A relatively new cluster of impact craters on Mars as seen by the HiRISE camera on the Mars Reconnaissance Orbiter. Credit: NASA/JPL-Caltech/MSSS/Univ. of Arizona
One of the benefits of having a spacecraft in orbit around another planet for several years is the ability to make long-term observations and interpretations. The Mars Reconnaissance Orbiter has been orbiting Mars for over seven years now, and by studying before-and-after images from the High Resolution Imaging Science Experiment (HiRISE) camera, scientists have been able to estimate that the Red Planet gets womped by more than 200 small asteroids or bits of comets per year, forming craters at least 3.9 meters (12.8 feet) across.
“It’s exciting to find these new craters right after they form,” said Ingrid Daubar of the University of Arizona, Tucson, lead author of the paper published online this month by the journal Icarus. “It reminds you Mars is an active planet, and we can study processes that are happening today.”
New impact site on Mars formed between November 2005 and October 2010. Credit: NASA/JPL-Caltech/MSSS/Univ. of Arizona
Over the last decade, researchers have identified 248 new impact sites on parts of the Martian surface in the past decade from spacecraft images, determining when the craters appeared. The 200-per-year planetwide estimate is a calculation based on the number found in a systematic survey of a portion of the planet.
The orbiters took pictures of the fresh craters at sites where before-and-after images by other cameras helped figure out when the impacts occurred. This combination provided a new way to make direct measurements of the impact rate on Mars. This will lead to better age estimates of recent features on Mars.
Daubar and co-authors calculated a rate for how frequently new craters at least 3.9 meters in diameter are excavated. The rate is equivalent to an average of one each year on each area of the Martian surface roughly the size of the U.S. state of Texas. Earlier estimates pegged the cratering rate at three to 10 times more craters per year. They were based on studies of craters on the moon and the ages of lunar rocks collected during NASA’s Apollo missions in the late 1960s and early 1970s.
“Mars now has the best-known current rate of cratering in the solar system,” said HiRISE Principal Investigator Alfred McEwen of the University of Arizona, a co-author on the paper.
Examples of craters listed in the paper ‘The Current Martian Cratering Rate.’ Credit: NASA/JPL/Univ. of Arizona.
These asteroids, or comet fragments, typically are no more than 3 to 6 feet (1 to 2 meters) in diameter. Space rocks too small to reach the ground on Earth cause craters on Mars because the Red Planet has a much thinner atmosphere.
For comparison, the meteor over Chelyabinsk, Russia, in February was about 10 times bigger than the objects that dug the fresh Martian craters.
HiRISE targeted places where dark spots had appeared during the time between images taken by the spacecraft’s Context Camera (CTX) or cameras on other orbiters. The new estimate of cratering rate is based on a portion of the 248 new craters detected. It comes from a systematic check of a dusty fraction of the planet with CTX since late 2006. The impacts disturb the dust, creating noticeable blast zones. In this part of the research, 44 fresh impact sites were identified.
Estimates of the rate at which new craters appear serve as scientists’ best yardstick for estimating the ages of exposed landscape surfaces on Mars and other worlds.
One of many fresh impact craters spotted by the UA-led HiRISE camera, orbiting the Red Planet on board NASA’s Mars Reconnaissance Orbiter since 2006. (Photo: NASA/JPL-Caltech/MSSS/UA).
Composite Spitzer, Hubble, and Chandra image of supernova remnant Cassiopeia A. A new study shows that a supernova as far away as 50 light years could have devastating effects on life on Earth. (NASA/JPL-Caltech/STScI/CXC/SAO)
“The total number of stars in the Universe is larger than all the grains of sand on all the beaches of the planet Earth,” Carl Sagan famously said in his iconic TV series Cosmos. But when two of those grains are made of a silicon-and-oxygen compound called silica, and they were found hiding deep inside ancient meteorites recovered from Antarctica, they very well may be from a star… possibly even the one whose explosive collapse sparked the formation of the Solar System itself.
