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Solar System News (miscellaneous articles)

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Draggendrop    5,747

Ices and shadows above Saturn

 

pia18355-1041.jpg

Image courtesy NASA/JPL-Caltech/Space Science Institute.

 

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Saturn's moon Tethys appears to float between two sets of rings in this view from NASA's Cassini spacecraft, but it's just a trick of geometry. The rings, which are seen nearly edge-on, are the dark bands above Tethys, while their curving shadows paint the planet at the bottom of the image.

 

Tethys (660 miles or 1,062 kilometers across) has a surface composed mostly of water ice, much like Saturn's rings. Water ice dominates the icy surfaces in the the far reaches of our solar system, but ammonia and methane ices also can be found.

 

The image was taken in visible light with the Cassini spacecraft wide-angle camera on Nov. 23, 2015. North on Tethys is up. The view was obtained at a distance of approximately 40,000 miles (65,000 kilometers) from Tethys. Image scale is 2.4 miles (4 kilometers) per pixel.

 

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

http://www.spacedaily.com/reports/Ices_and_shadows_above_Saturn_999.html

 

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Studying the Solar System with NASA's Webb Telescope

 

jwst_in_space.jpg

In addition to looking at distant stars, galaxies and exoplanets, NASA's James Webb Space Telescope will investigate our solar system. Image courtesy Northrup Grumman.

 

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NASA's James Webb Space Telescope will look across vast distances to find the earliest stars and galaxies and study the atmospheres of mysterious worlds orbiting other stars. But the observatory also will investigate objects in Earth's own neighborhood - planets, moons, comets and asteroids in our solar system. These studies will help scientists understand more about the formation of the solar system and how Earth became capable of supporting life.

 

"The James Webb Space Telescope will be an innovative tool for studying objects in the solar system and can help take planetary science to a new level," said Stefanie Milam, the Webb telescope's deputy project scientist for planetary science at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

 

Scheduled for launch in 2018, the Webb telescope will carry four science instruments to take images of and collect information about the physical characteristics and compositions of astronomical objects. Together, these instruments will cover the near- and mid-infrared parts of the spectrum, including wavelengths that are important when looking for water and other clues about the evolution and potential habitability of a planetary system.

 

From its vantage point a million miles beyond Earth, the Webb telescope will have a spectacular view of objects in the solar system. It will orbit the sun at a position called the Lagrange point 2, or L2, which will help to keep the telescope's temperature stable - instability distorts its view - and allows the large sun shield to protect the observatory from the light and heat of the sun and Earth.

 

Scientists envision using the observatory to monitor the water cycle on Mars, look at weather patterns on Saturn's moon Titan, and hunt for new rings around the giant planets. Comets could be tracked, and the water and gases they release during their journeys could be mapped. Ices and minerals could be identified on the surfaces of moons, asteroids and distant minor planets, helping researchers better understand the evolution of our solar system.

 

These and other possibilities are described in a 2016 special issue of the Publications of the Astronomical Society of the Pacific, with Milam serving as the guest editor. A total of 11 papers were contributed by authors from across the planetary science community, with Goddard scientists taking the lead on how to use the Webb telescope to study Mars, Titan and near-Earth objects.

more at the link...

http://www.spacedaily.com/reports/Studying_the_Solar_System_with_NASAs_Webb_Telescope_999.html

 

lagrange-points1.thumb.jpg.7ff69f585248e

Diagram of the Lagrange points associated with the sun-Earth system. 

Credit: NASA / WMAP Science Team

:)

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Draggendrop    5,747

NASA Says Man In India Likely Wasn't Killed By A Meteorite

 

gettyimages-509012502-126361652cc76307c7

Indian authorities inspect the site of a suspected meteorite landing that killed a bus driver and injured three others on Feb. 6.

 

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Remember the story scooting around the Internet earlier this week about a man in India who was reportedly killed by a meteorite? If you need a refresher, we wrote a post about it, creatively titled, "Did A Meteorite Kill A Bus Driver In India?"

 

Well, it turns out the answer is probably not.

 

The incident happened on a college campus in the southern state of Tamil Nadu on Saturday. There was an explosion, which also injured three other people, that reportedly left a 5-foot-deep crater and a small, blackish-blue rock behind.

 

Local officials in India were quick to blame the blast on space debris, but NASA scientists have weighed in, saying the man was not killed by anything extraterrestrial.

 

"Initial assessment based on photos posted online are not consistent with something from space," NASA spokesman Dwayne Brown said in a statement, according to ABC News. "Small meteorites do not start fires or cause explosions when they hit the ground. To form a crater the size of what has been posted online would have required a meteorite of at least several kilograms. While more details are forthcoming from local scientists, this is unlikely something from space."

 

The chief minister of the state, J. Jayalalithaa, promised compensation for the families of the driver, identified as V. Kamaraj, and for the injured people, The Times of India reported.

http://www.npr.org/sections/thetwo-way/2016/02/10/466293833/nasa-says-man-in-india-likely-wasnt-killed-by-a-meteorite

 

http://www.spacedaily.com/reports/Scientists_study_Indias_deadly_meteorite_999.html

 

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Support grows for a return to ice giants Uranus and Neptune

 

022016_icegiants_opener_free.jpg

THE OTHER BLUE PLANETS  Uranus (left) and Neptune (right) have not been visited since Voyager 2 sped by in the late 1980s. Many researchers argue that it’s time to go back.

 

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In the cold periphery of the solar system, two enigmatic sentinels saunter around the sun. One circuit along their vast orbits takes on the order of a century. Seasons are measured in decades. At such great distances from Earth, these worlds give up their secrets slowly. While every other planet in our solar system has been repeatedly poked and prodded by orbiters and landers, Neptune and Uranus, save a brief tour in the 1980s, remain largely unexplored.

