 2014. Credit and copyright: Göran Strand.
This mosaic of images from the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile shows two dramatic star formation regions in the southern Milky Way. The first of these, on the left, is dominated by the star cluster NGC 3603, located about 20 000 light-years away, in the Carina–Sagittarius spiral arm of the Milky Way galaxy. The second object, on the right, is a collection of glowing gas clouds known as NGC 3576 that lies only about half as far from Earth. Credit: ESO / G. Beccari
The universe is stunning. Images from even the most modest telescopes can unveil its brilliant beauty. But couple that with a profound reason — our ability to question and understand the physical laws that dominate that brilliant beauty — and the image transforms into something much more spectacular.
Take ESO’s latest image of two dramatic star formation regions in the southern Milky Way. John Herschel first observed the cluster on the left in 1834, during his three-year expedition to systematically survey the southern skies near Cape Town. He described it as a remarkable object and thought it might be a globular cluster. But future studies (and not to mention more dramatic images from larger telescopes) enriched our understanding, demonstrating that it was not an old globular but a young open cluster.
This chart shows the constellation of Carina and includes all the stars that can be seen with the unaided eye on a clear and dark night. The location of the open star cluster NGC 3603 is marked. This object is not spectacular in small telescopes, appearing as just a tight clump of stars surrounded by faint nebulosity. Credit: ESO
The Wide Field Imager at ESO’s La Silla Observatory in Chile recently captured the image again. The bright region on the left is the star cluster NGC 3603, located 20,000 light-years away in the Carina-Sagittarius spiral arm of the Milky Way galaxy. The bright region on the right is a collection of glowing gas clouds known as NGC 3576, located only 10,000 light-years away.
Stars are born in enormous clouds of gas and dust, largely hidden from view. But as small pockets in these clouds collapse under the pull of gravity, they become so hot they ignite nuclear fusion, and their light clears away — and brightens — the surrounding gas and dust.
Nearby regions of hydrogen gas are heated, and therefore partially ionized, by the ultraviolet radiation given off by the brilliant hot young stars. These regions, better known as HII regions, can measure several hundred light-years in diameter, and the one surrounding NGC 3603 has the distinction of being the most massive known in our galaxy.
Not only is NGC 3603 known for having the most massive HII region, it’s known for having the highest concentration of massive stars that have been discovered in our galaxy so far. At the center lies a Wolf-Rayet star system. These stars begin their lives at 20 times the mass of the Sun, but evolve quickly while shedding a considerable amount of their matter. Intense stellar winds blast the star’s surface into space at several million kilometers per hour.
Where NGC 3603 is notable for its extremes, NGC 3576 is notable for its extremities — the two huge curved objects in the outreaches of the cluster. Often described as the curled horns of a ram, these odd filaments are the result of stellar winds from the hot, young stars within the central regions of the nebula. The stars have blown the dust and gas outwards across a hundred light-years.
Additionally, the two dark silhouetted areas near the top of the nebula are known as Bok globules, dusty regions found near star formation sights. These dark clouds absorb nearby light and offer potential sites for the future formation of stars. They may further sculpt the dramatic landscape above, which is the smallest slice of our stunning universe
ISRO's Mars Orbiter Mission spacecraft is just 9 million km away from Mars as of Aug. 22, 2014. Credit: ISRO
India’s maiden foray to Mars is now just one month out from the Red Planet and closing in fast on the final stages of the history making rendezvous culminating on September 24, 2014.
As of Aug. 22, 2014, the Mars Orbiter Mission, or MOM, was just 9 million kilometers away from Mars and the crucial Mars Orbital Insertion (MOI) engine firing that places India’s first interplanetary voyager into orbit around the 4th planet from the Sun.
MOM was designed and developed by the Indian Space Research Organization’s (ISRO) at a cost of $69 Million and marks India’s maiden foray into interplanetary flight.
So far it has traveled a total distance of 602 million km in its heliocentric arc towards Mars, says ISRO. It is currently 189 million km away from Earth. Round trip radio signals communicating with MOM take 20 minutes and 47 seconds.
After streaking through space for some ten and a half months, the 1,350 kilogram (2,980 pound) MOM probe will fire its 440 Newton liquid fueled main engine to brake into orbit around the Red Planet on September 24, 2014 – where she will study the atmosphere and sniff for signals of methane.