Researchers from Washington University in St. Louis with support from the McDonnell Center for the Space Sciences have announced the discovery of two microscopic grains of silica in primitive meteorites originating from two different sources. This discovery is surprising because silica — one of the main components of sand on Earth today — is not one of the minerals thought to have formed within the Sun’s early circumstellar disk of material.
Instead, it’s thought that the two silica grains were created by a single supernova that seeded the early solar system with its cast-off material and helped set into motion the eventual formation of the planets.
According to a news release by Washington University, “it’s a bit like learning the secrets of the family that lived in your house in the 1800s by examining dust particles they left behind in cracks in the floorboards.”
A 3.5-cm chondrite meteorite found in Antarctica in Nov. 1998. Dark meteorites show up well against the icy terrain of Antarctica. (Carnegie Mellon University)
Until the 1960s most scientists believed the early Solar System got so hot that presolar material could not have survived. But in 1987 scientists at the University of Chicago discovered miniscule diamonds in a primitive meteorite (ones that had not been heated and reworked). Since then they’ve found grains of more than ten other minerals in primitive meteorites.
The scientists can tell these grains came from ancient stars because they have highly unusual isotopic signatures, and different stars produce different proportions of isotopes.
But the material from which our Solar System was fashioned was mixed and homogenized before the planets formed. So all of the planets and the Sun have the pretty much the same “solar” isotopic composition.
Meteorites, most of which are pieces of asteroids, have the solar composition as well, but trapped deep within the primitive ones are pure samples of stars, and the isotopic compositions of these presolar grains can provide clues to their complex nuclear and convective processes.
The layered structure of a star about to go supernova; different layers contain different elements (Wikimedia)
Some models of stellar evolution predict that silica could condense in the cooler outer atmospheres of stars, but others say silicon would be completely consumed by the formation of magnesium- or iron-rich silicates, leaving none to form silica.
“We didn’t know which model was right and which was not, because the models had so many parameters,” said Pierre Haenecour, a graduate student in Earth and Planetary Sciences at Washington University and the first author on a paper to be published in the May 1 issue of Astrophysical Journal Letters.
Under the guidance of physics professor Dr. Christine Floss, who found some of the first silica grains in a meteorite in 2009, Haenecour investigated slices of a primitive meteorite brought back from Antarctica and located a single grain of silica out of 138 presolar grains. The grain he found was rich in oxygen-18, signifying its source as from a core-collapse supernova.
Finding that along with another oxygen-18-enriched silica grain identified within another meteorite by graduate student Xuchao Zhao, Haenecour and his team set about figuring out how such silica grains could form within the collapsing layers of a dying star. They found they could reproduce the oxygen-18 enrichment of the two grains through the mixing of small amounts of material from a star’s oxygen-rich inner zones and the oxygen-18-rich helium/carbon zone with large amounts of material from the outer hydrogen envelope of the supernova.
In fact, Haenecour said, the mixing that produced the composition of the two grains was so similar, the grains might well have come from the same supernova — possibly the very same one that sparked the collapse of the molecular cloud that formed our Solar System.
“It’s a bit like learning the secrets of the family that lived in your house in the 1800s by examining dust particles they left behind in cracks in the floorboards.”
Ancient meteorites, a few microscopic grains of stellar sand, and a lot of lab work… it’s an example of cosmic forensics at its best!
Concept of asteroid capture in progress. Credit: NASA.
NASA’s FY2014 budget proposal includes a plan to robotically capture a small near-Earth asteroid and redirect it safely to a stable orbit in the Earth-moon system where astronauts can visit and explore it. A spacecraft would capture an asteroid — which hasn’t been chosen yet, but would be about 7 meters (25 feet) wide — in 2019. Then using an Orion space capsule, a crew of about four astronauts would station-keep with the space rock in 2021 to allow for EVAs for exploration.
NASA has released new images, a video and more information about the mission.
