The Milky Way measures 100 to 120 thousand light-years across, a distance that defies imagination. But clusters of galaxies, which comprise hundreds to thousands of galaxies swarming under a collective gravitational pull, can span tens of millions of light-years.
These massive clusters are a complex interplay between colliding galaxies and dark matter. They seem impossible to map precisely. But now an international team of astronomers using the NASA/ESA Hubble Space Telescope has done exactly this — precisely mapping a galaxy cluster, dubbed MCS J0416.1–2403, 4.5 billion light-years away.
“Although we’ve known how to map the mass of a cluster using strong lensing for more than twenty years, it’s taken a long time to get telescopes that can make sufficiently deep and sharp observations, and for our models to become sophisticated enough for us to map, in such unprecedented detail, a system as complicated as MCS J0416.1–2403,” said coauthor Jean-Paul Kneib in a press release.
Measuring the amount and distribution of mass within distant objects can be extremely difficult. Especially when three quarters of all matter in the Universe is dark matter, which cannot be seen directly as it does not emit or reflect any light. It interacts only by gravity.
But luckily large clumps of matter warp and distort the fabric of space-time around them. Acting like lenses, they appear to magnify and bend light that travels past them from more distant objects.
This effect, known as gravitational lensing, is only visible in rare cases and can only be spotted by the largest telescopes. Even galaxy clusters, despite their massive size, produce minimal gravitational effects on their surroundings. For the most part they cause weak lensing, making even more distant sources appear as only slightly more elliptical across the sky.
However, when the alignment of the cluster and distant object is just right, the effects can be substantial. The background galaxies can be both brightened and transformed into rings and arcs of light, appearing several times in the same image. It is this effect, known as strong lensing, which helped astronomers map the mass distribution in MCS J0416.1–2403.
“The depth of the data lets us see very faint objects and has allowed us to identify more strongly lensed galaxies than ever before,” said lead author Dr Jauzac. “Even though strong lensing magnifies the background galaxies they are still very far away and very faint. The depth of these data means that we can identify incredibly distant background galaxies. We now know of more than four times as many strongly lensed galaxies in the cluster than we did before.”
Using Hubble’s Advanced Camera for Surveys, the astronomers identified 51 new multiply imaged galaxies around the cluster, quadrupling the number found in previous surveys. This effect has allowed Jauzac and her colleagues to calculate the distribution of visible and dark matter in the cluster and produce a highly constrained map of its mass.
The total mass within the cluster is 160 trillion times the mass of the Sun, with an uncertainty of 0.5%. It’s the most precise map ever produced.
But Jauzac and colleagues don’t plan on stopping here. An even more accurate picture of the galaxy cluster will have to include measurements from weak lensing as well. So the team will continue to study the cluster using ultra-deep Hubble imaging.
They will also use ground-based observatories to measure any shifts in galaxies’ spectra and therefore note the velocities of the contents of the cluster. Combining all measurements will not only further enhance the detail, but also provide a 3D model of the galaxies within the cluster, shedding light on its history and evolution.
This work has been accepted for publication in the Monthly Notices of the Royal Astronomy and is available online.
Remember during the government shutdown when it looked as though a NASA Mars mission would be delayed? Launch preparations continued because delaying the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft — which could have pushed its window back by years — would cause “imminent risk to life or property”, administrator Charles Bolden told Universe Today in November.
Both NASA’s Mars Reconnaissance Orbiter and Mars Odyssey currently provide a vital data link to send huge streams of information from the rovers on the surface, Opportunity and Curiosity. (And the Mars 2020 rover is coming up in a few years, too.) While both orbiters are working well, they are both well over their design lifetimes. MAVEN is now on its way to Mars and should get there in September.
MAVEN’s mission, however, is only designed to last for a year. While it could last longer, NASA is already thinking ahead for satellite backups — especially for the 2020s. And that could include commercial participation, according to a new request for information the agency put out this week.
“NASA has no scheduled Mars science orbiters after MAVEN arrives on the Red Planet in the fall,” the agency warned in a press release. “This creates the need to identify cost-effective options to ensure continuity of reliable, high-performance telecommunications relay services for the future.”
The solicitation (which you can see here) proposes to have NASA purchase telecommunications services from some “commercial service provider” that would be responsible for operating and owning the satellites. This isn’t necessarily open only to industry, either. NASA says that organizations could include commercial providers, its own centers, universities, non-profits, federally funded research and development centers and even U.S. government and international organizations.
