The crew of Apollo 9: Commander James McDivitt, Command Module Pilot Dave Scott and Lunar Module Pilot Rusty Schweickart. Credit: NASA
“On the success of Apollo 9 mission hangs the hope for future manned missions to the Moon,” said famous CBS newsman Walter Cronkite. HD TV it’s not, but this is a fun look back at actual news footage from the Apollo 9 mission, which landed back on Earth on March 13, 1969, forty-four years ago today.
The ten-day Apollo 9 mission was the first manned flight of the lunar module and while in Earth orbit the crew tested the spacecraft for lunar operations. The crew included Commander Jim McDivitt, Command Module pilot Dave Scott and one of our favorite astronauts, the Lunar Module pilot Rusty Schweickart.
They successfully demonstrated the complete rendezvous and docking operations and conducted an EVA during their 151 Earth orbits. The mission carried the largest payload at that point in time to Earth orbit.
WISE J104915.57-531906 from NASA's WISE survey (centered) and resolved to should its binary nature by the Gemini Observatory (inset). (Credit: NASA/JPL/Gemini Observatory/AURA/NSF).
We now know our stellar neighbors just a little better, and a new discovery may help tell us how common brown dwarfs are in our region of the galaxy. Early this week, researchers at Pennsylvania State University announced the discovery of a binary brown dwarf system. With a parallax measurement of just under 0.5”, this pair is only 6.5 light years distant making it the third closest system to our own and the closest example of the sub-stellar class of objects known as brown dwarfs yet discovered.
Named WISE J104915.57-531906, the system was identified by analysis of multi-epoch astrometry carried out by NASA’s Wide-field Infrared Survey Explorer (WISE). The discovery was made by associate professor of astronomy and astrophysics at Penn State’s Center for Exoplanets and Habitable Worlds Kevin Luhman. The system’s binary nature and follow up observations were confirmed by spectroscopic analysis carried out by the Gemini Observatory’s Multi-Object Spectrographs (GMOS).
Animation showing the motion of WISE 1049-5319 across the All-WISE, 2MASS & Sloan Digital Sky Surveys from 1978 to 2010. (Credit: NASA/STScI/JPL/IPAC/University of Massachusetts.)
This find is also the closest stellar system discovered to our own solar system since the discovery of Barnard’s star by astronomer E.E. Barnard in 1916. Incidentally, Barnard’s star was the center of many spurious and controversial claims of extrasolar planet discoveries in the mid-20th century. Barnard’s star is 6 light years distant, and the closest star system to our own is Alpha Centauri measured to be 4.4 light years distant in 1839. In 1915, the Alpha Centauri system was determined to have a faint companion now known as Proxima Centauri at 4.2 light years distant. The Alpha Centauri system also made headlines last year with the discovery of the closest known exoplanet to Earth. WISE 1506+7027 is the closest brown dwarf to our solar system yet discovered. This also breaks the extended the All-WISE survey’s own previous record of the closest brown dwarf released in 2011, WISE 1506+7027 at 11.1 light years distant.
When looking for nearby stellar suspects, astronomers search for stars displaying a high proper motion across the sky. The very first parallax measurement of 11 light years distant was obtained by Friedrich Bessel for the star 61 Cygni in 1838. 61 Cygni was known as “Piazzi’s Flying Star” for its high 4.2” proper motion across the sky. To giving you an idea of just how tiny an arc second is, a Full Moon is about 1800” in diameter. With a proper motion of just under 3” per year, it would take WISE 1049-5319 over 600 years to cross the same apparent distance in the sky as viewed from the Earth!
An artist’s conception of looking back at Sol from the binary brown dwarf system WISE 1049-5319, 6.5 light years distant. (Credit: Janella Williams, Penn State University).