The do or die MOI burn on September 24 places MOM into an 377 km x 80,000 km elliptical orbit around Mars.
ISRO space engineers are taking care to precisely navigate MOM to keep it on course during its long heliocentric trajectory from Earth to Mars through a series of in flight Trajectory Correction Maneuvers (TMSs).
The last TCM was successfully performed on June 11 by firing the spacecraft’s 22 Newton thrusters for a duration of 16 seconds. TCM-1 was conducted on December 11, 2013 by firing the 22 Newton Thrusters for 40.5 seconds.
Engineers determined that a TCM planned for August was not needed.
The final TCM firing is planned in September 2014.
MOM’s trajectory to Mars. Credit: ISRO
Engineers also completed the checkout of the medium gain antenna in August, “which will be used to communicate with Earth during the critical MOI” maneuver, ISRO reported.
The probe is being continuously monitored by the Indian Deep Space Network (IDSN) and NASA JPL’s Deep Space Network (DSN) to maintain it on course.
Blastoff of the Indian developed Mars Orbiter Mission (MOM) on Nov. 5, 2013 from the Indian Space Research Organization’s (ISRO) Satish Dhawan Space Centre SHAR, Sriharikota. Credit: ISRO
MOM was launched on Nov. 5, 2013 from India’s spaceport at the Satish Dhawan Space Centre, Sriharikota, atop the nations indigenous four stage Polar Satellite Launch Vehicle (PSLV) which placed the probe into its initial Earth parking orbit.
Six subsequent orbit raising maneuvers raised its orbit and culminated with a liquid fueled main engine firing on Dec. 1, 2013. The Trans Mars Injection(TMI) maneuver that successfully placed MOM on its heliocentric trajectory to the Red Planet.
First ever image of Earth Taken by Mars Color Camera aboard India’s Mars Orbiter Mission (MOM) spacecraft while orbiting Earth and before the Trans Mars Insertion firing on Dec. 1, 2013. Image is focused on the Indian subcontinent. Credit: ISRO
MOM is streaking to Mars along with NASA’s MAVEN orbiter, which arrives at Mars about two days earlier.
MOM and MAVEN will join Earth’s fleet of 3 current orbiters from NASA and ESA as well as NASA’s pair of sister surface rovers Curiosity and Opportunity.
If all goes well, India will join an elite club of only four who have launched probes that successfully investigated the Red Planet from orbit or the surface – following the Soviet Union, the United States and the European Space Agency (ESA).
MOM’s main objective is a demonstration of technological capabilities and it will also study the planet’s atmosphere and surface.
The probe is equipped with five indigenous instruments to conduct meaningful science – including a multi color imager and a methane gas sniffer to study the Red Planet’s atmosphere, morphology, mineralogy and surface features. Methane on Earth originates from both geological and biological sources – and could be a potential marker for the existence of Martian microbes.
India’s Mars Orbiter Mission (MOM) marked 100 days out from Mars on June 16, 2014 and the Mars Orbit Insertion engine firing when it arrives at the Red Planet on September 24, 2014 after its 10 month interplanetary journey. Credit ISRO
ISRO is also working to determine if MOM can gather scientific measurements of
Comet C/2013 A1 Siding Spring during an extremely close flyby with the Red Planet on Oct. 19, 2014.
MAVEN and NASA’s other Mars probes will study the comet.
Stay tuned here for Ken’s continuing MOM, MAVEN, Opportunity, Curiosity, Mars rover and more planetary and human spaceflight news.
NASA’s Curiosity rover hammers into ‘Bonanza King’ rock outcrop evaluating potential as 4th drill site for sampling at ‘Hidden Valley’ in this photo mosaic view captured on Aug. 20, 2014, Sol 724. Inset MAHLI camera image at right shows resulting rock indentation that caused it to budge and be unsafe for further drilling. Note the background of treacherous sand dune ripples and deep wheel tracks inside Hidden Valley that forced quick exit to alternate route forward. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/MSSS/Ken Kremer-kenkremer.com/Marco Di Lorenzo
NASA’s Curiosity rover will skip drilling into a possible 4th rock target and instead resume the trek to Mount Sharp after finding it was unfortunately a slippery rock at the edge of a Martian valley of slippery sands and was therefore too risky to proceed with deep drilling and interior sampling for chemical analysis.
