Space and astronomy news
It’s July 16th, 1969. The Apollo 11 crew have completed their training, and they’re in the Columbia Command Module atop a Saturn V rocket, to this day the most powerful rocket ever built. At 9:32 EDT the rocket lifts off, delivering the crew into Earth orbit 12 minutes after launch.
Continue reading “Here’s a Deepfake of Nixon Giving a Eulogy for the Apollo 11 Astronauts if Their Mission Failed”
We live in a world where multiple technological revolutions are taking place at the same time. While the leaps that are taking place in the fields of computing, robotics, and biotechnology are gaining a great deal of attention, less attention is being given to a field that is just as promising. This would be the field of manufacturing, where technologies like 3D printing and autonomous robots are proving to be a huge game-changer.
For example, there is the work being pursued by MIT’s Center for Bits and Atoms (CBA). It is here that graduate student Benjamin Jenett and Professor Neil Gershenfeld (as part of Jenett’s doctoral thesis work) are working on tiny robots that are capable of assembling entire structures. This work could have implications for everything from aircraft and buildings to settlements in space.
Continue reading “An Army of Tiny Robots Could Assemble Huge Structures in Space”
Dick Battin stood on his driveway in the New England frosty pre-dawn back in October 1957, straining his eyes to see Sputnik fly overhead. It was amazing. Watching that little point of light scoot silently across the sky made Battin’s heart pound. A human-made hunk of metal was actually orbiting Earth!
Walking back to his house, Battin’s mind raced. Oh, how he wished he’d never left the MIT Instrumentation Laboratory a year and a half ago. He’d regretted it since the day he decided to move on to what he thought were greener pastures. But now, his regret became a steadfast resolve to somehow get back to the Lab again, because he knew – he was absolutely certain without a doubt – that Doc Draper would be getting his hand in this new venture of space exploration. And Battin wanted in, too.
Continue reading “The Story of the Apollo Guidance Computer, Part 1”
There are 20,000 objects orbiting Earth at this moment that are larger than 10 cm. Out of that number, only about 2,000 are operational satellites. The other 18,000 objects are pieces of junk of varying sizes. But it’s not just junk: it’s dangerous junk.
If that doesn’t sound like a problem, keep this in mind: Thanks to SpaceX and others, we’re living in the age of cheap access to space, and we’re seeing more and more satellites boosted into orbit. The problem won’t go away on its own.
Continue reading “Before We Ruin the Universe, We Should Follow Some Space Sustainability Guidelines”
In February of 2016, scientists working for the Laser Interferometer Gravitational-Wave Observatory (LIGO) made history when they announced the first-ever detection of gravitational waves. Not only did this discovery confirm a century-old prediction made by Einstein’s Theory of General Relativity, it also confirmed the existence of stellar binary black holes – which merged to produce the signal in the first place.
And now, an international team led by MIT astrophysicist Carl Rodriguez has produced a study that suggests that black holes may merge multiple times. According to their study, these “second-generation mergers” likely occur within globular clusters, the large and compact star clusters that typically orbit at the edges of galaxies – and which are densely-packed with hundreds of thousands to millions of stars.
The study, titled “Post-Newtonian Dynamics in Dense Star Clusters: Highly Eccentric, Highly Spinning, and Repeated Binary Black Hole Mergers“, recently appeared in the Physical Review Letters. The study was led by Carl Rodriguez, a Pappalardo fellow in MIT’s Department of Physics and the Kavli Institute for Astrophysics and Space Research, and included members from the Institute of Space Sciences and the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA).
As Carl Rodriguez explained in a recent MIT press release:
“We think these clusters formed with hundreds to thousands of black holes that rapidly sank down in the center. These kinds of clusters are essentially factories for black hole binaries, where you’ve got so many black holes hanging out in a small region of space that two black holes could merge and produce a more massive black hole. Then that new black hole can find another companion and merge again.”
Globular clusters have been a source of fascination ever since astronomers first observed them in the 17th century. These spherical collections of stars are among the oldest known stars in the Universe, and can be found in most galaxies. Depending on the size and type of galaxy they orbit, the number of clusters varies, with elliptical galaxies hosting tens of thousands while galaxies like the Milky Way have over 150.
