One of Apollo’s finest, astronaut Gene Cernan, has left Earth for the last time. Cernan, the last man to walk on the Moon, died Monday, January 16, 2017.
“Gene Cernan, Apollo astronaut and the last man to walk on the moon, has passed from our sphere, and we mourn his loss,” said NASA Administrator Charlie Bolden in statement. “Leaving the moon in 1972, Cernan said, ‘As I take these last steps from the surface for some time into the future to come, I’d just like to record that America’s challenge of today has forged man’s destiny of tomorrow.’ Truly, America has lost a patriot and pioneer who helped shape our country’s bold ambitions to do things that humankind had never before achieved.”
In a statement, Cernan’s family said he was humbled by his life experiences, and he recently commented, “I was just a young kid in America growing up with a dream. Today what’s most important to me is my desire to inspire the passion in the hearts and minds of future generations of young men and women to see their own impossible dreams become a reality.”
“Even at the age of 82, Gene was passionate about sharing his desire to see the continued human exploration of space and encouraged our nation’s leaders and young people to not let him remain the last man to walk on the Moon,” the family continued.
A trailer for the film “The Last Man on the Moon:”
Cernan was a Captain in the U.S. Navy but he is remembered most for his historic travels off Earth. He flew in space three times, twice to the Moon.
He was one of 14 astronauts selected by NASA in October 1963. He piloted the Gemini 9 mission with Commander Thomas Stafford on a three-day flight in June 1966. Cernan was the second American to conduct a spacewalk, and he logged more than two hours outside the Earth-orbiting Gemini capsule.
During his two hour, eight minute spacewalk on June 5, 1966, Gemini IXA pilot Eugene Cernan is seen outside the spacecraft. Credit: NASA/Tom Stafford.
In May 1969, he was the lunar module pilot of Apollo 10, and dramatically descended to within 5 km (50,000 ft) of the Moon’s surface to test out the lunar lander’s capabilities, paving the way for Apollo 11’s first lunar landing two months later.
As Cernan flew the lunar module close to the surface, he radioed back to Earth, “I’m telling you, we are low. We’re close baby! … We is down among ‘em!”
Apollo 17 Mission Commander Eugene A. Cernan during the second spacewalk on December 12, 1972, standing near the lunar rover. Credit: NASA.
But his ultimate mission was landing on the Moon and walking across its surface during the Apollo 17 mission, the sixth and final mission to land on the Moon. During three EVAs to conduct surface operations within the Taurus-Littrow landing site, Cernan and his crewmate Harrison “Jack” Schmitt collected samples of the lunar surface and deployed scientific instruments.
On December 14, 1972, Cernan returned to the lunar module Challenger after the end of the third moonwalk, officially becoming the last human to set foot upon Moon.
Nobody can take those footsteps I made on the surface of the moon away from me.” – Eugene Cernan
Bolden said that in his last conversation with Cernan, “he spoke of his lingering desire to inspire the youth of our nation to undertake the STEM (science, technology, engineering and mathematics) studies, and to dare to dream and explore. He was one of a kind and all of us in the NASA Family will miss him greatly.”
The words of Cernan as he left the Moon’s surface bring us hope, for one day embarking on human missions of exploration of space once more.
“We shall return, in peace and hope, for all mankind.” – Gene Cernan.
No mournful blare of trumpets but a forlorn Tweet announced
Another one had gone;
Another of the tallest redwoods in the forest of history
Had fallen, leaving a poorer world behind.
One by one they pass – the giants who dared to step
Off Terra, fly through a quarter million miles of deadly night
And stride across the Moon. On huge TVs in living rooms and schools
We watched them bounce across its ancient plains,
Snowmen stained by dust as cold and grey
As crematorium ash, mischievous boys with smiles flashing
Behind visors of burnished gold as they lolloped along,
Hopping like drunk kangaroos between boulders
Big as cars, so, so far away from Earth that their words
Came from the past –
Apollo 17 mission commander Gene Cernan, the last man to walk on the moon, looks skyward during a memorial service celebrating the life of Neil Armstrong in 2012. Credit: NASA/Bill Ingalls
Color view of M31 (The Andromeda Galaxy), with M32 (a satellite galaxy) shown to the lower left. Credit and copyright: Terry Hancock.
Welcome back to Messier Monday! In our ongoing tribute to the great Tammy Plotner, we take a look at dwarf elliptical galaxy known as Messier 32. Enjoy!
During the 18th century, famed French astronomer Charles Messier noted the presence of several “nebulous objects” in the night sky. Having originally mistaken them for comets, he began compiling a list of them so that others would not make the same mistake he did. In time, this list (known as the Messier Catalog) would come to include 100 of the most fabulous objects in the night sky.
One of these objects is the dwarf elliptical galaxy known as Messier 32 (aka. NGC 221). Located about 2.65 million light-years from Earth, in the direction of the Andromeda constellation, this dwarf is actually a satellite galaxy of the massive Andromeda Galaxy (M31). Along with Andromeda, the Milky Way and the Triangulum Galaxy (M33) is a member of the Local Group.
Description:
M32 is an elliptical dwarf galaxy which contains about 3 billion solar masses. While it looks small compared to its massive neighbor, this little guy actually stretches across space some 8,000 light years in diameter. Once you pick it up, you’ll notice it’s really quite bright on its own – and with very good reason – its nucleus is almost identical to M31. Both contain about 100 million solar masses in rapid motion around a central supermassive object!
The dwarf elliptical galaxy Messier 32 (Le Gentil). Credit: Wikisky
“M32 is the prototype for the relatively rare class of galaxies referred to as compact ellipticals. It has been suggested that M32 may be a tidally disturbed r1/4 elliptical galaxy or the remnant bulge of a disk-stripped early-type spiral galaxy reveals that the surface bightness profile, the velocity dispersion measurements, and the estimated supermassive black hole mass in M32 are inconsistent with the galaxy having, and probably ever having had, an r1/4 light profile. Instead, the radial surface brightness distribution of M32 resembles an almost perfect (bulge+exponential disk) profile; this is accompanied by a marked increase in the ellipticity profile and an associated change in the position angle profile where the “disk” starts to dominate. Compelling evidence that this bulge/disk interpretation is accurate comes from the best-fitting r1/n bulge model, which has a Sersic index of n=1.5, in agreement with the recently discovered relation between a bulge’s Sersic index and the mass of a bulge’s supermassive black hole.”
By probing deeply into Messier 32, we’ve learned this little galaxy is home to mainly mature red and yellow stars. And they’re good housekeepers, too… because there’s practically no dust or gas to be found. While this seems neat and tidy, it also means there isn’t any new star formation going on either, but there are signs of some lively doings in the not too distant past.