 

Thirty years ago, the Voyager 2 spacecraft tore past Uranus, then flew by Neptune less than four years later. These quick sojourns introduced scientists to two planets that had been vague blue splotches in their telescopes. In the years since, bigger and better instruments have teased out a bit more information and revealed a few surprises.

 

But there’s only so much planetary scientists can learn from a couple billion kilometers away. That’s why researchers in both the United States and Europe think it’s time to go back to Uranus or Neptune — the solar system’s “ice giants.” Unlike the show-stopping flyby of Pluto in 2015, a new mission to one of the blue worlds would have more time to take in the view.

 

In August, NASA’s Jim Green gave engineers at the Jet Propulsion Laboratory in Pasadena, Calif., one year to figure out what it would take to put a spacecraft in orbit around Uranus or Neptune. These worlds are “an important frontier,” says Green, director of the Planetary Science Division at NASA headquarters in Washington, D.C. “We really don’t know much about them.” New rocket designs and recent exoplanet discoveries have made the ice giants more accessible and more relevant than ever. “This is a really exciting time for us to be able to study them,” he says.

 

The ice giants aren’t frozen orbs; they’re actually quite gassy. But Uranus and Neptune have a lot of water, ammonia and methane, which astronomers refer to as ices, whether the compounds are frozen or not. Jupiter and Saturn, by comparison, are mostly hydrogen and helium, which remain gases at nearly any temperature. The inner planets are relatively tiny balls of rock.

lots of data and images at the link....

https://www.sciencenews.org/article/support-grows-return-ice-giants-uranus-and-neptune

 

:D

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Draggendrop    5,747

Here is the NASA rendition of SpaceX posters......

 

NASA's Gorgeous New Space Tourism Posters Are Retro-Futuristic and Fantastic

 

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Between Interstellar and The Martian, NASA's enjoying a banner pop culture revival. To tap into that growing awareness of what lies before us, the space agency's Jet Propulsion Lab commissioned Seattle-based Invisible Creature to produce a series of lush retro space-tourism posters.


The work is a preview of what to expect from the JPL's 2016 Visions of the Future calendar. "The Grand Voyage," above, was inspired by '60s sci-fi paperback covers and represents how Jupiter, Saturn, Uranus and Neptune align once every 175 years. Its last alignment, which happened in 1977, enabled the JPL to take advantage of their proximity to send two probes, Voyager 1 and Voyager 2, on a path to visit all four on the same trip.

http://www.adweek.com/adfreak/nasas-gorgeous-new-space-tourism-posters-are-retro-futuristic-and-fantastic-169633

 

 

nasa-posters-earth-2016.jpg

 

 

nasa-posters-venus-2016.jpg

 

 

nasa-posters-ceres-2016.jpg

 

 

nasa_enceladus_1.jpg

 

 

 

nasa_mars_1.jpg

 

:)

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DocM    16,610

SpaceX started something with their Mars posters.

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Unobscured Vision    2,678
Quote

Support grows for a return to ice giants Uranus and Neptune

022016_icegiants_opener_free.jpg

Now we're talking. But using SLS? Hmm ... it would give weight to its' existence. Something with those capabilities would have a strong argument for getting built. Sure, we could do a New Horizons-Class probe mission to each Ice Giant, but ... that's early-2000's technology. We've got way better gear now.

 

My idea of the perfect mission would be to take a New Horizons platform then perform upgrades with the current technology. We'd likely see a very good savings in power consumption, meaning it wouldn't require as much Plutonium in the RTG to do the same job -- possibly enough to power two probes -- top off the second RTG so that it's got enough; then poof, we've got a Uranus and a Neptune mission. Draw up flight plans, add aerobraking capability to the probes (hardware and software) after simulation has it nailed down as good as possible ... you get the idea.

 

Yeah .. :yes: 

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DocM    16,610

FH could launch a hellatious probe (or dual probes) into LEO using a Raptor upper stage, then refuel it from a tanker stage for the big push. Not to mention what a BFS based vehicle, a modified tanker, could do.

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DocM    16,610

Space Safety Magazine

 

http://www.spacesafetymagazine.com/space-debris/first-fatality-caused-by-meteorite/

 

Meteorite Fatality Confirmed by Preliminary Lab

 

A meteorite that struck southern India could be the first confirmed instance of a death caused by a space rock.

On February 6, a meteorite reportedly fell in the premises of a college in Vellore district in the state of Tamil Nadu. Witnesses described an explosion that could be heard at least 3 kilometers away.  The force of the explosion severely injured Kamraj, a bus driver employed by the college, who was walking inside the campus. He later died on his way to the hospital while three other workers also sustained injuries. The meteorite shattered window panes of buses and buildings and left a four-feet deep crater. The Chief Minister of the state confirmed the fatality and announced compensation for the victims. Scientists from the Indian Institute of Astrophysics visited the site and recovered a dark bluish stone reported to weigh about 10 grams. Meanwhile, experts at NASA who examined photographs of the crater suggested that it was more consistent with a land based explosion and not a meteorite strike.

 

Now lab reports from the National College 

 

Instrumentation Facility (NCIF), an advanced laboratory set up by the Department of Science and Technology under the Central government, based in Trichy, conclude that the fragments recovered from the site came from a meteorite.  K Anbarasu, geologist and principal of the NCIF spoke to the Indian Express. He said a preliminary Scanning Electron Microscope (SEM) study conducted on small pieces of black material found near the blast site showed evidence of carbonaceous chrondites ranging in size from about 10 to 50 micrometer. It was not a common type of meteorite like an iron meteorite or stony meteorite. Only further tests will give us a detailed answer.

 

The meteorite has been named BEC-1, referring to the site and sample number, as per international standards. This is the first time that a meteorite has caused a confirmed fatality. The odds of being killed by a meteorite are very low, about 1 in 250 million. According to data from the International Comet Quarterly, a previous fatality was attributed to a meteorite, although it was never confirmed.
 

vellore-blast-story-and-fb_647_021216112

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Unobscured Vision    2,678

Bound to happen eventually.