For years, Rodriguez has been investigating the behavior of black holes within globular clusters to see if they interact with their stars differently from black holes that occupy less densely-populated regions in space. To test this hypothesis, Rodriguez and his colleagues used the Quest supercomputer at Northwestern University to conduct simulations on 24 stellar clusters.
These clusters ranged in size from 200,000 to 2 million stars and covered a range of different densities and metallic compositions. The simulations modeled the evolution of individual stars within these clusters over the course of 12 billion years. This span of time was enough to follow these stars as they interacted with each other, and eventually formed black holes.
The simulations also modeled the evolution and trajectories of black holes once they formed. As Rodriguez explained:
“The neat thing is, because black holes are the most massive objects in these clusters, they sink to the center, where you get a high enough density of black holes to form binaries. Binary black holes are basically like giant targets hanging out in the cluster, and as you throw other black holes or stars at them, they undergo these crazy chaotic encounters.”
Whereas previous simulations were based on Newton’s physics, the team decided to add Einstein’s relativistic effects into their simulations of globular clusters. This was due to the fact that gravitational waves were not predicted by Newton’s theories, but by Einstein’s Theory of General Relativity. As Rodriguez indicated, this allowed for them to see how gravitational waves played a role:
“What people had done in the past was to treat this as a purely Newtonian problem. Newton’s theory of gravity works in 99.9 percent of all cases. The few cases in which it doesn’t work might be when you have two black holes whizzing by each other very closely, which normally doesn’t happen in most galaxies… In Einstein’s theory of general relativity, where I can emit gravitational waves, then when one black hole passes near another, it can actually emit a tiny pulse of gravitational waves. This can subtract enough energy from the system that the two black holes actually become bound, and then they will rapidly merge.”
What they observed was that inside the stellar clusters, black holes merge with each other to create new black holes. In previous simulations, Newtonian gravity predicted that most binary black holes would be kicked out of the cluster before they could merge. But by taking relativistic effects into account, Rodriguez and his team found that nearly half of the binary black holes merged to form more massive ones.
As Rodriguez explained, the difference between those that merged and those that were kicked out came down to spin:
“If the two black holes are spinning when they merge, the black hole they create will emit gravitational waves in a single preferred direction, like a rocket, creating a new black hole that can shoot out as fast as 5,000 kilometers per second — so, insanely fast. It only takes a kick of maybe a few tens to a hundred kilometers per second to escape one of these clusters.”
This raised another interesting fact about previous simulations, where astronomers believed that the product of any black hole merger would be kicked out of the cluster since most black holes are assumed to be rapidly spinning. However, the gravity wave measurements recently obtained from LIGO appear to contradict this, which has only detected the mergers of binary black holes with low spins.
This assumption, however, seems to contradict the measurements from LIGO, which has so far only detected binary black holes with low spins. To test the implications of this, Rodriguez and his colleagues reduced the spin rates of the black holes in their simulations. What they found was that nearly 20% of the binary black holes from clusters had at least one black hole that ranged from being 50 to 130 solar masses.
Essentially, this indicated that these were “second generation” black holes, since scientists believe that this mass cannot be achieved by a black hole that formed from a single star. Looking ahead, Rodriguez and his team anticipate that if LIGO detects an object with a mass within this range, it is likely the result of black holes merging within dense stellar cluster, rather than from a single star.
“If we wait long enough, then eventually LIGO will see something that could only have come from these star clusters, because it would be bigger than anything you could get from a single star,” Rodriguez says. “My co-authors and I have a bet against a couple people studying binary star formation that within the first 100 LIGO detections, LIGO will detect something within this upper mass gap. I get a nice bottle of wine if that happens to be true.”
The detection of gravitational waves was a historic accomplishment, and one that has enabled astronomers to conduct new and exciting research. Already, scientists are gaining new insight into black holes by studying the byproduct of their mergers. In the coming years, we can expect to learn a great deal more thanks to improve methods and increased cooperation between observatories.
Further Reading: MIT, Physical Review Letters
CAPE CANAVERAL AIR FORCE STATION, FL — A Cold War-era derived Peacekeeper ICBM missile formerly armed with multiple nuclear warheads and now modified as a payload orbiter successfully launched an urgently needed space situational awareness and space junk tracking satellite to equatorial orbit overnight this morning, Aug. 26, for the U.S. military from the Florida Space Coast.