“We are looking to broaden participation in the exploration of Mars to include new models for government and commercial partnerships,” stated John Grunsfeld, associate administrator of NASA’s science mission directorate. “Depending on the outcome, the new model could be a vital component in future science missions and the path for humans to Mars.”
And it’s possible these orbiters could explore new technologies for Mars — specifically, laser/optical communications, which were used to great success on the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission. And other laser missions are coming up. This could make it easier to send back movies from Mars as well as still pictures.
Apollo 11 Comes Home
The Apollo 11 crew await pickup by a helicopter from the USS Hornet, prime recovery ship for the historic lunar landing mission. The fourth man in the life raft is a United States Navy underwater demolition team swimmer. All four men are wearing biological isolation garments. They splashed down at 12:49 a.m. EDT, July 24, 1969, about 812 nautical miles southwest of Hawaii and only 12 nautical miles from the USS Hornet. Credit: NASA Story and gallery expanded[/caption]
The three man crew of NASA’s Apollo 11 splashed down in the Pacific Ocean 45 years ago today on July 24, 1969 – successfully concluding Earth’s first journey to land humans on another world and return them safely to our Home Planet.
Apollo 11 Commander Neil Armstrong became the first human to set foot on the Moon on July 20, 1969 after he stepped off the footpad of the Lunar Module Eagle soon after the start of the moonwalk EVA at 10:39 p.m. EDT and onto the lunar surface with his left foot at the Sea of Tranquility at 10:56 p.m. EDT. Lunar Module (LM) pilot Buzz Aldrin followed soon thereafter. They came in peace for all mankind!
The magnificent Lunar landing feat accomplished by US Apollo 11 astronauts Neil Armstrong and Buzz Aldrin marks the pinnacle of Mankind’s most momentous achievement.
The Apollo 11 crew consisting of Neil Armstrong, Buzz Aldrin and Command module pilot Michael Collins splashed down safely at 12:50 p.m. EDT on July 24 about 900 miles southwest of Hawaii in the North Pacific Ocean while seated inside the Command Module Columbia dangling at the end of a trio of massive parachutes that slowed their descent through the Earth’s atmosphere.
After a mission duration of 8 days, 3 hours, 18 minutes, 35 seconds from launch to landing the Apollo 11 crew were plucked from the ocean by helicopters from the USS Hornet recovery ship after splashdown only 12 nautical miles (24 km) away.
They had to don protective biological isolation garments (BIGs) in case they were infected by some unknown and potentially hazardous “moon germs.” Of course there were no pathogens, but this was not definitely known at the time.
After their return to Earth, the trio was scrubbed with a disinfect solution of sodium hypochlorite and had to remain in quarantine for 21 days inside a 30 feet (9.1 m) long quarantine facility known as the Lunar Receiving Laboratory (LRL).
They were welcomed back to Earth by President Nixon aboard the USS Hornet.
Armstrong passed away at age 82 on August 25, 2012 due to complications from heart bypass surgery. Read my prior tribute articles: here and here
Here we’ve collected a gallery of the mission and ocean splashdown that brought Apollo 11 to a close and fulfilled the lunar landing quest set by a young President John F. Kennedy early in the decade of the 1960s.
The trio blasted off atop a 363 foot-tall Saturn V rocket from Launch Complex 39A on their bold, quarter of a million mile moon mission from the Kennedy Space Center , Florida on July 16, 1969.
The three-stage Saturn V generated 7.5 million pounds of thrust and propelled the trio into space and immortality.
Read my story about the deep sea recovery of the Apollo 11 first stage F-1 engines in 2013 – here.
The crew arrived in lunar orbit three days later on July 19, 1969, inside the docked Apollo 11 Command/Service and Lunar Modules (CSM/LM).
Armstrong and Aldrin then moved into the Lunar Module, undocked and safely touched down at the Sea of Tranquility on the lunar surface on July 20, 1969 at 4:18 p.m EDT as hundreds of millions across the globe watched in awe.
Six hours later Armstrong climbed down the LM ladder and stepped onto the Moon and into immortality.
Armstrong’s first words:
“That’s one small step for [a] man, one giant leap for mankind.”