“Based on how this star system was moving in images from the WISE survey, I was able to extrapolate back in time to predict where it should have been located in older surveys,” stated Luhman. And sure enough, the brown dwarf was there in the Deep Near-Infrared Survey of the Southern Sky (DENIS), the Two Micron All-Sky Survey (2MASS) and the Sloan Digitized Sky Survey (SDSS) spanning a period from 1978 to 1999. Interestingly, Luhman also points out in the original paper that the pair’s close proximity to the star rich region of galactic plane in the constellation Vela deep in the southern hemisphere sky is most likely the reason why they were missed in previous surveys.
The discovery of the binary nature of the pair was also “an unexpected bonus,” Luhman said. “The sharp images from Gemini also revealed that the object actually was not just one, but a pair of brown dwarfs orbiting each other.” This find of a second brown dwarf companion will go a long way towards pinning down the mass of the objects. With an apparent separation of 1.5”, the physical separation of the pair is 3 astronomical units (1 AU= the Earth-Sun distance) in a 25 year orbit.
Size comparison of stellar vs substellar objects. (Credit: NASA/JPL-Caltech/UCB).
Brown dwarfs are sub-stellar objects with masses too low (below ~75 Jupiter masses) to sustain the traditional fusion of hydrogen into helium via the full proton-proton chain process. Instead, objects over 13 Jupiter masses begin the first portion of the process by generating heat via deuterium fusion. Brown dwarfs are thus only visible in the infrared, and run a spectral class of M (hottest), L, T, and Y (coolest). Interestingly, WISE 1049-5319 is suspected to be on the transition line between an L and T-class brown dwarf. To date, over 600 L-type brown dwarfs have been identified, primarily by the aforementioned SDSS, 2MASS & DENIS infrared surveys.
General location of WISE 1049-5319 in the constellation Vela. Note its proximity to the galactic plane. (Created by the author using Starry Night).
This discovery and others like it may go a long ways towards telling us how common brown dwarfs are in our region of the galaxy. Faint and hard to detect, we’re just now getting a sampling thanks to surveys such as WISE and 2MASS. The James Webb Space Telescope will do work in the infrared as well, possibly extending these results. Interestingly, Luhman notes in an interview with Universe Today that the potential still exists for the discovery of a brown dwarf closer to our solar system than Alpha Centauri. “No published study of the data from WISE or any other survey has ruled out this possibility… WISE is much more capable of doing this than any previous survey, but the necessary analysis would be fairly complex and time consuming. It’s easier to find something than to rule out its existence.” Said Luhman. Note that we’re talking a nearby brown dwarf that isn’t gravitationally bound to the Sun… this discussion is separate from such hypothetical solar companions as Nemesis and Tyche…and Nibiru conspiracy theorists need not apply!
The WISE 1049-5319 system is also a prime target in the search for nearby extra-solar planets. “Because brown dwarfs have very low masses, they exhibit larger reflex motions due to orbiting planets than more massive stars, and those larger reflex motions will be easier to detect.” Luhman told Universe Today. Said radial surveys for exoplanets would also be carried out in the IR band, and brown dwarfs also have the added bonus of not swamping out unseen planetary companions in the visible spectrum.
Congrats to Mr. Luhman and the Center for Exoplanets and Habitable Worlds on the discovery. You just never know what’s lying around in your own stellar backyard!
Comet C/2011 L4 (PANSTARRS) and the crescent Moon with earthshine over the Sonoran Desert. Credit and copyright: Nic Leister.
Astrophotographers were out in force last night to try and capture Comet PANSTARRS (C/2011 L4 PANSTARRS) as it posed next to the setting crescent Moon. Those with clear skies were rewarded with great views, such as this very picturesque view from Arizona by Nic Leister. See more below:
Comet PANSTARRS and the Waxing Crescent Moon as seen over Castroville, Texas on March 12, 2013. Credit and copyright: Adrian New.
Adrian New wrote via email: “Here in historic Castroville, Texas we had an impressive view of the Comet PANSTARRS and the waxing crescent Moon. Both were easily visible close to the horizon and not affected by the light towers. Taken with a Nikon D800 at ISO 800 and a 2 second exposure at F/4. Lens was a Nikon 300mm F/4.”
