Click for Video – Reconstructing Philae’s flight
12 November 2015
One year since Philae made its historic landing on a comet, mission teams remain hopeful for renewed contact with the lander, while also looking ahead to next year’s grand finale: making a controlled impact of the Rosetta orbiter on the comet.
Rosetta arrived at Comet 67P/Churyumov–Gerasimenko on 6 August 2014, and after an initial survey and selection of a landing site, Philae was delivered to the surface on 12 November.
After touching down in the Agilkia region as planned, Philae did not secure itself to the comet, and it bounced to a new location in Abydos. Its flight across the surface is depicted in a new animation, using data collected by Rosetta and Philae to reconstruct the lander’s rotation and attitude.
In the year since landing, a thorough analysis has also now been performed on why Philae bounced.
There were three methods to secure it after landing: ice screws, harpoons and a small thruster. The ice screws were designed with relatively soft material in mind, but Agilkia turned out to be very hard and they did not penetrate the surface.
The harpoons were capable of working in both softer and harder material. They were supposed to fire on contact and lock Philae to the surface, while a thruster on top of the lander was meant to push it down to counteract the recoil from the harpoon.
Attempts to arm the thruster the night before failed: it is thought that a seal did not open, although a sensor failure cannot be excluded.
Then, on landing, the harpoons themselves did not fire. “It seems that the problem was either with the four ‘bridge wires’ taking current to ignite the explosive that triggers the harpoons, or the explosive itself, which may have degraded over time,” explains Stephan Ulamec, Philae lander manager at the DLR German Aerospace Center.
“In any case, if we can regain contact with Philae, we might consider an attempt to retry the firing.”
The reason is scientific: the harpoons contain sensors that could measure the temperature below the surface.
Despite the unplanned bouncing, Philae completed 80% of its planned first science sequence before falling into hibernation in the early hours of 15 November when the primary battery was exhausted. There was not enough sunlight in Philae’s final location at Abydos to charge the secondary batteries and continue science measurements.
The hope was that as the comet moved nearer to the Sun, heading towards closest approach in August, there would be enough energy to reactivate Philae. Indeed, contact was made with the lander on 13 June but only eight intermittent contacts were made up to 9 July.
The problem was that the increasing sunlight also led to increased activity on the comet, forcing Rosetta to retreat to several hundred kilometres for safety, well out of range with Philae.
However, over the past few weeks, with the comet’s activity now subsiding, Rosetta has started to approach again. This week it reached 200 km, the limit for making good contact with Philae, and today it dips to within 170 km.
(Click on link and read entire article for more of this fascinating story.)
Astronomy Picture of the Day
26 February 2013
Does it rain on the Sun? Yes, although what falls is not water but extremely hot plasma. An example occurred in mid-July 2012 after an eruption on the Sun that produced both a Coronal Mass Ejection and a moderate solar flare. What was more unusual, however, was what happened next. Plasma in the nearby solar corona was imaged cooling and falling back, a phenomenon known as coronal rain. Because they are electrically charged, electrons, protons, and ions in the rain were gracefully channeled along existing magnetic loops near the Sun’s surface, making the scene appear as a surreal three-dimensional sourceless waterfall. The resulting surprisingly-serene spectacle is shown in ultraviolet light and highlights matter glowing at a temperature of about 50,000 Kelvin. Each second in the above time lapse video takes about 6 minutes in real time, so that the entire coronal rain sequence lasted about 10 hours.
Video Credit: Solar Dynamics Observatory, SVS, GSFC, NASA; Music: Thunderbolt by Lars Leonhard
As spectacularly beautiful as the coronal rain is — and it is indeed, God’s marvelous handiwork that has gone on for many thousands of years with no human able to enjoy it — I am amazed at the technology that brought this video to me. The satellite observatory that holds the camera. The beams that sent the images back to earth. The scientists and administrators that decided to share these images with the world. The internet that enabled them to do it. The computer on my desk with the color screen that allows me to view it.
Daniel 12:4 “… many shall run to and fro, and knowledge shall be increased.”
Knowledge. Data. Information. Whatever is learned, discovered or invented on earth was inspired in men by God, whether or not they acknowledge it. Some of it is practical; the study of our star is quite practical in the minds of scientists. The survival of our species, our entire solar system, may depend on it.
But some is also wonderfully beautiful, great art, great music, great images of space, and of the coronal rain.
For more fascinating information and images, visit Solar Dynamics Observatory: http://sdo.gsfc.nasa.gov/
Mars Landers, April 2023
Dream of going to space but don’t feel like putting in the work to become a NASA astronaut? Here’s your chance to possibly make that fantasy come true. Mars One, a Netherlands-based nonprofit, is seeking volunteers to help colonize the Red Planet, according to Mashable.
To meet an aggressive goal of putting people on Mars by 2023, Mars One released its basic astronaut requirements on January 8. Rather than recruiting scientists or pilots, the organization says it will consider anyone, so long as they are at least 18 years old. Intelligence, good mental and physical health and dedication to the project are all pluses. Chosen candidates will undergo eight years of training prior to the launch.
“We are more concerned with how well each astronaut works and lives with the others, in the long journey from Earth to Mars and for a lifetime of challenges ahead,” the company founder, Norbert Kraft, said.
To prepare for the colony, Mars One plans to launch robotic cargo missions between 2016 and 2021. The robots will get busy assembling an outpost ahead of the space explorers’ arrival. Four humans will first land on Mars in 2023, followed by another group every two years following the trailblazers’ arrival. No human has ever gone to Mars or traveled that far, and the journey is expected to take seven months.