They say that performing all the elements for the proposed asteroid initiative “integrates the best of NASA’s science, technology and human exploration capabilities and draws on the innovation of America’s brightest scientists and engineers.” The mission will combine existing technology along with capabilities being developed to find both large asteroids that pose a hazard to Earth and small asteroids that could be candidates for the proposed mission. NASA says this initiative will help accelerate technology development activities in high-powered solar electric propulsion and take advantage the Space Launch System rocket and Orion spacecraft currently being built, “helping to keep NASA on target to reach the President’s goal of sending humans to Mars in the 2030s.”
Here’s more of NASA’s info:
When astronauts don their spacesuits and venture out for a spacewalk on the surface of an asteroid, how they move and take samples of it will be based on years of knowledge built by NASA scientists and engineers who have assembled and operated the International Space Station, evaluated exploration mission concepts, sent scientific spacecraft to characterize near-Earth objects and performed ground-based analog missions.
As early as the 1970s, NASA examined potential ways to use existing hardware to visit an asteroid to understand better its characteristics. On the International Space Station, scientific investigations and technology demonstrations are improving knowledge of how humans can live and work in space. The agency also has examined many possible mission concepts to help define what capabilities are needed to push the boundaries of space exploration.
During the early space shuttle flights and through assembly of the space station, NASA has relied on testing both in space and on Earth to try out ideas through a host of analog missions, or field tests, that simulate the complexity of endeavors in space.
Concept of Spacecraft with Asteroid Capture Mechanism Deployed. Credit: NASA.
Through 16 missions in the National Oceanic and Atmospheric Administration’s underwater Aquarius Reef Base off the coast of Key Largo, Fla., aquanauts have tested techniques for human space exploration. These underwater tests have been built upon the experience gained by training astronauts in the Neutral Buoyancy Laboratory at NASA’s Johnson Space Center in Houston to assemble and maintain the space station. The NASA Extreme Environment Mission Operations (NEEMO) 15 and 16 missions in 2011 and 2012, respectively, simulated several challenges explorers will face when visiting an asteroid, including how to anchor to and move around the surface of a near-Earth object and how to collect samples of it.
NASA also has simulated an asteroid mission as part of its 2012 Research and Technology Studies ground test at Johnson. During the simulation, a team evaluated how astronauts might do a spacewalk on an asteroid and accomplish other goals. While performing a spacewalk on a captured asteroid will involve different techniques than the activities performed during recent analog exercises, decisions made about ways to best sample an asteroid will be informed by the agency’s on-going concept development and past work.
Artist’s Concept of a Solar Electric Propulsion System. Credit: NASA.
Scientific missions also have investigated the nature of asteroids to provide a glimpse of the origins of the solar system. From the Pioneer 10 spacecraft, which in 1972 was the first to venture into the Main Asteroid Belt, to the Dawn mission, which recently concluded its investigations of asteroid Vesta and is on its way to the dwarf planet Ceres, NASA’s forays help us understand the origins of the solar system and inform decisions about how to conduct missions to distant planetary bodies. Scientists both at NASA and across the world also continue to study asteroids to shed light on their unique characteristics.
As NASA ventures farther into the solar system, the agency continues to simulate and evaluate operations and technical concepts for visiting an asteroid.
An artist's illustration of an asteroid retrieval spacecraft capturing a 7-meter-wide, 500-ton asteroid. Rick Sternbach/Keck Institute for Space Studies.
Rumors have been leaking out for over a week, but now according to Alan Boyle at NBC News’ Cosmic Log, a senior Obama administration official has confirmed that $100 million is being sought for NASA’s budget request for the coming fiscal year for work to allow a robotic spaceship to capture a small asteroid and park it near the Moon for astronauts to explore. The spacecraft would capture a 500-ton, 7- meter (25-foot) asteroid in 2019. Then using an Orion space capsule, a crew of about four astronauts would station-keep with the space rock in 2021 to allow for EVAs for exploration. This plan would accelerate NASA’s deep space missions with Orion and prepare crews for going to Mars.
NBC news quoted the official — who spoke on condition of anonymity because there was no authorization to discuss the plan publicly — as saying the mission would “accomplish the president’s challenge of sending humans to visit an asteroid by 2025 in a more cost-effective and potentially quicker time frame than under other scenarios.”
