Opportunity's view of the far-off rim of Endeavour Crater. Credit: NASA/JPL-Caltech/Cornell University
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Back in September of 2008, Mars Exploration Rover Principal Investigator Steve Squyres announced the Opportunity rover would head out to a large, faraway crater named Endeavour, and Squyres said he hoped to one day see the view from the rim. Well, Oppy has now provided an improved view OF the rim: off in the distance in the image above are the “Endeavour Hills,” the mounds which surround the perimeter of the crater, about 13 km (8 miles) away, along with the rim of an even more distant crater, Iazu, on the right.
As the crow flies, Endeavour is about 12 km away from Oppy’s starting point in 2008, Victoria Crater. But while the intrepid rover has already traveled 7 km towards Endeavour, it still has 12 km to go, as the route chosen to avoid potentially hazardous dune fields is more like 19km, as presently charted, said Guy Webster at JPL. You can see an example of Opportunity’s circuitous driving below.
Opportunity's tracks show how the rover avoided driving through potentially dangerous sand dunes. Credit: NASA/JPL/U of AZ
The original target timing for Opportunity reaching Endeavour was about two years, but since the science team has had the rover spend several weeks stopping at interesting targets of study along the way, the rover will definitely not make it to Endeavour by September 2010. It might take another year, or even two.
Additionally, it is now winter on Mars, and according to A.S.J. Rayl’s Rover Update from the Planetary Society, Opportunity is now roving for only about 30 minutes at a time, which enables it to cover only 30-to-50 meters on a drive sol. And, the rover is also taking Martian days off to re-charge its batteries. Record cold temps this winter (down to -37 C) on Mars is slowing the aging rover.
But back in March Oppy reached 20 kilometers (12.43 miles) of total driving in its 74 months on Mars. Pretty amazing for a piece of hardware that was supposed to last six months and drive about 600 meters. Later this month, Oppy will surpass the Viking Lander 1’s record of 6 years and 116 days to become the longest-lived robot on Mars. The Spirit rover has already surpassed that record, but it is unknown if the rover is only hibernating and we’ll hear from it when it warms up again, or if Spirit is no longer with us (sniff!).
Endeavour Crater is 21 kilometers (13 miles) in diameter, which is about 25 times wider than Victoria crater. The view in the top image is an area about 140 kilometers (about 90 miles) wide. Orbital view of Opportunity's location from THEMIS. mage Credit: NASA/JPL-Caltech/Arizona State University
This view shows a top-down look at the area from orbit, and is a mosaic of daytime infrared images taken by the Thermal Emission Imaging System (THEMIS) camera on NASA’s Mars Odyssey orbiter.
Additionally, a new gif “movie” was released this week showing how Oppy emerged from Victoria crater about a year and a half ago. Click here to see it.
And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, let Fraser know if you can be a host, and he’ll schedule you into the calendar.
Finally, if you run a space-related blog, please post a link to the Carnival of Space. Help us get the word out.
The 60-inch telescope on Mount Lemmon is one of three telescopes used in the Catalina Sky Survey.
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The Near-Earth Asteroid (NEA) 2010 GU21 was discovered by the Catalina Sky Survey on April 5 2010 (MPEC 2010-G55) and has been designated as a Potentially Hazardous Asteroid (PHA) by the Minor Planet Center. The asteroid will pass within approximately 8 lunar distances on May 05.25 2010 UT… But why wait when we have Joe Brimacombe on our side?
2010 GU21 is photometrically surmised to be a X-type asteroid and very low-albedo… so dim, in fact, that it only manages about a magnitude 18. However, if you give Joe a magnitude 18 blip, he’ll send you back an image! Just watch how fast this crazy little thing travels….
And for heaven’s sake, don’t take the impact seriously! While eight moon distances (roughly two million miles) is darn close in astronomical terms, we’re quite safe when it comes to physical distance. But, with only a couple of million miles separating us, this would be a great time for radar targeting and studying (NEA) 2010 GU21’s rotation period. What’s more, it’s also on the list for the Delta-v for spacecraft rendezvous with all known near-Earth asteroids.
In the meantime, with only two days until 2010 GU21’s closest approach, you’d best keep up your car payments and still plan on keeping those weekend promises. It’s fun to surmise what might what might happen if it were a wee bit closer…
Or is it?
