Enceladus and Europa are all the rage these days, but classic Mars is still a great place to search for life. In fact, ESA’s ExoMars is scanning the planet’s atmosphere for methane, evidence that there might be life there right now. Let’s talk about the search for life on the Red Planet.
We usually record Astronomy Cast as a live Google+ Hangout on Air every Friday at 1:30 pm Pacific / 4:30 pm Eastern. You can watch here on Universe Today or from the Astronomy Cast Google+ page.
ULA Delta IV rocket poised for blastoff with the WGS-7 mission for the U.S. Air Force from Cape Canaveral Air Force Station, Fl, on July 23, 2015. Credit: Ken Kremer/kenkremer.com
ULA Delta IV rocket poised for blastoff with the WGS-7 mission for the U.S. Air Force from Cape Canaveral Air Force Station, Fl, on July 23, 2015. Credit: Ken Kremer/kenkremer.com
CAPE CANAVERAL AIR FORCE STATION, FL – Less than 24 hours from now the evening skies along the Florida Space Coast will light up with a spectacular burst of fire and fury as a Delta rocket roars to space with a super advanced tactical satcom for the U.S. Air Force that will provide a huge increase in communications bandwidth for American forces around the globe.
Blastoff of the Wideband Global SATCOM (WGS-8) mission for the U.S. Air Force is slated for 6:53 p.m. EST on Wednesday, Dec. 7, 2016 from Space Launch Complex-37 at Cape Canaveral Air Force Station, Florida.
WGS-8 will be delivered to a supersynchronous transfer orbit atop a United Launch Alliance Delta IV Medium+ rocket. The launch window runs for 49 minutes from 6:53-7:42 p.m. EST.
You can watch the Delta launch live on a ULA webcast. The live launch broadcast will begin at 6:33 p.m. EST here:
http://www.ulalaunch.com/webcast.aspx
The weather forecast for Wednesday Dec. 6, calls for an 80 percent chance of acceptable weather conditions at launch time.
In case of a scrub for any reason the chances for a favorable launch drop slightly to 60% GO.
WGS-8 is the first in a newly upgraded series of a trio of WGS satellites built by Boeing.
The major upgrade is inclusion of the Wideband Digital Channelizer, awarded to Boeing in June 2012.
The Wideband Digital Channelizer will provide a 90 percent improvement in satellite bandwidth for US forces.
It is also the only military satellite communications system that can support simultaneous X and Ka band communications.
WGS-8 can instantaneously filter and downlink up to 8.088 GHz of bandwidth compared to 4.410 GHz for the earlier Block I and II satellite series.
The prior Wideband Global SATCOM-7 (WGS-7) communications satellite was launched on July 23, 2015 from Space Launch Complex-37.
A United Launch Alliance (ULA) Delta IV rocket carrying the WGS-7 mission for the U.S. Air Force launches from Cape Canaveral Air Force Station, Fl, on July 23, 2015. Credit: Ken Kremer/kenkremer.com
The Wideband Global SATCOM system provides “anytime, anywhere communication” for allied military forces “through broadcast, multicast and point to point connections,” according to ULA.
The $426 million WGS 8 satellite is part of a significant upgraded constellation of high capacity communications satellites providing enhanced communications capabilities to American and allied troops in the field for the coming two decades.
“WGS provides essential communications services, allowing Combatant Commanders to exert command and control of their tactical forces, from peace time to military operations.”
WGS-8 is the eighth in a series of high capacity communication satellites that will broaden tactical communications for U.S. and allied forces at both a significantly higher capacity and lower cost.
“WGS satellites are important elements of a high-capacity satellite communications system providing enhanced communications capabilities to America’s troops in the field for the next decade and beyond,” according to a ULA factsheet.
“WGS enables more robust and flexible execution of Command and Control, Communications Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR), as well as battle management and combat support information functions. The WGS constellation augments the existing service available through the UHF Follow-on satellite by providing enhanced information broadcast capabilities.”
The 217 foot tall Delta IV Medium+ rocket will launch in the 5,4 configuration with a 5 meter diameter payload fairing and 4 solid rocket boosters to augment the first stage.
The is the sixth flight in the Medium+ (5,4) configuration; all of which were for prior WGS missions.
WGS-8 logo
WGS-8 also counts as the first of three launches from the Cape this December. A Pegasus XL rocket will launch on Dec. 12 carrying NASA’s CGYNSS hurricane monitoring satellites. And an Atlas V will launch on Dec. 12 with the EchoStar 23 comsat.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
The Geoid 2011 model, based on data from LAGEOS, GRACE, GOCE and surface data. Credit: GFZ
Gravity is a pretty awesome fundamental force. If it wasn’t for the Earth’s comfortable 1 g, which causes objects to fall towards the Earth at a speed of 9.8 m/s², we’d all float off into space. And without it, all us terrestrial species would slowly wither and die as our muscles degenerated, our bones became brittle and weak, and our organs ceased to function properly.
