A quasar resides in the hub of the nearby galaxy NGC 4438. Credit: NASA/ESA, Jeffrey Kenney (Yale University), Elizabeth Yale (Yale University)
50 million light-years away a quasar resides in the hub of galaxy NGC 4438, an incredibly bright source of light and radiation that’s the result of a supermassive black hole actively feeding on nearby gas and dust (and pretty much anything else that ventures too closely.) Shining with the energy of 1,000 Milky Ways, this quasar — and others like it — are the brightest objects in the visible Universe… so bright, in fact, that they are used as beacons for interplanetary navigation by various exploration spacecraft.
“I must go down to the seas again, to the lonely sea and the sky,
And all I ask is a tall ship and a star to steer her by.”
Deep-space missions require precise navigation, especially when approaching bodies such as Mars, Venus, or comets. It’s often necessary to pinpoint a spacecraft traveling 100 million km from Earth to within just 1 km. To achieve this level of accuracy, experts use quasars – the most luminous objects known in the Universe – as beacons in a technique known as Delta-Differential One-Way Ranging, or delta-DOR.
How delta-DOR works (ESA)
Delta-DOR uses two antennas in distant locations on Earth (such as Goldstone in California and Canberra in Australia) to simultaneously track a transmitting spacecraft in order to measure the time difference (delay) between signals arriving at the two stations.
Unfortunately the delay can be affected by several sources of error, such as the radio waves traveling through the troposphere, ionosphere, and solar plasma, as well as clock instabilities at the ground stations.
Delta-DOR corrects these errors by tracking a quasar that is located near the spacecraft for calibration — usually within ten degrees. The chosen quasar’s direction is already known extremely well through astronomical measurements, typically to closer than 50 billionths of a degree (one nanoradian, or 0.208533 milliarcsecond). The delay time of the quasar is subtracted from that of the spacecraft’s, providing the delta-DOR measurement and allowing for amazingly high-precision navigation across long distances.
“Quasar locations define a reference system. They enable engineers to improve the precision of the measurements taken by ground stations and improve the accuracy of the direction to the spacecraft to an order of a millionth of a degree.”
– Frank Budnik, ESA flight dynamics expert
So even though the quasar in NGC 4438 is located 50 million light-years from Earth, it can help engineers position a spacecraft located 100 million kilometers away to an accuracy of several hundred meters. Now that’s a star to steer her by!
A major goal was to test the Comex-designed Gandolfi spacewalk training suit (based on the Russian Orlan spacesuits) during the sojourn. The mission was considered the first step (literally and figuratively) to figuring out how Europeans can train their astronauts for possible Moon, asteroid and Mars missions in the decades to come.
“The Gandolfi suit is bulky, has limited motion freedom, and requires some physical effort – just like actual space suits. I really felt like I was working and walking on the Moon,” Clervoy stated.
Even the photos come pretty darn close to the real thing. Compare this picture of Apollo 12 commander Pete Conrad during his Moon walk in 1969:
Apollo 12 commander Pete Conrad on the moon in 1969. The glow is due to the sun being at a low angle, NASA says. Credit: NASA
Water is considered a useful training tool for spacewalk simulations. NASA in fact has a ginormous pool called the Neutral Buoyancy Laboratory. Inside are duplicate International Space Station modules. Astronauts are fitted with weights and flotation devices to make them “float” similarly to how they would during spacewalks.
With trained divers hovering nearby, the astronauts practice the procedures they’ll need so that it’s second nature by the time they get into orbit. (NASA astronaut Mike Massimino once told Universe Today that one thing he wasn’t prepared for was how spectacular the view was during his spacewalk. Guess it beats the walls of a pool.)
The first tests for the Apollo 11 underwater simulations began at a pool run by Comex, a deep diving specialist in France, before the big show took place in the Mediterranean Sea off Marseille on Sept. 4. The crew members used tools similar to the Apollo 11 astronauts to pick up soil samples from the ground.
ESA astronaut Jean-François Clervoy collecting a rock sample underwater off the coast of Marseille, France. He was simulating the Apollo 11 mission underwater to prepare for future missions to the Moon, Mars or an asteroid. Credit: Alexis Rosenfeld
“Comex will make me relive the underwater operations of [Neil] Armstrong on the moon, but with an ESA-Comex scuba suit and European flag,” Clervoy wrote in French on Twitter on June 4, several weeks ahead of the mission.