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Draggendrop    5,747

Chelyabinsk Superbolide Mystery Continues Three Years Later

 

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On 2013 February 15 the approach of asteroid (367943) Duende to our planet was being closely monitored by both the public and the scientific community worldwide when suddenly a superbolide entered the atmosphere above the region of Chelyabinsk in Russia.

 

Three years and hundreds of published scientific studies later, we are still looking for the origin of such an unexpected visitor, which caused damage to hundreds of buildings and injuries to nearly 1,500 people. Finding the precise value of its speed as it touched the top of the atmosphere appears to be the key to determine the orbit of the parent body of the Chelyabinsk superbolide.

 

"Three years have passed since the Chelyabinsk (Russia) great scare and during this time more than two hundred research papers -- 50 in the last year -- related directly or indirectly to the 19-m wide Chelyabinsk superbolide have been published in scientific peer-review journals," explains Carlos de la Fuente Marcos, co-author of one of these research works.

 

Among these studies, there is a catalog of 960 video recordings, published by the journal Astronomy & Astrophysics, that includes material automatically recorded by security cameras, traffic cameras, and dashcams -- very popular in Russia -- installed onboard all types of vehicles, and manual recordings made with video cameras and webcams of the many accidental witnesses of the impressive phenomenon who shared their experiences on the internet.

 

The images and diverse scientific data compiled during the event have allowed the calculation of the atmospheric entry trajectory of the meteoroid, which turned into a meteor when it crossed Earth's atmosphere, exploding at a height of 20 km and releasing 500 kilotons or energy, approximately thirty times the yield of the Hiroshima nuclear bomb. The shockwave generated by such an explosion caused damage out to a distance of 75 miles breaking the windows, and even the window frames in some cases, of hundreds of buildings and injuring 1,491 people mainly due to cuts inflicted by shattered and broken glass. Approximately five tons of meteoritic material reached the ground, including the 650-kg meteorite that was recovered by divers from the bottom of Lake Chebarkul.

 

The Chelyabinsk superbolide entry took place the same day, 2013 February 15, the asteroid (367943) Duende approached the Earth. Duende (discovered originally from Spain) passed nearly 27,700 km above the Earth's surface, well inside the boundaries of the ring of geosynchronous satellites but nearly perpendicular to it as expected, 16 hours after the Chelyabinsk superbolide explosion and the fall of the large meteorite on the Russian Lake Chebarkul.

 

At the beginning, it was thought that both events could be related and that the Chelyabinsk superbolide could have come from asteroid Duende itself or from a companion of this object, but when the orbits of both objects were analyzed and spectroscopic data of both asteroid Duende and the Chelyabinsk meteoritic material were studied in detail, the results obtained indicated that the two objects were completely independent and unrelated. It was a mere, albeit very unusual, coincidence in time of two spectacular cosmic events.

more info at the link...

http://spaceref.com/asteroids/chelyabinsk-superbolide-mystery-continues-three-years-later.html

 

Meteor Hits Russia Feb 15, 2013 - Event Archive

video is 10:11 min.

This is a large compilation of media shots, along with audio from the airbursts...this thing was huge.

 

 

 

:)

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Draggendrop    5,747

Test masses floating freely in LISA Pathfinder

 

Freely_Floating_in_space_large.jpg

Freely floating in space   ESA

 

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16 February 2016
ESA’s LISA Pathfinder has released both of its gold–platinum cubes, and will shortly begin its demanding science mission, placing these test masses in the most precise freefall ever obtained to demonstrate technologies for observing gravitational waves from space.

 

Launched on 3 December, LISA Pathfinder reached its operational location on 22 January, some 1.5 million km from Earth in the direction of the Sun.

As tests on the spacecraft and its precious payload continue, a major milestone was reached today. For the first time, the two masses – a pair of identical 46 mm gold–platinum cubes – in the heart of the spacecraft are floating freely, several millimetres from the walls of their housings. The cubes sit 38 cm apart linked only by laser beams.

 

Throughout LISA Pathfinder’s ground handling, launch, the burns that raised its orbit, and the six-week cruise to its work site, each cube was held firmly in place by eight ‘fingers’ pressing on its corners.

 

On 3 February, the locking fingers were retracted and a valve was opened to allow any residual gas molecules around the cubes to vent to space.

Each cube remained in the centre of its housing held by a pair of rods softly pushing on two opposite sides.

 

The rods were finally released from one test mass yesterday and from the other today, leaving the cubes floating freely, with no mechanical contact with the spacecraft.  

 

“This is why we sent the test cubes into space: to recreate conditions that are impossible to achieve in the gravitational field of our planet,” says Paul McNamara, ESA’s project scientist.

 

“Only under these conditions is it possible to test freefall in the purest achievable form. We can’t wait to start running experiments with this amazing gravity laboratory.”

 

It will be another week before the cubes are left completely at the mercy of gravity, with no other forces acting on them. Before then, minute electrostatic forces are being applied to move them around and make them follow the spacecraft as its flight through space is slightly perturbed by outside forces such as pressure from sunlight.

more at...

http://www.esa.int/Our_Activities/Space_Science/Test_cubes_floating_freely_inside_LISA_Pathfinder

 

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Small collection of space wallpapers...some nice planetoid's

https://imgur.com/a/LOAdB

 

sample

dphvD1d.jpg

 

:)

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Draggendrop    5,747

Puzzling asteroid observations explained by destruction of asteroids close to Sun

 

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An international team composed of researchers from Finland, France, the United States and the Czech Republic originally set out to construct a state-of-the-art model of the NEO population that is needed for planning future asteroid surveys and spacecraft missions. The model describes the NEOs' orbit distribution and estimates the number of NEOs of different sizes.