Mars One plans to fund their endeavors largely through a global reality television event following astronaut selection through the settlers’ first years on Mars. So far, the company says, more than 1,000 interested applicants have gotten in touch.
For people considering venturing into space, Mars One includes this obvious disclaimer:
No human space mission is without risks to human life. Mars and space are unforgiving environments where a small accident can result in large failures, injuries and death of the astronauts.
The move, by the way, is permanent. There are no plans to return the pioneers to Earth.
ScienceDaily (Nov. 20, 2012) — A metamaterial invisibility cloak that can adapt to hide different sized objects is demonstrated by in Nature Communications this week. The findings represent a useful advance for more practical applications of metamaterial cloaking. The research is led by Yonsei University, Korea.
Metamaterials have already been shown to hide objects from electromagnetic waves by manipulating the light so that it appears to have not interacted with anything. However, these cloaks need to be redesigned and rebuilt if the shape of the object changes.
Kyoungsik Kim and colleagues now present a smart metamaterial that is able to adapt to changes in the object shape, so that a range of objects may be hidden by one cloak. The cloak is based on elastic materials, which enable it to deform around the object. At the same, the deformation alters its properties to maintain invisibility.
The team build and demonstrate cloaks for objects whose height varies over around 10mm, using microwave frequency light incident for a range of angles. They report that the object remains well hidden in all cases.
These smart metamaterial cloaks provide a new avenue to explore adaptable, real-world applications of cloaking that are not limited by the objects they hide.
(This follows up previous research – see this earlier article, reported on the same Science Daily website)
Scientists Create First Free-Standing 3-D Cloak
ScienceDaily (Jan. 26, 2012) — Researchers in the US have, for the first time, cloaked a three-dimensional object standing in free space, bringing the much-talked-about invisibility cloak one step closer to reality.
Whilst previous studies have either been theoretical in nature or limited to the cloaking of two-dimensional objects, this study shows how ordinary objects can be cloaked in their natural environment in all directions and from all of an observer’s positions.
Published Jan. 26 in the Institute of Physics and German Physical Society’s New Journal of Physics, the researchers used a method known as “plasmonic cloaking” to hide an 18-centimetre cylindrical tube from microwaves.
Here’s an interesting little article from a Star Trek sci-fi fan page regarding the subject.
A cloaking device is a form of stealth technology that uses selective bending of light (and other forms of energy) to render a starship or other object completely invisible to the electromagnetic spectrum and most sensors. It has been encountered in varying forms over the centuries.
Humanity’s earliest-known encounter with cloaking technology came in the year 1986 in San Francisco. Admiral James T. Kirk decloaked the Klingon Bird-of-Prey he was commanding to waylay and frighten some whale hunters from killing two humpback whales. (Star Trek IV: The Voyage Home)
One of humanity’s earliest exposures to cloaking technology was in April of 2151, when agents of the Suliban Cabal approached the starship Enterprise undetected and kidnapped a Klingon national named Klaang from the ship’s sickbay. The Suliban used cloaking devices on many of their ships, including the cell ships, stealth-cruisers and salvage ships. The Suliban’s cloaking technology had been given to them by their mysterious benefactor from the 29th century.
Coronal hole emitting solar wind
Solar wind flowing from this coronal hole hit Earth’s magnetic field during the late hours of May 8, 2012 stirring geomagnetic activity and auroras over parts of Europe. The pair of CMEs en route to Earth (see below) could add to the effect of the solar wind stream, igniting even brighter auroras during the next 24-48 hours. NOAA forecasters estimate a 40% chance of geomagnetic storms on May 9th.
TWO INCOMING CMEs: A pair of solar eruptions on May 7th hurled coronal mass ejections (CMEs) toward Earth. Forecast tracks prepared by analysts at the Goddard Space Weather Lab suggests that clouds will arrive in succession on May 9th at 13:40 UT and May 10th at 07:54 UT (+/- 7 hours). The double impact could spark moderate geomagnetic storms. High-latitude sky watchers should be alert for auroras.
SUNSPOT SUNSET: Sunspot AR1476 is so large, people are noticing it without the aide of a solar telescope. The behemoth appears at sunrise and sunset when the light of the low-hanging sun is occasionally dimmed to human visibility.
Two M-Class Flares / Sunspot 1476
Solar activity increased to moderate levels thanks to newly numbered Sunspot 1476 (see image above). This new region rotated into view off the northeast limb and has so far produced a pair of M-Class flares. The latest event was an M1.3 at 23:01 UTC Saturday evening (May 8, 2012). Solar activity is again increasing.
Asteroid Mining Venture Backed by Google Execs, James Cameron Unveiled
by Mike Wall, SPACE.com Senior Writer
23 April 2012
The newly unveiled company with some high-profile backers — including filmmaker James Cameron and Google co-founder Larry Page — is set to announce plans to mine near-Earth asteroids for resources such as precious metals and water.
Planetary Resources, Inc. intends to sell these materials, generating a healthy profit for itself. But it also aims to advance humanity’s exploration and exploitation of space, with resource extraction serving as an anchor industry that helps our species spread throughout the solar system.
“If you look at space resources, the logical next step is to go to the near-Earth asteroids,” Planetary Resources co-founder and co-chairman Eric Anderson told SPACE.com. “They’re just so valuable, and so easy to reach energetically. Near-Earth asteroids really are the low-hanging fruit of the solar system.”
Here’s how it would work:
For more information, visit http://www.space.com/15395-asteroid-mining-planetary-resources.html