A week ago, Aviation Week reported that NASA was considering this asteroid mission, which was proposed by the Keck Institute for Space Studies last year. Keck’s proposal had a price tag of $2.6 billion, but no cost estimate for the space agency’s version has yet been released.
Then on April 5, the Associated Press quoted U.S. Sen. Bill Nelson, D-Florida, Nelson, chairman of the Senate science and space subcommittee, that President Obama is putting $100 million in planning money for the accelerated asteroid mission in the 2014 budget that comes out next week. The money would be used to find the right small asteroid.
“It really is a clever concept,” AP quoted Nelson said in a press conference in Orlando. “Go find your ideal candidate for an asteroid. Go get it robotically and bring it back.”
This would be the first time ever an object in space of this size would be manipulated in such a manner.
Donald Yeomans, who heads NASA’s Near Earth Object program, was quoted that while there are thousands of asteroids around 25-feet, finding the right one that comes by Earth at just the right time to be captured will not be easy. And once a suitable rock is found it would be captured with the space equivalent of “a baggie with a drawstring. You bag it. You attach the solar propulsion module to de-spin it and bring it back to where you want it.”
A 7- meter (25-foot) asteroid is not a threat to Earth because asteroids of that size would burn up in Earth’s atmosphere.
The official quoted by NBC said the plan has been under discussion for months, but after February’s meteor blast over Russia, the plan gained traction. The asteroid’s entry into Earth’s atmosphere and subsequent airblast injured more than 1,000 people, and sparked discussions about asteroid threats, including a series of congressional hearings. Congressional officials said they would support more funding to counter asteroid threats.
“This plan would help us prove we’re smarter than the dinosaurs,” NBC quoted said the official, referring to the asteroid that wiped out the dinosaurs and many other species 65 million years ago.
An impact structure on asteroid Vesta resembling a snowman. Credit: NASA
When Heinrich Wilhelm Olbers first glimpsed Vesta on March 29, 1807 — this date in history — the asteroid was but a small point of light. Asteroid science was very, very new at the time as the first asteroid (Ceres) had been discovered only six years before.
Fast-forward 200-plus years and we can treat Vesta as a little world in its own right. NASA sent the Dawn spacecraft in orbit for about a year, which has produced a wealth of weird results. (Stay tuned for what happens at Dawn’s next port of call: Ceres.)
Below are five strange things we’ve discovered about Vesta:
1) Vesta has a fresh face.
This image from NASA’s Dawn spacecraft shows a close up of part of the rim around the crater Canuleia on the giant asteroid Vesta. Canuleia, about 6 miles (10 kilometers) in diameter, is the large crater at the bottom-left of this image. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/PSI/Brown
Space “weathering” from tiny particles hitting the Moon has shaped the surface over time. Not so much on Vesta. It turns out the topography on the asteroid (and other factors) allow constant mixing of the surface, making it appear almost new even though the asteroid is several billion years old. “Vesta ‘dirt’ is very clean, well mixed and highly mobile,” said Carle Pieters, one of the lead authors and a Dawn team member based at Brown University, Providence, R.I. when the finding was made public.
2) Vesta might have stretch marks.
Dawn image of Vesta showing its nearly circumferential equatorial grooves (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)
While trying to wrap their mind around fault lines that circle Vesta’s equator, a group of scientists proposed these could be graban — features that show surface expansion. It’s possible these faults came to be after something big smashed into the planet, creating a gigantic crater with a peak that is almost three times as high as Mt. Everest. The expansion occurred as Vesta’s interior differentiated, or experienced a separation of its core, mantle and crust.
3) Vesta kind of looks like a planet.