 

The vast majority of NEOs originate in the doughnut-shaped main asteroid belt between the orbits of Mars and Jupiter. The orbit of a main-belt asteroid slowly changes as it is pushed by the uneven release of excess solar heat from the asteroid's surface. The asteroid's orbit eventually interacts with the orbital motions of Jupiter and Saturn changing the trajectory to bring the asteroid close to the Earth. An asteroid is classified as an NEO when its smallest distance from the Sun during an orbit is less than 1.3 times the average Earth-Sun distance.

 

The team used the properties of almost 9,000 NEOs detected in about 100,000 images acquired over about 8 years by the Catalina Sky Survey (CSS) near Tucson, Arizona, to construct the new population model. One of the most challenging problems facing the team was computing which asteroids they could actually detect. An asteroid appears as a moving point of light against a background of fixed stars but detecting it on an image depends on two factors - how bright it is and how fast it seems to be moving. If the telescope isn't looking in the right location at the right time when an asteroid is bright enough and slow enough to be detected, we simply may never find that asteroid. Accounting for these observational selection effects required a detailed understanding of the operations of the telescope and detector systems and a tremendous amount of computing time even with novel, fast mathematical techniques. The team produced the best-ever model of the NEO population by combining information about CSS's selection effects with the CSS data and theoretical models of the orbit distributions of NEOs that originate in different parts of the main asteroid belt.

 

But they noticed that their model had a problem - it predicted that there should be almost 10 times more objects on orbits that approach the Sun to within 10 solar diameters. The team then spent a year verifying their calculations before they came to the conclusion that the problem was not in their analysis but in their assumptions of how the Solar System works.

 

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Dr. Mikael Granvik, a research scientist at the University of Helsinki and lead author of the Nature article, hypothesized that their model would better match the observations if NEOs are destroyed close to the Sun but long before an actual collision. The team tested this idea and found an excellent agreement between the model and the observed population of NEOs when they eliminated asteroids that spend too much time within about 10 solar diameters of the Sun. "The discovery that asteroids must be breaking up when they approach too close to the Sun was surprising and that's why we spent so much time verifying our calculations," commented Dr. Robert Jedicke, a team member at the University of Hawai'i Institute for Astronomy.

 

The team's discovery helps to explain several other discrepancies between observations and predictions of the distribution of small objects in our Solar System. Meteors, commonly known as shooting stars, are tiny bits of dust and rock that are dislodged from the surfaces of asteroids and comets that then end their lives burning up as they enter our atmosphere. Meteors often travel in "streams" that follow the path of their parent object, but astronomers have been unable to match most of the meteor streams on orbits closely approaching the Sun with known parent objects.

 

This study suggests that the parent objects were completely destroyed when they came too close to the Sun - leaving behind streams of meteors but no parent NEOs. They also found that darker asteroids are destroyed farther from the Sun than brighter ones, explaining an earlier discovery that NEOs that approach closer to the Sun are brighter than those that keep their distance from the Sun. The fact that dark objects are more easily destroyed implies that dark and bright asteroids have a different internal composition and structure.

 

According to Granvik, their discovery of the catastrophic loss of asteroids before a collision with the Sun allows planetary scientists to understand a variety of recent observations from a new perspective but also leads to a more profound advance in asteroid science:

 

"Perhaps the most intriguing outcome of this study is that it is now possible to test models of asteroid interiors simply by keeping track of their orbits and sizes. This is truly remarkable and was completely unexpected when we first started constructing the new NEO model."

http://www.eurekalert.org/pub_releases/2016-02/uoh-pao021616.php

 

:)

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DocM    16,610

 

 

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Draggendrop    5,747
5 hours ago, DocM said:

 

 

That...would have been a jaw dropper to look up at....:D

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Draggendrop    5,747

Tethys, Enceladus and Mimas

 

ooPIA18357_ip.jpg

Tethys, Enceladus and Mimas       NASA

 

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Three of Saturn's moons -- Tethys, Enceladus and Mimas -- are captured in this group photo from NASA's Cassini spacecraft.

 

Tethys (660 miles or 1,062 kilometers across) appears above the rings, while Enceladus (313 miles or 504 kilometers across) sits just below center.

 

Mimas (246 miles or 396 kilometers across) hangs below and to the left of Enceladus.

 

This view looks toward the sunlit side of the rings from about 0.4 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 3, 2015.

 

The view was acquired at a distance of approximately 837,000 miles (1.35 million kilometers) from Enceladus, with an image scale of 5 miles (8 kilometers) per pixel. Tethys was approximately 1.2 million miles (1.9 million kilometers) away with an image scale of 7 miles (11 kilometers) per pixel. Mimas was approximately 1.1 million miles (1.7 million kilometers) away with an image scale of 6 miles (10 kilometers) per pixel.

 

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

http://spaceref.com/saturn/tethys-enceladus-and-mimas.html

 

:)

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LOC    1,165

Awesome. And to sit here wondering if there is any sort of life undear that ice on Enceladus (or any other moon besides ours obviously) really makes you think sometimes. Like, are they getting Netflix OK out there yet and what do they think of the new season of Survivor (not much if they are intelligent in any way, tee hee).

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Unobscured Vision    2,678
11 hours ago, LOC said:

Awesome. And to sit here wondering if there is any sort of life undear that ice on Enceladus (or any other moon besides ours obviously) really makes you think sometimes. Like, are they getting Netflix OK out there yet and what do they think of the new season of Survivor (not much if they are intelligent in any way, tee hee).

Nah, they're binge watching Fuller House. :rofl:

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Draggendrop    5,747

NASA's IBEX observations pin down interstellar magnetic field

 

110010_web.jpg

(Artist concept) Far beyond the orbit of Neptune, the solar wind and the interstellar medium interact to create a region known as the inner heliosheath, bounded on the inside by the termination shock, and on the outside by the heliopause. Image courtesy NASA/IBEX/Adler Planetarium.