So one can say without exaggerations that gravity is not only a fact of life here on Earth, but a prerequisite for it. However, since human beings seem intent on getting off this rock – escaping the “surly bonds of Earth”, as it were – understanding Earth’s gravity and what it takes to escape it is necessary. So just how strong is Earth’s gravity?
Definition:
To break it down, gravity is a natural phenomena in which all things that possess mass are brought towards one another – i.e. asteroids, planets, stars, galaxies, super clusters, etc. The more mass an object has, the more gravity it will exert on objects around it. The gravitational force of an object is also dependent on distance – i.e. the amount it exerts on an object decreases with increased distance.
Artist’s impression of the effect Earth’s gravity has on spacetime. Credit: NASA
Gravity is also one of the four fundamental forces which govern all interactions in nature (along with weak nuclear force, strong nuclear force, and electromagnetism). Of these forces, gravity is the weakest, being approximately 1038 times weaker than the strong nuclear force, 1036 times weaker than the electromagnetic force and 1029 times weaker than the weak nuclear force.
As a consequence, gravity has a negligible influence on matter at the smallest of scales (i.e. subatomic particles). However, at the macroscopic level – that of planets, stars, galaxies, etc. – gravity is the dominant force affecting the interactions of matter. It causes the formation, shape and trajectory of astronomical bodies, and governs astronomical behavior. It also played a major role in the evolution of the early Universe.
It was responsible for matter clumping together to form clouds of gas that underwent gravitational collapse, forming the first stars – which were then drawn together to form the first galaxies. And within individual star systems, it caused dust and gas to coalesce to form the planets. It also governs the orbits of the planets around stars, of moons around planets, the rotation of stars around their galaxy’s center, and the merging of galaxies.
Universal Gravitation and Relativity:
Since energy and mass are equivalent, all forms of energy, including light, also cause gravitation and are under the influence of it. This is consistent with Einstein’s General Theory of Relativity, which remains the best means of describing gravity’s behavior. According to this theory, gravity is not a force, but a consequence of the curvature of spacetime caused by the uneven distribution of mass/energy.
Artist’s impression of the frame-dragging effect in which space and time are dragged around a massive body. Credit: einstein.stanford.edu
The most extreme example of this curvature of spacetime is a black hole, from which nothing can escape. Black holes are usually the product of a supermassive star that has gone supernova, leaving behind a white dwarf remnant that has so much mass, it’s escape velocity is greater than the speed of light. An increase in gravity also results in gravitational time dilation, where the passage of time occurs more slowly.
For most applications though, gravity is best explained by Newton’s Law of Universal Gravitation, which states that gravity exists as an attraction between two bodies. The strength of this attraction can calculated mathematically, where the attractive force is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
Earth’s Gravity:
On Earth, gravity gives weight to physical objects and causes the ocean tides. The force of Earth’s gravity is the result of the planets mass and density – 5.97237 × 1024 kg (1.31668×1025 lbs) and 5.514 g/cm3, respectively. This results in Earth having a gravitational strength of 9.8 m/s² close to the surface (also known as 1 g), which naturally decreases the farther away one is from the surface.
In addition, the force of gravity on Earth actually changes depending on where you’re standing on it. The first reason is because the Earth is rotating. This means that the gravity of Earth at the equator is 9.789 m/s2, while the force of gravity at the poles is 9.832 m/s2. In other words, you weigh more at the poles than you do at the equator because of this centripetal force, but only slightly more.
The International Space Station (ISS), seen here from an undocked crew mission with Earth as a backdrop. Credit: NASA
Finally, the force of gravity can change depending on what’s under the Earth beneath you. Higher concentrations of mass, like high-density rocks or minerals can change the force of gravity that you feel. But of course, this amount is too slight to be noticeable. NASA missions have mapped the Earth’s gravity field with incredible accuracy, showing variations in its strength, depending on location.
Gravity also decreases with altitude, since you’re further away from the Earth’s center. The decrease in force from climbing to the top of a mountain is pretty minimal (0.28% less gravity at the top of Mount Everest), but if you’re high enough to reach the International Space Station (ISS), you would experience 90% of the force of gravity you’d feel on the surface.
However, since the station is in a state of free fall (and also in the vacuum of space) objects and astronauts aboard the ISS are capable of floating around. Basically, since everything aboard the station is falling at the same rate towards the Earth, those aboard the ISS have the feeling of being weightless – even though they still weight about 90% of what they would on Earth’s surface.
Earth’s gravity is also responsible for our planet having an “escape velocity” of 11.186 km/s (or 6.951 mi/s). Essentially, this means that a rocket needs to achieve this speed before it can hope to break free of Earth’s gravity and reach space. And with most rocket launches, the majority of their thrust is dedicated to this task alone.
Because of the difference between Earth’s gravity and the gravitational force on other bodies – like the Moon (1.62 m/s²; 0.1654 g) and Mars (3.711 m/s²; 0.376 g) – scientists are uncertain what the effects would be to astronauts who went on long-term missions to these bodies.