After pounding into the “Bonanza King” rock outcrop on Wednesday, Aug. 20, to evaluate its potential as Curiosity’s 4th drill target on Mars and seeing that it moved on impact, the team decided it was not even safe enough to continue with the preliminary ‘mini-drill’ operation that day.
So they cancelled the entire drill campaign at “Bonanza King” and decided to set the rover loose to drive onwards to her mountain climbing destination.
This image from the front Hazcam on NASA’s Curiosity Mars rover shows the rover’s drill in place during a test of whether the rock beneath it, “Bonanza King,” would be an acceptable target for drilling to collect a sample. Subsequent analysis showed the rock budged during the Aug. 19, 2014, test. Credit: NASA/JPL-Caltech
“We have decided that the rocks under consideration for drilling, based on the tests we did, are not good candidates for drilling,” said Curiosity Project Manager Jim Erickson of NASA’s Jet Propulsion Laboratory, Pasadena, California, in a statement.
“Instead of drilling here, we will resume driving toward Mount Sharp.”
Bonanza King was an enticing target because the outcrop possessed thin, white, cross-cutting mineral veins which could indicate that liquid water flowed here in the distant past. Water is a prerequisite for life as we know it.
Loose, unstable rocks pose a prospective hazard to the 1 ton robots hardware and health if they become dislodged during impact by the percussive drill located at the end of the robotic arm.
It’s worth recalling that whirling rocks during the nailbiting Red Planet touchdown two years ago on Aug. 6, 2012, inside Gale Crater are suspected to have slightly damaged Curiosity’s REMS meteorological instrument station.
Each drill target must pass a series of tests. And the prior three at more extensive outcrops all met those criteria. By comparison, imagery showed Bonanza King was clearly part of a much smaller outcrop. See our Bonanza King photo mosaics herein.
NASA’s Curiosity rover looks back to ramp with potential 4th drill site target at ‘Bonanza King’ rock outcrop in ‘Hidden Valley’ in this photo mosaic view captured on Aug. 6, 2014, Sol 711. Inset shows results of brushing on Aug. 17, Sol 722, that revealed gray patch beneath red dust. Note the rover’s partial selfie, valley walls, deep wheel tracks in the sand dunes and distant rim of Gale crater beyond the ramp. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer-kenkremer.com/Marco Di Lorenzo
“One step in the procedure, called “start hole,” uses the hammering action of the percussive drill to create a small indentation in the rock. During this part of the test, the rock moved slightly, the rover sensed that instability in the target, and protective software properly halted the procedure,” according to a NASA statement.
This pale, flat Martian rock thus failed to pass the team’s safety criteria for drilling when it budged.
Bonanza King sits in an bright outcrop on the low ramp at the northeastern end of a spot leading in and out of an area called “Hidden Valley” which lies between Curiosity’s August 2012 landing site in Gale Crater and her ultimate destinations on Mount Sharp which dominates the center of the crater.
Just days ago, the rover team commanded a quick exit from “Hidden Valley” to backtrack out of the dune filled valley because of fears the six wheeled robot could get stuck in slippery sands extending the length of a football field.
“Hidden Valley” looked like it could turn into “Death Valley.”
As Curiosity tested the outcrop, the rover team was simultaneously searching for an alternate safe path forward to the sedimentary layers of Mount Sharp because she arrived at Hidden Valley after recently driving over a field of sharp edged rocks in the “Zabriskie Plateau” that caused further rips and tears in the already damaged 20 inch diameter aluminum wheels.
It will take a route skirting the north side of the sandy-floored valley taking care to steer away from the pointiest rocks. Curiosity rover looks back to the rocky plains of the Zabriskie plateau from sandy ramp into ‘Hidden Valley’ with 4th drill site target at ‘Bonanza King’ rock outcrop as shown in this photo mosaic view captured on Aug. 14, 2014, Sol 719. Sharp edged rocks at Zabriskie tore new holes into rover wheels. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Marco Di Lorenzo/Ken Kremer-kenkremer.com
“After further analysis of the sand, Hidden Valley does not appear to be navigable with the desired degree of confidence,” Erickson said. “We will use a route avoiding the worst of the sharp rocks as we drive slightly to the north of Hidden Valley.”