 

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Immediately after its 2008 launch, NASA's Interstellar Boundary Explorer, or IBEX, spotted a curiosity in a thin slice of space: More particles streamed in through a long, skinny swath in the sky than anywhere else. The origin of the so-called IBEX ribbon was unknown - but its very existence opened doors to observing what lies outside our solar system, the way drops of rain on a window tell you more about the weather outside.

 

Now, a new study uses IBEX data and simulations of the interstellar boundary - which lies at the very edge of the giant magnetic bubble surrounding our solar system called the heliosphere - to better describe space in our galactic neighborhood. The paper, published Feb. 8, 2016, in Astrophysical Journal Letters, precisely determines the strength and direction of the magnetic field outside the heliosphere. Such information gives us a peek into the magnetic forces that dominate the galaxy beyond, teaching us more about our home in space.

 

The new paper is based on one particular theory of the origin of the IBEX ribbon, in which the particles streaming in from the ribbon are actually solar material reflected back at us after a long journey to the edges of the sun's magnetic boundaries. A giant bubble, known as the heliosphere, exists around the sun and is filled with what's called solar wind, the sun's constant outflow of ionized gas, known as plasma. When these particles reach the edges of the heliosphere, their motion becomes more complicated.

 

"The theory says that some solar wind protons are sent flying back towards the sun as neutral atoms after a complex series of charge exchanges, creating the IBEX ribbon," said Eric Zirnstein, a space scientist at the Southwest Research Institute in San Antonio, Texas, and lead author on the study. "Simulations and IBEX observations pinpoint this process - which takes anywhere from three to six years on average - as the most likely origin of the IBEX ribbon."

 

Outside the heliosphere lies the interstellar medium, with plasma that has different speed, density, and temperature than solar wind plasma, as well as neutral gases. These materials interact at the heliosphere's edge to create a region known as the inner heliosheath, bounded on the inside by the termination shock - which is more than twice as far from us as the orbit of Pluto - and on the outside by the heliopause, the boundary between the solar wind and the comparatively dense interstellar medium.

 

Some solar wind protons that flow out from the sun to this boundary region will gain an electron, making them neutral and allowing them to cross the heliopause. Once in the interstellar medium, they can lose that electron again, making them gyrate around the interstellar magnetic field.

If those particles pick up another electron at the right place and time, they can be fired back into the heliosphere, travel all the way back toward Earth, and collide with IBEX's detector. The particles carry information about all that interaction with the interstellar magnetic field, and as they hit the detector they can give us unprecedented insight into the characteristics of that region of space.

 

"Only Voyager 1 has ever made direct observations of the interstellar magnetic field, and those are close to the heliopause, where it's distorted," said Zirnstein. "But this analysis provides a nice determination of its strength and direction farther out."

 

The directions of different ribbon particles shooting back toward Earth are determined by the characteristics of the interstellar magnetic field. For instance, simulations show that the most energetic particles come from a different region of space than the least energetic particles, which gives clues as to how the interstellar magnetic field interacts with the heliosphere.

 

For the recent study, such observations were used to seed simulations of the ribbon's origin. Not only do these simulations correctly predict the locations of neutral ribbon particles at different energies, but the deduced interstellar magnetic field agrees with Voyager 1 measurements, the deflection of interstellar neutral gases, and observations of distant polarized starlight.

 

However, some early simulations of the interstellar magnetic field don't quite line up. Those pre-IBEX estimates were based largely on two data points - the distances at which Voyagers 1 and 2 crossed the termination shock.

 

"Voyager 1 crossed the termination shock at 94 astronomical units, or AU, from the sun, and Voyager 2 at 84 AU," said Zirnstein. One AU is equal to about 93 million miles, the average distance between Earth and the sun. "That difference of almost 930 million miles was mostly explained by a strong, very tilted interstellar magnetic field pushing on the heliosphere."

 

But that difference may be accounted for by considering a stronger influence from the solar cycle, which can lead to changes in the strength of the solar wind and thus change the distance to the termination shock in the directions of Voyager 1 and 2. The two Voyager spacecraft made their measurements almost three years apart, giving plenty of time for the variable solar wind to change the distance of the termination shock.

"Scientists in the field are developing more sophisticated models of the time-dependent solar wind," said Zirnstein.

The simulations generally jibe well with the Voyager data.

 

"The new findings can be used to better understand how our space environment interacts with the interstellar environment beyond the heliopause," said Eric Christian, IBEX program scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who was not involved in this study. "In turn, understanding that interaction could help explain the mystery of what causes the IBEX ribbon once and for all."

http://www.spacedaily.com/reports/NASAs_IBEX_observations_pin_down_interstellar_magnetic_field_999.html

 

http://www.eurekalert.org/multimedia/pub/110010.php

 

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Draggendrop    5,747

Tethys and Janus

 

oopia18356-1041.jpg

Tethys and Janus               NASA

 

Quote

Although Tethys and Janus both orbit Saturn and are both made of more or less the same materials, they are very different worlds. Their contrasts are related, in large part, to their sizes.

 

Tethys (660 miles or 1,062 kilometers across) is large enough to be spherical and to have varied geology, like chasms and smooth plains, along with some puzzling arc-shaped features (see PIA19637). Much smaller Janus (111 miles or 179 kilometers across) is irregularly shaped and has (so far) shown few signs of geologic activity apart from impact craters.

 

This view looks toward the sunlit side of the rings from about 1 degree above the ring plane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Nov. 23, 2015.

 

The view was acquired at a distance of approximately 28,000 miles (44,000 kilometers) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 54 degrees. Image scale is 1.8 miles (3 kilometers) per pixel.