Because M32 has shared “space” with neighboring massive M31, the strong tidal field of the larger galaxy may have ripped away what once could have been spiral arms – leaving only its central bulge and triggering starburst in the core. As Kenji Bekki (et al) wrote in their 2001 study:
“The origin of M32, the closest compact elliptical galaxy (cE), is a long-standing puzzle of galaxy formation in the Local Group. Our N-body/smoothed particle hydrodynamics simulations suggest a new scenario in which the strong tidal field of M31 can transform a spiral galaxy into a compact elliptical galaxy. As a low-luminosity spiral galaxy plunges into the central region of M31, most of the outer stellar and gaseous components of its disk are dramatically stripped as a result of M31’s tidal field. The central bulge component on the other hand, is just weakly influenced by the tidal field, owing to its compact configuration, and retains its morphology. M31’s strong tidal field also induces rapid gas transfer to the central region, triggers a nuclear starburst, and consequently forms the central high-density and more metal-rich stellar populations with relatively young ages. Thus, in this scenario, M32 was previously the bulge of a spiral galaxy tidally interacting with M31 several gigayears ago. Furthermore, we suggest that cE’s like M32 are rare, the result of both the rather narrow parameter space for tidal interactions that morphologically transform spiral galaxies into cE’s and the very short timescale (less than a few times 109 yr) for cE’s to be swallowed by their giant host galaxies (via dynamical friction) after their formation.”
Messier 31 (the Andromeda Galaxy), along with Messier 32 and Messier 110. Credit: Wikisky
History of Observation:
M32 was discovered by Guillaume Le Gentil on October 29th, 1749 and became the first elliptical galaxy ever observed. Although it wasn’t cataloged by Charles Messier until August 3rd, 1764, he had also seen it some seven years earlier while studying at the Paris Observatory, but his notes had been suppressed. But no matter, for he made sure to include it in his notes with a drawing! As he wrote of the object:
“I have examined in the same night [August 3 to 4, 1764], and with the same instruments, the small nebula which is below and at some [arc] minutes from that in the girdle of Andromeda. M. le Gentil discovered it on October 29, 1749. I saw it for the first time in 1757. When I examined the former, I did not know previously of the discovery which had been made by M. Le Gentil, although he had published it in the second volume of the Memoires de Savans erangers, page 137. Here is what I found written in my journal of 1764. That small nebula is round and may have a diameter of 2 minutes of arc: between that small nebula and that in the girdle of Andromeda one sees two small telescopic stars. In 1757, I made a drawing of that nebula, together with the old one, and I have not found and change at each time I have reviewed it: One sees with difficulty that nebula with an ordinary refractor of three feet and a half; its light is fainter than that of the old one, and it doesn’t contain any star. At the passage of that new nebula through the Meridian, comparing it with the star Gamma Andromedae, I have determined its position in right ascension as 7d 27′ 32″, and its declination as 38d 45′ 34″ north.”
Later, Messier 32 would be examined again, this time by Admiral Symth who said:
“An overpowering nebula, with a companion about 25′ in the south vertical M32 … The companion of M31 was discovered in November, 1749, by Le Gentil, and was described by him as being about an eighth of the size of the principal one. The light is certainly more feeble than here assigned. Messier – whose No. 32 it is – observed it closely in 1764, and remarked, that no change had taken place since the time of its being first recorded. In form it is nearly circular. The powerful telescope of Lord Rosse is a reflector of three feet in diameter, of performance hitherto unequalled. It was executed by the Earl of Rosse, under a rare union of skill, assiduity, perseverance, and muniference. The years of application required to accomplish this, have not worn his Lordship’s zeal and spirit; like a giant refreshed, he has returned to his task, and is now occupied upon a metallic disc of no less than six feet in diameter. Should the figure of this prove as perfect as the present one, we may soon over-lap what many absurdly look upon as the boundaries of the creation.”
The location of Messier 32 location in the Andromeda constellation. Credit: Roberto Mura
Locating Messier 32:
Locating M32 is as easy as locating the Andromeda Galaxy, but it will require large binoculars or at least a small telescope to see. Even under moderately light polluted skies the Great Andromeda Galaxy can be easily be found with the unaided eye – if you know where to look. Seasoned amateur astronomers can literally point to the sky and show you the location of M31, but perhaps you have never tried to find it.
Believe it or not, this is an easy galaxy to spot even under the moonlight. Simply identify the large diamond-shaped pattern of stars that is the Great Square of Pegasus. The northernmost star is Alpha, and it is here we will begin our hop. Stay with the northern chain of stars and look four finger widths away from Alpha for an easily seen star.
The next along the chain is about three more finger widths away… And we’re almost there. Two more finger widths to the north and you will see a dimmer star that looks like it has something smudgy nearby. Point your binoculars there, because that’s no cloud – it’s the Andromeda Galaxy!
Now aim your binoculars or telescope its way… Perhaps one of the most outstanding of all galaxies to the novice observer, M31 spans so much sky that it takes up several fields of view in a larger telescope, and even contains its own clusters and nebulae with New General Catalog designations. If you have larger binoculars or a telescope, you will be able to pick up M31’s two companions – M32 and M110. Messier 32 is the elliptical galaxy to the south.
Why not stretch your own boundaries? Go observing! Halton Arp included Messier 32 as No. 168 in his Catalogue of Peculiar Galaxies. It’s bright, easy and fun! And here are the quick facts on this Messier Object to help you get started:
Object Name: Messier 32 Alternative Designations: M32, NGC 221 Object Type: Type E2, Elliptical Galaxy Constellation: Andromeda Right Ascension: 00 : 42.7 (h:m) Declination: +40 : 52 (deg:m) Distance: 2900 (kly) Visual Brightness: 8.1 (mag) Apparent Dimension: 8×6 (arc min)
This peculiar rock, photographed on Jan. 12 (Sol 1577) by NASA's Curiosity rover, appears to be a metal meteorite. When confirmed, this will be the rover's third meteorite find on the Red Planet. Click for the high resolution original. Credit: NASA/JPL-Caltech/MSSS
This peculiar rock, photographed on Jan. 12 (Sol 1577) by NASA’s Curiosity rover, appears to be a metal meteorite. When confirmed, this would be the rover’s third meteorite find on the Red Planet. Click for the high resolution original. Credit: NASA/JPL-Caltech/MSSS
Rolling up the slopes of Mt. Sharp recently, NASA’s Curiosity rover appears to have stumbled across yet another meteorite, its third since touching down nearly four and a half years ago. While not yet confirmed, the turkey-shaped object has a gray, metallic luster and a lightly-dimpled texture that hints of regmaglypts. Regmaglypts, indentations that resemble thumbprints in Play-Doh, are commonly seen in meteorites and caused by softer materials stripped from the rock’s surface during the brief but intense heat and pressure of its plunge through the atmosphere.