Comet PANSTARRS and the lunar crescent in a colorful Arizona sunset, March 12, 2013. Credit and copyright: Chris Schur.
Chris Schur said, “The comet was an easy naked eye object with tail from Arizona, at our elevation of 5150 feet.” This image was taken March 12th around 7:15 MST.
Comet PANSTARRS and the very young Moon, seen in Salem, Missouri on March 12, 2013. Credit and copyright: Joe Shuster, Lake County Astronomical Society.
Joe Shuster from Missouri said he managed to outlast some clouds to get a shot of PANSTARRS and the very young Moon. He used a Canon T1i, Nikon 200mm AIS lens, ISO 800, 4s.
Crescent Moon and Comet PANSTARRS over Columbia, Missouri, March 12, 2013. Credit and copyright: Naghrenhel on Flickr.
Naghrenhel on Flickr shared the story of this image: “It was a very cloudy night and I’d almost given up locating the comet PanStarrs. Then I caught a glimpse of the moon, only 2% illuminated, and decided to take a picture. I was pleasantly surprised to see the moon’s companion appear. I still couldn’t see it with an unaided eye, probably due to city light pollution. But the right exposure of the camera caught the comet. Thanks to the Universe Today website informing me of their close proximity or I would have missed the comet completely.”
Comet PANSTARRS as seen from Gastonia, North Carolina on March 12, 2013. Credit and copyright: Jim Craig.Comet PANSTARRS from 3/12/2013 at about 7:50 pm. up on Mt. Wilson above Los Angeles. Credit: Tim Song Jones.Comet PANSTARRS as seen through the clouds in Indianapolis, Indiana. Credit: John Chumack.
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This set of images shows the results from the rock abrasion tool from Opportunity (left) and the drill from NASA's Curiosity rover (right). Note how the rock grindings from Opportunity are brownish red, indicating the presence of hematite, a strongly oxidized iron-bearing mineral. Such minerals are less supportive of habitability and also may degrade organic compounds. On the right is the hole produced by Curiosity during the first drilling into a rock on Mars to collect a sample from inside the rock. In this case, the rock produced gray tailings -- not red -- suggesting the presence of iron that is less oxidized. Curiosity also found clay minerals that form in more neutral water friendly to the formation of life. Credit: NASA
After analyzing the first powder ever drilled from the interior of a Martian rock, NASA’sCuriosity rover discovered some of the key chemical ingredients necessary for life to have thrived on early Mars billions of years ago.
Curiosity has achieved her goal of discovering a habitable environment on the Red Planet, mission scientists reported today at a briefing held at NASA headquarters in Washington, D.C.
Data collected by Curiosity’s two analytical chemistry labs (SAM and CheMin) confirm that the gray powder collected from inside the sedimentary rock where the rover is exploring – near an ancient Martian stream bed – possesses a significant amount of phyllosilicate clay minerals; indicating an environment where Martian microbes could once have thrived in the distant past.
“We have found a habitable environment which is so benign and supportive of life that probably if this water was around, and you had been on the planet, you would have been able to drink it,” said John Grotzinger, the chief scientist for the Curiosity Mars Science Laboratory mission at the California Institute of Technology in Pasadena, Calif.
Curiosity cored the rocky sample from a fine-grained, sedimentary outcrop named “John Klein” inside a shallow basin named Yellowknife Bay, and delivered pulverized powered to the Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments inside the robot.
The presence of abundant phyllosilicate clay minerals in the John Klein drill powder indicates a fresh water environment. Further evidence derives from the veiny sedimentary bedrock shot through with calcium sulfate mineral veins that form in a neutral to mildly alkaline pH environment.