And ESA promises there is more to come: “Further development for planetary surface simulations in Europe will be co-financed by the EU [European Union] as part of the Moonwalk project,” the agency wrote.
Clervoy isn’t the only European astronaut working in water these days. Starting Tuesday (Sept. 9), Andreas Mogensen and Thomas Pesquet joined an underwater lab as part of a five-person crew. Called Space Environment Analog for Testing EVA Systems and Training (SEATEST), it also includes NASA astronauts Joe Acaba and Kate Rubins, as well as Japanese Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi.
JAXA astronaut Soichi Noguchi underwater during the September 2013 SEATEST mission in the Atlantic Ocean about seven miles from Key Largo, Fla. Credit: Soichi Noguchi (Twitter)
“The crew will spend five days in Florida International University’s Aquarius Reef Base undersea research habitat, conducting proof-of-concept engineering demonstrations and refining techniques in team communication. Additional test objectives will look at just-in-time training applications and spacewalking tool designs,” NASA stated on Sept. 6.
“We made it to Aquarius n [sic] did our first “spacewalk” today. From the ocean floor to space: Aquanaut to Astronaut. It is quite the adventure,” Acaba wrote on Twitter on Sept. 10. He walked twice in space on shuttle mission STS-119 in March 2009.
And a few days ago, ESA astronauts Alexander Gerst and Reid Wiseman, both bound for the station in 2014, were doing underwater training in the Neutral Buoyancy Laboratory. “Worked with @astro_reid in the pool today, and guess who we met?”, Gerst said on Twitter Sept. 5 while posting this picture below.
“Worked with @astro_reid [ESA astronaut Reid Wiseman] in the pool today, and guess who we met?” joked ESA astronaut Alexander Gerst on Twitter on Sept. 5, 2013. Presumably the joke referred to the protagonist in WALL-E, a 2008 Pixar-animated film that features space exploration. Credit: Alexander Gerst/Twitter
An artist's conception of the European Space Agency's ExoMars rover, scheduled to launch in 2018. Credit: ESA
Signs of life on the Martian surface would still be visible even after bacteria were zapped with a potentially fatal dose of radiation, according to new research — if life ever existed there, of course.
Using “model” bacteria expected to resemble what microbes could look like on the Red Planet, the research team used a Raman spectrometer — an instrument type that the ExoMars rover will carry in 2018 — to see how the signal from the bacteria change as they get exposed to more and more radiation.
The bottom line is the study authors believe the European Space Agency rover’s instrument would be capable of seeing bacteria on Mars — from the past or the present — if the bacteria were there in the first place.
Readings from the NASA Mars Curiosity rover recently found that humans on the surface of Mars would have a higher risk of cancer due to the increased radiation level on the surface. Mars does not have a global magnetic field to deflect radiation from solar flares, nor a thick atmosphere to shelter the surface.
The new study still found the signature of life in these model microbes at 15,000 Gray of radiation, which is thousands of times higher than the radiation dose that would kill a human. At 10 times more, or 150,000 Gray, the signature is erased.
ExoMars 2016 Mission to the Red Planet. It consists of two spacecraft – the Trace Gas Orbiter (TGO) and the Entry, Descent and Landing Demonstrator Module (EDM) which will land. Credit: ESA
“What we’ve been able to show is how the tell-tale signature of life is erased as the energetic radiation smashes up the cells’ molecules,” stated Lewis Dartnell, an astrobiology researcher at the University of Leicester who led the study.
Specifically, the spectrometer detected carotenoid molecules, which can be used to protect a microorganism against difficult conditions in the environment. The research teams stated that these cartenoids have been proposed as “good biosignatures of life” on Mars.
This image shows a river that sprang from a past glacier from an unnamed crater in Mars’ middle latitudes. Credit: NASA/JPL/MSSS
“In this study we’ve used a bacterium with unrivaled resistance to radiation as a model for the type of bacteria we might find signs of on Mars. What we want to explore now is how other signs of life might be distorted or degraded by irradiation,” Dartnell added. “This is crucial work for understanding what signs to look for to detect remnants of ancient life on Mars that has been exposed to the bombardment of cosmic radiation for very long periods of time.”
Many scientists believe flowing water existed on the planet, though, based on rock findings from three NASA rovers and the appearance of channels, streams and perhaps even oceans as spotted by orbiting satellites. Some scientists say the atmosphere of Mars was much thicker in the past, but it then dissipated for reasons that are still being investigated. Water, however, does not necessarily point to life.