Following a nearly 3 hour delay due to day long dismal weather causing locally heavy rain storms and lighting in central Florida, an Orbital ATK Minotaur IV rocket carrying the ORS-5 tracking satellite for the USAF finally lifted off in the wee hours Saturday morning, Aug. 26 at 2:04 a.m. EDT from Cape Canaveral Air Force Station in Florida.
The five stage solid fueled Minotaur IV roared rapidly off Space Launch Complex 46 (SLC-46) on a half million pounds of thrust and quickly disappeared into the clouds from the perspective of our nearby media launch viewing site on this inaugural launch of the rocket from the Cape.
Check back here to see the expanding gallery of launch photos and videos recorded by myself and space journalist colleagues!
The gap filling ORS-5 space surveillance satellite is a low cost mission technology demonstration mission that will track orbiting threats for the U.S. Air Force – and offered a thrilling nighttime launch experience to those who stayed awake and braved the post midnight time slot.
The converted ICBM motor ignition produced a flash of extremely bright light that briefly turned night into day. The maiden Minotaur from the Cape gushed intensely at liftoff and left a huge exhaust trailing in its wake as it accelerated to orbit.
The ORS-5 is a single satellite constellation with a primary mission to provide space situational awareness of the geosynchronous orbit belt for Combatant Commanders’ urgent needs, according to Brig. Gen. Wayne Monteith, 45th Space Wing commander and mission Launch Decision Authority at Cape Canaveral Air Force Station
The ORS-5 mission, which stands for Operationally Responsive Space-5, marks the first launch of a Minotaur IV rocket from Cape Canaveral Air Force Station and the first use of SLC-46 since 1999.
SLC-46 is operated under license by Space Florida, which invested more than $6 million dollars of state funds into pad upgrades and renovations.
The ORS-5 satellite built for the USAF Operationally Responsive Space Office will provide the US military with space-based surveillance and tracking of other satellites both friend and foe as well as space debris in geosynchronous orbit, 22,236 miles above the equator.
ORS-5 is like a telescope wrapped in a satellite that will aim up to seek threats from LEO to GEO using cameras and spectrometer sensors.
Also known as SensorSat, ORS-5 is designed to scan for other satellites and debris to aid the U.S. military’s tracking of objects in geosynchronous orbit for a minimum of three years and possibly longer if its on board sensor and spacecraft systems continue functioning in a useful and productive manner.
The Minotaur IV is a five stage rocket comprised of three stages of a decommissioned Cold War-era Peacekeeper Intercontinental Ballistic Missile (ICBM) that has been modified to add two additional Orbital ATK Orion 38 solid rocket motors for the upper stages.
Approximately 28 minutes after liftoff at 2:04 a.m. EDT, the Minotaur IV deployed the ORS-5 satellite into its targeted low inclination orbit 372 miles (599 kilometers) above the earth, Orbital ATK confirmed.
“From this orbit, ORS-5 will deliver timely, reliable and accurate space situational awareness information to the United States Strategic Command through the Joint Space Operations Center.”
“This was our first Minotaur launch from Cape Canaveral Air Force Station, demonstrating the rocket’s capability to launch from all four major U.S. spaceports,” said Rich Straka, Vice President and General Manager of Orbital ATK’s Launch Vehicles Division.
This Minotaur IV rocket is a retired Cold War-era ICBM missile once armed with nuclear warheads aimed at the former Soviet Union that can now launch satellites for purposes other than offensive nuclear war retaliation.
So on the event of a nuclear first or retaliatory strike, this is how the world could potentially end in utter destruction and nuclear catastrophy.
To get an up-close feeling of the sounds and fury watch this Minotaur IV/ORS-5 launch video compilation from colleague Jeff Seibert from our media launch viewing site from the roof of the 5th Space Launch Squadron building on Cape Canaveral Air Force Station, FL.
Video Caption: Orbital ATK launch of Minotaur ORS 5 at 2:04 a.m. EDT on Aug. 26, 2017. None of the videos are sped up, it really takes off that fast. The solid fuel Peacekeeper missile segments were repurposed to launch the ORS-5 satellite from Launch Complex 46 on CCAFS., Fl. Credit: Jeff Seibert
Overall the ORS-5 launch was the 26th blastoff in Orbital ATK’s Minotaur family of launch vehicles which enjoy a 100% success rate to date.