This side-by-side comparison shows the X-ray diffraction patterns of two different samples collected from the Martian surface by NASA’s Curiosity rover. These images were obtained by Curiosity’s Chemistry and Mineralogy instrument (CheMin) and show the patterns obtained from a drift of windblown dust and sand called “Rocknest” (left) and from a powdered rock sample drilled by Curiosity from the “John Klein” bedrock (right). The presence of abundant phyllosilicate clay minerals in the John Klein drill powder suggest a fresh water environment. The presence of calcium sulfates suggests a neutral to mildly alkaline pH environment. NASA/JPL-Caltech/Ames
“Clay minerals make up at least 20 percent of the composition of this sample,” said David Blake, principal investigator for the CheMin instrument at NASA’s Ames Research Center in Moffett Field, Calif.
The rovers 7 foot (2.1 meter) long robotic arm fed aspirin sized samples of the gray, pulverized powder into the miniaturized CheMin SAM analytical instruments on Feb. 22 and 23, or Sols 195 and 196. The samples were analyzed on Sol 200.
Scientists were able to identify carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus in the sample – all of which are essential constituents for life as we know it based on organic molecules.
“The range of chemical ingredients we have identified in the sample is impressive, and it suggests pairings such as sulfates and sulfides that indicate a possible chemical energy source for micro-organisms,” said Paul Mahaffy, principal investigator of the SAM suite of instruments at NASA’s Goddard Space Flight Center in Greenbelt, Md.
Curiosity accomplished Historic 1st drilling into Martian rock at John Klein outcrop on Feb 8, 2013 (Sol 182), shown in this context mosaic view of the Yellowknife Bay basin taken on Jan. 26 (Sol 169) where the robot is currently working. The robotic arm is pressing down on the surface at John Klein outcrop of veined hydrated minerals – dramatically back dropped with her ultimate destination; Mount Sharp. Credit: NASA/JPL-Caltech/Ken Kremer/Marco Di Lorenzo
The discovery of phyllosilicates on the floor of Gale crater was unexpected and has delighted the scientists. Based on spectral observations from Mars orbit. Grotzinger told me previously that phyllosilicates had only been detected in the lower reaches of Mount Sharp, the 3 mile (5 km) high mountain that is Curiosity’s ultimate destination.
Grotzinger said today that Curiosity will remain in the Yellowknife Bay area for several additional weeks or months to fully characterize the area. The rover will also conduct at least one more drilling campaign to try and replicate the results, check for organic molecules and search for new discoveries.
Comet PANSTARRS seen over Venice, California on March 11, 2013. Credit and copyright: Thad Szabo.
NASA scientist Fred Espenak captured this wonderful timelapse video of Comet PANSTARRS as it set over the Dos Cabezas Mountains in Arizona. The photos were taken from San Simon, AZ using a Nikon D90 and Nikkor 18-200 VR zoom lens at 200mm. All exposures were 2 seconds at F/5.6 (ISO 800).
I’m now seriously jealous, as my location has been socked in with clouds all week so far. If you’re in the same boat, enjoy some more images of Comet PANSTARRS from Universe Today readers:
Comet PANSTARRS as seen over Fountain Hills, Arizona. Credit and copyright: Nice Leister,Comet PANSTARRS from Tucson, Arizona on March 11, 2013. Credit and copyright: Rob Sparks.Comet PANSTARRS on March 11, 2013. Credit: Adam Block/Mount Lemmon Sky Center.Comet PANSTARRS over Alabama USA. Credit an copyright: Kristen Lyles..
Cassini image of Saturn's rings from Dec. 20, 2012 (NASA/JPL-Caltech/SSI)
As Saturn steadily moves along its 29.7-year-long orbit toward summertime in its northern hemisphere NASA’s Cassini spacecraft is along for the ride, giving astronomers a front-row seat to seasonal changes taking place on the ringed planet.
One of these fluctuations is the anticipated disappearance of the “spokes” found in the rings, a few of which can be seen above in an image captured on Dec. 20 of last year.
First identified by Voyager in 1980, spokes are ghostly streaks of varying size and brightness that stretch radially across Saturn’s ring system. They orbit around the planet with the ring particles and can last for hours before fading away.
Under the right lighting conditions spokes can appear dark, as seen in this image from Jan. 2010 (NASA/JPL/SSI)
One of the most elusive and transient of features found on Saturn, spokes are thought to be made up of larger microscopic particles of ice — each at least a micron or more — although exactly what makes them gather together isn’t yet known.
They are believed to be associated with interactions between ring particles and Saturn’s electromagnetic field.
“The spokes are most prominent at a point in the rings where the ring particles are moving at the same speed as Saturn’s electromagnetic field,” said Brad Wallis, Cassini rings discipline scientist. “That idea and variations of it are still the most prominent theories about the spokes.”
Other researchers have suggested that they may be caused by electron beams issuing outwards along magnetic field lines from lightning storms in Saturn’s atmosphere.
Regardless of how they are created, spokes are more often observed when sunlight is striking the rings edge-on — that is, during the spring and autumn equinoxes. Perhaps the increased solar radiation along Saturn’s equator increases the formation of lightning-generating storms, in turn creating more spokes? It’s only a guess, but Cassini — and astronomers — will be watching to see if these furtive features do in fact fail to appear during Saturn’s northern summer, the height of which arrives in 2016.
Aurora seen from Nøss, Nordland in Norway, on March 4, 2013. Credit and copyright: Frank Olsen.
Photographer Frank Olsen from Norway heads out almost nightly this time of year to regularly see and photograph what many of us can only dream about seeing: beautiful, shimmering aurorae. These beautiful sights must be payback for enduring the long winters in northern Norway. You can see more of Frank’s beautiful imagery of aurora, the night sky and more at his Flickr page, his website (he has prints for sale) or his Facebook page.
More below:
Aurora seen in Roksøy, Norway. March 2013. Credit and copyright: Frank Olsen.Aurora as seen over Nøss, Nordland in Norway, on March 4, 2013. Credit and copyright: Frank Olsen.
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Curiosity's risky landing built on lessons learned from the mistakes of past missions, according to NASA. Credit: NASA
Mars is a graveyard; a spot where many a spacecraft slammed into the surface or perhaps, burned up in the atmosphere. This added drama to the Mars Curiosity rover landing last August.
Roger Gibbs, deputy manager for NASA’s Mars Exploration Program at the Jet Propulsion Laboratory, shared how NASA implemented “lessons learned” from Mars 6 (which died on this day in 1974) and other failed Mars missions when creating Curiosity’s game plan. We’ll get more into Curiosity in a moment, but here are the basic principles NASA uses.
Vigorous peer review. NASA wants its Mars teams to be close-knit. From working together and designing a challenging mission together, they form a common language that will serve them well during the challenging landing and mission. But that same closeness can lead to blind spots, so NASA undertakes regular peer reviews with scientists outside of the mission and sometimes even outside of the country. “The peers will come in. They are not vested in this. They haven’t become too engaged in that culture. They will ask pressing questions, and sometimes obnoxious and challenging questions,” Gibbs said.
Building for unknown dangers. Mars is an alien environment to NASA, not just because it’s outside of Earth but also because it has risks we may not know of. In the early days, some spacecraft miscalculated and grazed the atmosphere because we didn’t understand how much the thin gases expand in space, Gibbs said. So the engineers need to recalibrate the computer models with the latest information. “We model the atmosphere of Mars and say, what’s the density, what are the winds and speeds, how fast to change if a dust storm happens and the atmosphere warms up, and how much the atmosphere rises or”blooms.”
The Mars Polar Lander, which crashed and failed on Mars. Credit: NASA
Verifying and validating. Those words sound similar, but in NASA parlance they have entirely different meanings. Verification means they are making sure the design is meeting what they intend to meet. If NASA wants a change in velocity of 1,000 meters per second, for example, as the spacecraft inserts itself into orbit, it designs a system that can meet those specifications with fuel, thrusters and mass. The validation comes next. “It’s asking if 1,000 meters is the right number,” Gibbs said. “It’s a distinction that is sometimes lost on people, but it’s important.”
So how did this process help Curiosity? Well, this especially came to play when the team was designing the so-called “seven minutes of terror” — those final moments before the rover touched the ground. The team not only used parachutes, but also a device called a “sky crane” that used rockets and a sort of cable that lowered the rover carefully to the surface.
Imagine the measurements that must have taken, taking into account how different the Mars environment is from Earth. To gain understanding, the team reviewed again all the past mishap reports from failed Mars missions, such as the Mars Polar Lander and the European Space Agency’s Beagle 2.
Then, according to Gibbs, they spent “a lot of effort” on doing the verification and validation. Curiosity’s landing would be extremely difficult to model, but the team threw every bit of data they had in there.
The NASA team threw in every bit of data they could to model the Mars Curiosity landing. Credit: NASA
They created an atmospheric model of Mars, modelled the trajectory of the incoming spacecraft, and tried to figure out how the various systems would respond to the environment. Next, they tried to tweak the variables to see how far they could change without posing a danger to the mission.
“There’s a paranoia where the folks will ask, did we do it to the best of our knowledge,” Gibbs acknowledged. “What is it that we’re missing?”
If Curiosity had failed, NASA would have opened an inquiry board to figure out what had happened. These boards produce final reports that can be downloaded by anyone. Then, the agency would have tried to prevent the same situation from happening the next time a rover landed.
“It’s a lot easier to learn from someone else’s bad experience, by reading the report understanding the root cause,” Gibbs said.
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.
Cassini looks over the heavily cratered surface of Rhea during the spacecraft's flyby of the moon on March 10, 2012. Credit: NASA/JPL-Caltech/SSI.
“Take a good, long, luxurious look at these sights from another world,” said Cassini Imaging Team Leader Carolyn Porco, “as they will be the last close-ups you’ll ever see of this particular moon.”
On Saturday, March 9, 2013 Cassini made the last close flyby of Rhea during its mission, coming within 620 miles (997km) of the surface of the moon. Cassini’s mission is slated to end in 2017 with a controlled fall into Saturn’s atmosphere. Cassini has been in orbit around Saturn since 2004 and is in its second mission extension.
“Our mission at Saturn has been ongoing for nearly 9 years and is slated to continue for another 4,” Porco said in an email message. “Targeted flybys of the moons Dione, in June and August of 2015, and Enceladus, in October and December of 2015, are all that remains on the docket for detailed exploration of Saturn’s medium-sized moons.”
See more below:
This raw, unprocessed image of Rhea was taken on March 9, 2013. Credit: NASA/JPL-Caltech/Space Science Institute
Besides these great final shots, NASA said the primary purpose of this last close flyby of Rhea was to probe the internal structure of the moon by measuring the gravitational pull of Rhea against the spacecraft’s steady radio link to NASA’s Deep Space Network here on Earth. The results will help scientists understand whether the moon is homogeneous all the way through or whether it has differentiated into the layers of core, mantle and crust.
In addition, Cassini’s imaging cameras will take ultraviolet, infrared and visible-light data from Rhea’s surface. The cosmic dust analyzer will try to detect any dusty debris flying off the surface from tiny meteoroid bombardments to further scientists’ understanding of the rate at which “foreign” objects are raining into the Saturn system.
“We’re nearing the end of this historic expedition,” Porco said. “Let’s enjoy the finale while we can.”
This raw, unprocessed image of Rhea was taken on March 10, 2013 and received on Earth March 10, 2013. The camera was pointing toward Rhea at approximately 280,317 kilometers away, and the image was taken using the CL1 and CL2 filters. Credit: NASA/JPL-Caltech/SSI