The dark material in Becquerel crater on Mars might have come from a volcanic eruption. Credit: ESA/DLR/FU Berlin (G. Neukum)
At first glance, it looks like somebody dropped a huge paint can on Mars, spilling black stuff all over Becquerel crater. That dark material, however, is likely blown from another location on the Red Planet. It could even be volcanic eruption remnants, the European Space Agency says.
A set of stunning new images of the spot in the Arabia Terra region — which straddles the so-called “transition zone” between the north and south regions of the planet — reveal a combination of probable effects from wind, water and perhaps even the tilt of the axis of Mars. These pictures came courtesy of ESA’s Mars Express, which is orbiting the planet.
The crater — named after French physicist Antoine Henri Becquerel, a co-discoverer of radioactivity — is 103 miles (167 kilometers) in diameter and sinks 2.2 miles (3.5 km) below the rest of the area. This depression might have held water at some point.
“The mound rises about 1 km [0.62 miles] above the crater floor and comprises hundreds of layers of light-toned sediments, each just a few metres thick, made of sulphate-bearing rocks,” ESA stated. “On Earth, sulphates are most often formed via the evaporation of water, so the presence of these minerals in Becquerel crater suggests that water may once have pooled here in a vast crater lake, before evaporating away.”
This view of Becquerel Crater on Mars shows the effects of wind on the Red Planet. Credit: ESA/DLR/FU Berlin (G. Neukum)
The mystery of Mars’ missing water is one that is still puzzling scientists — NASA’s Spirit, Curiosity and Opportunity rovers all found rocks that likely formed in the presence of water, and several spacecraft have spotted features that appear to be similar to riverbeds or perhaps even oceans.
“One popular theory is that large changes in the tilt of the rotational axis of Mars leads to significant changes in its climate, reflected in the thickness and repeating patterns found in the layers of sediment,” ESA added. “A change in the environmental conditions would affect the way in which the sediments were initially deposited, as well as their subsequent resistance to erosion.”
Speaking of sediments, the image above shows the dark material extending far beyond the crater walls, a sign of powerful winds on the Red Planet. Now who’s tempted to go down there with a shovel to see what’s underneath?
As a point of trivia, another spot in Arabia Terra (Vernal Crater) was once considered a possible landing site for Mars Curiosity because scientists found evidence of ancient hot springs on the Red Planet. On Earth, these locations are usually filled with bacterial life.
The topography of Becquerel crater on Mars. Credit: ESA/DLR/FU Berlin (G. Neukum)
Safety in spaceflight comes from working the procedures in training so often that responses become automatic, says German astronaut Alexander Gerst, shown here during spacewalk training. Credit: NASA
Routines. They tell you when to get up in the morning, what to do at your day job and how to handle myriad tasks ranging from house cleaning to using a computer. Memorizing these procedures makes it a lot easier to handle things that come up in life.
In space, establishing routines is even more important because they will help guide your thinking during an emergency. That’s why astronauts spend thousands of hours learning, simulating and memorizing before heading up to space.
European Space Agency astronaut Alexander Gerst, who will fly to the International Space Station in 2014 during Expedition 40/41, gave Universe Today some insight on how it’s done.
Why train so often? According to Gerst, practicing an emergency procedure on the ground makes it easier to think clearly during a situation up in space. An astronaut’s reaction to any problem on station — a fire, a depressurization, toxic air — is to begin with the procedures. “They sink in and become a memorized response or a natural reaction,” he said. In a fire situation, for example, “Immediately when you hear the sound of the alarm, I will grab the nearest gas mask and the nearest emergency book and head to our control post, which is part of the emergency response.” (Chris Cassidy, a former Navy SEAL on station right now, had more to say to Universe Today in March about “muscle memory” during emergencies.)
European Space Agency astronauts Alexander Gerst (left) and Samantha Cristoforetti in Russian Orlan spacesuits during training in 2012. Credit: GCTC
What’s the biggest challenge? The complexity of the station. The American and Russian sides have different procedures and different equipment. There are three types of gas masks on station, for example, and three kinds of fire extinguishing systems. (According to Gerst, all but the most stubborn fires on station are extinguished after cutting ventilation and electricity to the affected area.) To address the complexity, the astronauts spend hours in the classroom discussing what to look for in the fire sensors, pressure sensors, ammonia sensors and other parts of the vehicle. The signatures look different for depressurizations, fires and other conditions in space and it’s key to know what they mean at a glance.