 

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

http://spaceref.com/saturn/tethys-and-janus.html

 

---------------------------------

 

MAVEN Observes Mars Moon Phobos in the Mid- and Far-Ultraviolet

 

oophobos_composite.jpg

Phobos and Mars                  NASA

 

Quote

NASA scientists are closer to solving the mystery of how Mars' moon Phobos formed.

 

Phobos as observed by MAVEN's Imaging Ultraviolet Spectrograph. Orange shows mid-ultraviolet (MUV) sunlight reflected from the surface of Phobos, exposing the moon's irregular shape and many craters. Blue shows far ultraviolet light detected at 121.6 nm, which is scattered off of hydrogen gas in the extended upper atmosphere of Mars. Phobos, observed here at a range of 300km, blocks this light, eclipsing the ultraviolet sky. Credits: CU/LASP and NASA

 

In late November and early December 2015, NASA's Mars Atmosphere and Volatile Evolution (MAVEN) mission made a series of close approaches to the Martian moon Phobos, collecting data from within 300 miles (500 kilometers) of the moon.

 

Comparing MAVEN's images and spectra of the surface of Phobos to similar data from asteroids and meteorites will help planetary scientists understand the moon's origin whether it is a captured asteroid or was formed in orbit around Mars. The MAVEN data, when fully analyzed, will also help scientists look for organic molecules on the surface. Evidence for such molecules has been reported by previous measurements from the ultraviolet spectrograph on the Mars Express spacecraft.

 

The observations were made by the Imaging Ultraviolet Spectrograph instrument aboard MAVEN.

 

MAVEN's principal investigator is based at the University of Colorado's Laboratory for Atmospheric and Space Physics, and NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the MAVEN project. Partner institutions include Lockheed Martin, the University of California at Berkeley, and NASA's Jet Propulsion Laboratory.

 

For more information on MAVEN, visit: http://www.nasa.gov/maven

http://spaceref.com/mars/maven-observes-mars-moon-phobos-in-the-mid--and-far-ultraviolet.html

 

--------------------------

 

Opportunity Mars Rover Goes Six-Wheeling up a Ridge

 

ooPIA20319.jpg

View Ahead From Opportunity                      NASA

 

Quote

NASA's senior Mars rover, Opportunity, is working adeptly in some of the most challenging terrain of the vehicle's 12 years on Mars, on a slope of about 30 degrees.


Researchers are using Opportunity this month to examine rocks that may have been chemically altered by water billions of years ago. The mission's current targets of investigation are from ruddy-tinted swaths the researchers call "red zones," in contrast to tan bedrock around these zones.

The targets lie on "Knudsen Ridge," atop the southern flank of "Marathon Valley," which slices through the western rim of Endeavour Crater.

more at...

http://spaceref.com/mars/opportunity-mars-rover-goes-six-wheeling-up-a-ridge.html

 

PIA20319_ip.jpg

Knudsen Ridge                 NASA

 

Quote

This scene from NASA's Mars Exploration Rover Opportunity looks upward at "Knudsen Ridge" on the southern edge of "Marathon Valley" from inside the valley.

 

In this version of the scene the landscape is presented in enhanced color to make differences in surface materials more easily visible. Reddish rock, such as within and between the knobs near the top of the scene, is what the rover team calls "red zone" material. Red zone locations in Marathon Valley correspond to locations of clay minerals mapped from orbit. Another view of Marathon Valley red zone material is at PIA19820.

 

An approximately true color version of the Knudsen Ridge scene is at PIA20318. A stereo version is at PIA20320.

 

The informal name Knudsen Ridge was chosen by the Opportunity science team to honor the memory of Danish astrophysicist and planetary scientist Jens Martin Knudsen (1930-2005), a founding member of the team.

 

The view combines multiple images taken with the panoramic camera (Pancam) on Opportunity's mast on Oct. 29 and Oct. 30, 2015, during the 4,182nd and 4,183rd Martian days, or sols, of the rover's work on Mars. By February 2016, the rover ascended slopes of about 30 degrees onto the flank of Knudsen Ridge, headed for targets of red zone material to examine there.

 

Color in the scene comes from component images taken through three of the Pancam's color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). The view spans from southeast on the left to southwest on the right.

 

Marathon Valley cuts generally east-west through the western rim of Endeavour Crater. The valley's name refers to the distance Opportunity drove from its 2004 landing site to arrival at this location in 2014. The valley was a high-priority destination for the rover mission because observations from orbit detected clay minerals there.

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA20319

 

:D

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LOC    1,165

For the next rover or whatever they wind up sending to Mars, they should just livestream 24/7 on Earth since days here and on Mars are practically the same length compared to other bodies in the Solar System. (If I remember correctly a day on Mars like about 45 minutes longer than on Earth)

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Draggendrop    5,747

We will have a lot of activity around Mars during the 2020 and beyond. Some of the activity is covered in the ExoMars and Insight threads. Land based DSN is the present bottleneck, but upgrades, with new technology, is in the works. I also believe that we will see a communications structure from SpaceX for the Mars colonization projects.

 

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Draggendrop    5,747

This post is about 2 Mars articles, which are intertwined. The articles cover the theory about the initial growth of the huge Tharsis volcanic plain, the largest in the solar system. It appears that science is leaning towards the huge growth causing a crustal displacement and also shifting water erosion plains, and that the erosion may have been taking place during the Tharsis region buildup. This would explain erosion plain shift as well as underground water reserves being in the wrong location, due to crustal displacement.   Reminiscent of early earth crustal displacement theory. What do you guys think. Seems quite plausible with the enormous mass imbalance of the full grown Tharsis plain, which is so huge, if one where standing on the plain, it travels further than the horizon.

 

Monster volcano gave Mars extreme makeover: study

 

Quote

A volcano on Mars half the size of France spewed so much lava 3.5 billion years ago that the weight displaced the Red Planet's outer layers, according to a study released Wednesday.

 

Mars' original north and south poles, in other words, are no longer where they once were.