‘Rainbow-Colored Palette’ of Southern Hemisphere of Asteroid Vesta from NASA Dawn Orbiter. This mosaic using color data obtained by the framing camera aboard NASA’s Dawn spacecraft shows Vesta’s southern hemisphere in false color, centered on the Rheasilvia impact basin, about 290 miles (467 kilometers) in diameter with a central mound reaching about 14 miles (23 kilometers) high. The black hole in the middle is data that have been omitted due to the angle between the sun, Vesta and the spacecraft. The green areas suggest the presence of the iron-rich mineral pyroxene or large-sized particles. This mosaic was assembled using images obtained during Dawn’s approach to Vesta, at a resolution of 480 meters per pixel. The German Aerospace Center and the Max Planck Institute for Solar System Research provided the Framing Camera instrument and funding as international partners on the mission team. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Looking at Vesta in false color — wavelengths that let different kinds of minerals shine — show a veritable cornucopia of different types of stuff. There’s the iron-rich mineral pyroxene, there’s diagenite material (characteristic of stony meteorites), and various particles of different sizes and ages. “Vesta is a transitional body between a small asteroid and a planet and is unique in many ways,” said mission scientist Vishnu Reddy of the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany. “We do not know why Vesta is so special.”
4) Vesta has hydrogen.
Hydrated minerals are circling the equator of the little world. It’s not quite water, but still an interesting find for scientists. “The source of the hydrogen within Vesta’s surface appears to be hydrated minerals delivered by carbon-rich space rocks that collided with Vesta at speeds slow enough to preserve their volatile content,” stated Thomas Prettyman, lead scientist for Dawn’s gamma ray and neutron detector (GRaND) from the Planetary Science Institute.
5) The northern and southern hemispheres look completely different.
Shaded-relief topographic map of Vesta southern hemisphere showing two large impact basins – Rheasilvia and Older Basin. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
It’s fun to get to a new world and end up with something fundamentally surprising. Some of the very first pictures of Vesta showed a vast difference between different regions of the planet, giving scientists a workout in terms of figuring out how that came to be. “The northern hemisphere is older and heavily cratered in contrast to the brighter southern hemisphere where the texture is more smooth and there are lots of sets of grooves. There is a massive mountain at the South Pole. One of the more surprising aspects is the set of deep equatorial troughs,” said Carol Raymond, Dawn deputy principal investigator, of NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
Here’s a video where you can see that for yourself:
It was an event that took the world by surprise: On the morning of February 15, 2013 a 7,000-ton asteroid crashed into the Earth’s atmosphere. According to NASA, the Siberian meteor exploded with the power of 30 Hiroshima bombs and was the largest object to burst in the atmosphere since the Tunguska event of 1908. This video from PBS’s science show NOVA aired last night on television and is now available to watch online. (Note: the video may not yet be available to watch in all areas of the world.)
The show reveals what scientists have gleaned so far about this object from the numerous dashcam videos in Russia and other data, and how this event could have been much worse.
It features interviews with several scientists, including Peter Brown and Margaret Campbell-Brown from the University of Western Ontario, Mark Boslough from the University of New Mexico, Dan Durda from the Southwest Research Institute and Apollo 9 astronaut Rusty Schweickart, who is now Chair Emeritus of the B612 Foundation, the organization that is building the “Sentinel” telescope to search for asteroids heading for Earth.
These radar images of asteroid 2013 ET were obtained when the asteroid was about 693,000 miles from Earth. The images span 1.3 hours or about 1/3 or the asteroid's rotation rate. Click to enlarge. Credit: NASA/JPL-Caltech/GSSR
Another space rock sat pretty for NASA’s big dish photographer. The 70-meter (230-feet) Goldstone antenna zinged radio waves at 2013 ET on March 10 when the asteroid flew by Earth at 2.9 lunar distances or about 693,000 miles (1.1 million km).
By studying the returned echoes, astronomers pieced together 18 images of a rugged, irregular-shaped object about 130 feet (40 m) across. Radar measurements of an asteroid’s distance and speed nail down its orbit with great accuracy, enabling scientists to predict whether or not it might become a danger to the planet at a future date.
The Goldstone dish dish, based in the Mojave Desert near Barstow, Cal. is used for radar mapping of planets, comets, asteroids and the moon. Credit: NASA
It’s also the only way outside of a sending a spacecraft to the object of seeing a small asteroid’s shape and surface features. Most optical telescopes cannot resolve asteroids as anything more than points of light.
By convention, radar images appear “lit” from above. That’s the side closest to the antenna. As you examine a radar image from top to bottom, distance from the antenna increases and the asteroid fades. If the equator of the asteroid faces the antenna, it will appear brightly illuminated at the top of the image. If the antenna faces one of the poles, the pole will be on top and lit up. It takes a bit of getting used to.
Nine radar images of near-Earth asteroid 2007 PA8 obtained between by NASA’s 230-foot-wide (70-meter) Deep Space Network antenna. The part of the asteroid closest to the antenna is at top. Credit: NASA/JPL-Caltech
The asteroid’s width in the images depends on the asteroid’s rotation rate and the antenna’s perspective. If the antenna stares directly down over the equator and the asteroid rotates rapidly, the images will be stretched from Doppler-shifting of the returned radar echo.
Radio waves are a form of light just like the familiar colors of the rainbow. If radio light is moving toward you, its waves bunch together more tightly and appear slightly bluer than if they were at rest. Astronomers call this a Doppler shift or blueshift. If they’re moving away, the light waves get stretched and become “redshifted”.
Three views of asteroid 4179 Toutatis made in early Dec. 2012 by Goldstone. In all three, distance from the antenna increases from top to bottom and Doppler frequency increases toward the right, indicating Toutatis rotates from right to left, since that’s the side of the asteroid approaching the observer. Credit: NASA/JPL-Caltech
A slow-rotating asteroid will appear narrower to radar eyes, and if it doesn’t rotate at all, will show up as a “spike” of light. When the antenna happens to be point directly at a pole, the asteroid will appear to be rotating neither toward nor away from the observer and also look like a spike.
Most asteroids fall somewhere in between, and their radar portraits are close to their true shapes. Radar images show us surface textures, shape, size, rotation rate and surface features like craters. 2013 ET joins the ranks of numerous asteroids probed by radio waves from Earth as we try to grasp the complexity of our planetary neighborhood while hoping for we don’t stare down cosmic disaster anytime soon.
In this new video from Big Think, astrophysicist Neil deGrasse Tyson says he’s almost embarrassed for our species that it takes a warning shot across our bow before legislators take seriously the advice they’ve been receiving from astronomers about getting serious about asteroid detection and deflection; that it’s a matter of when not if Earth will get smacked by an asteroid. “But it took an actual meteor over Russia exploding with 25 times the power of the atom bomb in Hiroshima to convince people that maybe we should start doing something about it.”
Installation of new KaBOOM asteroid detection radar dish antenna system at the Kennedy Space Center, Florida. Credit: Ken Kremer (kenkremer.com)
Over the past month, about a half dozen rather large asteroids have careened nearby our home planet and in one case caused significant injury and property damage with no forewarning – showcasing the hidden lurking dangers from lackluster attitudes towards Asteroid Detection & Planetary Defense.
Now in a prescient coincidence of timing, NASA is funding an experimental asteroid radar detection array called ‘KaBOOM’ that may one day help thwart Earth’s untimely Ka-boom – and which I inspected first-hand this past week at the Kennedy Space Center (KSC),following the SpaceXFalcon 9 blastoff for the ISS.
“KaBOOM takes evolutionary steps towards a revolutionary capability,” said Dr. Barry Geldzahler, KaBOOM Chief Scientist of NASA Headquarters, in an exclusive interview with Universe Today.
If successful, KaBOOM will serve as a prelude to a US National Radar Facility and help contribute to an eventual Near Earth Object (NEO) Planetary Defense System to avert Earth’s demise.
“It will enable us to reach the goal of tracking asteroids farther out than we can today.”
First some background – This weekend a space rock the size of a city block whizzed past Earth at a distance of just 2.5 times the distance to our Moon. The asteroid – dubbed 2013 ET – is noteworthy because it went completely undetected until a few days beforehand on March 3 and measures about 460 feet (140 meters) in diameter.
KaBOOM experimental asteroid radar array at KSC consists of three 12 meter wide dish antennas mounted on pedestals at the Kennedy Space Center in Florida. Credit: Ken Kremer (kenkremer.com)
2013 ET follows close on the heels of the Feb. 15 Russian meteor that exploded violently with no prior warning and injured over 1200 people on the same day as Asteroid 2012 DA 14 zoomed past Earth barely 17,000 miles above the surface – scarcely a whisker astronomically speaking.
Had any of these chunky asteroids actually impacted cities or other populated areas, the death toll and devastation would have been absolutely catastrophic – potentially hundreds of billions of dollars !
Taken together, this rash of uncomfortably close asteroid flybys is a wake-up call for a significantly improved asteroid detection and early warning system. KaBOOM takes a key step along the path to those asteroid warning goals.
KaBOOM asteroid radar under construction near alligator infested swamps at the Kennedy Space Center in Florida. Credit: Ken Kremer (kenkremer.com)
‘KaBOOM’ – the acronym stands for ‘Ka-Band Objects Observation and Monitoring Project’ – is a new test bed demonstration radar array aimed at developing the techniques required for tracking and characterizing Near Earth Objects (NEO’s) at much further distances and far higher resolution than currently available.
“The purpose of KaBOOM is to be a ‘proof of concept’ using coherent uplink arraying of three widely spaced antennas at a high frequency; Ka band- 30 GHz,” KaBOOM Chief Scientist Geldzahler told me.
Currently the KaBOOM array consists of a trio of 12 meter wide radar antennas spaced 60 meters apart – whose installation was just completed in late February at a remote site at KSC near an alligator infested swamp.
I visited the array just days after the reflectors were assembled and erected, with Michael Miller, KaBOOM project manager of the Kennedy Space Center. “Ka Band offers greater resolution with shorter wavelengths to image smaller space objects such as NEO’s and space debris.”
“The more you learn about the NEO’s the more you can react.”
“This is a small test bed demonstration to prove out the concept, first in X-band and then in Ka band,” Miller explained. “The experiment will run about two to three years.”
Miller showed how the dish antennae’s are movable and can be easily slewed to different directions as desired.
“The KaBOOM concept is similar to that of normal phased arrays, but in this case, instead of the antenna elements being separated by ~ 1 wavelength [1 cm], they are separated by ~ 6000 wavelengths. In addition, we want to correct for the atmospheric twinkling in real time,” Geldzahler told me.
Why are big antennae’s needed?
“The reason we are using large antennas is to send more powerful radar signals to track and characterize asteroids farther out than we can today. We want to determine their size, shape, spin and surface porosity; is it a loose agglomeration of pebbles? composed of solid iron? etc.”
Such physical characterization data would be absolutely invaluable in determining the forces required for implementing an asteroid deflection strategy in case the urgent need arises.
How does KaBOOM compare with and improve upon existing NEO radars in terms of distance and resolution?
“Currently at NASA¹s Goldstone 70 meter antenna in California, we can track an object that is about 0.1 AU away [1 astronomical unit is the average distance between the Earth and the sun, 93 million miles, so 0.1 AU is ~ 9 million miles]. We would like to track objects 0.5 AU or more away, perhaps 1 AU.”
“In addition, the resolution achievable with Goldstone is at best 400 cm in the direction along the line of sight to the object. At Ka band, we should be able to reduce that to 5 cm – that’s 80 times better !”
“In the end, we want a high power, high resolution radar system,” Geldzahler explained.
Thumbs Up for Science & Planetary Defense !
Ken Kremer; Universe Today and Mike Miller; NASA KSC KaBOOM project manager. Credit: Ken Kremer (kenkremer.com)
Another significant advantage compared to Goldstone, is that the Ka radar array would be dedicated 24/7 to tracking and characterizing NEO’s and orbital debris, explained Miller.
Goldstone is only available about 2 to 3% of the time since it’s heavily involved in numerous other applications including deep space planetary missions like Curiosity, Cassini, Deep Impact, Voyager, etc.
‘Time is precious’ at Goldstone – which communicates with some 100 spacecraft per day, says Miller.
“If/when the proof of concept is successful, then we can envision an array of many more elements that will enable us to reach the goal of tracking asteroids farther out than we can today,” Geldzahler elaborated.