To date, Curiosity’s odometer totals over 5.5 miles (9.0 kilometers) since landing inside Gale Crater on Mars in August 2012. She has taken over 179,000 images.
Curiosity still has about another 2 miles (3 kilometers) to go to reach the entry way at a gap in the treacherous sand dunes at the foothills of Mount Sharp sometime later this year.
Hidden Valley gives a foretaste of the rippely slippery sand dune challenges lurking ahead!
Mount Sharp is a layered mountain that dominates most of Gale Crater and towers 3.4 miles (5.5 kilometers) into the Martian sky and is taller than Mount Rainier.
“Getting to Mount Sharp is the next big step for Curiosity and we expect that in the Fall of this year,” Dr. Jim Green, NASA’s Director of Planetary Sciences at NASA Headquarters, Washington, DC, told me in an interview marking the 2nd anniversary since touchdown on Aug. 6.
“Drilling on the crater floor will provide needed geologic context before Curiosity climbs the mountain.”
The team may go back to its original plan to drill at the potential science destination known as “Pahrump Hills” which was changed due to the route change forced by the slippery sands in Hidden Valley.
The main map here shows the assortment of landforms near the location of NASA’s Curiosity Mars rover as the rover’s second anniversary of landing on Mars nears. The gold traverse line entering from upper right ends at Curiosity’s position as of Sol 705 on Mars (July 31, 2014). The inset map shows the mission’s entire traverse from the landing on Aug. 5, 2012, PDT (Aug. 6, EDT) to Sol 705, and the remaining distance to long-term science destinations near Murray Buttes, at the base of Mount Sharp. The label “Aug. 5, 2013” indicates where Curiosity was one year after landing. Credit: NASA/JPL-Caltech/Univ. of Arizona
Read an Italian language version of this story by my imaging partner Marco Di Lorenzo – here
Stay tuned here for Ken’s continuing Rosetta, Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, Dream Chaser, commercial space, MAVEN, MOM, Mars and more planetary and human spaceflight news.
Curiosity rover panorama of Mount Sharp captured on June 6, 2014 (Sol 651) during traverse inside Gale Crater. Note rover wheel tracks at left. She will eventually ascend the mountain at the ‘Murray Buttes’ at right later this year. Assembled from Mastcam color camera raw images and stitched by Marco Di Lorenzo and Ken Kremer. Credit: NASA/JPL/MSSS/Marco Di Lorenzo/Ken Kremer-kenkremer.com Up close view of hole in one of rover Curiosity’s six wheels caused by recent driving over rough Martian rocks. Mosaic assembled from Mastcam raw images taken on Dec. 22, 2013 (Sol 490). Credit: NASA/JPL/MSSS/Ken Kremer – kenkremer.com/Marco Di Lorenzo
SpaceX's F9R rocket prototype during a successful test in May 2014. Credit: SpaceX/YouTube (screenshot)
No injuries are reported after a SpaceX rocket prototype detonated in Texas today (Aug. 22) after an anomaly was found in the rocket, the company said in a statement.
“Today’s test was particularly complex, pushing the limits of the vehicle further than any previous test,” SpaceX said in a statement (which you can read in full below the jump.) “As is our practice, the company will be reviewing the flight record details to learn more about the performance of the vehicle prior to our next test.”
The company said it would provide more updates as it found information. SpaceX founder Elon Musk issued a brief statement of his own on Twitter:
Three engine F9R Dev1 vehicle auto-terminated during test flight. No injuries or near injuries. Rockets are tricky …
Earlier today, in McGregor, Texas, SpaceX conducted a test flight of a three-engine version of the F9R test vehicle (successor to Grasshopper.) During the flight, an anomaly was detected in the vehicle and the flight termination system automatically terminated the mission.
Throughout the test and subsequent flight termination, the vehicle remained in the designated flight area. There were no injuries or near injuries. An FAA representative was present at all times.
With research and development projects, detecting vehicle anomalies during the testing is the purpose of the program. Today’s test was particularly complex, pushing the limits of the vehicle further than any previous test. As is our practice, the company will be reviewing the flight record details to learn more about the performance of the vehicle prior to our next test.