 

The findings explain the unexpected location of dry river beds and underground reservoirs of water ice, as well as other Martian mysteries that have long perplexed scientists, the lead researcher told AFP.

 

"If a similar shift happened on Earth, Paris would be in the Polar Circle," said Sylvain Bouley, a geomorphologist at Universite Paris-Sud.

"We'd see Northern Lights in France, and wine grapes would be grown in Sudan."

 

The volcanic upheaval, which lasted a couple of hundred million years, tilted the surface of Mars 20 to 25 degrees, according to the study.

 

The lava flow created a plateau called the Tharsis dome more than 5,000 square kilometres (2,000 square miles) wide and 12 km (7.5 mi) thick on a planet half the diameter of Earth.

 

"The Tharsis dome is enormous, especially in relation to the size of Mars. It's an aberration," Bouley said.

 

This outcropping -- upward of a billion billion tonnes in weight -- was so huge it caused Mars' top two layers, the crust and the mantle, to swivel around, like the skin and flesh of a peach shifting in relation to its pit.

 

Already in 2010, a theoretical study showed that if the Tharsis dome were removed from Mars, the planet would shift on its axis.

 

- It suddenly makes sense -

Bouley and colleagues matched these computer models with simulations and observations -- their own and those of other scientists.

 

Many things on Mars that begged explanation suddenly make sense in light of the new paradigm.

 

"Scientists couldn't figure out why the rivers" -- dry riverbeds today -- "were where they are. The positioning seemed arbitrary," Bouley told AFP.

"But if you take into account the shift in the surface, they all line up on the same tropical band."

 

Likewise the huge underground reservoirs of frozen water ice that should be closer to the poles. Once upon a time, we now know, they were.

 

The new theory also explains why the Tharsis dome is situated on the "new" equator, exactly where it would need to be for the planet to regain its equilibrium.

 

The findings, published in Nature, likewise challenge the standard chronology which assumes the Red Planet's rivers were formed after the Tharsis dome.

 

Most of these ancient waterways would have flowed from the cratered highlands of the Red Planet's southern hemisphere to the low plains of the north even without the massive lava fields, the study concluded.

 

"But there are still a lot of unanswered questions," cautioned Bouley.

 

"Did the tilt cause the magnetic fields to shut down? Did it contribute to the disappearance of Mars' atmosphere, or cause the rivers to stop flowing? These are things we don't know yet."

http://www.marsdaily.com/reports/Monster_volcano_gave_Mars_extreme_makeover_study_999.html

 

and

 

Mars' Ancient Face-Lift: Water Carved Planet's Features, Not Massive Volcano

 

mars-globe-edited.jpg?interpolation=lanc

An artist's impression of what Mars might have looked like 4 billion years ago, according to a new study.
Credit: Didier Florentz

 

Quote

The face of Mars has changed since the planet's younger days. Billions of years ago, rain or snow may have carved major valleys on Mars, just as the largest volcanic structure in the solar system was forming on the Red Planet, new research suggests.

 

Understanding how Mars has matured over the years could help explain other mysteries of the Red Planet, such as why vast ice deposits lie buried under the Martian surface far from its poles, scientists added.

 

Mars is home to Tharsis, the solar system's largest volcanic structure. This continent-size bulge near the equator in the western hemisphere of Mars is about 7.5 miles (12 kilometers) high and 3,100 miles (5,000 km) wide, and hosts giant volcanoes up to 100 times larger than any on Earth, the researchers said. [Photos of the Red Planet from Orbit]

 

Previous research found that Tharsis started forming more than 3.7 billion years ago during the Noachian period. Prior work also found that its enormous mass — about a billion billion tons, or one-seventieth the mass of Earth's moon — was enough to pivot the outermost layers of Mars over the rest of the planet, a dramatic phenomenon known as "true polar wander," which caused the locations of Mars' north and south poles to shift.

Scientists previously found that many valleys on the Red Planet that formed by the end of the Noachian period more than 3.5 billion years ago were strangely oriented the same way as each other. The timing of the formation of these valleys and Tharsis suggested that Tharsis' effects on the hard rocky shell of Mars — its lithosphere — might have somehow influenced the directions in which these valleys ran, researchers said.

 

However, researchers now suggest that falling rain or snow helped carve these valley networks.

 

"We finally understand why the rivers formed where we see their dry beds today," the study's lead author, Sylvain Bouley, a planetary scientist at the University of Paris-Sud in Orsay, France, told Space.com.

 

The scientists carried out computer simulations to reconstruct how the Martian surface looked before, during and after the formation of Tharsis. They found that Tharsis would not have warped the Martian surface in ways that would explain the directions in which these valley networks formed.

 

mars-magnetic-poles-chronology.JPG?14569

A chronology of Mars' shifting magnetic poles, based on new research. Left image text: Formation of the dichotomy, Heavy bombardment, Adjustment of the polar axis. Middle image text: Tharsis formation, Tropical precipitation with valley networks formation. Right image text: Tharsis formation causes a TPW, Valley networks on a small circle, Tharsis bulge on the equator.
Credit: Sylvain Bouley

 

Quote

To help solve the mystery behind the orientation of these valleys, the researchers noted that these valley networks occur in a band that runs around Mars. This circle is tilted with respect to the Martian equator.

 

The researchers suggest this circle of valleys originally lay parallel to and southward of the Martian equator. Their models suggest that substantial rainfall or snowfall in the tropical regions of Mars could have led to rivers that ran southward mostly parallel to each other, cutting valleys into the rock of Mars during the birth and growth of the Tharsis bulge. Later, during true polar wander, the position of this band of valley networks shifted, making it tilted with respect to the current equator of Mars.

 

These new findings suggest that these valley networks were born about the same time as Tharsis, instead of after Tharsis' formation, as previous research proposed. This in turn suggests that Mars' atmosphere was cold and substantially denser than it is today, which could have led to snowfall that helps explain why the Red Planet has giant ice deposits buried far from its poles, Bouley said.