During their 2 ½ hour long moonwalk Armstrong and Aldrin unveiled a plaque on the side of the lunar module. Armstrong read the words;
“Here men from the planet Earth first set foot upon the moon. July 1969 A.D. We came in peace for all mankind.”
The duo collected about 50 pounds (22 kg) of priceless moon rocks and set out the first science experiments placed by humans on another world. The moon rocks were invaluable in informing us about the origin of the Earth – Moon system.
Here is NASA’s restored video of the Apollo 11 EVA on July 20, 1969:
Video Caption: Original Mission Video as aired in July 1969 depicting the Apollo 11 astronauts conducting several tasks during extravehicular activity (EVA) operations on the surface of the moon. The EVA lasted approximately 2.5 hours with all scientific activities being completed satisfactorily. The Apollo 11 EVA began at 10:39:33 p.m. EDT on July 20, 1969 when Astronaut Neil Armstrong emerged from the spacecraft first. While descending, he released the Modularized Equipment Stowage Assembly on the Lunar Module’s descent stage.
Altogether Armstrong and Aldrin spent about 21 hours on the moon’s surface. Then they said goodbye to the greatest adventure and fired up the LM ascent engine to rejoin Michael Collins circling above in the Apollo 11 Command Module.
“The whole world was together at that particular moment,” says NASA Administrator Charles Bolden in a CNN interview. “In spite of all we are going through there is hope!”
Stay tuned here for Ken’s Earth & Planetary science and human spaceflight news.
Surprise! Three planets believed to be good candidates for having water vapor in their atmosphere actually have much lower quantities than expected.
The planets (HD 189733b, HD 209458b, and WASP-12b) are “hot Jupiters” that are orbiting very close to their parent star, at a distance where it was expected the extreme temperatures would turn water into a vapor that could be seen from afar.
But observations of the planets with the Hubble Space Telescope, who have temperatures between 816 and 2,204 degrees Celsius (1,500 and 4,000 degrees Fahrenheit), show only a tenth to a thousandth of the water astronomers expected.
“Our water measurement in one of the planets, HD 209458b, is the highest-precision measurement of any chemical compound in a planet outside our solar system, and we can now say with much greater certainty than ever before that we’ve found water in an exoplanet,” stated Nikku Madhusudhan, an astrophysicist at the University of Cambridge, England who led the research. “However, the low water abundance we have found so far is quite astonishing.”
This finding, if confirmed by other observations, could force exoplanet formation theory to be revised and could even have implications for how much water is available in so-called “super-Earths”, rocky planets that are somewhat larger than our own, the astronomers said.
That theory states that planets form over time as small dust particles stick to each other and grow into larger bodies. As it becomes a planet and takes on an atmosphere from surrounding gas bits, it’s believed that those elements should be “enhanced” in proportion to its star, especially in the case of oxygen. That oxygen in turn should be filled with water.
“We should be prepared for much lower water abundances than predicted when looking at super-Earths (rocky planets that are several times the mass of Earth),” Madhusudhan stated.
The research will be published today (July 24) in the Astrophysical Journal.
Rosetta’s “rubber duckie” comet appears to be wearing a collar! New images of Comet 67P/Churyumov-Gerasimenko from the spacecraft, which is speeding towards an orbit of the comet next month, show that the “neck” region of the nucleus appears to be brighter than the rest.
Last week, images from the spacecraft revealed that the comet likely has a “contact binary” nucleus, meaning that there are two parts of the nucleus that are just barely joined together under low gravity. There are many theories for why this happened, but it will take a closer examination to begin to come up with answers. The shape of the nucleus reminds many of a rubber duckie.
As for why the “neck” region appears brighter, that’s not known right now. There could be different grains in that region of the nucleus, or it could be some feature of the surface. Or perhaps it is a different type of material there. The scientists plan to get more spectral information from this region in the coming weeks, which could reveal what elements are there.
“Even though the images taken from a distance of 5500 kilometers are still not highly resolved, the scientists feel remotely reminded of comet 103P/Hartley,” stated the Max Planck Institute for Solar System Research.
“This body was visited in a flyby by NASA’s EPOXI mission in 2010. While Hartley’s ends show a rather rough surface, its middle is much smoother. Scientists believe this waist to be a gravitational low: since it contains the body’s center of mass, emitted material that cannot leave the comet’s gravitational field is most likely to be re-deposited there.”
Rosetta is expected to arrive at the comet on August 6, and to send out its spider-like lander (Philae) in November. The spacecraft will remain with the comet through its closest approach to the sun in 2015, between the orbits of Earth and Mars.
The winged Dream Chaser mini-shuttle under development by Sierra Nevada Corp. (SNC) has successfully completed a series of risk reduction milestone tests on key flight hardware systems thereby moving the private reusable spacecraft closer to its critical design review (CDR) and first flight under NASA’s Commercial Crew Program aimed at restoring America’s indigenous human spaceflight access to low Earth orbit and the space station.
SNC announced that it passed NASA’s Milestones 9 and 9a involving numerous Risk Reduction and Technology Readiness Level (TRL) advancement tests of critical Dream Chaser® systems under its Commercial Crew Integrated Capability (CCiCap) agreement with the agency.
Seven specific hardware systems underwent extensive testing and passed a major comprehensive review with NASA including; the Main Propulsion System, Reaction Control System, Crew Systems, Environmental Control and Life Support Systems (ECLSS), Structures, Thermal Control (TCS) and Thermal Protection Systems (TPS).
The tests are among the milestones SNC must complete to receive continued funding from the Commercial Crew Integrated Capability initiative (CCiCAP) under the auspices of NASA’s Commercial Crew Program.
Over 3,500 tests were involved in completing the Risk Reduction and TRL advancement tests on the seven hardware systems whose purpose is to significantly retire overall program risk enable a continued maturation of the Dream Chaser’s design.
Dream Chaser is a reusable lifting-body design spaceship that will carry a mix of cargo and up to a seven crewmembers to the ISS. It will also be able to land on commercial runways anywhere in the world, according to SNC.
“By thoroughly assessing and mitigating each of the previously identified design risks, SNC is continuing to prove that Dream Chaser is a safe, robust, and reliable spacecraft,” said Mark N. Sirangelo, corporate vice president of SNC’s Space Systems, in a statement.
“These crucial validations are vital steps in our Critical Design Review and in showing that we have a very advanced and capable spacecraft. This will allow us to quickly and confidently move forward in restoring cutting-edge transportation to low-Earth orbit from the U.S.”
The Dream Chaser is among a trio of US private sector manned spaceships being developed with seed money from NASA’s Commercial Crew Program in a public/private partnership to develop a next-generation crew transportation vehicle to ferry astronauts to and from the International Space Station by 2017 – a capability totally lost following the space shuttle’s forced retirement in 2011.
The SpaceXDragon and BoeingCST-100 ‘space taxis’ are also vying for funding in the next round of contracts to be awarded by NASA around August/September 2014.
“Our partners are making great progress as they refine their systems for safe, reliable and cost-effective spaceflight,” said Kathy Lueders, manager of NASA’s Commercial Crew Program.
“It is extremely impressive to hear and see the interchange between the company and NASA engineering teams as they delve into the very details of the systems that help assure the safety of passengers.”
After completing milestones 9 and 9a, SNC has now received 92% of its total CCiCAP Phase 1 NASA award of $227.5 million.
“We are on schedule to launch our first orbital flight in November of 2016, which will mark the beginning of the restoration of U.S. crew capability to low-Earth orbit,” says Sirangelo.
Dream Chaser measures about 29 feet long with a 23 foot wide wing span and is about one third the size of NASA’s space shuttle orbiters.
It will launch atop a United Launch Alliance (ULA) Atlas V rocket from Cape Canaveral Launch Complex 41 in Florida.
Since the forced shutdown of NASA’s Space Shuttle program following its final flight in 2011, US astronauts have been 100% dependent on the Russians and their cramped but effective Soyuz capsule for rides to the station and back – at a cost exceeding $70 million per seat.
The Dream Chaser design builds on the experience gained from NASA Langley’s earlier exploratory engineering work with the HL-20 manned lifting-body vehicle.
Read my prior story detailing the wind tunnel testing milestone – here.
Stay tuned here for Ken’s continuing Sierra Nevada, Boeing, SpaceX, Orbital Sciences, commercial space, Orion, Curiosity, Mars rover, MAVEN, MOM and more planetary and human spaceflight news.
You might think the image above of the famous Antenna Galaxies was taken by a large ground-based or even a space telescope. Think again. Amateur astronomer Rolf Wahl Olsen from New Zealand compiled a total of 75 hours of observing time to create this ultra-deep view.
“To obtain a unique deep view of the faint tidal streams and numerous distant background galaxies I gathered 75 hours on this target during 38 nights from January to June 2014,” Rolf said via email. “At times it was rather frustrating because clouds kept interrupting my sessions.”
But he persisted, and the results are stunning.
He used his new 12.5″ f/4 Serrurier Truss Newtonian telescope, which he said gathers approximately 156% the amount of light over his old 10″ f/5 telescope.
Rolf even has put together comparison shots from the Hubble Space Telescope and the Very Large Telescope of the same field of view:
And if you look even closer you can see an incredible field of distant background galaxies. “Apart from the Antennae itself, what I like most about this scene is the incredible number of distant background galaxies,” Rolf told Universe Today. “This area in Corvus seems very rich indeed. The full resolution image is worth having a look at just to see all these faint galaxies littering the background. There are many beautiful interacting pairs and groups which would be fantastic targets in themselves if they were only closer.”
Here’s a collage of some of the background galaxies that Rolf compiled:
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
Another snapshot of our strange universe: astronomers recently caught a pulsar — a particular kind of dense star — switch off its radio beacon while powerful gamma rays brightened fivefold.
“It’s almost as if someone flipped a switch, morphing the system from a lower-energy state to a higher-energy one,” stated lead researcher Benjamin Stappers, an astrophysicist at the University of Manchester, England.
“The change appears to reflect an erratic interaction between the pulsar and its companion, one that allows us an opportunity to explore a rare transitional phase in the life of this binary.”
The binary system includes pulsar J1023+0038 and another star that has a fifth of the mass of the sun. They’re close orbiting, spinning around each other every 4.8 hours. This means the companion’s days are numbered, because the pulsar is pulling it apart.
In NASA’s words, here is what is going on:
In J1023, the stars are close enough that a stream of gas flows from the sun-like star toward the pulsar. The pulsar’s rapid rotation and intense magnetic field are responsible for both the radio beam and its powerful pulsar wind. When the radio beam is detectable, the pulsar wind holds back the companion’s gas stream, preventing it from approaching too closely. But now and then the stream surges, pushing its way closer to the pulsar and establishing an accretion disk.
Gas in the disk becomes compressed and heated, reaching temperatures hot enough to emit X-rays. Next, material along the inner edge of the disk quickly loses orbital energy and descends toward the pulsar. When it falls to an altitude of about 50 miles (80 km), processes involved in creating the radio beam are either shut down or, more likely, obscured.
The inner edge of the disk probably fluctuates considerably at this altitude. Some of it may become accelerated outward at nearly the speed of light, forming dual particle jets firing in opposite directions — a phenomenon more typically associated with accreting black holes. Shock waves within and along the periphery of these jets are a likely source of the bright gamma-ray emission detected by Fermi.
We’ve got vertigo watching this video, but in a good way! This is a sped-up view of Earth from the International Space Station from the Cupola, a wraparound window that is usually used for cargo ship berthings and Earth observations.
In the video you can see a solar array from the space station gliding by the view on the left, and Canadarm2 (the robotic arm used for dockings) just barely visible on the right side, near the end.
Behind the camera is the prolific video poster Reid Wiseman, an Expedition 40/41 NASA astronaut who has been quite active on social media. He’s been posting pictures of the Earth on Twitter as well as numerous other Vine videos.
While the Camelopardalid shower only produced a few meteors, the lack of flashy disintegrations showed astronomers something new, a new study reveals: the dust from its parent comet (Comet 209P/Linear) was much more fragile than the usual. The reasons are still being investigated, but one theory is that after a century in space, there wasn’t much left to run into.
“Some mechanism was at work that efficiently fragmented the larger meteoroids,” stated Peter Jenniskens, a meteor astronomer with the SETI Institute who, along with colleague Esko Lyytinen, first predicted the existence of the shower a decade ago.
“Our best meteor was no more luminous than the star Vega,” added Jenniskens, “but it gave us a clue as to why there were few bright ones: It was so fragile that the meteoroid suddenly dispersed into a cloud of dust at the end of its trajectory.”
This ‘weak” shower stands in contrast to two meteor showers that took place out of interactions with comet 21P/Giacobinni-Zinner. This produced meteor “storms” in 1933 and 1946 during the Draconids. That comet was more active and the dust grains that left it likely had a lot of ice in them. Comet 209P/Linear did not have that type of ejection, nor was it very active.