What happens during a simulation? After discussing what actions to take, it’s time to play them out. “We don’t light our modules on fire, but the trainers are creative in creating that [emergency] condition,” Gerst said. Sometimes smoke machines will be used during a fire simulation, for example, or the astronauts will simply be informed by instructors that there is a fire in a section of the station. As the astronauts go through the procedures, trainers keep an eye on them and give feedback. In more complex situations, 10 to 20 flight controllers can join in to simulate communications with Mission Control in Houston or its equivalent in Russia.
ESA astronaut Alexander Gerst (left) and NASA astronaut Gregory Reid Wiseman (middle) during training at NASA’s Johnson Space Center. Credit: ESA–S. Corvaja
What about dealing with emergencies in a smaller spacecraft? Astronauts can spend anywhere from hours to days on a Russian Soyuz getting to and from the station. If there’s a fire on board, the three people squashed inside the capsule wouldn’t have much room to deploy fire extinguishers. The response is essentially for astronauts to slam shut the visors on their spacesuits and vent the spacecraft. During a depressurization, the procedure is also to close the visor. “You don’t even have to get out of your seat to deal with the emergency, which makes it quite different,” Gerst said.
What about emergencies during a spacewalk? Astronauts spend hundreds of hours inside the Neutral Buoyancy Laboratory in Houston, a huge pool with a mockup of most of the International Space Station inside. They practice spacewalk procedures such as how to bring an unconscious crew member back to the airlock, or what to do if air leaks out of a spacesuit. Gerst credits this sort of training for helping out during a recent incident involving fellow ESA astronaut Luca Parmitano. In July, emergency procedures kicked in for real when Parmitano’s spacesuit sprung a water leak during a spacewalk. In a nutshell, the crew worked to bring Parmitano back inside as quickly as possible, which led to a safe (but early) end to the work. (Read Parmitano’s nail-biting first-hand account of the incident here.)
What’s the big takeaway? Gerst emphasizes that emergency training is a “huge topic”. He and Reid Wiseman recently got checked out for emergency procedures on the United States side of the station, only to fly to Moscow and then have to do the same thing for the Russian side in mid-August. And there’s other training to do as well — another huge topic is medical emergencies , which Gerst practiced in a German hospital in July.
A subsurface spacecraft prototype is deliberately slammed into 10 tonnes of ice in a rocket facility. Credit: European Space Agency/YouTube (screenshot)
If you want to get inside a planet or moon fast, the European Space Agency says lobbing a spacecraft at the surface might be a good approach.
This concept may sound like suicide. A recent prototype test, however, shows the spacecraft structure is mostly okay. Next step is figuring out what can survive on the inside.
ESA, like NASA and other agencies, isn’t afraid to test out new landing concepts if they suit better than the traditional ones (which use rockets and/or parachutes to land a spacecraft softly on the surface). Witness the Curiosity rover’s “seven minutes of terror” concept as a successful example.
Imagine that you want to look at water below the surface of Mars, or (like the people in Europa Report) you wish to plumb into the ice of Jupiter’s moon, Europa. One option could be a drill. Another one could be a subsurface spacecraft.
“One benefit over landers and rovers is that penetrators provide access to the subsurface without the need for additional drilling or digging,” ESA stated.
To test this out, engineers put 12 solid-propellant boosters on to a 44-pound (20 kilogram) prototype and fired it at almost the speed of sound at sea level: 1,118 feet a second (341 meters/second). (More technical details on the test).
The 1.5-second test, shown in the video, saw the prototype careening into 10 tonnes of ice at a deceleration of 24,000 times the force of gravity. Astronauts, by contrast, usually only withstand 3-4 g when going into space.
The scuffed and dented spacecraft was retrieved successfully, and now ESA is reviewing how well the internal structure held up in the chaos. They also plan to develop battery and communications systems that could somehow survive intact.
High-speed tests are not only useful for spacecraft landings, but also for meteor simulations.
Most meteors are comet dust striking at the atmosphere at speeds so high, they vaporiz in a blaze of light. This is a meteor from the Leonid shower in 2001. Credit: Bob King
An article in Wired recently covered the progress of the NASA Ames Vertical Gun range in its nearly 50 years of operation.