Today’s launch was the 6th for the Minotaur IV version.
“With a perfect track record of 26 successful launches, the Minotaur family has proven to be a valuable and reliable asset for the Department of Defense,” said Straka.
“Orbital ATK has launched nearly 100 space launch and strategic rockets for the U.S. Air Force,” said Scott Lehr, President of Orbital ATK’s Flight Systems Group. “We’re proud to be a partner they can count on.”
The past two weeks have been a super busy time at the Kennedy Space Center and Cape Canaveral. This morning’s post midnight launch was the third in just 11 days – and the second in a week!
A ULA Atlas V launched the NASA TDRS-M science relay satellite last Friday, Aug 18. And a SpaceX Falcon 9 launched the Dragon CRS-12 cargo resupply mission to the International Space Station (ISS) on Monday, Aug. 14.
“The ORS-5 Minotaur IV launch was the true epitome of partnership,” Gen. Monteith said.
“A collaborative effort between multiple mission partners, each group came together flawlessly to revolutionize how we work together on the Eastern Range. Teamwork is pivotal to making us the ‘World’s Premier Gateway to Space’ and I couldn’t be prouder to lead a Wing that not only has launched over a quarter of the world’s launches this year, but also three successful, launches from three different providers, in less than two weeks.”
ORS-5 was designed and built by Massachusetts Institute of Technology’s Lincoln Laboratory facility in Lexington, Massachusetts at a cost of $49 million.
The ORS-5 or SensorSat satellite will provide the US military with space-based surveillance and tracking of other satellites both friend and foe and space debris in geosynchronous orbit 22,236 miles above the equator. Credit: MIT Lincoln Laboratory
In July 2015 the U.S. Air Force’s Operationally Responsive Space (ORS) Office awarded Orbital ATK a $23.6 million contract to launch the ORS-5 SensorSat on the Minotaur IV launch vehicle.
ORS-5/SensorSat was processed for launch and encapsulation inside the 2.3 meter diameter payload fairing at Astrotech Space Operations processing facility in Titusville, Florida.
Watch for Ken’s continuing onsite Minotaur IV ORS-5, TDRS-M, CRS-12, and NASA and space mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
CAPE CANAVERAL AIR FORCE STATION, FL — A gap filling space surveillance satellite that will track orbiting threats for the U.S. Air Force is set for an thrilling nighttime blastoff Friday, Aug. 25 on the maiden mission of the Minotaur IV rocket from Cape Canaveral that’s powered by a retired Cold War-era ICBM missile – once armed with nuclear warheads.
The ORS-5 satellite will provide the US military with space-based surveillance and tracking of other satellites both friend and foe as well as space debris in geosynchronous orbit, 22,236 miles above the equator.
The Orbital ATK Minotaur IV rocket carrying the ORS-5 tracking satellite for the USAF Operationally Responsive Space Office is targeting liftoff just before midnight Friday at 11:15 p.m. EDT from Space Launch Complex-46 (SLC-46) at Cape Canaveral Air Force Station.
“We are go for launch of Orbital ATK’s Minotaur IV rocket Friday night,” Orbital ATK confirmed.
The ORS-5 mission, which stands for Operationally Responsive Space-5, marks the first launch of a Minotaur IV rocket from Cape Canaveral and the first use of SLC-46 since 1999.
The Minotaur IV is a five stage rocket comprised of three stages of a decommissioned Cold War-era Peacekeeper Intercontinental Ballistic Missile (ICBM) that has been modified to add two additional Orbital ATK Orion 38 solid rocket motors for the upper stages.
Being a night launch and the first of its kind will surely make for a spectacular sky show.
Plus if you want to see how the world could potentially end in nuclear catastrophy, come watch the near midnight launch of the Orbital ATK Minotaur IV rocket that’s a retired Peacekeeper ICBM once armed with nuclear warheads aimed at the Russians but now carrying the USAF ORS-5 surveillance satellite instead.
Its well worth your time if you can watch the Minotaur launch with your own eyeballs. It can be easily viewed from numerous local area beaches, parks, restaurants and more.
Furthermore, its been in a super busy time at the Kennedy Space Center and Cape Canaveral. Because, if all goes well Friday’s midnight launch will be the third in just 11 days – and the second in a week!