 

The scientists detailed their findings online today (March 2) in the journal Nature.

http://www.space.com/32128-mars-ancient-facelift-carved-by-water.html

 

:D

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Unobscured Vision    2,678

WOW! :D

 

That's so fascinating! Who would have ever believed that the Tharsis Complex could have wrought such havoc? The ultimate demonstration of centrifugal force ... yikes. Never occurred to me that it could affect an entire planet.

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LOC    1,165

Tharsis you say? Cannibals in space! (I hope some of you get that reference, its still new!)

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Draggendrop    5,747

Cosmochemists find evidence for unstable heavy element at solar system formation

 

110329_web.jpg

Origins Lab, University of Chicago

 

Image description

 

Quote

This close-up picture shows a ceramic-like refractory inclusion (pink inclusion) still embedded into the meteorite in which it was found. Refractory inclusions are the oldest-known rocks in the solar system (4.5 billion years old). Analysis of the uranium isotope ratios of such inclusions demonstrates that a long-lived isotope of the radioactive element curium was present in the solar system when this inclusion was formed. The inclusion measures 1.5 centimers (.59 inches) in length.

Main article excerpt...

 

Quote

University of Chicago scientists have discovered evidence in a meteorite that a rare element, curium, was present during the formation of the solar system. This finding ends a 35-year-old debate on the possible presence of curium in the early solar system, and plays a crucial role in reassessing models of stellar evolution and synthesis of elements in stars. Details of the discovery appear in the March 4 edition of Science Advances.

 

Quote

"Curium is an elusive element. It is one of the heaviest-known elements, yet it does not occur naturally because all of its isotopes are radioactive and decay rapidly on a geological time scale," said the study's lead author, François Tissot, UChicago PhD'15, now a W.O. Crosby Postdoctoral Fellow at the Massachusetts Institute of Technology.

 

And yet Tissot and his co-authors, UChicago's Nicolas Dauphas and Lawrence Grossman, have found evidence of curium in an unusual ceramic inclusion they called "Curious Marie," taken from a carbonaceous meteorite. Curium became incorporated into the inclusion when it condensed from the gaseous cloud that formed the sun early in the history of the solar system.

 

Curious Marie and curium are both named after Marie Curie, whose pioneering work laid the foundation of the theory of radioactivity. Curium was only discovered in 1944, by Glenn Seaborg and his collaborators at the University of California, Berkeley, who, by bombarding atoms of plutonium with alpha particles (atoms of helium) synthesized a new, very radioactive element.

In depth article at the link...great read

http://www.eurekalert.org/pub_releases/2016-03/uoc-cfe030216.php

 

:D

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Draggendrop    5,747

China's lunar probe sets record for longest stay

 

china-lunar-rover-yutu-from-lander-chang

File image of the Yutu rover.

 

Quote

Chang'e-3, China's first lunar lander, has been operating on the moon for over two years, the longest time for an active probe, according to a Chinese scientist.

 

The probe has exceeded its operational life of one year and has been in service for 15 extra months since landing on the moon on Dec. 14, 2013.

 

"It seems that Chang'e-3 will continue to keep working," said Ye Peijian, chief scientist with the Chang'e-3 program.

 

The State Administration for Science, Technology and Industry for National Defense (SASTIND) announced on Feb. 18 that Chang'e-3 had woken automatically after hibernating for the lunar night, and had entered its 28th lunar day.

 

Its astronomical telescope and other surveying devices are still working well, SASTIND said.

 

Lunar rover Yutu, which hitched a ride with Chang'e-3, was designed to operate for six months.

 

"Now, because of a mechanical control abnormality, Yutu is immobile. The defect also affected the solar panels that cover the rover during the lunar night to protect it from the harsh temperatures. Despite the panels not working, Yutu still continues to collect and sent data to Earth thanks to its innovative temperature control system," said Ye.

 

China has shared the data collected by Chang'e-3 probe with the world, helping scientists understand more about the moon and space, Ye said.

http://www.spacedaily.com/reports/Chinas_lunar_probe_sets_record_for_longest_stay_999.html

 

-------------------

 

China to use data relay satellite to explore dark side of moon

 

chang-e-1-china-lunar-lg.jpg

Chang'e 1 in orbit above the Moon (artwork)

 

Quote

China will launch a data relay satellite to ensure communication between Earth and the lunar probe during an expedition to the far side of the moon, Ye Peijian, chief scientist with China's lunar exploration program, said Tuesday.

 

China in January announced plans to send the Chang'e-4 probe to the dark side of the moon around 2018. Due to gravitational forces, this part of the moon is not visible to Earth and has never been explored by humans. The data relay satellite will be launched six months before the probe.

 

Earth can contact Chang'e-4 with the help of a "communication station" on the Lagrange point L2 of the Earth-moon system, 80,000 kilometers away from the moon, according to Ye.

 

"The moon is too small to block the signal transmission between Earth and the data relay satellite," said Ye.

 

Chang'e-1 mission in 2007 began the era of China's lunar exploration, the launch of the Chang'e-2 and Chang'e-3 followed soon after. The latter marked completion of the second phase of China's lunar program, which includes orbiting, landing and returning to Earth.

 

Chang'e-3 delivered a rover and stationary lander to the moon in 2013, making China the third country after the Soviet Union and the United States to carry out such a mission.

 

China is preparing for its next lunar probe mission, Chang'e-5, which is expected to be launched around 2017.

 

The probe will be tasked with landing on the moon, collecting samples and returning to Earth.

http://www.space-travel.com/reports/China_to_use_data_relay_satellite_to_explore_dark_side_of_moon_999.html

 

It's nice to see them maintaining an interest in the moon and they share their data with the scientific community.

:D

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