Oddly, only one photo of the assumed meteorite shows up on the Mars raw image site. Curiosity snapped the image on Jan. 12 at 11:21 UT with its color mast camera. If you look closely at the photo a short distance above and to the right of the bright reflection a third of the way up from the bottom of the rock, you’ll spy three shiny spots in a row. Hmmm. Looks like it got zapped by Curiosity’s ChemCam laser. The rover fires a laser which vaporizes part of the meteorite’s surface while a spectrometer analyzes the resulting cloud of plasma to determine its composition. The mirror-like shimmer of the spots is further evidence that the gray lump is an iron-nickel meteorite.
Meet Egg Rock, another iron-nickel meteorite and Curiosity’s second meteorite find. The white spots/holes are where the object was zapped by the rover’s laser to determine its composition. The rover spotted Egg Rock (about the size of a golfball) on Oct. 27, 2016. Credit: NASA/JPL-Caltech
Curiosity has driven more than 9.3 miles (15 km) since landing inside Mars’ Gale Crater in August 2012. It spent last summer and part of fall in a New Mexican-like landscape of scenic mesas and buttes called “Murray Buttes.” It’s since departed and continues to climb to sequentially higher and younger layers of the lower part of Mt. Sharp to investigate additional rocks. Scientists hope to create a timeline of how the region’s climate changed from an ancient freshwater lake environment with conditions favorable for microbial life (if such ever evolved) to today’s windswept, frigid desert.
Assuming the examination of the rock proves a metallic composition, this new rock would be the eighth discovered by our roving machines. All of them have been irons despite the fact that at least on Earth, iron meteorites are rather rare. About 95% of all found or seen-to-fall meteorites are the stony variety (mostly chondrites), 4.4% are irons and 1% stony-irons.
Curiosity found this iron meteorite called “Lebanon” back in 2014. It’s about two yards or two meters wide (left to right). The smaller piece in the foreground is named “Lebanon B. This photo combines a series of high-resolution circular images across the middle taken by the Remote Micro-Imager (RMI) with a MastCam image. Credit: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGNantes/CNRS/IAS/MSSS
NASA’s Opportunity rover found five metal meteorites, and Curiosity’s rumbled by its first find, a honking hunk of metallic gorgeousness named Lebanon, in May 2014. If this were Earth, the new meteorite’s smooth, shiny texture would indicate a relatively recent fall, but who’s to say how long it’s been sitting on Mars. The planet’s not without erosion from wind and temperature changes, but it lacks the oxygen and water that would really eat into an iron-nickel specimen like this one. Still, the new find looks polished to my eye, possibly smoothed by wind-whipped sand grains during the countless Martian dust storms that have raged over the eons.
Curiosity really knows how to put you on Mars. This view of exposed bedrock and dark sands was taken by the rover’s navigation camera on Friday, Jan. 13. Credit: NASA/JPL-Caltech/MSSS
Why no large stony meteorites have yet to be been found on Mars is puzzling. They should be far more common; like irons, stonies would also display beautiful thumprinting and dark fusion crust to boot. Maybe they simply blend in too well with all the other rocks littering the Martian landscape. Or perhaps they erode more quickly on Mars than the metal variety.
Every time a meteorite turns up on Mars in images taken by the rovers, I get a kick out of how our planet and the Red One not only share water, ice and wind but also getting whacked by space rocks.
The term UFO has a way of stirring up speculation and controversy. Even though this bland acronym refers only to an airborne object who’s appearance hasn’t been explained yet – with no references whatsoever to “aliens” or “extra-terrestrials” – one cannot mention it without inspiring talk of little green men and massive conspiracies.
This has certainly been the reaction to a video that was recently released by the Committee for the Study of Anomalous Air Phenomena (CEFAA), the Chilean government agency responsible for investigating UFOs. Originally captured by a helicopter belonging to the Chilean navy two years ago, the release of this 10-minute video coincided with the conclusion of the Committee’s investigation into the anomaly.
Such is the procedure of the CEFAA whenever a UFO – or Unidentified Aerial Phenomena (UAP) as they call them – comes to their attention. And once an investigation into the sighting is concluded, the details are released to the public. Interestingly, this particular encounter – which took place on November 11th, 2014, in the coastal region between San Antonio and Quinteros – had them stumped.
A Chilean Navy version of the Europcopter Airbus Cougar AS-532, which was being flown by the aircrew that spotted the UFO. Credit: Wikipedia Commons/Evogol
According to their report, a Chilean navy helicopter (an Airbus Cougar AS-532, like the one pictured above) was conducting a daytime patrol when a technician aboard spotted an object flying in their airspace. The technician then directed the helicopter’s infrared camera towards it and began filming. As the CEFAA recently indicated on their website:
“At 1:52 pm, while filming the terrain, the technician observed a strange object flying to the left over the ocean. Soon both men observed it with the naked eye. They noticed that the velocity and the altitude of the object appeared to be about the same as the helicopter, and estimated that the object was approximately 35 to 40 miles (55-65 km) away. It was traveling W/NW, according to the Captain. The technician aimed the camera at the object immediately and zoomed in with the infra red (IR) for better clarity.”
Further details from the investigation revealed that the officers reported the sighting to the General Directorate of Civil Aviation (DGAC) in Santiago. The DGAC reported that no air traffic was authorized to be in the region, and that they could detect no trace of the object on their radar. They also confirmed that their attempts to communicate using the standard radio frequencies (which the helicopter crew had also attempted) yielded no response.
What was even more strange was the way the object appeared as two “hot spots”, which looked to be connected. In addition, on two occasions, the object threw off some kind of trail before finally disappearing into the clouds. According to the technician who filmed it, the plume of material appeared to be very hot, which was indicated from the footage that showed how the stream glowed bright in the infrared band.
The route of the helicopter, based on the displayed geographic coordinates displayed on the camera. Credit: CEFAA
Much like the object itself, the CEFAA investigation was hard-pressed to explain the appearance of these hot plumes:
“Some analysts have suggested the hypothesis that it is a medium-sized line aircraft and that the stelae of the detachable element may be the reserve water inside the apparatus, thrown by the crew. However, meteorology asserts that neither the altitude at which the object moved, nor the ambient temperature of that moment, allowed such a wake of condensation.”
After the encounter, the Chilean Navy submitted the footage to the CEFAA, which has spent the past two years looking into it. However, their investigation proved inconclusive. As General Ricardo Bermúdez, Director of CEFAA during the investigation, told Leslie Kean of the Huffington Post, “We do not know what it was, but we do know what it was not.”