Many thanks to Joe Brimacombe for sharing his awesome video with us!
How did you do in last week’s Universe Puzzle? Did you easily find out where the green valley is, but have no clue as to why it’s called a ‘valley’?
Do you enjoy these puzzles? What do you particularly like? Dislike? Would like to see changed? Would like to see more of? Let me know please!
Once again, this week’s puzzle requires you to cudgel your brains a bit and do some lateral thinking (five minutes spent googling likely won’t be enough). But, as with all Universe Puzzles, this is a puzzle on a “Universal” topic – astronomy and astronomers; space, satellites, missions, and astronauts; planets, moons, telescopes, and so on.
Which is the “odd one out”? And why?
α, β, γ, μ, ν, and τ.
In case the Greek symbols don’t display properly, these are (lower case, or small) alpha, beta, gamma, mu, nu, and tau.
UPDATE: Answer has been posted below.
There are, of course, many answers. For example, τ (tau) is alone, because neither of its two neighbors in the Greek alphabet are in the list. But that’s not a particularly good answer, and this week’s puzzle asks for the best answer (which may be τ (tau)!), so the explanation of your choice is what counts.
I think Hon. Salacious B. Crumb’s answer is very good (“tau is the odd one out. The rest are al rings of the planet Uranus by increasing radius from the planet’s disk. alpha, beta, gamma are inner rings, nu and mu are the outmost rings.“)
I also like Navneeth’s (“alpha, because it’s a composite “particle” while the others are truly elementary (as far as we know)“) – gopher65 gave much the same answer, iantresman’s (“alpha particles are the only non-fermions. Neutrinos (nu) are the only ones to come in different flavours“), and the several of you who picked gamma because the photon is massless (though I think iantresman’s “it’s the only gauge boson” is a better reason for choosing it; you could also say it’s the only force carrier particle).
Star designations? If someone had come up with a good answer along those lines, they’d’ve got my vote; but, as far as I know there is nothing “odd” about any of these Greek letters.
My own answer was the tau … it’s the only particle as yet undetected, directly, by any spacecraft or Earth-based facility, originating out in space (Fermi detects gammas; plenty of instruments on spacecraft detect alpha particles, electrons, and muons; and neutrinos from the Sun and SN1987A have been detected; but no taus!)
Apologies for the lack of posts the past few days, but here’s a round-up across the Universe (and the world wide web) of some of the latest and best space news. Above, watch a video about the site being chosen for the E-ELT.
Well, here’s a bit of a first for AWAT, because this is a story about a telescope. But it’s not your average telescope, being composed of a huge chunk of Antarctic ice with a very large cosmic ray muon filter attached to the back of it, which is called the Earth.
Commenced in 2005, the IceCube Neutrino Observatory is now approaching completion with recent installation of a key component DeepCore. With DeepCore, the Antarctic observatory is now able to observe the southern sky, as well as the northern sky.
Neutrinos have no charge and are weakly interactive with other kinds of matter, making them difficult to detect. The method employed by IceCube and by many other neutrino detectors is to look for Cherenkov radiation which, in the context of IceCube, is emitted when a neutrino interacts with an ice atom creating a highly energized charged particle, such as an electron or a muon – which shoots off at a speed greater than the speed of light, at least greater than the speed of light in ice.
The advantage of using Antarctic ice as a neutrino detector is that it is available in large volumes and thousands of years of sedimentary compression has squeezed most impurities out of it, making it a very dense, consistent and transparent medium. So, not only can you see the little flashes of Cherenkov radiation, but you can also make reliable predictions about the trajectory and energy level of the neutrino which caused each little flash.
The structure of IceCube incorporates strings of evenly spaced basketball-sized Cherenkov detectors lowered into the ice through drill holes to depths of nearly 2.5 kilometers. The DeepCore component is a more compact array of detectors, positioned in the clearest ice deep within IceCube, designed to enhance the sensitivity of IceCube for neutrino energies less than 1 TeV.
Prior to DeepCore being finished, it was only feasible to accurately measure the effects of upwardly moving neutrinos – that is, neutrinos that had already passed through the Earth and, if of a cosmic origin, had actually come from the northern sky. Any downwardly moving neutrinos from the southern sky were lost in noise created by cosmic ray muons which are able to penetrate IceCube, creating their own Cherenkov radiation without neutrinos being involved.