A high power, high resolution radar system can determine the NEO orbits about 100,000 times more precisely than can be done optically.
Lead KaBOOM scientist Barry Geldzahler ‘assists’ with dish antenna installation at the Kennedy Space Center; – ‘I’m from Headquarters and I’m here to help’ – is Barry’s mantra. Credit: NASA/KSC
So – what are the implications for Planetary Defense ?
“If we can track asteroids that are up to 0.5 AU rather than 0.1 AU distant, we can track many more than we can track today.”
“This will give us a better chance of finding potentially hazardous asteroids.”
“If we were to find that a NEO might hit the Earth, NASA and others are exploring ways of mitigating the potential danger,” Geldzahler told me.
Kaboom’s ‘First light’ is on schedule for late March 2013.
An illustration of the Jabberwocky first published in 1871. Credit: Public domain/Wikipedia
Cats, celebrities and fictional creatures all have a home in the asteroid belt. That’s because the people that found these asteroids often have the privilege of naming the minor planets after anything they want — with a few guidelines, of course.
So what are the rules? According to the International Astronomical Union’s Minor Planet Center, all “minor planets” should adhere to the following guidelines:
– 16 characters long, or less;
– One word, if possible;
– Pronounceable, non-offensive and not too similar to names of other minor planets or natural planetary satellites;
– If named after a military/political persona, 100 years must have passed since the person died or the event occurred;
– No commercial names;
– Names of pets are strongly discouraged. (More on that later.)
Below are some of the more whimsical names of asteroids. What’s awesome about them is how willing the discoverer was to show his or her light side on what must have been a solemn occasion for them.
9) James Bond (9007): This actually isn’t too surprising, since Bond has been to space a few times, most notably attempting “re-entry” during the film Moonraker. Still, it’s a fair stretch from flying the space shuttle to navigating the asteroid belt.
8) Odysseus (1143): This ever-patient sailor probably would have been unhappy with a trip into space in addition to seeing his friends die in war, fighting with the Cyclops and getting stranded far from home.
7) Beowulf (38086): Named after the hero in an Old English epic poem. He’ll be handy in case we come across any Grendel-like creatures in outer space.
6) Tomhanks (12818) and (5) Megryan (8353): Cue the “sleepless in space” jokes, which accelerated in other media when the two asteroids came within 40 million miles of each other in 2011 (relatively close for asteroids.) That said, Tom Hanks is a well-known advocate of the space program. He starred in Apollo 13, was prominent behind the scenes in HBO’s From the Earth to the Moon miniseries and is a friend of astronauts.
4) Apophis (99942): This asteroid has come under a lot of scrutiny because for a while, astronomers weren’t clear on if it would hit the Earth. But we know now it is definitely not a threat. The asteroid is actually named after a nemesis character in the sci-fi series Stargate SG-1.
3) Monty Python (13681): The famed British comedy troupe now has a permanent monument to their silly walks and elderberry insults in space. Not only that, but each of the members of the group has an asteroid named after him.
2) Mr. Spock (2309): This asteroid was not named after the famous Star Trek character, but after the cat of discoverer James B. Gibson. The feline, like its namesake, was also “imperturbable, logical, intelligent, and had pointed ears,” according to a notice published in September 1985 in the Minor Planet Center.
1) Jabberwock (7470): In the ultimate expression of gyring and gimbling in the wabe, Lewis Carroll’s famous Jabberwocky poem has a namesake. We just hope it didn’t inherit the jaws and claws.
We also wanted to mention another named asteroid, even though we don’t think it has a weird name at all: Asteroid 158092 Frasercain, named after our esteemed publisher of Universe Today. This asteroid was officially designated on August 21, 2008. You can read about it here.
Also, while looking for silly asteroid names, we stumbled across one that is quite meaningful and perhaps the most appropriate space name ever.
45 Eugenia has a moon called Petit-Prince, honoring Antoine de Saint-Exupéry’s The Little Prince. The children’s book follows the exploit of a boy who lived on an asteroid and explored other asteroids, as well as Earth.