While studies have shown that long-duration missions in microgravity (i.e. on the ISS) have a detrimental effect on astronaut health (including loss of bone density, muscle degeneration, damage to organs and to eyesight) no studies have been conducted regarding the effects of lower-gravity environments. But given the multiple proposals made to return to the Moon, and NASA’s proposed “Journey to Mars“, that information should be forthcoming!
As terrestrial beings, we humans are both blessed and cursed by the force of Earth’s gravity. On the one hand, it makes getting into space rather difficult and expensive. On the other, it ensures our health, since our species is the product of billions of years of species evolution that took place in a 1 g environment.
If we ever hope to become a truly space-faring and interplanetary species, we better figure out how we’re going to deal with microgravity and lower-gravity. Otherwise, none of us are likely to get off-world for very long!
This graphic shows the closest approaches of Cassini's final two orbital phases. Ring-grazing orbits are shown in gray (at left); Grand Finale orbits are shown in blue. The orange line shows the spacecraft's Sept. 2017 final plunge into Saturn. Credit: NASA/JPL-Caltech
The Cassini-Huygens mission is coming to an end.
Cassini was launched in 1997 and reached Saturn in 2004. It will end its mission by plunging into the gas giant. But before then, it will dive through Saturn’s rings a total of 20 times.
An artist’s illustration of Cassini entering orbit around Saturn. Public Domain, https://commons.wikimedia.org/w/index.php?curid=626636
The first dive through the rings was just completed, and represents the beginning of Cassini’s final mission phase. On December 4th at 5:09 PST the 2,150 kg, plutonium-powered probe, crossed through a faint and dusty ring created by the moons Janus and Epimetheus. This brought it to within 11,000 km of Saturn’s F-ring.
Though the end of a mission might seem sad, people behind the mission are excited about this final phase, a series of close encounters with the most iconic structures in our Solar System: Saturn’s glorious rings.
“This is a remarkable time in what’s already been a thrilling journey.” – Linda Spilker, NASA/JPL
“It’s taken years of planning, but now that we’re finally here, the whole Cassini team is excited to begin studying the data that come from these ring-grazing orbits,” said Linda Spilker, Cassini project scientist at JPL. “This is a remarkable time in what’s already been a thrilling journey.”
Even casual followers of space news have enjoyed the steady stream of eye candy from Cassini. But this first orbit through Saturn’s rings is more about science than pictures. The probe’s cameras captured images 2 days before crossing through the plane of the rings, but not during the closest approach. In future ring-grazing orbits, Cassini will give us some of the best views yet of Saturn’s outer rings and some of the small moons that reside there.
Cassini is about more than just beautiful images though. It’s a vital link in a series of missions that have opened up our understanding of the Solar System we inhabit. Here are some of Cassini’s important discoveries:
New Moons
The Cassini mission discovered 7 new moons orbiting Saturn. Methone, Pallene and Polydeuces were all discovered in 2004. Daphnis, Anthe, and Aegaeon were discovered between 2005 and 2009. The final moon is currently named S/2009 S 1.
This image shows the moon Daphnis in the Keeler gap in Saturn’s A ring. The moon’s gravity causes the wave shapes in the rings. By NASA/JPL/Space Science Institute – http://www.esa.int/SPECIALS/Cassini-Huygens/SEM1XQ5TI8E_1.html, Public Domain, https://commons.wikimedia.org/w/index.php?curid=17953334
In 2014, NASA reported that yet another new moon may be forming in Saturn’s A ring.
This Cassini image shows what might be a new moon forming in Saturn’s rings. The new moon, if it is one, is only about 1 km in diameter. By NASA/JPL-Caltech/Space Science Institute – http://photojournal.jpl.nasa.gov/jpeg/PIA18078.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=32184174
Huygens lands on Titan
The Huygens lander detached from the Cassini orbiter on Christmas Day 2004. It landed on the frigid surface of Saturn’s moon Titan after a 2 1/2 hour descent. The lander transmitted 350 pictures of Titan’s descent to the surface. An unfortunate software error caused the loss of another 350 pictures.
The first-ever images of the surface of a new moon or planet are always exciting. This image was taken by the Huygens probe at its landing site on Titan. Image Credit: ESA/NASA/JPL/University of Arizona
Enceladus Flyby
Cassini performed several flybys of the moon Enceladus. The first was in 2005, and the last one was in 2015. The discovery of ice-plumes and a salty liquid ocean were huge for the mission. The presence of liquid water on Enceladus makes it one of the most likely places for microbial life to exist in our Solar System.
In 2005 Cassini discovered jets of water vapor and ice erupting form the surface of Enceladus. The water could be from an subsurface sea. Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
Each of Cassini’s final ring-grazing orbits will last one week. Cassini’s final orbit will bring it close to Saturn’s moon Titan. That encounter will change Cassini’s path. Cassini will leap over the rings and make the first of 22 plunges through the gap between Saturn and its rings.