A ULA Atlas V launched the NASA TDRS-M science relay satellite last Friday, Aug 18. And a SpaceX Falcon 9 launched the Dragon CRS-12 cargo resupply mission to the International Space Station (ISS) on Monday, Aug. 14.
You can watch the launch live via the Orbital ATK website here: www.orbitalatk.com
The live Orbital ATK broadcast will begin approximately 20 minutes before the launch window opens.
The webcast will be hosted by former CNN space reporter John Zarrella.
The launch window opens at 11:15 p.m. EDT August 25. It extends for four hours until 3:15 a.m. EDT August 26.
In the event of delay for any reason, the next launch opportunity is Saturday, Aug. 26. The launch window remains the same from 11:15 p.m. EDT August 26 to 3:15 a.m. EDT August 27.
The weather looks somewhat iffy at this time with only a 60% chance of favorable conditions at launch time according to U.S. Air Force meteorologists with the 45th Space Wing Weather Squadron at Patrick Air Force Base. The primary concerns on Aug. 25 are for thick clouds and cumulus clouds.
The weather odds deteriorate to only 40% favorable for the 24 hour scrub turnaround day on Aug. 26. The primary concerns on Aug. 26 are for thick clouds, cumulus clouds and lightning.
The ORS-5 or SensorSat satellite will provide the US military with space-based surveillance and tracking of other satellites both friend and foe and space debris in geosynchronous orbit 22,236 miles above the equator. Credit: MIT Lincoln Laboratory
ORS-5 is like a telescope wrapped in a satellite that will aim up to seek threats from LEO to GEO.
ORS-5, also known as SensorSat, is designed to scan for other satellites and debris to aid the U.S. military’s tracking of objects in geosynchronous orbit for a minimum of three years and possibly longer if its on boards sensor and satellite systems continue functioning in a useful and productive manner.
“The delivery and upcoming launch of ORS-5 marks a significant milestone in fulfilling our commitment to the space situational awareness mission and U.S. Strategic Command,” said Lt. Gen. John F. Thompson, commander of the Space and Missile Systems Center and Air Force program executive officer for Space. “It’s an important asset for the warfighter and will be employed for at least three years.”
The ORS-5 satellite has a payload mass of 140 kg. It will be launched into a low inclination equatorial orbit of 600 km x 600 km (373 mi x 373 mi) at zero degrees.
“This will be the largest low-Earth orbit inclination plane change in history – 28.5 degrees latitude to equatorial orbit,” says Orbital ATK.
“The Minotaur IV 4th stage will put ORS-5 into initial orbit & the payload insertion stage will make a hard left to get to equatorial orbit.”
The Cape Canaveral AFB launch site for this Minotaur IV was chosen, rather than NASA’s Wallops Flight Facility in Virginia based on the final orbit required for ORS-5, Orbital ATK told Universe Today at a prelaunch media briefing.
The Minotaur IV is not powerful enough to deliver ORS-5 to the desired orbit from Wallops.
ORS-5 was designed and built by Massachusetts Institute of Technology’s Lincoln Laboratory facility in Lexington, Massachusetts at a cost of $49 million.
In July 2015 the U.S. Air Force’s Operationally Responsive Space (ORS) Office awarded Orbital ATK a $23.6 million contract to launch the ORS-5 SensorSat on the Minotaur IV launch vehicle.
ORS-5/SensorSat was processed for launch and encapsulation inside the 2.3 meter diameter payload fairing at Astrotech Space Operations processing facility in Titusville, Florida.
The Minotaur IV is quite similar to Orbital ATK’s Minotaur V launch vehicle which successfully propelled NASA’s LADEE lunar orbiter to the Moon for NASA during a night launch from the agency’s Wallops Flight Facility in Virginia in Sept. 2013.
The Minotaur V also utilizes the first three stages of the decommissioned Peacekeeper ICBM missile.
Overall the ORS-5 launch will be the 26th blastoff in Orbital ATK’s Minotaur family of launch vehicles which enjoy a 100% success rate to date.
The U.S. Air Force has a stockpile of about 180 surplus Peacekeeper motors, but not all are launch capable, the USAF told Universe Today at a prelaunch media briefing.
The USAF furnishes the Peacekeeper motors to Orbital ATK after first refurbishing the booster stages at Vandenberg AFB, Ca.
Orbital ATK then upgrades the stages by adding their own “flight-proven avionics, structures, software and other components that are common among Orbital ATK’s space launch vehicles” and integrating the firms Orion 38 solid rocket motors for the two upper stages.
“A combined government and contractor team of mission partners executed final ground activities including a Launch Base Compatibility Test to verify satellite integrity after shipment, an intersegment test to verify communication compatibility from the satellite to the on-orbit operations center and the final battery reconditioning for launch, prior to its integration with the Minotaur IV launch vehicle,” says the USAF.
Watch for Ken’s continuing onsite Minotaur IV ORS-5, TDRS-M, CRS-12, and NASA and space mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
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Learn more about the 2017 Total Solar Eclipse, upcoming Minotaur IV ORS-5 military launch on Aug. 25, recent ULA Atlas TDRS-M NASA comsat on Aug. 18, 2017 , SpaceX Dragon CRS-12 resupply launch to ISS on Aug. 14, NASA missions and more at Ken’s upcoming outreach events at Kennedy Space Center Quality Inn, Titusville, FL:
Aug 25-26: “2017 Total Solar Eclipse, Minotaur IV ORS-5, TDRS-M NASA comsat, SpaceX CRS-12 resupply launches to the ISS, Intelsat35e, BulgariaSat 1 and NRO Spysat, SLS, Orion, Commercial crew capsules from Boeing and SpaceX , Heroes and Legends at KSCVC, ULA Atlas/John Glenn Cygnus launch to ISS, SBIRS GEO 3 launch, GOES-R weather satellite launch, OSIRIS-Rex, Juno at Jupiter, InSight Mars lander, SpaceX and Orbital ATK cargo missions to the ISS, ULA Delta 4 Heavy spy satellite, Curiosity and Opportunity explore Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings
When it comes to the study of planets, moons, and stars, magnetic fields are kind of a big deal. Believed to be the result of convection in a planet, these fields can be the difference between a planet giving rise to life or becoming a lifeless ball of rock. For some time, scientists have known that has a Earth’s magnetic field, which is powered by a dynamo effect created by convection in its liquid, outer core.
Scientists have also long held that the Moon once had a magnetic field, which was also powered by convection in its core. Previously, it was believed that this field disappeared roughly 1 billion years after the Moon formed (ca. 3 to 3.5 billion years ago). But according to a new study from the Massachusetts Institute of Technology (MIT), it now appears that the Moon’s magnetic field continued to exist for another billion years.
The study, titled “A two-billion-year history for the lunar dynamo“, recently appeared in the journal Science Advances. Led by Dr. Sonia Tikoo, an Assistant Professor at Rutger’s University and a former researcher at MIT, the team analyzed ancient lunar rocks collected by NASA’s Apollo 15 mission. What they found was that the rock showed signs of a being in magnetic field when it was formed between 1 and 2.5 billion years ago.
The age of this rock sample means that it is significantly younger than others returned by the Apollo missions. Using a technique they developed, the team examined the sample’s glassy composition with a magnometer to determine its magnetic properties. They then exposed the sample to a lab-generated magnetic field and other conditions that were similar to those that existed on the Moon when the rock would have formed.
This was done by placing the rocks into a specially-designed oxygen-deprived oven, which was built with the help of Clement Suavet and Timothy Grove – two researchers from MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS) and co-authors on the study. The team then exposed the rocks to a tenuous, oxygen-free environment and heated them to extreme temperatures.
As Benjamin Weiss – a professor of planetary sciences at EAPS – explained:
“You see how magnetized it gets from getting heated in that known magnetic field, then you compare that field to the natural magnetic field you measured beforehand, and from that you can figure out what the ancient field strength was… In this way, we finally have gotten an accurate measurement of the lunar field.”
From this, they determined the lunar rock became magnetized in a field with a strength of about 5 microtesla. That’s many times weaker than Earth’s magnetic field when measured from the surface (25 – 65 microteslas), and two orders of magnitude weaker than what it was 3 to 4 billion years ago. These findings were quite significant, since they may help to resolve an enduring mystery about the Moon.
Previously, scientists suspected that the Moon’s magnetic field died out 1.5 billion years after the Moon formed (ca. 3 billion years ago). However, they were unsure if this process happened rapidly, or if the Moon’s magnetic field endured, but in a weakened state. The results of this study indicate that the magnetic field did in fact linger for an additional billion years, dissipating about 2.5 billion years ago.
As Weiss indicated, this study raises new questions about the Moon’s geological history:
“The concept of a planetary magnetic field produced by moving liquid metal is an idea that is really only a few decades old. What powers this motion on Earth and other bodies, particularly on the moon, is not well-understood. We can figure this out by knowing the lifetime of the lunar dynamo.”
In other words, this new timeline of the Moon casts some doubt on the theory that a lunar dynamo alone is what powered its magnetic field in the past. Basically, it is now seen as a distinct possibility that the Moon’s magnetic field was powered by two mechanisms. Whereas one allowed for a dynamo in the core that powered its magnetic field for a good billion years after the Moon’s formation, a second one kept it going afterwards.
In the past, scientists have proposed that the Moon’s dynamo was powered by Earth’s gravitational pull, which would have caused tidal flexing in the Moon’s interior (much in the same way that Jupiter and Saturn’s powerful gravity drives geological activity in their moons interiors). In addition, the Moon once orbited much closer to Earth, which may have been enough to power its once-stronger magnetic field.
However, the Moon gradually moved away from Earth, eventually reaching its current orbit about 3 billion years ago. This coincides with the timeline of the Moon’s magnetic field, which began to dissipate at about the same time. This could mean that by about 3 billion years ago, without the gravitational pull of the Earth, the core slowly cooled. One billion years later, the core had solidified to the point that it arrested the Moon;s magnetic field. As Weiss explained:
“As the moon cools, its core acts like a lava lamp – low-density stuff rises because it’s hot or because its composition is different from that of the surrounding fluid. That’s how we think the Earth’s dynamo works, and that’s what we suggest the late lunar dynamo was doing as well… Today the moon’s field is essentially zero. And we now know it turned off somewhere between the formation of this rock and today.”
These findings were made possible thanks in part by the availability of younger lunar rocks. In the future, the researchers are planning on analyzing even younger samples to precisely determine where the Moon’s dynamo died out completely. This will not only serve to validate the findings of this study, but could also lead to a more comprehensive timeline of the Moon’s geological history.
The results of these and other studies that seek to understand how the Moon formed and changed over time will also go a long way towards improving our understanding of how Earth, the Solar System, and extra-solar systems came to be.
Further Reading: Science Advances, MIT News
Welcome, come in to the 480th Carnival of Space! The Carnival is a community of space science and astronomy writers and bloggers, who submit their best work each week for your benefit. I’m Susie Murph, part of the team at Universe Today and CosmoQuest. So now, on to this week’s stories!
Continue reading “Carnival of Space #480”
Update: This year’s Nobel Prize in Physics has been awarded to David J. Thouless (University of Washington), F. Duncan M. Haldane (Princeton University), and J. Michael Kosterlitz of Brown University for “theoretical discoveries of topological phase transitions and topological phases of matter”. One half of the prize was awarded to Thouless while the other half was jointly awarded to Haldane and Kosterlitz.
The Nobel Prize in physics is a coveted award. Every year, the prize is bestowed upon the individual who is deemed to have made the greatest contribution to the field of physics during the preceding year. And this year, the groundbreaking discovery of gravitational waves is anticipated to be the main focus.
This discovery, which was announced on February 11th, 2016, was made possible thanks to the development of the Laser Interferometer Gravitational-Wave Observatory (LIGO). As such, it is expected that the three scientists that are most responsible for the invention of the technology will receive the Nobel Prize for their work. However, there are those in the scientific community who feel that another scientist – Barry Barish – should also be recognized.
But first, some background is needed to help put all this into perspective. For starers, gravitational waves are ripples in the curvature of spacetime that are generated by certain gravitational interactions and which propagate at the speed of light. The existence of such waves has been postulated since the late 19th century.
However, it was not until the late 20th century, thanks in large part to Einstein and his theory of General Relativity, that gravitational-wave research began to emerge as a branch of astronomy. Since the 1960s, various gravitational-wave detectors have been built, which includes the LIGO observatory.
Founded as a Caltech/MIT project, LIGO was officially approved by the National Science Board (NSF) in 1984. A decade later, construction began on the facility’s two locations – in Hanford, Washington and Livingston, Louisiana. By 2002, it began to obtain data, and work began on improving its original detectors in 2008 (known as the Advanced LIGO Project).