“Though it’s called a gun, the facility doesn’t look much like any firearm you’ve ever seen,” wrote Adam Mann. “The main chassis is a long metal barrel as thick as a cannon mounted on an enormous red pole that forks at the end into two legs.”
Tagus Valles on Mars. Credit: ESA/DLR/FU Berlin (G. Neukum)
Don’t let the dry appearance of the Martian desert region near Tagus Valles fool you. Some pictures snapped by the European Space Agency’s Mars Express shows there was plenty of water in that area of the Red Planet in the past. The pictures show yet another example of how water once shaped the planet, as scientists try to figure out when and how it disappeared.
“This region is one of many that exposes evidence of the Red Planet’s active past, and shows that the marks of water are engraved in even the most unlikely ancient crater-strewn fields,” ESA stated.
The unnamed region, which is just a few degrees south of the Martian equator, partially caught scientists’ attention because of that crater you see in the top left of the image. (A closer view is below.)
Deformation in a crater that was once flooded on Mars. Credit: ESA/DLR/FU Berlin (G. Neukum)
“Numerous landslides have occurred within this crater, perhaps facilitated by the presence of water weakening the crater walls,” ESA stated. “Grooves etched into the crater’s inner walls mark the paths of tumbling rocks, while larger piles of material have slumped en masse to litter the crater floor.”
Scientists saw evidence of mesas (flat-topped blocks) and yardangs, which were both features that were built from sediments that a regional flood once deposited there. The lighter bits have eroded away, but you can still see the leftovers.
There also is evidence of volcanic activity, as there was ash scattered around the area. Scientists guess the origin was the Elysium volcanic region to the northeast.
This image shows 20 of the quenched galaxies — galaxies that are no longer forming stars — seen in the Hubble COSMOS observations. Each galaxy is identified by a crosshair at the centre of each frame. Quenched galaxies in the distant Universe are much smaller than those seen nearby. It was thought that these small galaxies merged with other smaller, gas-free galaxies to grow bigger, but it turns out that larger galaxies were "switching off" at later times and adding their numbers to those of their smaller and older siblings, giving the mistaken impression of individual galaxy growth over time. Credit: NASA, ESA, M. Carollo (ETH Zurich)
Are you ready for a new galactic puzzle? Then let’s start with some clues. It has been long assumed that some galaxies reach a point in their evolution when star formation stops. In the distant past, these saturated galaxies appeared smaller than those formed more recently. This is what baffles astronomers. Why do some galaxies continue to grow if they are no longer forming stars? Thanks to some very astute Hubble Space Telescope observations, a team of astronomers has found what appears to be a rather simple explanation. Which came first? The chicken or the egg?
Until now, these diminutive, turned-off galaxies were theorized to continue to grow into the more massive, saturated galaxies observed closer to us. Because they no longer have active star-forming regions, it was assumed they gained their extra mass by combining with other smaller galaxies – ones five to ten times less in overall size. However, for this theory to be plausible, it would take a host of small galaxies to be present for the saturated population to consume… and it’s just not happening. Because we simply did not have the data available about such a large number of galaxies, it was impossible to count and identify potential candidates, but the Hubble COSMOS survey has provided an eight billion year look at the cosmic history of turned-off galaxies.
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“The apparent puffing up of quenched galaxies has been one of the biggest puzzles about galaxy evolution for many years,” says Marcella Carollo of ETH Zurich, Switzerland, lead author on a new paper exploring these galaxies. “No single collection of images has been large enough to enable us to study very large numbers of galaxies in exactly the same way — until Hubble’s COSMOS,” adds co-author Nick Scoville of Caltech, USA.
According to the news release, the team utilized a large set of COSMOS images – the product of close to a 1,000 hours of observations and consisting of 575 over-lapped images taken with the Advanced Camera for Surveys (ACS) . Needless to say, it was one of the most ambitious projects ever undertaken by Hubble. The HST data was combined with additional observations from Canada-France-Hawaii Telescope and the Subaru Telescope to look back to when the Universe was about half its present age. This huge data set covered an area of sky almost nine times the size of the full Moon! The saturated – or “quenched” – galaxies present at that age were small and compact… and apparently remained in that state. Instead of getting larger as they evolved, they kept their small size – apparently the same size they were when star-formation ceased. Yet, these galaxy types appear to be gaining in girth as time passes. What gives?