In September 2017, the Cassini probe will finally reach the end of its epic mission. In order to prevent any possible contamination of Saturn’s moons, the probe will make one last glorious plunge into Saturn’s atmosphere, transmitting data until it is destroyed.
Looking for great holiday gifts for that special someone who is interested in space and the stars? Two writers for Universe Today have you covered whether it’s exploration of the Solar System or learning what to look for in the night sky.
Universe Today’s Contributing Editor Nancy Atkinson shares the insights of over 35 NASA scientists and engineers in her new book “Incredible Stories from Space.” And if that gives you the itch to go outside and look up, be sure to get a copy of Bob King’s “Night Sky with the Naked Eye” to help you explore space from your own backyard.
In “Incredible Stories from Space: A Behind-the-Scenes Look at the Missions Changing our View of the Cosmos” Nancy takes readers inside the robotic space missions that are transforming our understanding of the solar system and beyond.
Weaving together one-on-one interviews along with the extraordinary sagas of missions, this book provides a detailed look at both current and future unmanned missions. It chronicles the struggles and triumphs of nine current spacecraft and captures the true spirit of exploration and discovery. Full color images throughout reveal scientific discoveries and the stunning, breathtaking views of our universe, sent back to Earth by our robotic emissaries to the cosmos.
From the first-ever mission to Pluto to the unprecedented hunt for planets outside our solar system, readers will journey along with missions like New Horizons, Kepler, the Curiosity Mars rover, and the iconic Hubble Space Telescope as they unlock the mysteries of the universe. Learn more about the latest findings in our solar system with the Cassini mission to Saturn, Dawn’s visit to the asteroid belt, the Solar Dynamics Observatory, and the Mars and Lunar Reconnaissance Orbiters. Explore the future of space exploration with a preview of upcoming missions.
Over the next couple of weeks, Nancy will be sharing “writing-of” stories and other insights garnered during her interviews and travels for the book. Also look for a preview of one chapter here on Universe Today during the week of Dec. 19.
Cover of Bob King’s book. Credit: Bob King/Page Street Publishing
“Night Sky with the Naked Eye: How to Find Planets, Constellations, Satellites and Other Night Sky Wonders without a Telescope” will help you gain a deeper appreciation of the universe and our place in it while advancing your knowledge of the night sky.
Bob lays out a series of activities that are fun and educational while teaching you how to spot the International Space Station, follow the moon through its phases, forecast an aurora and watch a meteor shower along with traditional night sky activities like identifying the planets, stars and constellations. Unique illustrations and stunning photos help the reader understand the concepts presented.
Bob also shows readers how to use a smart phone, the Internet and other resources to enhance time spent under the stars, making this a truly modern and updated night sky book. Many people curious about the night sky think you need expensive equipment to enjoy it. You don’t. This book shows how we can learn a lot about the universe and deepen our appreciation of its beauty using nothing more than our eyeballs.
Both books were published by Page Street Publishing, a subsidiary of Macmillan. They are available at Amazon, Barnes & Noble and IndiBound (links below, with great discounts available at this time!) While Nancy’s book doesn’t come out until Dec. 20, its available for pre-order with delivery on the 20th, just in time for the holidays.
Apollo 11 moonwalker Buzz Aldrin trekking across Antarctica as the oldest man to reach the South Pole, prior to emergency medical evacuation on Dec. 1, 2016. Credit: Team Buzz
Apollo 11 moonwalker Buzz Aldrin trekking across Antarctica as the oldest man to reach the South Pole, prior to emergency medical evacuation on Dec. 1, 2016. Credit: Team Buzz
Buzz Aldrin – the second man to walk on the Moon – is recovering nicely today in a New Zealand hospital after an emergency medical evacuation cut short his record setting Antarctic expedition as the oldest man to reach the South Pole – which Team Buzz lightheartly noted would make him “insufferable”!
“He’s recovering well in NZ [New Zealand],” Team Buzz said in an official statement about his evacuation from the South Pole.
Apollo 11 moonwalker Buzz Aldrin, who followed Neil Armstrong in descending to the lunar surface in 1969 on America’s first Moon landing mission, had to be suddenly flown out of the Admunsen-Scott Science Station late last week per doctors orders after suffering from shortness of breath and lung congestion during his all too brief foray to the bottom of the world.
He was flown to a hospital in Christchurch, New Zealand for emergency medical treatment on Dec. 1.
Upon learning from the National Science Foundation (NSF) that Aldrin “now holds the record as the oldest person to reach the South Pole at the age of 86,” his Mission Director Christina Korp jokingly said: ‘He’ll be insufferable now.”
“Buzz Aldrin is resting in hospital in Christchurch, New Zealand. He still has some congestion in his lungs so has been advised not to take the long flight home to the States and to rest in New Zealand until it clears up,” Team Buzz said in an official statement on Dec. 3.
Buzz had been at the South Pole for only a few hours when he took ill, apparently from low oxygen levels and symptoms of altitude sickness.