SpaceX will provide another update when the flight data has been fully analyzed.
Here are some recent Universe Today stories on the rocket:
A screenshot of an experiment in the Flame Extinguishment Experiment - 2 (FLEX-2) on the International Space Station, taken during Expedition 40 in August 2014. Credit: Reid Wiseman/Vine
Reid Wiseman, NASA astronaut and part-time master of Vine videos, has done it again. This time he’s showing off a flame experiment on the International Space Station called the Flame Extinguishment Experiment-2 (FLEX-2).
“Ignition, jellyfish of fire, warp-drive finish!” wrote Wiseman on Vine yesterday (Aug. 22). He also posted a slow-motion capture of flames in action, which you can see below the jump. FLEX-2, as the name implies, is the second flame experiment on board the International Space Station. NASA states the goal is to understand how small fuel droplets burn in space.
“The FLEX-2 experiment studies how quickly fuel burns, the conditions required for soot to form, and how mixtures of fuels evaporate before burning. Understanding these processes could lead to the production of a safer spacecraft as well as increased fuel efficiency for engines using liquid fuel on Earth,” the agency wrote.
The Meteorite of Serooskerken (Source: Sterrenwacht Sonnenborgh)
Here’s a bit of good news: the Serooskerken meteorite, which was stolen from the Sonnenborgh Museum and Observatory in Utrecht, Netherlands on Monday night, has been recovered. It was found in a bag left in some bushes alongside a tennis court and turned in to the police.
It’s not quite “game, set, match” though; unfortunately the meteorite was broken during the theft. (See a photo here via Twitter follower Marieke Baan.) Still, the Sonnenborgh Museum director is glad to have the pieces back, which he said will remain useful for research and can still be exhibited. (Source)
The Serooskerken meteorite was recovered from a fall in the Dutch province of Zeeland on August 28, 1925. Classified as a diogenite (HED) it is thought to have originated from the protoplanet Vesta, the second most massive object in the main asteroid belt between the orbits of Mars and Jupiter (and the previous target of NASA’s Dawn mission.) It is one of only five meteorite specimens ever recovered in the Netherlands.
The meteorite was one of several items reported stolen from the Sonnenborgh Museum on the night of August 18-19, 2014.
The southern hemisphere of Neptune's moon Triton, at a resolution of 600 meters (1,969 feet) per pixel. Credit: Paul Schenk (LPI, Houston) from Voyager 2 images acquired August 1989
Talk about recycling! Twenty-five years after Voyager 2 zinged past Neptune’s moon Triton, scientists have put together a new map of the icy moon’s surface using the old data. The information has special relevance right now because the New Horizons spacecraft is approaching Pluto fast, getting to the dwarf planet in less than a year. And it’s quite possible that Pluto and Triton will look similar.
Triton has an exciting history. Scientists believed it used to be a lone wanderer until Neptune captured it, causing tidal heating that in turn created fractures, volcanoes and other features on the surface. While Triton and Pluto aren’t twins — this certainly didn’t happen to Pluto — Pluto also has frozen volatiles on its surface such as carbon monoxide, methane and nitrogen.
What you see in the map is a slightly enhanced version of Triton’s natural colors, bearing in mind that Voyager’s sensors are a little different from the human eye. Voyager 2 only did a brief flyby, so only about half the planet has been imaged. Nonetheless, the encounter was an exciting time for Paul Schenk, a planetary scientist at the Lunar and Planetary Institute in Houston. He led the creation of the new Triton map, and wrote about the experience of Voyager 2 in a blog post.
“Triton is a near twin of Pluto,” wrote Schenk. “Triton and Pluto are both slightly smaller than Earth’s Moon, have very thin nitrogen atmospheres, frozen ices on the surface (carbon monoxide, carbon dioxide, methane and nitrogen), and similar bulk composition (a mixture of ices, including water ice, and rock. Triton however was captured by Neptune long time ago and has been wracked by intense heating ever since. This has remade its surface into a tortured landscape of overturned layers, volcanism, and erupting geysers.”
He also added speculation about what will be seen at Pluto. Will it be a dead planet, or will geology still be affecting its surface? How close will Triton be to Pluto, particularly regarding its volcanoes? Only a year until we know for sure.
Holger Sierks, OSIRIS principal investigator, discusses spectacular hi res comet images returned so far by Rosetta during the Aug. 6 ESA webcast from mission control at ESOC, Darmstadt, Germany. Credit: Roland Keller
Animation Caption: Possible landing sites on Comet 67P/Churyumov-Gerasimenko. The model shows the illumination of the comets surface and regions under landing site consideration for the Philae lander on board ESA’s Rosetta spececraft . Credit: CNES
“The race is on” to find a safe and scientifically interesting landing site for the Philae lander piggybacked on ESA’s Rosetta spacecraft as it swoops in ever closer to the heavily cratered Comet 67P/Churyumov-Gerasimenko since arriving two weeks ago after a decade long chase of 6.4 billion kilometers (4 Billion miles).
Rosetta made history by becoming the first ever probe from Earth to orbit a comet upon arrival on Aug. 6, 2014.
The probe discovered an utterly alien and bizarre icy wanderer that science team member Mark McCaughrean, of ESA’s Science Directorate, delightedly calls a ‘Scientific Disneyland.’
“It’s just astonishing,” he said during a live ESA webcast of the Aug. 6 arrival event.
Now, another audacious and history making event is on tap – Landing on the comet!
To enable a safe landing, Rosetta is moving in closer to the comet to gather higher resolution imaging and spectroscopic data. When Rosetta arrived on Aug. 6, it was initially orbiting at a distance of about 100 km (62 miles). As of today, carefully timed thruster firings have brought it to within about 80 km distance. And it will get far closer.
Right now a top priority task for the science and engineering team leading Rosetta is “Finding a landing strip” for the Philae comet lander.
Philae’s landing on comet 67P is currently scheduled for Nov. 11, 2014. The 100 kg lander is equipped with 10 science instruments
“The challenge ahead is to map the surface and find a landing strip,” said Andrea Accomazzo, ESA Rosetta Spacecraft Operations Manager, at the Aug. 6 ESA webcast.
The team responsibility for choosing the candidate sites comprises “the Landing Site Selection Group (LSSG), which comprises engineers and scientists from Philae’s Science, Operations and Navigation Centre (SONC) at CNES, the Lander Control Centre (LCC) at DLR, scientists representing the Philae Lander instruments, and supported by the ESA Rosetta team, which includes representatives from science, operations and flight dynamics,” according to an ESA statement.
This week the team is intensively combing through a preliminary list of 10 potential landing sites.
Over the weekend they will whittle the list down to five candidate landing sites for continued detailed analysis.
ESA will announce the Top 5 landing site candidates on Monday, Aug. 25.
Where will Philae land?
This image of comet 67P/Churyumov-Gerasimenko shows the diversity of surface structures on the comet’s nucleus. It was taken by the Rosetta spacecraft’s OSIRIS narrow-angle camera on August 7, 2014. At the time, the spacecraft was 65 miles (104 kilometers) away from the 2.5 mile (4 kilometer) wide nucleus. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA/Enhanced processing Marco Di Lorenzo/Ken Kremer
The decision rests on the results of Rosetta’s ongoing global mapping campaign, including high resolution imaging from the OSIRIS and NAVCAM cameras and further observations from the other science instruments, especially MIRO, VIRTIS, ALICE, GIADA and ROSINA.
The surface criteria for a suitable landing site include day time landing illumination, a balance between day and night to allow the solar panels to recharge the batteries, avoiding steep slopes, large boulders and deep crevasses so it doesn’t topple over.
Of course the team also must consider the comet’s rotation period (12.4 hours) and axis of rotation (see animation at top). Sites near the equator offering roughly equal periods of day and night may be preferred.
The selection of the primary landing site is slated for mid-October after consultation between ESA and the lander team on a “Go/No Go” decision.
The three-legged lander will fire two harpoons and use ice screws to anchor itself to the 4 kilometer (2.5 mile) wide comet’s surface. Philae will collect stereo and panoramic images and also drill 23 centimeters into and sample its incredibly varied surface.
Artist impression of Philae on the surface of comet 67P/Churyumov-Gerasimenko. Credit: ESA/ATG medialab
Read an Italian language version of this story by my imaging partner Marco Di Lorenzo – here
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