“We found that a large number of the bigger galaxies instead switch off at later times, joining their smaller quenched siblings and giving the mistaken impression of individual galaxy growth over time,” says co-author Simon Lilly, also of ETH Zurich. “It’s like saying that the increase in the average apartment size in a city is not due to the addition of new rooms to old buildings, but rather to the construction of new, larger apartments,” adds co-author Alvio Renzini of INAF Padua Observatory, Italy.
If eight billion years teaches us anything, it teaches us that we don’t know everything…. and sometimes the most simple of answers could be the correct one. We knew that actively star-forming galaxies were far less massive in the early Universe and that explains why they were smaller when star-formation turned off.
“COSMOS provided us with simply the best set of observations for this sort of work — it lets us study very large numbers of galaxies in exactly the same way, which hasn’t been possible before,” adds co-author Peter Capak, also of Caltech. “Our study offers a surprisingly simple and obvious explanation to this puzzle. Whenever we see simplicity in nature amidst apparent complexity, it’s very satisfying,” concludes Carollo.
Curiosity On the Road to Mount Sharp and treacherous Sand Dunes - Sol 338 - July 19. Curiosity captured this panoramic view of the path ahead to the base of Mount Sharp and potentially dangerous sand dunes after her most recent drive on July 19, 2013. She must safely cross over the dark dune field to climb and reach the lower sedimentary layers of Mount Sharp. Credit: NASA/JPL-Caltech/Ken Kremer-(kenkremer.com)/Marco Di Lorenzo
Curiosity On the Road to Mount Sharp and treacherous Sand Dunes – Sol 338 – July 19
Curiosity captured this panoramic view of the path ahead to the base of Mount Sharp and potentially dangerous sand dunes after her most recent drive on July 19, 2013. She must safely cross over the dark dune field to climb and reach the lower sedimentary layers of Mount Sharp. Stowed robotic arm on rover deck seen at center.
See JPL traverse map below pinpointing the view from this location
Credit: NASA/JPL-Caltech/Ken Kremer-(kenkremer.com)/Marco Di Lorenzo[/caption]
NASA’s state-of-the-art Curiosity Mars rover is stepping up the driving pace and rolling relentlessly across alien Martian terrain towards the towering mystery mountain known as Mount Sharp that’s holds the keys to the Red Planets past evolution and whether its an abode for Life.
To uncover the latest scoop on the robots otherworldly adventures, Universe Today conducted an exclusive interview with the Curiosity Project Manager Jim Erickson, of NASA’s Jet Propulsion Laboratory (JPL).
In Part 2 of my conversation with Jim Erickson we’ll discuss more about the rover’s traverse across alien territory that’s simultaneously a science gold mine and a potential death trap, as well as Comet ISON and nighttime observations and science planning.
“When Comet ISON is in the sky I’m sure we’ll do some observations of it depending on when its visible,” Erickson told me.
Today, July 20, is Sol 339 of the rovers mission to Mars. And also the 44th anniversary of the 1st human Moonwalks in 1969.
And Curiosity just drove another 34 meters yesterday, Sol 338 (July 19) – for a total distance exceeding 1.1 kilometers.
Curiosity’s Traverse Map Through Sol 338
This map shows the route driven by NASA’s Mars rover Curiosity through Sol 338 of the rover’s mission on Mars (July 19, 2013). Numbering of the dots along the line indicate the sol number of each drive. North is up. The scale bar is 200 meters (656 feet). From Sol 337 to Sol 338, Curiosity had driven a straight line distance of about 122.90 feet (32.59 meters). The base image from the map is from the High Resolution Imaging Science Experiment Camera (HiRISE) in NASA’s Mars Reconnaissance Orbiter. Image Credit: NASA/JPL-Caltech/Univ. of Arizona
As for Martian sand dunes, they dunes offer both exciting opportunities and lurking dangers to the rovers well being.
Indeed fields of Martian sand dunes are potential death traps and the six wheeled rover has no choice but to traverse across an extensive dune field as she closes in on the base of Mount Sharp
Recall that NASA’s now long lived Opportunity rover nearly perished rather early in her mission at the ‘Purgatory’ dune field on Meridiani Planum.
Spirit died after more than six highly productive years on the Red Planet when she was unable to escape a hidden sand trap she had accidentally fallen wheels deep into as the vehicle was merrily roving beside an eroded volcano at Gusev Crater on the approach to the mysterious Von Braun mound.
So, dunes are serious business
Here is Part 2 of my interview with Jim Erickson.
Ken Kremer: Which direction is Curiosity headed? Will she be following the southwest route shown in the ellipse on the JPL map – see traverse map below – or reinvestigate any other spots nearer the landing site first?
Jim Erickson: We have a good general idea. We will be on a general heading of southwest, not west which would have taken us back near the landing site [at Bradbury Landing].
Curiosity Route Map From ‘Glenelg’ to Mount Sharp
This map shows where NASA’s Mars rover Curiosity landed in August 2012 at “Bradbury Landing”; the area where the rover worked from November 2012 through May 2013 at and near the “John Klein” target rock in the “Glenelg” area; and the mission’s next major destination, the entry point to the base of Mount Sharp. Credit: NASA/JPL-Caltech/Univ. of Arizona
Ken: So the rover will not pass by the Hottah outcrop of concretions formed in water and investigated early in the mission?
Jim Erickson: No. The intent for the ellipse [shown on the map] is that we will be traveling in it to get to an area where the sand dunes look better for crossing [to the base of Mount Sharp]. When we get there we will know reality. And we will pick a safe spot to cross.
The dunes can be both an issue or in some cases easy sailing.
My experience on MER [Spirit & Opportunity] was that when you are going with the dunes, down a trough, they tend to be well packed and that was great driving.
But if you need to make a right turn, that can be a challenge for a couple of reasons. It is harder to see what is inside the next trough. And you have to drive to the top of the dune. So your driving is limited until you can see what’s inside the next dune.
Level ground is more straightforward. You know exactly what to look for if the terrain doesn’t change the next day. So you can do the same thing you did last night based on the new set of images.
If the terrain is changing then it gets more complicated.
Ken: Will you be straddling the dunes or driving alongside some safe distance away?
Jim Erickson: We have been going through various options of different planned routes. At some point we have to go with the dune directions.
So we’ll be traveling down some troughs later on. We will definitely have to pick our way through them.
Part of it is gaining experience in this new area of Mars with how the sand dunes and troughs themselves actually are.
So we’ll have to wait and see. We know we’ll have to deal with the dunes. Depending on how these dunes act we may have to do different things compared to MER.
Ken: What’s the health status of Curiosity?
Jim Erickson: We’re doing great. There are always active things we are looking at.
We had the anomaly before conjunction and have put in place a number of software mitigations and reconfigured the A side memory so that we can work around the hardware problem that happened. If we have another problem, both the A and B side memory can handle it gracefully, unlike the last time.
Ken: Describe the rover’s power situation? And the ability to do nighttime observations like the recent imagery of Phobos rising?
And certainly will be able to do nighttime observations.
Ken: What’s the plan for observations of Comet ISON?
Jim Erickson: When we get to the point when Comet ISON is in the sky I’m sure we’ll do some observations of it, depending on the time period when its visible.
Note: NASA’s Curiosity and Opportunity rovers will have a view of ISON in October with Oct. 1, 2013, being the comet’s closest approach to Mars.
NASA’s Directory of Planetary Science Jim Green told me previously that NASA is very interested in using its orbiting and surface assets at Mars to study Comet ISON. It’s a once in a lifetime opportunity.
Early October 2013 will be the prime viewing time for ISON from the vicinity of the Red Planet.
Let’s hope that NASA’s quartet of spacecraft and ESA’s lone orbiter capture some breathtaking imagery and science observations.
Ken: About the recent Phobos nighttime images, a Universe Today reader asked whether the other points of light beside Phobos were stars or hot pixels?
Jim Erickson: The specks are hot pixels [not stars], intensified by the long exposure times for the image.
Video Caption: ‘Phobos Rising’ – This movie clip shows Phobos, the larger of the two moons of Mars, passing overhead, as observed by Curiosity in a series of images centered straight overhead starting shortly after sunset on June 28, 2013. Phobos first appears near the lower center of the view and moves toward the top of the view. The apparent ring is an imaging artifact. The other bright spots are hot pixels – not stars. Credit: NASA/JPL-Caltech
Ken: How about the prospects for science along the way to the mountain?
Jim Erickson: We expect to do science along the way to Mount Sharp, for example in terms of atmospheric measurements.
We will stop at some preplanned sites. Exactly which ones is still being debated by the scientists.
And we’ll do the right thing – If we see something spectacular along the way. Just because we may not have identified it previously, that doesn’t mean we won’t stop and examine it.
Things are going very well, says Erickson.
Erickson has worked in key positions on many NASA planetary science missions dating back to Viking in the 1970’s. These include the Galileo mission to Jupiter, both MER rovers Spirit & Opportunity, as well as a stint with the Mars Reconnaissance Orbiter (MRO).
I’ll have more upcoming from Jim about Curiosity’s Martian drilling activities.
As of today (July 20) Curiosity has driven nine times since leaving the Glenelg/Yellowknife Bay area on July 4 (Sol 324), totaling nearly 300 meters.
This photomosic shows NASA’s Curiosity departing at last for Mount Sharp- her main science destination. Note the wheel tracks on the Red Planet’s surface. The navcam camera images were taken on July 4, 2013 (Sol 324). Credit: NASA/JPL-Caltech/Ken Kremer (kenkremer.com)/Marco Di LorenzoMount Sharp inside Gale Crater – is the primary destination of NASA’s Curiosity rover mission to Mars. Curiosity landed on the right side of the mountain as shown here, near the dune field colored dark blue. Mount Sharp dominates Gale Crater. It is 3.4 mile (5.5 km) high. Gale Crater is 154 km wide. This image was taken by the High Resolution Stereo Camera (HRSC) of ESA’s Mars Express orbiter. Credit: ESA/DLR/FU Berlin (G. Neukum)
ALMA/Spitzer image of a monster star in the process of forming
Even though it comprises over 99% of the mass of the Solar System (with Jupiter taking up most of the rest) our Sun is, in terms of the entire Milky Way, a fairly average star. There are lots of less massive stars than the Sun out there in the galaxy, as well as some real stellar monsters… and based on new observations from the Atacama Large Millimeter/submillimeter Array, there’s about to be one more.
Early science observations with ALMA have provided astronomers with the best view yet of a monster star in the process of forming within a dark cloud of dust and gas. Located 11,000 light-years away, Spitzer Dark Cloud 335.579-0.292 is a stellar womb containing over 500 times the mass of the Sun — and it’s still growing. Inside this cloud is an embryonic star hungrily feeding on inwardly-flowing material, and when it’s born it’s expected to be at least 100 times the mass of our Sun… a true stellar monster.
The location of SDC 335.579-0.292 in the southern constellation of Norma (ESO, IAU and Sky & Telescope)
The star-forming region is the largest ever found in our galaxy.
“The remarkable observations from ALMA allowed us to get the first really in-depth look at what was going on within this cloud,” said Nicolas Peretto of CEA/AIM Paris-Saclay, France, and Cardiff University, UK. “We wanted to see how monster stars form and grow, and we certainly achieved our aim! One of the sources we have found is an absolute giant — the largest protostellar core ever spotted in the Milky Way.”
SDC 335.579-0.292 had already been identified with NASA’s Spitzer and ESA’s Herschel space telescopes, but it took the unique sensitivity of ALMA to observe in detail both the amount of dust present and the motion of the gas within the dark cloud, revealing the massive embryonic star inside.
“Not only are these stars rare, but their birth is extremely rapid and their childhood is short, so finding such a massive object so early in its evolution is a spectacular result.”
– Team member Gary Fuller, University of Manchester, UK
The image above, a combination of data acquired by both Spitzer and ALMA (see below for separate images) shows tendrils of infalling material flowing toward a bright center where the huge protostar is located. These observations show how such massive stars form — through a steady collapse of the entire cloud, rather than through fragmented clustering.
SDC 335.579-0.292 seen in different wavelengths of light.
“Even though we already believed that the region was a good candidate for being a massive star-forming cloud, we were not expecting to find such a massive embryonic star at its center,” said Peretto. “This object is expected to form a star that is up to 100 times more massive than the Sun. Only about one in ten thousand of all the stars in the Milky Way reach that kind of mass!”
(Although, with at least 200 billion stars in the galaxy, that means there are still 20 million such giants roaming around out there!)
!["Worked with @astro_reid [ESA astronaut Reid Wiseman] in the pool today, and guess who we met?" joked ESA astronaut Alexander Gerst on Twitter on Sept. 5, 2013. Presumably the joke referred to the protagonist in WALL-E, a 2008 Pixar-animated film that features space exploration. Credit: Alexander Gerst/Twitter](https://www.universetoday.com/wp-content/uploads/2013/09/NBL_shot.jpg)