“I’m extremely grateful to the National Science Foundation (NSF) for their swift response and help in evacuating me from the Admunsen-Scott Science Station to McMurdo Station and on to New Zealand. I had been having a great time with the group at White Desert’s camp before we ventured further south. I really enjoyed the time I spent talking with the Science Station’s staff too,” said Aldrin from his hospital room in a statement.
Apollo 11 moonwalker Buzz Aldrin being evacuated from Antarctica for emergency medical treatment on Dec. 1, 2016. Credit: Team Buzz
Prior to the planned Antarctic journey, his doctors had cleared him to take the long trip – which he views as “the capstone of his personal exploration achievements”.
Apollo 11 moonwalker Buzz Aldrin is seen recovering well in New Zealand hospital on Dec. 2 after medical emergency evacuation from expedition to the South Pole on Dec. 1, 2016. Credit: Team Buzz
Buzz’s goal in visiting the South Pole was to see “what life could be like on Mars” – which he has been avidly advocating as the next goal for a daring human spaceflight journey to deep space.
“His primary interest in coming to Antarctica was to experience and study conditions akin to Mars that are more similar there than any other place on earth,” Team Buzz elaborated.
He had hoped to speak more to the resident scientists about their research but it was all cut short by his sudden illness.
“I started to feel a bit short of breath so the staff decided to check my vitals. After some examination they noticed congestion in my lungs and that my oxygen levels were low which indicated symptoms of altitude sickness. This prompted them to get me out on the next flight to McMurdo and once I was at sea level I began to feel much better. I didn’t get as much time to spend with the scientists as I would have liked to discuss the research they’re doing in relation to Mars. My visit was cut short and I had to leave after a couple of hours. I really enjoyed my short time in Antarctica and seeing what life could be like on Mars,” Aldrin explained.
Buzz also thanked everyone who sent him well wishes.
“Finally, thanks to everyone from around the world for their well wishes and support. I’m being very well looked after in Christchurch. I’m looking forward to getting home soon to spend Christmas with my family and to continue my quest for Cycling Pathways and a permanent settlement on Mars. You ain’t seen nothing yet!”, concluded Aldrin.
Destination Mars is a holographic exhibit at the Kennedy Space Center visitor complex in Florida. Be sure to catch it soon because the limited time run end on New Year’s Day 2017.
Apollo 11 moonwalker Buzz Aldrin discusses the human ‘Journey to Mars with Universe Today at newly opened ‘Destination Mars’ holographic experience during media preview at the Kennedy Space Center visitor complex in Florida on Sept. 18, 2016. Credit: Ken Kremer/kenkremer.com
The new ‘Destination Mars’ limited engagement exhibit magically transports you to the surface of the Red Planet via Microsoft HoloLens technology.
It literally allows you to ‘Walk on Mars’ using real imagery taken by NASA’s Mars Curiosity rover and explore the alien terrain, just like real life scientists on a geology research expedition – with Buzz Aldrin as your guide.
Here’s my Q & A with moonwalker Buzz Aldrin speaking to Universe Today at Destination Mars:
Video Caption: Buzz Aldrin at ‘Destination Mars’ Grand Opening at KSCVC. Apollo 11 moonwalker Buzz Aldrin talks to Universe Today/Ken Kremer during Q&A at ‘Destination Mars’ Holographic Exhibit Grand Opening ceremony at Kennedy Space Center Visitor Complex (KSCVC) in Florida on 9/18/16. Credit: Ken Kremer/kenkremer.com
Learn more about ULA Delta 4 launch on Dec 7, GOES-R weather satellite, Heroes and Legends at KSCVC, OSIRIS-REx, InSight Mars lander, ULA, SpaceX and Orbital ATK missions, Juno at Jupiter, SpaceX AMOS-6 & CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Orbital ATK Cygnus, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:
Dec 5-7: “ULA Delta 4 Dec 7 launch, GOES-R weather satellite launch, OSIRIS-Rex, SpaceX and Orbital ATK missions to the ISS, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings
Using data provided by the Very Large Telescope in Chile, the ESO has been able to discern the "fingerprints" of the early Universe. Credit: ESO
Back in November, a team of researchers from the Swinburne University of Technology and the University of Cambridge published some very interesting findings about a galaxy located about 8 billion light years away. Using the La Silla Observatory’s Very Large Telescope (VLT), they examined the light coming from the supermassive black hole (SMBH) at its center.
In so doing, they were able to determine that the electromagnetic energy coming from this distant galaxy was the same as what we observe here in the Milky Way. This showed that a fundamental force of the Universe (electromagnetism) is constant over time. And on Monday, Dec. 4th, the ESO followed-up on this historic find by releasing the color spectrum readings of this distant galaxy – known as HE 0940-1050.
To recap, most large galaxies in the Universe have SMBHs at their center. These huge black holes are known for consuming the matter that orbits all around them, expelling tremendous amounts of radio, microwave, infrared, optical, ultra-violet (UV), X-ray and gamma ray energy in the process. Because of this, they are some of the brightest objects in the known Universe, and are visible even from billions of light years away.