In essence, they ruled that the anomalous object could not have been a military or civilian aircraft. They also ruled out the possibility that the clouds it emitted were caused by the expulsion of waste water, and that the object was too low to emit contrails. In the end, the CEFAA cataloged this object as an UAP, which is standard practice whenever a particular sighting merits that designation.
Image captured from the footage shot by the Chilean Navy helicopter, showing the thermal trail cast by the object, and its two bright spots. Credit: CEFAA
However, since the video went public, one UFO hoax-buster has come forward with what he believes to be a sound explanation for the sighting. According to Mick West, an administrator at Metabunk.org – a website dedicated to debunking unscientific theories – what was seen in the video was actually the result a four-engine airplane leaving flying out of Santiago and leaving aerodynamic contrails in its wake.
Using online flight records, West tracked down two flights that were in the same airspace at the time – LA330 (from Santiago to La Serena) and IB6830 (from Santiago to Madrid). After examining the flights GPS data and conducting a 3D analysis, West concluded that the four-engine IB6830 was the likeliest culprit. The thermal plumes were engine exhaust, and its failure to show up on radar was because the radar operators were looking in the wrong place.
As West explained in his write-up about the incident:
“At the time this was spotted (the very first sighting on the video, at 13:52:34) IB6830 was actually around 35 miles away. However it would very quickly get further away. By 13:57 IB6830 would be 65 miles away. This explain why it was not seen on radar (IB6830 was on radar, just not where they thought it was).”
Image captured from the video showing two connected white circular lights, or “hot spots”. “Envoltura” means “envelope”, refers to the glow surrounding the two spots. Credit: CEFAA
In addition to being in exactly the right position (according to West), aerodynamic contrails explains the thermal flare and the two “thermal spotlights” on the object itself (see image above). Basically, the pilots were looking at the plane’s engine glow, which was caused by its two engines on either side of the fuselage glowing hot and giving the appearance of two connected hot spots.
As the plane climbed, its engine exhaust created hot trails that looked like plumes when viewed through an IR camera. Given the fact that the plane was at a higher altitude than originally reported, the presence of contrails would therefore be a possibility, which is something the CEFAA had ruled because the object was believed to be too close to the ground for those to form.
As William of Ockham famously said, “Among competing hypotheses, the one with the fewest assumptions should be selected.” In this case, it would seem that West’s hypothesis accounts for all the knowns and unknowns in this case, and is therefore the correct one. In the coming weeks and months, the Chilean government may choose to revisit their ruling and reconsider designating this a UAP.
But in the meantime, UFO enthusiasts are likely to interpret this however they want. And many (not all) may indeed see this video as further confirmation that extra-terrestrials are already among us!
Cue the theme music from X-Files! And be sure to watch West’s video explaining his conclusions:
Picture perfect blastoff of SpaceX Falcon 9 on Jan. 14, 2017, Return to Flight launch from Vandenberg Air Force Base in California carrying fleet of ten advanced Iridium NEXT comsats to low Earth orbit. Credit: SpaceX
Picture perfect blastoff of SpaceX Falcon 9 on Jan. 14, 2017, Return to Flight launch from Vandenberg Air Force Base in California carrying fleet of ten advanced Iridium NEXT comsats to low Earth orbit. Credit: SpaceX
The primary goal of SpaceX’sFalcon 9 launch from Space Launch Complex 4E on Vandenberg Air Force Base in California was to deploy the payload of the first ten Iridium Next communication satellites to low Earth orbit on the Iridium-1 mission.
“Thanks @elonmusk – a perfect flight! Loved watching sats deploy with you in the control room,” tweeted Matt Desch, Iridium Communications CEO, soon after receiving full confirmation that all 10 Iridium NEXT satellites were successfully deployed from their second stage satellite dispensers.
“More to go, but now to celebrate!!”
The inaugural ten will serve as the vanguard of a fleet that will eventually comprise 81 satellites.
SpaceX Falcon 9 first stage successfully soft lands on drone ship stationed in the Pacific Ocean off California coast after launching on Jan. 14, 2017, from Vandenberg Air Force Base in California carrying fleet of ten advanced Iridium NEXT comsats to low Earth orbit. Credit: SpaceX
Another launch failure would have dealt a devastating blow to confidence in SpaceX’s hard won reputation.
The Sept. 1, 2016 calamity was the second Falcon 9 failure within 15 months time. Both occurred inside the second stage and called into question the rockets reliability.
The 229-foot (70-meter) Falcon 9 rocket was rolled out from its processing hangar to the launch pad and raised vertically yesterday.
Picture perfect blastoff of SpaceX Falcon 9 on Jan. 14, 2017, Return to Flight launch from Vandenberg Air Force Base in California carrying fleet of ten advanced Iridium NEXT comsats to low Earth orbit. Credit: SpaceX
Today’s entire land, landing and satellite deployment event was shown live on a SpaceX hosted webcast. It offered extremely sharp views of Saturdays on time liftoff at 9:54:34 a.m. PST or 12:54:34 p.m. EST, and unbelievably clear images of the first stage descending back to Earth towards a tiny drone ship.
“Overall a wonderfully nominal mission,” gushed the SpaceX commentator during the webcast.
Since the Iridium 1 mission only had an instantaneous launch opportunity precisely at 9:54:34 a.m. PST or 12:54:34 p.m. EST, there was no margin for any technical or weather delays. And none happened. Although an errant boat had to be quickly escorted out of the exclusion zone less than 20 minutes before blastoff.
Confirmation of a successful deployment of all 10 Iridium NEXT satellites came at about T plus 1 hour and 17 minutes after liftoff from Vandenberg.
“So, so excited – finally breathing again!” tweeted Desch.
“Thanks for all the great vibes – I felt it! All 10 sats deployed; good orbit; good telemetry! WOW.”
The mobile relay satellites were delivered into a circular orbit at an altitude of 625 kilometers (388 miles) above Earth.
They were released one at a time from a pair of specially designed satellite dispensers at approximately 100 second intervals.
“It was a clean sweep, 10 for 10,” said SpaceX commentator John Insprucker during the live webcast.
“All the bridge wires show open, and that is a conclusion of the primary mission today, a great one for the first stage, second stage, and the customer’s satellites deployed into a good orbit.”
The Iridium NEXT satellites were built by Thales Alenia and Orbital ATK.
In the final moments before the propulsive landing, you could read the lettering on the “Just Read the Instructions” drone ship as the engine was firing to slow the descent and the landing legs deployed.
Really there was no cutout or loss of signal the whole way down. So the world could watch every key moment as it happened in real time.
The first stage softly landed approx. 8 minutes and 18 seconds after the California liftoff.
“First stage has landed on Just Read the Instructions,” SpaceX tweeted post landing.