The credit for the creation of LIGO goes to three scientists, which includes Rainer Weiss, a professor of physics emeritus at the Massachusetts Institute of Technology (MIT); Ronald Drever, an experimental physics who was professor emeritus at the California Institute of Technology and a professor at Glasgow University; and Kip Thorne, the Feynman Professor of Theoretical Physics at Caltech.
In 1967 and 68, Weiss and Thorne initiated efforts to construct prototype detectors, and produced theoretical work to prove that gravitational waves could be successfully analyzed. By the 1970s, using different methods, Weiss and Denver both succeeded in building detectors. In the coming years, all three men remained pivotal and influential, helping to make gravitational astronomy a legitimate field of research.
However, it has been argued that without Barish – a particle physicist at Caltech – the discovery would never have been made. Having become the Principal Investigator of LIGO in 1994, he inherited the project at a very crucial time. It had begun funding a decade prior, but coordinating the work of Wiess, Thorne and Drever (from MIT, Caltech and the University of Glasgow, respectively) proved difficult.
As such, it was decided that a single director was needed. Between 1987 and 1994, Rochus Vogt – a professor emeritus of Physics at Caltech – was appointed by the NSF to fill this role. While Vogt brought the initial team together and helped to get the construction of the project approved, he proved difficult when it came to dealing with bureaucracy and documenting his researchers progress.
As such, between 1989 through 1994, LIGO failed to progress technically and organizationally, and had trouble acquiring funding as well. By 1994, Caltech eased Vogt out of his position and appointed Barish to the position of director. Barish got to work quickly, making significant changes to the way LIGO was administered, expanding the research team, and developing a detailed work plan for the NSF.
Barish was also responsible for expanding LIGO beyond its Caltech and MIT constraints. This he did through the creation of the independent LIGO Scientific Collaboration (LSC), which gave access to outside researchers and institutions. This was instrumental in creating crucial partnerships, which included the UK Science and Technology Facilities Council, the Max Planck Society of Germany, and the Australian Research Council.
By 1999, construction had wrapped up on the LIGO observatories, and by 2002, they began taking their first bits of data. By 2004, the funding and groundwork was laid for the next phase of LIGO development, which involved a multi-year shut-down while the detectors were replaced with improved “Advanced LIGO” versions.
All of this was made possible by Barish, who retired in 2005 to head up other projects. Thanks to his sweeping reforms, LIGO got to work after an abortive start, began to produce data, procured funding, crucial partnerships, and now has more than 1000 collaborators worldwide, thanks to the LSC program he established.
Little wonder then why some scientists think the Nobel Prize should be split four-ways, awarding the three scientists who conceived of LIGO and the one scientist who made it happen. And as Barish himself was quoted as saying by Science:
“I think there’s a bit of truth that LIGO wouldn’t be here if I didn’t do it, so I don’t think I’m undeserving. If they wait a year and give it to these three guys, at least I’ll feel that they thought about it,” he says. “If they decide [to give it to them] this October, I’ll have more bad feelings because they won’t have done their homework.”
However, there is good reason to believe that the award will ultimately be split three ways, leaving Barish out. For instance, Weiss, Drever, and Thorne have been honored three times already this year for their work on LIGO. This has included the Special Breakthrough Prize in Fundamental Physics, the Gruber Cosmology Prize, and Kavli Prize in Astrophysics.
What’s more, in the past, the Nobel Prize in physics has tended to be awarded to those responsible for the intellectual contributions leading to a major breakthrough, rather than to those who did the leg work. Out of the last six Prizes issued (between 2010 and 2015), five have been awarded for the development of experimental methods, observational studies, and theoretical discoveries.
Only one award was given for a technical development. This was the case in 2014 where the award was given jointly to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura for “the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources”.
Basically, the Nobel Prize is a complicated matter. Every year, it is awarded to those who made a considerable contribution to science, or were responsible for a major breakthrough. But contributions and breakthroughs are perhaps a bit relative. Whom we choose to honor, and for what, can also be seen as an indication of what is valued most in the scientific community.
In the end, this year’s award may serve to highlight how significant contributions do not just entail the development of new ideas and methods, but also in bringing them to fruition.
Further Reading: Science, LIGO, Nobelprize.org