However, with the greater sensitivity offered by DeepCore, coupled with IceTop, which is a set of surface level Cherenkov detectors able to differentiate external muons entering from the surface, it is now possible for IceCube to make neutrino observations of the southern sky as well.
Adapted from Halzen (2009, arXiv:0911.2676)
IceCube’s key scientific goal is to identify neutrino point sources in the sky, which may include supernova and gamma ray bursts. Neutrinos are speculated to account for 99% of the energy release of a Type 2 supernova – suggesting that we may be missing a lot of information when we just focus on the electromagnetic radiation that is emitted.
It is also speculated that IceCube might provide indirect evidence of dark matter. The thinking is that if some dark matter was caught in the centre of the Sun, it would be annihilated by the extreme gravitational compression present there. Such an event should produce a sudden burst of high energy neutrinos, independent of the normal neutrino output resulting from solar fusion reactions. That’s a long chain of suppositions to gain indirect evidence of something, but we’ll see.
Astronomers have been cataloging star positions for thousands of years, from the first calculations made by Hipparchus, to the more recent star catalogs made by the spacecraft named after him. This is astrometry; another way to find our place in the Universe.
This week’s Carnival of Space is hosted by Bruce over at Bruceleeeowe’s Blog/Weird Science.
Click here to read the Carnival of Space #151
And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, let Fraser know if you can be a host, and he’ll schedule you into the calendar.
Finally, if you run a space-related blog, please post a link to the Carnival of Space. Help us get the word out.
Ready for another Where In The Universe Challenge? Here’s #102! Take a look and see if you can name where in the Universe this image is from. Give yourself extra points if you can name the spacecraft responsible for the image. We provide the image today, but won’t reveal the answer until tomorrow. This gives you a chance to mull over the image and provide your answer/guess in the comment section. Please, no links or extensive explanations of what you think this is — give everyone the chance to guess.
UPDATE: The answer has now been posted below.
This is the Apollo 17 landing site as seen by the Lunar Reconnaissance Orbiter camera. The image was part of a set of images, the first taken by LROC of the Apollo landing sites, from July 2009. See more at this link at the LRO website
Very early concept diagrams, circa 1959, of the Saturn I, Saturn V and Nova C8 rockets. Source: Wikipedia
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Note: To celebrate the 40th anniversary of the Apollo 13 mission, for 13 days, Universe Today will feature “13 Things That Saved Apollo 13,” discussing different turning points of the mission with NASA engineer Jerry Woodfill.
Going to the Moon was big. It was a giant stride in doing what had once been thought impossible. Initially many scientists and engineers had big plans for huge rockets akin to the ships imagined in science fiction: one piece vehicles that took off from Earth, landed intact bottom down on the Moon and had the ability to launch again from the lunar surface. But other rocket engineers had different ideas, and this caused some big arguments. The method of going to the Moon that eventually won out used — in part — a little lunar lander. This decision ended up being instrumental in saving the crew of Apollo 13. And that was big.
The three different Apollo flight modes. Credit: NASA
There were three different methods to choose from in reaching the Moon. One, called the Direct Ascent Mode, would have used the big Flash Gordon-like enormous rocket – which was known as a Nova class rocket –to fly straight to the Moon, land and return. Second, the Earth Orbital Rendezvous technique called for two not-quite-as big Saturn V boosters to launch and rendezvous in Earth orbit. In this mode, one rocket would carry a single Apollo vehicle and its crew, and the other, more fuel, which would be transferred to Apollo in Earth orbit, and then the spacecraft would head off to the Moon. The third option was Lunar Orbit Rendezvous which used only one three-stage Saturn V booster, and split the Apollo vehicle into two separate vehicles – a combined Command and Service Module (CSM), and a Lunar Module (LM).
Those familiar with NASA history know that Lunar Orbit Rendezvous was the final choice.
But this mode wasn’t an obvious choice, said NASA engineer Jerry Woodfill.