This was the first launch by SpaceX since last August from the Florida Space Coast, and it came off without a hitch.
Iridium 1 is the first of seven planned Falcon 9 launches to establish the Iridium NEXT constellation which will eventually consist of 81 advanced satellites.
At least 70 will be launched by SpaceX.
The inaugural launch of the advanced Iridium NEXT satellites will start the process of replacing an aging Iridium fleet in orbit for nearly two decades.
SpaceX Falcon 9 poised for Jan. 14, 2017, Return to Flight launch from Vandenberg Air Force Base in California carrying ten Iridium NEXT comsats to orbit. Credit: SpaceX
This Falcon 9 was been outfitted with four landing lags and grid fins for a controlled landing on the tiny barge prepositioned in the Pacific Ocean several hundred miles off the west coast of California.
SpaceX Falcon 9 booster from Thaicom-8 launch on May 27, 2016 arrives at mouth of Port Canaveral, FL on June 2, 2016. Credit: Ken Kremer/kenkremer.com
Watch this space for continuing updates on SpaceX.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
IridiumNEXT satellites being fueled, pressurized & stacked on dispenser tiers at Vandenberg AFB for Falcon 9 launch. Credit: IridiumMission patch for Iridium-1 mission showing launch of the first 10 Iridium NEXT voice and data relay satellites on SpaceX Falcon 9 from Vandenberg Air Force Base, California, for Iridium Communications, and planned landing of the first stage on a droneship in the Pacific Ocean. Credit: SpaceX/Iridium
Artist depiction of Huygens landing on Titan. Credit: ESA
Twelve years ago today, the Huygens probe landed on Titan, marking the farthest point from Earth any spacecraft has ever landed. While a twelfth anniversary may be an odd number to mark with a special article, as we said in our previous article (with footage from the landing), this is the last opportunity to celebrate the success of Huygens before its partner spacecraft Cassini ends its mission on September 15, 2017 with a fateful plunge into Saturn’s atmosphere.
But Huygens is also worth celebrating because, amazingly, the mission almost failed, but yet was a marvelous success. If not for the insistence of one ESA engineer to complete an in-flight test of Huygens’ radio system, none of the spacecraft’s incredible data from Saturn’s largest and mysterious moon would have ever been received, and likely, no one would have ever known why.
The first-ever images of the surface Titan, taken by the Huygens probe. Image Credit: ESA/NASA/JPL/University of Arizona
As I detail in my new book “Incredible Stories From Space: A Behind-the-Scenes-Look at the Missions Changing Our View of the Cosmos,” in 1999, the Cassini orbiter and the piggybacking Huygens lander were on their way to the Saturn system. The duo launched in 1997, but instead of making a beeline for the 6th planet from the Sun, they took a looping path called the VVEJGA trajectory (Venus-Venus-Earth-Jupiter Gravity Assist), swinging around Venus twice and flying past Earth 2 years later.
While all the flybys gave the spacecraft added boosts to help get it to Saturn, the Earth flyby also provided a chance for the teams to test out various systems and instruments and get immediate feedback.
“The European group wanted to test the Huygens receiver by transmitting the data from Earth,” said Earl Maize, Project Manager for the Cassini mission at JPL, who I interviewed for the book. “That’s a great in-flight test, because there’s the old adage of flight engineers, ‘test as you fly, fly as you test.’”
The way the Huygens mission would work at the Saturn system was that Cassini would release Huygens when the duo approached Titan. Huygens would drop through Titan’s thick and obscuring atmosphere like a skydiver on a parachute, transmitting data all the while. The Huygens probe didn’t have enough power or a large enough dish to transmit all its data directly to Earth, so Cassini would gather and store Huygens’ data on board and later transmit it to Earth.
Boris Smeds was head of ESOC’s Systems and Requirements Section, Darmstadt, Germany. Credit: ESA.
ESA engineer Boris Smeds wanted to ensure this data handoff was going to work, otherwise a crucial part of the mission would be lost. So he proposed a test during the 1999 Earth flyby.
Maize said that for some reason, there was quite a bit of opposition to the test from some of the ESA officials, but Smeds and Claudio Sollazzo, Huygens’s ground operations manager at ESA’s European Space Operation Centre (ESOC) in Darmstadt, Germany were insistent the test was necessary.
NASA’s Deep Space Network is responsible for communicating with spacecraft. Pictured is the Goldstone facility in California, one of three facilities that make up the Network. Image: NASA/JPL
“They were not to be denied,” Maize said, “so they eventually got permission for the test. The Cassini team organized it, going to the Goldstone tracking station [in California] of the Deep Space Network (DSN) and did what’s called a ‘suitcase test,’ broke into the signal, and during the Earth flyby, Huygens, Cassini and Goldstone were all programmed to simulate the probe descending to Titan. It all worked great.”
Except for one thing: Cassini received almost no simulated data, and what it did receive was garbled. No one could figure out why.
Six months of painstaking investigation finally identified the problem. The variation in speed between the two spacecraft hadn’t been properly compensated for, causing a communication problem. It was as if the spacecraft were each communicating on a different frequency.
Artist concept of the Huygens probe descending to Titan. Credit: ESA.
“The European team came to us and said we didn’t have a mission,” Maize said. “But we put together ‘Tiger Teams’ to try and figure it out.”
The short answer was that the idiosyncrasies in the communications system were hardwired in. With the spacecraft now millions of miles away, nothing could be fixed. But engineers came up with an ingenious solution using a basic principal known as the Doppler Effect.
The metaphor Maize likes to use is this: if you are sitting on the shore and a speed boat goes by close to the coast, it zooms past you quickly. But that same boat going the same speed out on the horizon looks like it is barely moving.
“Since we couldn’t change Huygens’ signal, the only thing we could change was the way Cassini flew,” Maize said. “If we could move Cassini farther away and make it appear as if Huygens was moving slower, it would receive lander’s radio waves at a lower frequency, solving the problem.”
Maize said it took two years of “fancy coding modifications and some pretty amazing trajectory computations.” Huygens’ landing was also delayed two months for the new trajectory that was needed overcome the radio system design flaw.
Additionally, with Cassini needing to be farther away from Huygens than originally planned, it would eventually fly out of range to capture all of Huygens’ data. Astronomers instigated a plan where radio telescopes around the world would listen for Huygens’ faint signals and capture anything Cassini missed.
Huygens was released from the Cassini spacecraft on Christmas Day 2004, and arrived at Titan on January 14, 2005. The probe began transmitting data to Cassini four minutes into its descent through Titan’s murky atmosphere, snapping photos and taking data all the while. Then it touched down, the first time a probe had landed on an extraterrestrial world in the outer Solar System.