Artist’s interpretation of ULAS J1120+0641, a very distant quasar. Credit: ESO/M. Kornmesser
But because of their distance, the energy which they emit has to pass through the intergalactic medium, where it comes into contact with incredible amount of matter. While most of this consists of hydrogen and helium, there are trace amounts of other elements as well. These absorb much of the light that travels between distant galaxies and us, and the absorption lines this creates can tell us of lot about the kinds of elements that are out there.
At the same time, studying the absorption lines produced by light passing through space can tell us how much light was removed from the original quasar spectrum. Using the Ultraviolet and Visual Echelle Spectrograph (UVES) instrument aboard the VLT, the Swinburne and Cambridge team were able to do just that, thus sneaking a peak at the “fingerprints of the early Universe“.
What they found was that the energy coming from HE 0940-1050 was very similar to that observed in the Milky Way galaxy. Basically, they obtained proof that electromagnetic energy is consistent over time, something which was previously a mystery to scientists. As they state in their study, which was published in the Monthly Notices of the Royal Astronomical Society:
“The Standard Model of particle physics is incomplete because it cannot explain the values of fundamental constants, or predict their dependence on parameters such as time and space. Therefore, without a theory that is able to properly explain these numbers, their constancy can only be probed by measuring them in different places, times and conditions. Furthermore, many theories which attempt to unify gravity with the other three forces of nature invoke fundamental constants that are varying.“
A laser beam launched from the Very Large Telescope (VLT) at the ESO’s La Silla Observatory in Chile. Credit: ESO
Since it is 8 billion light years away, and its strong intervening metal-absorption-line system, probing the electromagnetic spectrum being put out by HE 0940-1050 central quasar – not to mention the ability to correct for all the light that was absorbed by the intervening intergalactic medium – provided a unique opportunity to precisely measure how this fundamental force can vary over a very long period of time.
On top of that, the spectral information they obtained happened to be of the highest quality ever observed from a quasar. As they further indicated in their study:
“The largest systematic error in all (but one) previous similar measurements, including the large samples, was long-range distortions in the wavelength calibration. These would add a ?2 ppm systematic error to our measurement and up to ?10 ppm to other measurements using Mg and Fe transitions.”
However, the team corrected for this by comparing the UVES spectra to well-calibrated spectra obtained from the High Accuracy Radial velocity Planet Searcher (HARPS) – which is also located at the at the La Silla Observatory. By combining these readings, they were left with a residual systematic uncertainty of just 0.59 ppm, the lowest margin of error from any spectrographic survey to date.
High Accuracy Radial velocity Planet Searcher at the ESO La Silla 3.6m telescope. Credit: ESO
This is exciting news, and for more reasons that one. On the one hand, precise measurements of distant galaxies allow us to test some of the most tricky aspects of our current cosmological models. On the other, determining that electromagnetism behaves in a consistent way over time is a major find, largely because it is responsible for such much of what goes on in our daily lives.
But perhaps most importantly of all, understanding how a fundamental force like electromagnetism behaves across time and space is intrinsic to finding out how it – as well as weak and strong nuclear force – unifies with gravity. This too has been a preoccupation of scientists, who are still at a loss when it comes to explaining how the laws governing particles interactions (i.e. quantum theory) unify with explanations of how gravity works (i.e general relativity).
By finding measurements of how these forces operate that are not varying could help in creating a working Grand Unifying Theory (GUT). One step closer to truly understanding how the Universe works!
The 2015 Geminids over the LAMOST observatory in China. Image credit and copyright: SteedJoy.
One of the best yearly meteor showers contends with the nearly Full Moon this year, but don’t despair; you may yet catch the Geminids.
The Geminid meteor shower peaks next week on the evening of Tuesday night into Wednesday morning, December 13th/14th. The Geminids are always worth keeping an eye on in early through mid-December. As an added bonus, the radiant also clears the northeastern horizon in the late evening as seen from mid-northern latitudes. The Geminids are therefore also exceptional among meteor showers for displaying early evening activity.
The Geminid radiant, looking east around 11 PM local on the evening of December 13th. Note the nearby Moon in the same constellation. Image credit: Stellarium.
First, though, here is the low down of the specifics for the 2016 Geminids: the Geminid meteors are expected to peak on December 13th/14th at midnight Universal Time (UT), favoring Western Europe. The shower is active for a two week period from December 4th to December 17th and can vary with a Zenithal Hourly Rate (ZHR) of 50 to 80 meteors per hour, to short outbursts briefly topping 200 per hour. In 2016, the Geminids are expected to produce a maximum ideal ZHR of 120 meteors per hour. The radiant of the Geminids is located at right ascension 7 hours 48 minutes, declination 32 degrees north at the time of the peak, in the constellation of Gemini.
The Moon is a 98% illuminated waning gibbous just 20 degrees from the radiant at the peak of the Geminids, making 2016 an unfavorable year for this shower. In previous years, the Geminids produced short outbursts topping 200 per hour, as last occurred in 2014.
The Geminid meteors strike the Earth at a relatively slow velocity of 35 kilometers per second, and produce many fireballs with an r vaule of 2.6. The source of the Geminid meteors is actually an asteroid: 3200 Phaethon.
The orientation of the radiant versus the Sun, Moon and Earth’s shadow just past midnight Universal Time on the evening of December 13th/14th. (Created using Orbitron).
A moderate shower in the late 20th century, the Geminids have increased in intensity during the opening decade and a half of the 21st century, surpassing the Perseids for the title of the top annual meteor shower.
The orbit of 3200 Phaethon. Image credit: NASA JPL.
The Geminid shower seems to have breached the background sporadic rate around the mid-19th century. Astronomers A.C. Twining and R.P. Greg observing from either side of the pond in the United States and the United Kingdom both first independently noted the shower in 1862.
Orbiting the Sun once every 524 days, 3200 Phaethon wasn’t identified as the source of the Geminids until 1983. The asteroid is still a bit of a mystery; reaching perihelion just 0.14 astronomical units (AU) from the Sun, (interior to Mercury’s orbit) 3200 Phaethon is routinely baked by the Sun. Is it an inactive comet nucleus? Or a ‘rock comet’ in a transitional state?
Observing meteors is as simple as setting out in a lawn chair, laying back and watching with nothing more technical than a good ole’ Mk-1 pair of human eyeballs. Our advice for 2016 is to start watching early, like say this weekend, before the Moon reaches Full on Wednesday, December 14th. This will enable you to watch for the Geminids after morning moonset under dark skies pre-peak, and before moonrise on evenings post-peak.
Two other minor showers are also active next week: the Coma Bernicids peaking on December 15th, and the Leo Minorids peaking on December 19th. If you can trace a suspect meteor back to the vicinity of the Gemini ‘twin’ stars of Castor and Pollux, then you’ve most likely spied a Geminid and not an impostor.
And speaking of the Moon, next week’s Full Moon is not only known as the Full Cold Moon (For obvious reasons) from Algonquin native American lore, but is also the closest Full Moon to the December 21st, northward solstice. This means that next week’s Full Moon rides highest in the sky for 2016, passing straight overhead for locales sited along latitude 17 degrees north, including Guatemala City and Mumbai, India.
A 2015 Geminid over Sariska Palace in Rajastan, India. Image credit and copyright: Abhinav Singhai.
Photographing the Geminids is also as simple as setting a camera on a tripod and taking wide-field exposures of the sky. We like to use an intervalometer to take automated sequences about 30 seconds to 3 minutes in length. Said Full Moon will most likely necessitate shorter exposures in 2016. Keep a fresh set of backup batteries handy in a warm pocket, as the cold December night will drain camera batteries in a pinch.
Our humble meteor imaging rig. Credit: Dave Dickinson.
And although the Geminids might be a bust in 2016, another moderate shower, the Ursids has much better prospects right around the solstice… more on that next week!
Landing on the surface of Mars is very difficult. In fact, it’s probably the toughest planet to land on in the whole Solar System. Today we’ll talk about what it’s going to take to get to and return from Mars!
We usually record Astronomy Cast as a live Google+ Hangout on Air every Friday at 1:30 pm Pacific / 4:30 pm Eastern. You can watch here on Universe Today or from the Astronomy Cast Google+ page.
Upgraded SpaceX Falcon 9 blasts off with Thaicom-8 communications satellite on May 27, 2016 from Space Launch Complex 40 at Cape Canaveral Air Force Station, FL. 1st stage booster landed safely at sea minutes later. Credit: Ken Kremer/kenkremer.com
Upgraded SpaceX Falcon 9 blasts off with Thaicom-8 communications satellite on May 27, 2016 from Space Launch Complex 40 at Cape Canaveral Air Force Station, FL. 1st stage booster landed safely at sea minutes later. Credit: Ken Kremer/kenkremer.com
Iridium Communications announced on Thursday that the first launch of a slew of its next-generation global satellite constellation, dubbed Iridium NEXT, will launch atop a SpaceX Falcon 9 rocket on December 16, 2016 at 12:36 p.m. PST from SpaceX’s west coast launch pad on Vandenberg Air Force Base in California.
Iridium NEXT satellites being processed for launch by SpaceX. Credit: SpaceX/Iridium
However the launch is dependent on achieving FAA approval for the Falcon 9 launch.
All SpaceX Falcon 9 launches immediately ground to a halt following the colossal eruption of a fireball from the Falcon 9 at the launch pad that suddenly destroyed the rocket and completely consumed its $200 million Israeli Amos-6 commercial payload on Sept. 1 during a routine fueling and planned static fire engine test at Cape Canaveral Air Force Station in Florida.
The explosive anomaly resulted from a “large breach” in the cryogenic helium system of the second stage liquid oxygen tank and subsequent ignition of the highly flammable oxygen propellant.
“This launch is contingent upon the FAA’s approval of SpaceX’s return to flight following the anomaly that occurred on September 1, 2016 at Cape Canaveral Air Force Station, Florida,” Iridium said in a statement.