“At first, Werner Von Braun wanted to use the Nova class rocket Direct Ascent approach, and so did President Kennedy’s science advisor, ” Woodfill said. “But a group at Langley Research Center led by Dr. John Houbolt came up with the Lunar Orbit Rendezvous design. And most everyone ignored them at first.” NASA engineer John C. Houbolt describes the Lunar Orbit Rendezvous concept at the chalkboard in July 1962. Image Credit: NASA
But Houbolt insisted the one-rocket system was not feasible. In a NASA interview Houbolt said, “It can not be done. I said you must include rendezvous in your thinking — to simplify, to manage your energy much better.”
Houbolt said it turned into a two-and-a-half year fight to convince people, but he and his team had the facts and figures to back up their claims.
Woodfill said one of his colleagues, former NASA engineer Bob Lacy was part of the discussions on which plan to use. “He said it was unbelievable,” Woodfill recalled. “They were debating in a meeting room at Langley about the best way to go to the Moon. One side was for sending a single vehicle requiring a huge booster to get it there. The other group wanted a two spaceship method. No one seemed agreeable to the other side’s approach. Tempers were starting to flare. To ease the situation someone said, ‘Let’s flip a coin to settle the score.’ Can you believe that?”
No one flipped a coin, but the story demonstrates the intensity of the debate.
In the race to get to the Moon, the Soviet Union had embraced the Nova rocket concept. “The Soviets pressed forward with the direct assent approach to use a Nova class booster,” said Woodfill. “Designated N-1, it clustered 30 engines on its first stage. The design achieved a Herculean thrust of 10-12 millions pounds. Additionally, this uncomplicated direct ascent launch would be less complex was thought to take less time to accomplish. Designing, building, testing and launching two separate spaceships might not win the race to the Moon.”
Woodfill said the Nova rocket may have proved to be the best choice except for the failure of just one of those 30 engines at launch. “This would unbalance the entire assemblage,” Woodfill said.
And twice in 1969 – one occurring just weeks before the scheduled launch of Apollo 11 — the Soviet N-1 booster exploded at liftoff. The huge rocket proved to be too complicated, while the Lunar Orbit Rendezvous method had a simple elegance that was also more economical. A diagram of the lunar-orbit rendezvous used on Apollo by John Houbolt. Credit: NASA
In November 1961, Houbolt boldly wrote a letter to NASA associate administrator Robert C. Seamans, “Do we want to go to the Moon or not?” he wrote. “Why is Nova, with its ponderous size simply just accepted, and why is a much less grandiose scheme involving rendezvous ostracized or put on the defensive? I fully realize that contacting you in this manner is somewhat unorthodox,” Houbolt admitted, “but the issues at stake are crucial enough to us all that an unusual course is warranted.”
The bold move paid off, and Seamans saw to it that NASA took a closer look at Houbolt’s design, and surprisingly, it soon became the favored approach – after a little debate..
Houbolt’s design separated the spacecraft into two specialized vehicles. This allowed the spacecraft to take advantage of the Moon’s low gravity. The lunar lander could be made quite small and lightweight, reducing bulk, fuel, and thrust requirements. The Lunar Module Aquarius, after it was jettisoned from the CSM. Farewell Aquarius, we thank you, the crew radioed. Credit: NASA
When the oxygen tank in Apollo 13’s Service Module exploded, the Lunar Module “Aquarius” played an unexpected role in saving the lives of the three astronauts, serving as a lifeboat to return the astronauts safely back to Earth. Additionally, its descent stage engine was used for propulsion, and its batteries supplied power for the trip home while recharging the Command Module’s batteries critical for re-entry. And with ingenuity of Mission Control the LM’s life support system – which was originally designed to support two astronauts for 45 hours, — was stretched to support three astronauts for 90 hours.
Imagine, Woodfill said, if Apollo 13 had been a single vehicle employing the Direct Ascent approach. “After the explosion and subsequent loss of the fuel cells, only those entry batteries would have been available to sustain life. Their life, even if all systems except life support, were turned off would be less than 24 hours. And Lovell, Swigert and Haise along with Apollo 13 would return to Earth on that “free-return-trajectory” being cremated in the fiery heat of reentry. But for the clever Lunar Orbit Rendezvous approach, Apollo 13 would have been a casket. Instead, its lunar lander became a wonderful lifeboat” Woodfill said.
Next: Part 13: Houston
Earlier articles from the “13 Things That Saved Apollo 13” series:
