Nancy has been with Universe Today since 2004, and has published over 6,000 articles on space exploration, astronomy, science and technology. She is the author of two books: "Eight Years to the Moon: the History of the Apollo Missions," (2019) which shares the stories of 60 engineers and scientists who worked behind the scenes to make landing on the Moon possible; and "Incredible Stories from Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos" (2016) tells the stories of those who work on NASA's robotic missions to explore the Solar System and beyond.
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Credit: X-ray(NASA/CXC/Stanford/S.Allen); Optical/Lensing(NASA/STScI/UC Santa Barbara/M.Bradac)
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A powerful collision of galaxy clusters captured by NASA’s Hubble Space Telescope and Chandra X-ray Observatory provides evidence for dark matter and insight into its properties. Observations of the cluster known as MACS J0025.4-1222 indicate that a titanic collision has separated dark matter from ordinary matter. The images also provide an independent confirmation of a similar effect detected previously in a region called the Bullet Cluster. Like the Bullet Cluster, this newly studied cluster shows a clear separation between dark and ordinary matter.
MACS J0025 formed after an enormously energetic collision between two large clusters. Using visible-light images from Hubble, the team was able to infer the distribution of the total mass — dark and ordinary matter. Hubble was used to map the dark matter (colored in blue) using a technique known as gravitational lensing. The Chandra data enabled the astronomers to accurately map the position of the ordinary matter, mostly in the form of hot gas, which glows brightly in X-rays (pink).
As the two clusters that formed MACS J0025 (each almost a whopping quadrillion times the mass of the Sun) merged at speeds of millions of miles per hour, the hot gas in the two clusters collided and slowed down, but the dark matter passed right through the smashup. The separation between the material shown in pink and blue therefore provides observational evidence for dark matter and supports the view that dark-matter particles interact with each other only very weakly or not at all, apart from the pull of gravity.
Via Twitter, the Phoenix lander said, “I saw this beautiful sunrise yestersol. Bittersweet, as it means an end to midnight sun in the Martian arctic.” At Phoenix’s location above Mars arctic circle, the sun doesn’t set during the peak of summer in the northern hemisphere. If you recall, Phoenix took a montage of images of the non-setting sun last month.
But now, the period of maximum solar energy is past. On Sol 86, or the 86th Martian day after Phoenix landed, the sun set fully behind a slight rise to the north for about a half hour. This red-filter image taken by the lander’s Surface Stereo Imager, shows the sun rising on the morning of sol 90, Aug. 25, 2008, the last day of the Phoenix nominal mission.
Color poster from UnmannedSpaceflight.com
The image was taken at 51 minutes past midnight local solar time during the slow sunrise that followed a 75 minute “night.” The skylight in the image is light scattered off atmospheric dust particles and ice crystals.
The folks over at Unmanned Spaceflight created a color poster of the sunrise in honor of Phoenix’s 90th sol on Mars:
Download your very own large or medium size poster.
Phoenix will continue working for another month on Mars, through September 30. It seems there’s many people out there hoping for another short mission extension — for as long as the carbon dioxide ice stays away!
With the Phoenix lander busily working away on Mars and grabbing the recent headlines, we haven’t heard much from the other two robots on the Red Planet, the Mars Exploration Rovers, Spirit and Opportunity. Spirit has been hunkered down, trying to survive the harshest weeks of southern Martian winter. She’s waiting for the sun’s rays to get a little stronger before moving on, but has been taking images of her spot in the Home Plate area of Gusev Crater to create the panorama, shown here. Opportunity is now getting ready to head ’em up and move ’em out of Victoria Crater, where she’s been for nearly a year. So, what’s coming up for the two Energizer Bunny-like, long-lasting rovers?
“Both rovers show signs of aging, but they are both still capable of exciting exploration and scientific discovery,” said JPL’s John Callas, project manager for Spirit and Opportunity.
The team’s plan for future months is to drive Spirit south of Home Plate to an area where the rover last year found some bright, silica-rich soil. This could be possible evidence of effects of hot water. Click here for an extra large version of Spirit’s panorama.
Opportunity will soon be on to new adventures.
“We’ve done everything we entered Victoria Crater to do and more,” said Bruce Banerdt, of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Banerdt is project scientist for the two rovers. Opportunity is heading back out to the Red Planet’s surrounding plains and check out some loose cobbles, or rocks that it drove by nearly a year ago before descending into the large Victoria crater to examine exposed ancient rock layers. But now that survey is complete.
Some of the cobbles that the rover will look at are approximately fist-size and larger. They were thrown long distances from impacts on Mars surface, and are interesting in that they might provide information about Mars’ subsurface varying areas. Image from Opportunity's Pancam from Sol 1628. Image: NASA/JPL/Cornell
“Our experience tells us there’s lots of diversity among the cobbles,” said Scott McLennan of the State University of New York, Stony Brook. McLennan is a long-term planning leader for the rover science team. “We want to get a better characterization of them. A statistical sampling from examining more of them will be important for understanding the geology of the area.”
Opportunity entered Victoria Crater on Sept. 11, 2007, after a year of scouting from the rim. Once inside, the rover drove close to the base of a cliff called “Cape Verde,” part of the crater rim, to capture detailed images of a stack of layers 6 meters (20 feet) tall. The information Opportunity has returned about the layers in Victoria suggest the sediments were deposited by wind and then altered by groundwater.
“The patterns broadly resemble what we saw at the smaller craters Opportunity explored earlier,” McLennan said. “By looking deeper into the layering, we are looking farther back in time.” The crater stretches approximately 800 meters (half a mile) in diameter and is deeper than any other seen by Opportunity.
Engineers are programming Opportunity to climb out of the crater at the same place it entered. A spike in electric current drawn by the rover’s left front wheel last month quickly settled discussions about whether to keep trying to edge even closer to the base of Cape Verde on a steep slope. The spike resembled one seen on Spirit when that rover lost the use of its right front wheel in 2006. Opportunity’s six wheels are all still working after 10 times more use than they were designed to perform, but the team took the spike in current as a reminder that one could quit.
“If Opportunity were driving with only five wheels, like Spirit, it probably would never get out of Victoria Crater,” said JPL’s Bill Nelson, a rover mission manager. “We also know from experience with Spirit that if Opportunity were to lose the use of a wheel after it is out on the level ground, mobility should not be a problem.”
Opportunity now drives with its robotic arm out of the stowed position. A shoulder motor has degraded over the years to the point where the rover team chose not to risk having it stop working while the arm is stowed on a hook. If the motor were to stop working with the arm unstowed, the arm would remain usable.
First light image reveals bright emission in the plane of the Milky Way (center), bright pulsars and super-massive black holes. Credit: NASA/DOE/International LAT Team
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With “first light” successfully observed by the Gamma Ray Large Area Space Telescope, or GLAST, as it has been called until now, NASA has christened the space observatory with its new official name: The Fermi Gamma Ray Space Telescope. Named for Italian physicist Enrico Fermi, the telescope will delve into the mysteries of the high energy end of the electromagnetic spectrum. This new space telescope will try to determine what the mysterious dark matter is composed of, how black holes emit immense jets of material to nearly the speed of light, and help crack the mysteries of solar flares, cosmic rays and the power explosions called gamma ray bursts. At a news conference today to announce the new name and first light observations, Steve Ritz, Project Scientist for the telescope said scientists world-wide are very excited about the telescope’s breakthrough capability. “GLAST has great discovery potential. We’re expecting surprises,” he said.
Since the spacecraft’s launch on June 11, the project team has been busy turning on the spacecraft’s various subsystems and calibrating the instruments. GLAST was developed in cooperation with the US Department of Energy and international partners in France, Germany, Italy, Japan and Sweden. Over 100 international scientists are collaborating on this project. Fermi’s primary mission is for five years, with a goal of ten years of total operations.
The first image as seen above shows the bright gamma ray emissions in the plane of the Milky Way (center), bright pulsars and super-massive black holes. The Fermi Telescope saw in four days what a previous gamma ray mission, EGRET (Energetic Gamma Ray Experiment Telescope) imaged in nine years.
It also made detections of two active galaxies, and a blazar in the southern galactic plane, called 3C454.3, located about 7 billion light years from Earth, and a pulsar, called the Vela Pulsar located about 10 billion 1000 light years from Earth.
Fermi Gamma-ray Space Telescope's first all-sky map made into a sphere to produce this view of the gamma-ray universe. Credit: NASA/DOE/International LAT Team
The big advantage is Fermi’s huge field of view compared to previous gamma ray observatories. The entire sky is viewed about every two orbits or every 3 hours. Scientists say this is especially important because the gamma ray sky is constantly changing. With the telescope’s Burst Monitor, about one gamma ray burst has been detected every day from all areas of the sky.
Turning on the telescope has gone extremely smooth. “Everything worked as expected and then some,” said Ritz. “None of us could have asked for such a smooth turn on. It’s a credit to the world wide team of engineers, scientists, programmers and support people who all worked together as a seamless team over many years. It went like clockwork that went ahead of the clock. That doesn’t happen by accident. It was due to the great preparation work.”
Jon Morse from NASA’s Astrophysics Division calls the Fermi Telescope ‘The Extreme Machine’ and said to expect an exciting pace of new discoveries in the days and years ahead.
Here’s Fermi’s new logo: New Logo for the Fermi Telescope
Atlantis rolls over to the Vehicle Assembly Building. Credit: NASA
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Space shuttle Atlantis was rolled over the the Vehicle Assembly Building after hunkering down in the Orbiter Processing Facility at Kennedy Space Center during Tropical Storm Fay. In the VAB, Atlantis will be attached to its external fuel tank and twin solid rocket boosters. NASA announced that Atlantis will be moved out to Launch Pad 39A next Saturday, August 30 to prepare for launch on the STS-125 mission to service the Hubble Space Telescope one last time, targeted for an Oct. 8 liftoff.
The mobile launcher platform will bring Atlantis to he pad, atop a crawler-transporter. The crawler will travel slower than 1 mph during the 3.4-mile journey. The process is expected to take approximately six hours.
Repairs to Launch Pad 39A’s flame trench wall were completed Aug. 5 after crews installed a steel grid structure and covered it in a heat-resistant material. The pad’s north flame trench was damaged when bricks tore away from the wall during the May 31 launch of space shuttle Discovery.
NASA has several videos about the final Hubble servicing mission. Find them here.
Deep trench dug by Phoenix. Credit:NASA/JPL/Caltech/U of AZ
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The next sample of Martian soil being grabbed for analysis is coming from a trench about three times deeper than any other trench NASA’s Phoenix Mars Lander has dug. On Tuesday, August 26, the scoop on the lander’s robotic arm will pick up a sample of soil from the bottom of a trench called “Stone Soup” which is about 18 centimeters, or 7 inches deep. Tuesday will be the 90th Martian day or sol that the lander has been on the Red Planet, which was the original amount of time set for Phoenix’s primary mission. NASA has extended the mission through September, but the clock is ticking for the plucky little lander and the oncoming winter at Mars’ north polar region.
The soil sample from the deep trench will be delivered into the third cell of the wet chemistry laboratory. This deck-mounted laboratory, part of Phoenix’s Microscopy, Electrochemistry and Conductivity Analyzer (MECA), has previously used two of its four soil-testing cells.
“In the first two cells we analyzed samples from the surface and the ice interface, and the results look similar. Our objective for Cell 3 is to use it as an exploratory cell to look at something that might be different,” said JPL’s Michael Hecht, lead scientist for MECA. “The appeal of Stone Soup is that this deep area may collect and concentrate different kinds of materials.”
Stone Soup lies on the borderline, or natural trough, between two of the low, polygon-shaped hummocks that characterize the arctic plain where Phoenix landed. The trench is toward the left, or west, end of the robotic arm’s work area on the north side of the lander. Deep Dig 3-D. Credit: NASA/JPL/Caltech/A of AZ
When digging near a polygon center, Phoenix has hit a layer of icy soil, as hard as concrete, about 5 centimeters, or 2 inches, beneath the ground surface. In the Stone Soup trench at a polygon margin, the digging has not yet hit an icy layer like that.
“The trough between polygons is sort of a trap where things can accumulate,” Hecht said. “Over a long timescale, there may even be circulation of material sinking at the margins and rising at the center.”
The science team had considered two finalist sites as sources for the next sample to be delivered to the wet chemistry lab. This past weekend, Stone Soup won out. “We had a shootout between Stone Soup and white stuff in a trench called ‘Upper Cupboard,'” Hecht said. “If we had been able to confirm that the white material was a salt-rich deposit, we would have analyzed that, but we were unable to confirm that with various methods.”
Both candidates for the sampling location offered a chance to gain more information about salt distribution in the Phoenix work area, which could be an indicator of whether or not liquid water has been present. Salt would concentrate in places that may have been wet.
While proceeding toward delivery of a sample from Stone Soup into the wet chemistry laboratory, Phoenix is also using its Thermal and Evolved-Gas Analyzer to examine a soil sample collected last week from another trench, at a depth intermediate between the surface and the hard, icy layer.
Artist's conception shows the Near Earth Asteroid Rendezvous (NEAR) spacecraft orbiting an asteroid. credit: NASA
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Remember a competition we reported on back in April called “Move An Asteroid”? It was an international technical paper competition looking for unique and innovative concepts for how to deflect an asteroid or comet that might be on a collision course for Earth. The winners have been announced and first prize went to Australian PhD student Mary D’Souza who came up with quite a novel concept: wrap the asteroid with reflective sheeting. Such a coating may increase the asteroid’s reflectivity, enabling deflection by solar radiation pressure.
The asteroid in question, known as Apophis, will pass close to Earth in 2029. Although the 207 meter- wide Apophis is not expected to impact Earth, its current trajectory has it approaching Earth no closer than 29,470 km (18,300 miles), which is well inside the orbit of the moon. This, in conjuction with the 100th anniversary of the Tunguska explosion, was the impetus behind the competition.
D’Souza’s paper was titled “A Body Solar Sail Concept for the Deflection of 99942 Apophis.” Her concept involves using a satellite orbiting Apophis to wrap it with ribbons of reflective Mylar sheeting. Covering just half of the asteroid would change its surface from dull to reflective, possibly enough to allow solar pressure to change the asteroid’s trajectory.
“What happens then is light from the sun shines on the body [of the asteroid] so more of it is reflected … and it actually acts to move it away from the sun and the earth,” said D’Souza, a student at University of Queensland’s School of Engineering.
The competition was sponsored by the Space Generation Advisory Council, a group representing youth perspectives on space exploration to the United Nations and national space programs. SGAC said they received submissions to the competition from all over the world. “It is great to see such an interest in this topic from young people all over the world. Hopefully with competitions like this, SGAC can further increase the involvement of youth in this important field of current space research,” said Alex Karl, Co-Chairperson of the SGAC.
By winning the competition, D’Souza will travel to Glasgow at the end of September to present her plan at the International Astronautical Congress.
Second place was awarded to Andrew Bacon of the Department of Electronic and Electrical Engineering at the University of Bath for his paper entitled “The Use of Electromechanical Resonators for the Mitigation of Earth Threatening Asteroids and Comets.” Bacon’s concept involves the use of electromechanical resonators to build up waves within an asteroid or comet that would break it up. He will also present his plan at the IAC.
Sources: Space Generation press release, The Register
Asteroid Steins imaged by Rosetta's OSIRIS camera in two locations.
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ESA’s Rosetta spacecraft will make an historic encounter with asteroid (2867) Steins on September 5, 2008 at 20:58 CEST (Central European Summer Time), 2:58 pm EDT (US Eastern Daylight Time.) A few days ago, Rosetta conducted a successful trajectory correction maneuver using images from the spacecraft’s cameras to calculate the asteroid’s location, to optimize its trajectory for the fly-by. Rosetta will rendezvous with the asteroid while one its way to its primary mission, to visit comet 67/P Churyumov-Gerasimenko. At its closest approach to the asteroid, the spacecraft will be just 800 km from Steins.
At closest approach, however, the spacecraft will not be in communication with Earth. First ground contact with the spacecraft to verify a successful flyby will occur about an hour and half after the encounter. The first images and results will be available for presentation to the media during a press conference on Saturday, September 6 at 12:00 CEST.
Artist's impression of Rosetta and Asteroid Steins. Credit: ESA
Steins is Rosetta’s first nominal scientific target. The study of asteroids is extremely important as they represent a sample of Solar System material at different stages of evolution – key to understanding the origin of our own planet and of our planetary neighborhood. Rosetta will also encounter (21) Lutetia on June 10, 2010.
We’ll post the images and information from the flyby here on Universe Today as soon as they are available.
The bright blue blob is an ancient galaxy cluster. Credits: ESA XMM-Newton/EPIC, LBT/LBC, AIP (J. Kohnert)
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A massive cluster of galaxies seen in the distant universe by ESA’s orbiting XMM-Newton x-ray observatory is so big that astronomers believe there can only be a few of them that far away in space and time. “Such massive galaxy clusters are thought to be rare objects in the distant Universe,” said Georg Lamer, Astrophysikalisches Institut in Potsdam, Germany. “They can be used to test cosmological theories. Indeed, the very presence of this cluster confirms the existence of a mysterious component of the Universe called dark energy.†The astronomers compared the rare find to a cosmic ‘needle in a haystack.’
The newly-discovered monster, known by the catalogue number 2XMM J083026+524133, is 7.7 thousand million light-years distant and is estimated to contain as much mass as a thousand large galaxies. Much of it is in the form of 100-million-degree hot gas. The bright blue blob of gas was found during a systematic analysis of catalogued objects as Lamer and his team were looking for patches of X-rays that could either be nearby galaxies of distant clusters of galaxies.
Based on 3,500 observations performed with XMM-Newton’s European Photon Imaging Camera (EPIC) covering about 1% of the entire sky, the catalogue contains more than 190,000 individual X-ray sources. J083026+524133 stood out because it was so bright. While checking visual images from the Sloan Digital Sky Survey, the team could not find any obvious nearby galaxy in that location. So they turned to the Large Binocular Telescope in Arizona and took a deep exposure, which found a cluster of galaxies in that location.
The astronomers were surprised to find the cluster contains a thousand times the mass of our own Milky Way Galaxy.
No one knows what dark energy is, but it is causing the expansion of the Universe to accelerate. This hampers the growth of massive galaxy clusters in more recent times, indicating that they must have formed earlier in the Universe. “The existence of the cluster can only be explained with dark energy,†says Lamer.
Yet he does not expect to find more of them in the XMM-Newton catalogue. “According to the current cosmological theories, we should only expect to find this one cluster in the 1% of sky that we have searched,†says Lamer.
I thought this year would be different and finally I could make it through the month of August without receiving a forwarded email from an excited acquaintance, wondering if I knew about this incredible news that will happen only once in a lifetime. The email claims Mars is coming closer to Earth and will look as big as the full moon!
Please, this is a complete falsehood and entirely not true. The email about this “once in a lifetime event” has been circulating like clockwork every August for the past five years and is full of errors. If you don’t believe me, here are Universe Today articles dubunking this erroneous email in 2007, 2006, and 2005. If you don’t believe Fraser, Phil Plait the Bad Astronomer debunks the email here, here , here, and here’s the original one back in 2003. I don’t know if the general public really is so uneducated/gullible/in the dark to fall for this every year, or if the folks who start circulating this email every year are trying to determine how uneducated/gullible/in the dark the world actually is.
This began in August 2003 when Mars actually did make its closest approach to Earth in the past 60,000 years. On August 27th, 2003, Mars was 55,758,006 kilometers (34,646,418 miles) away from Earth. Mars just looked like a bright “star” in the sky, not much different than how it usually looks to the naked eye whenever the two planets are at their closest approach. The view of Mars in a telescope was a little better than usual back in 2003, as the bigger telescopes could see the ice caps a little clearer, and possibly some other features. Someone got some bad information as to how big Mars would look at this closest approach and got excited about this bad information, then sent said bad information out in an email which spread like wildfire through the wonders of email forwarding.
This year in August, Mars is about 360 million kilometers (about 215 million miles) from Earth, not very close at all. Since Mars and the Earth are in different orbits around the Sun, and they each take different amounts of time to go around the sun (Earth 365 days, Mars 687 Earth days) the distance between the two planets grows and shrinks, with the closest approaches occurring about every 26 months. But the distance changes with every approach because of the way celestial mechanics works.
If you still need more info, NASA has a page debunking this email, too. Please, let’s work hard to let everyone know this Mars email is completely wrong so that we don’t have to write this article again next year.