Because of the communication problem, Huygens was not able to gather as much information as originally planned, as it could only transmit on one channel instead of two. But amazingly, Cassini captured absolutely all the data sent by Huygens until it flew out of range.
“It was beautiful,” Maize said, “I’ll never forget it. We got it all, and it was a wonderful example of international cooperation. The fact that 19 countries could get everything coordinated and launched in the first place was pretty amazing, but there’s nothing that compares to the worldwide effort we put into recovering the Huygens mission. From an engineering standpoint, that might trump everything else we’ve done on this mission.”
The view of Titan from the descending Huygens spacecraft on January 14, 2005. Credit: ESA/NASA/JPL/University of Arizona.
With its ground-breaking mission, Huygens provided the first real view of the surface of Titan. The data has been invaluable for understanding this unique and mysterious moon, showing geological and meteorological processes that are more similar to those on the surface of the Earth than anywhere else in the Solar System. ESA has details on the top discoveries by Huygens here.
Noted space journalist Jim Oberg has written several detailed and very interesting articles about the Huygens’ recovery, including one at IEEE Spectrum and another at The Space Review. These articles provide much more insight into the test, Smeds’ remarkable insistence for the test, the recovery work that was done and the subsequent success of the mission.
As Oberg says in IEEE Spectrum, “Smeds continued a glorious engineering tradition of rescuing deep-space missions from doom with sheer persistence, insight, and lots of improvisation.”
A modest Smeds was quoted by ESA: “This has happened before. Almost any mission has some design problem,” says Smeds, who says he’s worked on recovering from pre- and post-launch telecom issues that have arisen with several past missions. “To me, it’s just part of my normal work.”
For more stories about Huygens, Cassini and several other current robotic space missions, “Incredible Stories From Space” tells many behind-the-scenes stories from the amazing people who work on these missions.
SpaceX Falcon 9 poised for Jan. 14, 2017, Return to Flight launch from Vandenberg Air Force Base in California carrying ten Iridium NEXT comsats to orbit. Credit: SpaceX
SpaceX Falcon 9 poised for Jan. 14, 2017, Return to Flight launch from Vandenberg Air Force Base in California carrying ten Iridium NEXT comsats to orbit. Credit: SpaceX
Barely four and a half months after another Falcon 9 and its $200 million Israeli commercial payload were suddenly destroyed during a prelaunch fueling test on the Florida Space Coast on Sept. 1, 2016, SpaceX says all systems are GO for the ‘Return to Flight’ launch of a new Falcon 9 on the Iridium-1 mission from the California coast tomorrow.
Another launch failure would deal a devastating blow to confidence in SpaceX’s hard won reputation – so ‘Failure is Not an Option’ as they say in the space business.
The Sept. 1, 2016 calamity was the second Falcon 9 failure within 15 months time. Both occurred inside the second stage and called into question the rockets reliability.
The 229-foot (70-meter) Falcon 9 rocket has been rolled out from its processing hangar to the launch pad and raised vertically.
“Beautiful picture of our ride to space tomorrow on the launch pad this morning!” tweeted Matt Desch, Iridium Communications CEO, featuring the lead photo in this story.
A license for permission to proceed with the launch originally last Sunday was only granted by the FAA last Friday, Jan. 6. But poor California weather in the form of stormy rains and high winds forced further delays to Saturday.
Today, Friday the 13th, it’s T-Minus 1 Day to the inaugural launch of the advanced Iridium NEXT voice and data relay satellites.
Liftoff of the SpaceX Falcon 9 with the payload of 10 identical next generation Iridium NEXT communications satellites is slated for 9:54:39 am PST or 5:54:39 pm UTC from Space Launch Complex 4E on Vandenberg Air Force Base in California.
The Iridium 1 mission only has an instantaneous launch opportunity precisely at 9:54:34 a.m. PST or 12:54:34 p.m. EST.
You can watch the launch live via a SpaceX webcast starting about 20 minutes prior to the planned liftoff time:
Weather forecasters currently predict about a 60 percent chance of favorable conditions at launch time.
Sunday, Jan. 15 is available as a back-up launch opportunity in case of a delay for any reason including technical and weather related issues.
The Iridium NEXT payload has been secured to the SpaceX Falcon 9 rocket at T-2 days to launch. Credit: SpaceX/Iridium
“The teams from Iridium, SpaceX and our partners are in the homestretch for the first launch of the Iridium NEXT satellite constellation,” said satellite owner Iridium Communications.
Meanwhile the launch teams have completed the countdown dress rehearsal’ and Launch Readiness Review in anticipation of the morning liftoff.
“Final preparations are being made for tomorrow’s inaugural launch, and with that comes a number of high-stakes verifications, involving all parties. Traditionally referred to as the ‘countdown dress rehearsal’ and ‘Launch Readiness Review’ (LRR), these milestones represent the final hurdles to clearing the path for the January 14th launch.”
“The countdown dress rehearsal and LRR include several prelaunch inspections and quality control measures. These include final clearances for the SpaceX Falcon 9 rocket, Iridium NEXT payload, SpaceX and Iridium® ground infrastructure and associated team member responsibilities.”
Iridium says that every precaution has been taken to ensure a successful launch.
“There are so many variables that need to be considered when finalizing launch preparations, and a slight deviation or unexpected behavior by any of them can jeopardize the launch integrity,” said Iridium COO Scott Smith, in a statement.
“We’ve perfected the necessary procedures, taken every precaution we can imagine, and tomorrow, after what has felt like centuries, we’ll take the first step on a long-awaited journey to revolutionize satellite communications. The success of today’s events has brought us to an apex moment.”
IridiumNEXT satellites being fueled, pressurized & stacked on dispenser tiers at Vandenberg AFB for Falcon 9 launch. Credit: Iridium
Iridium 1 is the first of seven planned Falcon 9 launches to establish the Iridium NEXT constellation which will eventually consist of 81 advanced satellites.
At least 70 will be launched by SpaceX.
The inaugural launch of the advanced Iridium NEXT satellites will start the process of replacing an aging Iridium fleet in orbit for nearly two decades.
Mission patch for Iridium-1 mission showing launch of the first 10 Iridium NEXT voice and data relay satellites on SpaceX Falcon 9 from Vandenberg Air Force Base, California, for Iridium Communications, and planned landing of the first stage on a droneship in the Pacific Ocean. Credit: SpaceX/Iridium
After the Sept .1 calamity SpaceX conducted a four month long investigation seeking to determine the root cause.
And it was just last Friday, Jan. 6, that the FAA finally granted SpaceX a license to launch the ‘Return to Flight’ Falcon 9 mission – as I confirmed with the FAA.
“The FAA accepted the investigation report on the AMOS-6 mishap and has closed the investigation,” FAA spokesman Hank Price confirmed to Universe Today.
“SpaceX applied for a license to launch the Iridium NEXT satellites from Vandenberg Air Force Base. The FAA has granted a license for that purpose.”
The SpaceX investigation report into the total loss of the Falcon 9 rocket and AMOS-6 payload has not been released at this time. The FAA has oversight responsibility to encourage, facilitate, and promote U.S. commercial space transportation and ensure the protection of public safety.
Incredible sight of pleasure craft zooming past SpaceX Falcon 9 booster from Thaicom-8 launch on May 27, 2016 as it arrives at the mouth of Port Canaveral, FL, atop droneship platform on June 2, 2016. Credit: Ken Kremer/kenkremer.com
In addition to the launch, SpaceX plans to continue its secondary objective of recovering the Falcon 9 first stage via a propulsive soft landing – as done several times previously and witnessed by this author.
The Iridium-1 mission patch featured herein highlights both the launch and landing objectives.
The goal is to eventually recycle and reuse the first stage – and thereby dramatically slash launch costs per Musk’s vision.
This Falcon 9 has been outfitted with four landing legs and grid fins for a controlled landing on a tiny barge prepositioned in the Pacific Ocean several hundred miles off the west coast of California.
Watch this space for continuing updates on SpaceX.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
The constellation Capricornus as it can be seen with the naked eye. Credit: AlltheSKy/Till Credner
Welcome back to Constellation Friday! Today, in honor of the late and great Tammy Plotner, we will be dealing with the “Sea Goat” – aka. Capricornus!
In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of all the then-known 48 constellations. This treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come, effectively becoming astrological and astronomical canon until the early Modern Age.
The name Capricornus is derived from Latin, which translates to “goat horn” or “horns of the goat”. This arises from the fact that representations dating back to the Middle Bronze Age consistently depict the constellation as a hybrid of a goat and fish. This may be due to the fact that at that time, the northern hemisphere’s Winter Solstice occurred while the sun was in Capricorn.
Mesopotamian low relief depicting Sumerian sun-god Shamash rising in the center. From left to right, he is flanked by Ninurta (thunderstorms), Ishtar (morning star), Enki (water) and Usmu (Enki’s vizier). Credit: britannica.com
The concern for the Sun’s rebirth might have rendered astronomical and astrological observation of this region of space very important. For the same reason, the Sun’s most southerly position, which is attained at the northern hemisphere’s winter solstice, is now called the Tropic of Capricorn, a term which also applies to the line on Earth where the Sun is directly overhead at noon on that solstice.
The earliest recorded evidence of this constellation is dated to the 21st century BCE, where the “Sea Goat” was depicted on a Sumerian cylinder-seal. In the Babylonian star catalogues, which are dated to ca. 1000 BCE, Capricornus was named suhurmašu (“The Goat Fish”). The constellation would later become the symbol of Ea (Enki) and was associated with the winter solstice.
In Greek mythology, the constellation was sometimes identified as Amalthea, the goat that suckled Zeus after Rhea saved him from Cronos. The goat’s broken horn was transformed into the cornucopia or horn of plenty, and ancient sources claim that this derives from the sun “taking nourishment” while in the constellation, in preparation for its climb back northward.
However, the constellation is often depicted as a sea-goat (i.e. a goat with a fish’s tail). One myth that deals with this says that when the goat-god Pan was attacked by the monster Typhon, he dived into the Nile. The parts of him that were above the water remained a goat, but those under the water transformed into a fish.
Johannes Hevelius’ depiction of Capricornus, from Uranographia (1690). Credit: chandra.harvard.edu
The Greeks regarded the constellation area with an alternative interpretation, namely the Augean Stable – a stable full uncleanliness – representing the concept of sin accumulated during the year. The Aquarius constellation, who was said to have poured out a river, then represent the yearly cleaning rains, associating to one of The Twelve Labors of Hercules.
History of Observation:
Despite being a faint constellation, Capricornus is one of the oldest recognized constellations. As with the other constellations associated with the Zodiac, Capricornus was catalogued by Ptolemy in the 2nd century CE and included in his treatise the Almagest. Despite its faintness, the constellation has also been recognized by other cultures around the world.
For example, in Chinese astronomy, Capriconus lies in The Black Tortoise of the North, one of the four symbols of the Chinese constellations. In 1922, Capricornus included in the list of 88 modern constellations recognized by the International Astronomical Union.
Capricornus as a sea-goat, from Urania’s Mirror (1825). Credit: US Library of Congress/ Sidney Hall
Notable Features:
In terms of stars few bright stars or Deep Sky Objects. It’s brightest star is also not its primary, but Delta Capricorni. Also known as its traditional names Deneb Algedi and Sheddi (from the Arabic danab al-jady, “the tail of the goat”), this magnitude 2.85 star is actually a four-star system located approximately 39 light years from Earth. Its brightest star (Delta Capricorni A) being a white giant with a luminosity 8.5 times that of the Sun.
It’s second brightest star, Beta Capricorni, is also known by the traditional name Dabih – which comes from the Arabic al-dhibii (which means “the butcher”). Located 328 light years way, this star system consists of Dabih Major (Beta-1) and Dabih Minor (Beta-2); both of which is actually composed of multiple stars – Beta-1 is composed of a three stars while Beta-2 is a double star.
It’s primary star, Alpha Capricorni, is also known as Algiedi (or Algedi), which is derived from the Arabic al-jady (“the billy goat”.) It is composed of two star systems, Prima Giedi (Alpha-2 Capricorni) and Secunda Giedi (Alpha-2 Capricorni); the former being a double star located 690 light-years away, and the latter is a G-type yellow giant 109 light years away.
The only Deep Sky Object associated with this constellation is Messier 30, a globular cluster located approximately 28,000 light years from Earth. This cluster is currently approaching us at a speed of about 180 km per second, and was one of the first Deep Sky Objects discovered by Charles Messier in 1764 (and included in The Messier Catalog).
Messier 30, imaged by the Hubble Telescope. Credit: NASA/Wikisky
Finding Capricornus:
The constellation is located in an area of sky called the Sea or Water, consisting of many watery constellations such as Aquarius, Pisces, and Eridanus. For binocular observers, the best place to start is to the northwestern corner first to find Alpha Capricorni. This is an absolutely beautiful optical double star that goes by the traditional name of Algiedi. The more western of the pair is Alpha¹ Capricorni, or Prima Giedi.
Put a telescope on it, because Prima Giedi is a true binary star. Located 690 light years from Earth, Alpha¹ Capricorni A, is a yellow G-type supergiant with an apparent magnitude of +4.30. Its companion, Alpha¹ Capricorni B, is an eighth magnitude star, separated by 0.65 arcseconds from the primary. Now go back and look at Alpha² Capricorni, aka. Secunda Giedi. Alpha² Capricorni is a yellow G-type giant with an apparent magnitude of +3.58.
For even more fun, aim your telescope all the way across the constellation at the northeastern corner for Delta Capricorni. Now you’re in for a real treat because Deneb Algedi is a a quaternary star system. Located 39 light years away, Delta Capricorni A, is classified a white giant star of the spectral type “A”. The system is a spectroscopic binary whose two components are of magnitude +3.2 and +5.2, and separated by 0.0018 arc seconds.
Similar to Algol, Delta Capricorni A is an eclipsing binary. Its unresolved companion orbits with Capricorni A around their common centre of mass every 1.022768 days, causing the brightness to drop 0.2 magnitudes during eclipses. Two other stars are thought to orbit further out in the system. The sixteenth magnitude Delta Capricorni C is one arc minute away, while the thirteenth magnitude Delta Capricorni D is two arc minutes away from the primary.
Location of the constellation Capricornus. Credit: IAU/Sky&Telescope magazine
Now go back to binoculars and hop one bright star west to take a look at Gamma Capricorni. Nashira, or “the bearer of good news” is one of those really cool stars right on the ecliptic that’s often occulted by the Moon. Gamma Capricorni is also a blue-white A-type (A7III) giant star with a mean apparent magnitude of +3.69. It is approximately 139 light years from Earth.
It is classified as an Alpha2 Canum Venaticorum type variable star and its brightness varies by 0.03 magnitudes. Now, go right in the center for Theta. It’s name is Dorsum – the Latin word for “Back”. Theta Capricorni is a white A-type main sequence dwarf with an apparent magnitude of +4.08. It is approximately 158 light years from our solar system. Want more viewing opportunities? Then go back west with binoculars and look at Beta.
Now, keep your binoculars handy and use the chart to help you located Messier 30. This one is rather hard to see in binoculars. But with a telescope, its stars can be resolved. It’s brightest red giant stars are about of apparent visual magnitude 12.1, its horizontal branch giants at magnitude 15.1. Only about 12 variable stars have been found in this globular cluster.
The core of M30 exhibits an extremely dense stellar population, and has undergone a core collapse. Despite its compressed core, close encounters of the member stars of globular cluster M30 seem to have occurred comparatively rare, as it appears to contain only few X-ray binary stars.
The NGC 6907 spiral galaxy, located in the direction of the Capricornus constellation. Credit: NOAO/KPNO
For more advanced telescope observing, try the NGC 7103 galaxy group (RA 21 39 51 Dec -22 28 24). Averaging about 15th magnitude elliptical is extremely faint and a definite big scope challenge. It pairs with NGC 7104, which is also 15th magnitude and has no classification. More realistically, try NGC 6907 (RA 20 25 1 Dec -24 49).
At slightly fainter than magnitude 11, this classy spiral galaxy shows some nice arm structure to even mid-sized telescopes. Why? Because it is doing a little galaxy interaction with background lenticular galaxy NGC 6908. This pair of spirals is engaging in some galaxy cannibalism! This act has caused some nice supernovae events within recent history and makes for some great observing – as well as astro-imaging opportunities!
The constellation of Capricornus also has a meteor shower associated with it. The Capricornid meteor stream peaks on or about July 30 and is active about a week before and after that date. The average fall rate is about 10 to 30 per hour and it is know to produce bolides.
Astronaut Alan Shepard poses next to the American flag on the Moon during the Apollo 14 mission. Credit: NASA
For decades, scientists have been of the belief that the Moon, Earth’s only natural satellite, was four and a half billion years old. According to this theory, the Moon was created from a fiery cataclysm produced by a collision between the Earth with a Mars-sized object (named Theia) roughly 100 million years after the formation of primordial Earth.
But according to a new study by researchers from UCLA (who re-examined some of the Apollo Moon Rocks), these estimates may have been off by about 40 to 140 million years. Far from simply adjusting our notions of the Moon’s proper age, these findings are also critical to our understanding of the Solar System and the formation and evolution of its rocky planets.
This study, titled “Early formation of the Moon 4.51 billion years ago“, was published recently in the journal Science Advances. Led by Melanie Barboni – a professor from the Department of Earth, Planetary, and Space Sciences at UCLA – the research team conducted uranium-lead dating on fragments of the Moon rocks that were brought back by the Apollo 14 astronauts.
Artist’s concept of a collision that is believed to have taken place in the HD 172555 star system between a moon-sized object and a Mercury-sized planet. Credit: NASA/JPL-Caltech
These fragments were of a compound known as zircon, a type of silicate mineral that contains trace amounts of radioactive elements (like uranium, thorium, and lutetium). As Kevin McKeegan, a UCLA professor of geochemistry and cosmochemistry and a co-author of the study, explained, “Zircons are nature’s best clocks. They are the best mineral in preserving geological history and revealing where they originated.”
By examining the radioactive decay of these elements, and correcting for cosmic ray exposure, the research team was able to get highly precise estimates of the zircon fragments ages. Using one of UCLA’s mass spectrometers, they were able to measure the rate at which the deposits of uranium in the zircon turned into lead, and the deposits of lutetium turned into hafnium.
In the end, their data indicated that the Moon formed about 4.51 billion years ago, which places its birth within the first 60 million years of the Solar System or so. Previously, dating Moon rocks proved difficult, mainly because most of them contained fragments of many different kinds of rocks, and these samples were determined to be tainted by the effects of multiple impacts.
However, Barboni and her team were able to examine eight zircons that were in good condition. More importantly, these silicate deposits are believed to have formed shortly after the collision between Earth and Theia, when the Moon was still an unsolidified mass covered in oceans of magma. As these oceans gradually cooled, the Moon’s body became differentiated between its crust, mantle and core.
Zircon deposits found in the Moon rocks returned by the Apollo 17 mission. Credit: NASA//Nicholas E. Timms.
Because zircon minerals were formed during the initial magma ocean, uranium-lead dating reaches all the way back to a time before the Moon became a solidified mass. As Edward Young, a UCLA professor of geochemistry and cosmochemistry and a co-author of the study, put it, “Mélanie was very clever in figuring out the Moon’s real age dates back to its pre-history before it solidified, not to its solidification.”
These findings have not only determined the age of the Moon with a high degree of accuracy (and for the first time), it also has implications for our understanding of when and how rocky planes formed within the Solar System. By placing accurate dates on when certain bodies formed, we are able to understand the context in which they formed, which also helps to determine what mechanisms were involved.
And this was just the first revelation produced by the research team, which hopes to continue studying the zircon fragments to see what they can learn about the Moon’s early history.
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