SpaceX quickly started an investigation to determine the cause of the anomaly that destroyed the rocket and its payload and significantly damaged the infrastructure at launch pad 40.
“The investigation has been conducted with FAA oversight. Iridium expects to be SpaceX’s first return to flight launch customer.”
SpaceX Falcon 9 rocket moments after catastrophic explosion destroys the rocket and Amos-6 Israeli satellite payload at launch pad 40 at Cape Canaveral Air Force Station, FL, on Sept. 1, 2016. A static hot fire test was planned ahead of scheduled launch on Sept. 3, 2016. Credit: USLaunchReport
The goal of the privately contracted mission is to deliver the first 10 Iridium NEXT satellites into low-earth orbit to inaugurate what will be a new constellation of satellites dedicated to mobile voice and data communications.
Iridium eventually plans to launch a constellation of 81 Iridium NEXT satellites into low-earth orbit.
“At least 70 of which will be launched by SpaceX,” per Iridium’s contract with SpaceX.
“We’re excited to launch the first batch of our new satellite constellation. We have remained confident in SpaceX’s ability as a launch partner throughout the Falcon 9 investigation,” said Matt Desch, chief executive officer at Iridium, in a statement.
“We are grateful for their transparency and hard work to plan for their return to flight. We are looking forward to the inaugural launch of Iridium NEXT, and what will begin a new chapter in our history.”
SpaceX Falcon 9 Stage 1 arriving in California for Iridium NEXT launch – with a Rainbow! Credit: SpaceX/Iridium
Altogether seven Falcon 9 launches will be required to deploy the constellation of 70 Iridium NEXT satellites by early 2018, if all goes well.
The initial batch of Iridium NEXT satellites for this launch began arriving at SpaceX’s Vandenberg AFB satellite processing facility in early August 2016. They were built by Orbital ATK.
Following up on earlier statements by SpaceX President Gwynne Shotwell, SpaceX founder and CEO Elon Musk had said in a televised CNBC interview on Nov. 4 that the firm was aiming to resume launches of the booster in mid-December.
“We are looking forward to return to flight with the first Iridium NEXT launch,” said Gwynne Shotwell, president and chief operating officer of SpaceX.
“Iridium has been a great partner for nearly a decade, and we appreciate their working with us to put their first 10 Iridium NEXT satellites into orbit.”
Aerial view of pad and strongback damage at SpaceX Launch Complex-40 as seen from the VAB roof on Sept. 8, 2016 after fueling test explosion destroyed the Falcon 9 rocket and AMOS-6 payload at Cape Canaveral Air Force Station, FL on Sept. 1, 2016. Credit: Ken Kremer/kenkremer.com
Musk said the Sept 1 explosion at pad 40 was related to some type of interaction between the liquid helium bottles , carbon composites and solidification of the liquid oxygen propellant in the SpaceX Falcon 9 second stage.
“It basically involves a combination of liquid helium, advanced carbon fiber composites, and solid oxygen, Musk elaborated to CNBC.
“Oxygen so cold that it enters the solid phase.”
The explosion took place without warning as liquid oxygen and RP-1 propellants were being loaded into the second stage of the 229-foot-tall (70-meter) Falcon 9 during a routine fueling test and engine firing test at SpaceX’s Space Launch Complex-40 launch facility at approximately 9:07 a.m. EDT on Sept. 1 on Cape Canaveral Air Force Station, Fl.
But the rocket blew up during the fueling operations and the SpaceX launch team never even got to the point of igniting the first stage engines for the static fire test.
Pad 40 is out of action until extensive repairs and testing are completed.
The Sept. 1 calamity was the second Falcon 9 failure within 15 months time and called into question the rockets overall reliability.
The first Falcon 9 failure involved a catastrophic mid air explosion about two and a half minutes after liftoff, during the Dragon CRS-9 cargo resupply launch for NASA to the International Space Station on June 28, 2015 – and witnessed by this author.
SpaceX Falcon 9 second stage arriving at Vandenberg AFB in California in early November 2016 for Iridium NEXT launch. Credit: SpaceX/Iridium
SpaceX maintains launch pads on both the US East and West coasts.
On the Florida Space Coast, SpaceX plans to initially resume launches at the Kennedy Space Center (KSC) from pad 39A, the former shuttle pad that SpaceX has leased from NASA, while pad 40 is repaired and refurbished.
KSC launches could start as soon as early January 2017 with the EchoStar 23 communications satellite.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Learn more about ULA Delta 4 launch on Dec 7, GOES-R weather satellite, Heroes and Legends at KSCVC, OSIRIS-REx, InSight Mars lander, ULA, SpaceX and Orbital ATK missions, Juno at Jupiter, SpaceX AMOS-6 & CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Orbital ATK Cygnus, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:
Dec 5-7: “ULA Delta 4 Dec 7 launch, GOES-R weather satellite launch, OSIRIS-Rex, SpaceX and Orbital ATK missions to the ISS, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings
