Mysteries in Nili Fossae

ESA - Mars Express Mission patch.

22 January 2015

Nili Fossae

These new images from the high-resolution stereo camera on ESA’s Mars Express show Nili Fossae, one of the most enticing regions on Mars. This ‘graben system’ lies northeast of the volcanic region of Syrtis Major on the northwestern edge of the large Isidis impact basin – and intriguing hints of methane have been seen here.

Grabens are blocks of land that have fallen between parallel faults, sometimes forming rift valleys. The graben system in Nili Fossae contains numerous troughs oriented concentrically around the edges of an impact basin, as can be seen in the context map.

Nili Fossae in context

The easternmost of these troughs is partially visible at the lower left of the images. It is perhaps most obvious as a depression in the topography map from Mars Express.

The graben is most likely associated with the formation of the Isidis impact basin. Flooding of the basin with basaltic lava may have resulted in subsidence, which added stress to the planet’s crust and was then released through fracturing and trough formation.

Nili Fossae topography

Mars Express and other spacecraft have shown that the region displays a fascinating mineral diversity, drawing the attention of many planetary scientists. The minerals include phyllosilicates (clays), carbonates and opaline silica. These indicate a diverse history for this area resulting from the huge geological and tectonic forces that have been at play.

Perspective view of Nili Fossae

Water has played an important role here, too. The visible trough’s flanks are very steep (see the topography map) and some layered materials can be spotted at the walls. On the plateau, several depressions can be observed. Some of them appear to extend into the trough and show a resemblance to small ‘sapping valleys’.

Sapping valleys develop when groundwater removes material from underneath the surface. This gradually relocates the spring line further upstream, carving a valley in the process.

 Nili Fossae in 3D

The images also contain evidence for percolating hydrothermal fluids in the subsurface of the region. A large, 55 km-diameter impact crater with a central pit is clearly seen in the main colour, topography and 3D images. The pit is believed to have been excavated when water or ice, trapped below the surface, was rapidly heated by the impact that shaped the crater. The sudden heating caused a violent steam explosion that either weakened the rocky surface, leading to its collapse, or it may even have blasted it away, leaving the rocky hole and rocky debris.

Mars Express

In addition to the variety of interesting geological features, Nili Fossae is of particular interest because it is a site where atmospheric methane may have been detected by Earth-based telescopes. Methane may be produced here, but its origin remains mysterious, and could be geological or perhaps even biological.

There is certainly a huge amount to study here. Nili Fossae was on the shortlist of landing sites for NASA’s Curiosity rover, even though ultimately the choice was made to send the robotic explorer to Gale Crater.

More about...:

Looking at Mars: http://www.esa.int/Our_Activities/Space_Science/Mars_Express

Mars Express overview: http://www.esa.int/Our_Activities/Space_Science/Mars_Express_overview

Mars Express 10 year brochure: http://esamultimedia.esa.int/multimedia/publications/BR-312/

Related links:

High Resolution Stereo Camera: http://berlinadmin.dlr.de/Missions/express/indexeng.shtml

Behind the lens...: http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Behind_the_lens

Frequently asked questions: http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Frequently_asked_questions

ESA Planetary Science archive (PSA): http://www.rssd.esa.int/PSA

NASA Planetary Data System: http://pds-geosciences.wustl.edu/missions/mars_express/hrsc.htm

HRSC data viewer: http://hrscview.fu-berlin.de/

In depth:

Mars Express in depth: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=9

Mars Express top 10 discoveries: http://sci.esa.int/jump.cfm?oid=51820

Mars Express blog: http://blogs.esa.int/mex/

Mars Webcam: http://blogs.esa.int/vmc

Images, Text, Credits: ESA/Alex Lutkus/DLR/FU Berlin, CC BY-SA 3.0 IGO/NASA MGS MOLA Science Team.

Greetings, Orbiter.ch

Telescope To Seek Dust Where Other Earths May Lie

Large Binocular Telescope Interferometer (LBTI) logo.

January 20, 2015

The NASA-funded Large Binocular Telescope Interferometer, or LBTI, has completed its first study of dust in the "habitable zone" around a star, opening a new door to finding planets like Earth. Dust is a natural byproduct of the planet-formation process, but too much of it can block our view of planets.

The findings will help in the design of future space missions that have the goal of taking pictures of planets similar to Earth, called exo-Earths.

"Kepler told us how common Earth-like planets are," said Phil Hinz, the principal investigator of the LBTI project at the University of Arizona, Tucson, referring to NASA's planet-hunting Kepler mission, which has identified more than 4,000 planetary candidates around stars. "Now we want to find out just how dusty and obscured planetary environments are, and how difficult the planets will be to image."

Image above: The Large Binocular Telescope at Mt. Graham, Arizona. Image Credit: Large Binocular Telescope Observatory.

The new instrument, based at the Large Binocular Telescope Observatory at the top of Mount Graham in southeastern Arizona, will obtain the best infrared images yet of dust permeating a star's habitable zone, the region around the star where water -- an essential ingredient for life as we know it -- could pool on a planet. Earth sits comfortably within our sun's habitable zone, hence its glistening surface of oceans.

Scientists want to take pictures of exo-Earths and break up their light into a rainbow of colors. This color information is displayed in plots, called spectra, which reveal chemical clues about whether a planet could sustain life. But dust -- which comes from colliding asteroids and evaporating comets -- can outshine the feeble light of a planet, making this task difficult.

"Imagine trying to view a firefly buzzing around a lighthouse in Canada from Los Angeles," said Denis Defrère of the University of Arizona, lead author of the new study that appears in the Jan. 14 issue of the Astrophysical Journal. "Now imagine that fog is in the way. The fog is like our stardust. We want to eliminate the stars with fog from our list of targets to study in the future."

A previous NASA project, called the Keck Interferometer, had a similar task of seeking out this dust, finding good news for planet hunters: The stars they observed didn't seem to be all that dusty on average. LBTI is taking the research a step further, more precisely quantifying the amount of dust around stars. It will be 10 times more sensitive than the Keck Interferometer, and is specially designed to target a star's inner region -- its sweet spot, the habitable zone.

The new study reports LBTI's first test observations of stardust, in this case around a mature, sun-like star called eta Corvi known to be unusually dusty. According to the science team, this star is 10,000 times dustier than our own solar system, likely due to a recent impact between planetary bodies in its inner regions. The surplus of dust gives the telescope a good place to practice its dust-detecting skills.

Image above: The Large Binocular Telescope Interferometer (LBTI) instrument set its eyes on a dusty star system called Eta Corvi, depicted here in this artist's concept. Recent collisions between comets and rocky bodies within the star system are thought to have generated the surplus of dust. Image Credit: NASA/JPL-Caltech.

The results showed the telescope works as intended, but also yielded a surprise: The dust was observed to be significantly closer to the star than previously thought, lying between the star and its habitable zone. NASA's Spitzer Space Telescope has previously estimated the dust to be farther out, based on models of the size of the dust grains.

"With LBTI, we can really see where the dust is," said Hinz. "This star is a not a good candidate for direct imaging of planets, but it demonstrates what LBTI is good for: We are figuring out the architecture of planetary systems in a way that has not been done before."

LBTI will begin its official science operations this spring, and will operate for at least three years. One of the project's goals is to find stars 10 times less dusty than our solar system -- the good candidates for planet imaging. These survey results will inform designs and strategies for upcoming exo-Earth imaging missions now in early planning stages. The journey to find worlds ripe for life begins in part by following a trail of dust.

LBTI is funded by NASA Headquarters. It is managed by the agency's Jet Propulsion Laboratory, Pasadena, California, for NASA's Exoplanet Exploration Program office, and operated by the University of Arizona. The Large Binocular Telescope Observatory is operated by an international collaboration among institutions in the United States, Italy and Germany. JPL is a division of the California Institute of Technology in Pasadena.

The Astrophysical Journal paper is online at: http://iopscience.iop.org/0004-637X/799/1/42/article

For more information about Large Binocular Telescope Interferometer (LBTI), visit: http://lbti.as.arizona.edu/LBTI/index.html and http://www.jpl.nasa.gov/missions/large-binocular-telescope-interferometer-lbti/

Images (mentioned), Text, Credits: NASA/JPL/Whitney Clavin.

Greetings, Orbiter.ch

Telescope on NASA’s SDO Collects Its 100-Millionth Image

NASA - Solar Dynamics Observatory (SDO) patch.

Jan. 20, 2015

On Jan. 19, 2015, at 12:49 p.m. EST, an instrument on NASA's Solar Dynamics Observatory captured its 100 millionth image of the sun. The instrument is the Atmospheric Imaging Assembly, or AIA, which uses four telescopes working parallel to gather eight images of the sun – cycling through 10 different wavelengths -- every 12 seconds.

Image above: The Atmospheric Imaging Assembly on NASA's Solar Dynamics Observatory captured its 100 millionth image of the sun on Jan. 19, 2015. The dark areas at the bottom and the top of the image are coronal holes -- areas of less dense gas, where solar material has flowed away from the sun. Credit: NASA/SDO/AIA/LMSAL.

Between the AIA and two other instruments on board, the Helioseismic Magnetic Imager and the Extreme Ultraviolet Variability Experiment, SDO sends down a whopping 1.5 terabytes of data a day. AIA is responsible for about half of that. Every day it provides 57,600 detailed images of the sun that show the dance of how solar material sways and sometimes erupts in the solar atmosphere, the corona.

Image above: Processed image of SDO multiwavelength blend from Jan. 19, 2015, the date of the spacecraft's 100th millionth image release. Image Credits: NASA/SDO.

In the almost five years since its launch on Feb. 11, 2010, SDO has provided images of the sun to help scientists better understand how the roiling corona gets to temperatures some 1000 times hotter than the sun's surface, what causes giant eruptions such as solar flares, and why the sun's magnetic fields are constantly on the move.

Images above: This image shows an early SDO image (2010) and SDO's 100th millionth image (2015). Images Credits: NASA/SDO.

In honor of the 100 millionth image, Dean Pesnell, SDO's project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland and Karel Schrijver, the AIA principal investigator at Lockheed Martin in Palo Alto, California, chose some of their favorite images produced by SDO so far.

Related Links:

NASA's SDO website: http://www.nasa.gov/sdo

How SDO gathers images: http://www.nasa.gov/content/goddard/why-nasa-studies-the-ultraviolet-sun/

View "100 million images" mosaic: http://www.nasa.gov/content/goddard/100-millionth-image-from-sdos-aia-mosaic/

SDO Images: Scientists' Picks: http://www.nasa.gov/content/goddard/sdo-telescope-collects-its-100-millionth-image/index.html#lowerAccordion-set1-slide7

Images (mentioned), Text, Credits: NASA's Goddard Space Flight Center/Karen C. Fox.

Cheers, Orbiter.ch

SolarImpulse - First Round-The-World Solar Flight

SolarImpulse - Around the World patch.

20 January 2015

After the Solar Impulse prototype’s 8 world records, when it became the first solar airplane ever to fly through the night, between two continents, and across the United States, it is time for Bertrand Piccard and André Borschberg to move on to the final phase of the adventure: the 2015 round-the-world flight.

Image above: From Abu Dhabi to the first solar flight around the world, the route map.

What better way to demonstrate the importance of the pioneering, innovatory spirit than by achieving “impossible” things with renewable energy and highlighting new solutions for environmental problems?

Image above: SI2 has 17'248 solar cells, powering four 17,4hp electric motor.

The route: Si2 will take-off from Abu Dhabi, capital of the United Arab Emirate, in late February or early March and return by late July or early August 2015. The route includes stops in Muscat, Oman; Ahmedabad and Varanasi, India; Mandalay, Myanmar; and Chongqing and Nanjing, China. After crossing the Pacific Ocean via Hawaii, Si2 will fly across the Continental U.S.A. stopping in three locations – Phoenix, and New York City at JFK. A location in the Midwest will be decided dependent on weather conditions. After crossing the Atlantic, the final legs include a stop-over in Southern Europe or North Africa before arriving back in Abu Dhabi. Solar Impulse unveiled the flight path in Abu Dhabi alongside partner representatives. This included main partners Solvay, Omega, Schindler and ABB. They were also joined by official partners Altran, Bayer, Google, Swiss Re Corporate Solutions, Swisscom and Moët Hennessy alongside Solar Impulse’s host partner Masdar, Abu Dhabi’s renewable energy company.

Image above: SI2 is a single-seater airplane, for one pilot to live in for flight of 120 hours!

A great historic first: for such an adventure, as for any premiere, there are no references. We were, and will be, faced with a number of challenges, leading us to push the limits of technological, human and piloting performance.

For more information about SolarImpulse, visit: http://www.solarimpulse.com/

Images, Text, Credit: SolarImpulse.

Best regards, Orbiter.ch

Two new planets to the bottom of the solar system?

Astronomy - Astrophysics logo.

January 19, 2015

British and Spanish scientists have discovered that at least two stars could be "hidden" behind Neptune, they argue in a study.

The solar system could contain more planets than expected

The solar system could house two additional planets, according to British and Spanish researchers deduct the unexpected trajectory of the various objects observed behind Neptune suffer the influence of the unknown planets.

In 2006, the International Astronomical Union withdrew Pluto's planet status given its small size which relates now to the category of dwarf planets, dropping the number of planets in the solar system to eight.

A debate for decades

This has not stopped the debate stirred astronomers around the world for decades: other planets exist beyond Pluto?

In a study published in the journal "Monthly notices of the Royal astronomical society letters" the researchers provide "at least two planets" are hidden behind Neptune.

"Unexpected orbital parameters"

The researchers based their particular deduction on the study of the orbital behavior of a dozen extreme Trans-Neptunian Objects (ETNO).

They have "unexpected orbital parameters" that "suggest that unseen forces affect their orbital distribution," said astrophysicist Carlos de la Fuente Marcos, the agency of Spanish scientific information Sinc.

Neptune

Number unknown

"We believe that the most likely explanation is that other unknown planets exist beyond Neptune and Pluto," said the researcher at the Complutense University of Madrid and co-author of the study with scientists from the University of Cambridge.

"Their exact number is unknown, because our data are limited, but our calculations suggest that there are at least two planets, and probably more, on the borders of our solar system," he added.

A possible revolution in astronomy

The authors of the study, however, recognize that their theory contradicts the currently accepted model of the formation of the solar system, according to which there are no other planets in circular orbit behind Neptune.

Moreover, the calculations are based on the study of a small number of objects, but researchers ensure that other results will be published in the coming months, broadening the sample. "If confirmed, our findings could revolutionize astronomy," considers Mr. Marcos Fuente.

Related link:

Monthly notices of the Royal astronomical society letters: http://mnras.oxfordjournals.org/

Images, Text, Credits: AFP/Wikimedia/NASA&ESA Hubble/Translation: Orbiter.ch Aerospace.

Cheers, Orbiter.ch

Dawn Delivers New Image of Ceres

NASA - Dawn Mission patch.

January 19, 2015

Animation above: The Dawn spacecraft observed Ceres for an hour on Jan. 13, 2015, from a distance of 238,000 miles (383,000 kilometers). A little more than half of its surface was observed at a resolution of 27 pixels. This animated GIF shows bright and dark features.Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI.

As NASA's Dawn spacecraft closes in on Ceres, new images show the dwarf planet at 27 pixels across, about three times better than the calibration images taken in early December. These are the first in a series of images that will be taken for navigation purposes during the approach to Ceres.

Over the next several weeks, Dawn will deliver increasingly better and better images of the dwarf planet, leading up to the spacecraft's capture into orbit around Ceres on March 6. The images will continue to improve as the spacecraft spirals closer to the surface during its 16-month study of the dwarf planet.

"We know so much about the solar system and yet so little about dwarf planet Ceres. Now, Dawn is ready to change that," said Marc Rayman, Dawn's chief engineer and mission director, based at NASA's Jet Propulsion Laboratory in Pasadena, California.

Image above: This is a raw image, taken Jan. 13, 2015, showing the dwarf planet Ceres as seen from the Dawn spacecraft on its approach. Dawn's framing camera took this image at 238,000 miles (383,000 kilometers) from Ceres. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR.

The best images of Ceres so far were taken by NASA's Hubble Space Telescope in 2003 and 2004. This most recent images from Dawn, taken January 13, 2015, at about 80 percent of Hubble resolution, are not quite as sharp. But Dawn's images will surpass Hubble's resolution at the next imaging opportunity, which will be at the end of January.

"Already, the [latest] images hint at first surface structures such as craters," said Andreas Nathues, lead investigator for the framing camera team at the Max Planck Institute for Solar System Research, Gottingen, Germany.

Ceres is the largest body in the main asteroid belt, which lies between Mars and Jupiter. It has an average diameter of 590 miles (950 kilometers), and is thought to contain a large amount of ice. Some scientists think it's possible that the surface conceals an ocean.

Image above: This processed image, taken Jan. 13, 2015, shows the dwarf planet Ceres as seen from the Dawn spacecraft. The image hints at craters on the surface of Ceres. Dawn's framing camera took this image at 238,000 miles (383,000 kilometers) from Ceres Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

Dawn's arrival at Ceres will mark the first time a spacecraft has ever visited a dwarf planet.

"The team is very excited to examine the surface of Ceres in never-before-seen detail," said Chris Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles. "We look forward to the surprises this mysterious world may bring."

The spacecraft has already delivered more than 30,000 images and many insights about Vesta, the second most massive body in the asteroid belt. Dawn orbited Vesta, which has an average diameter of 326 miles (525 kilometers), from 2011 to 2012. Thanks to its ion propulsion system, Dawn is the first spacecraft ever targeted to orbit two deep-space destinations.

JPL manages the Dawn mission for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. The University of California at Los Angeles (UCLA) is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Virginia, designed and built the spacecraft. UCLA is responsible for overall Dawn mission science. The Dawn framing cameras were developed and built under the leadership of the Max Planck Institute for Solar System Research, Gottingen, Germany, with significant contributions by German Aerospace Center (DLR), Institute of Planetary Research, Berlin, and in coordination with the Institute of Computer and Communication Network Engineering, Braunschweig. The Framing Camera project is funded by the Max Planck Society, DLR, and NASA/JPL. The Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.

More information about Dawn is online at http://dawn.jpl.nasa.gov.

Images (mentioned), Animation (mentioned), Text, Credit: NASA.

Greetings, Orbiter.ch

A stormy shape-shifter

ESA - Venus Express Mission patch.

19 January 2015

Venus Express snaps swirling vortex

This ghostly puff of smoke is actually a mass of swirling gas and cloud at Venus’ south pole, as seen by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) aboard ESA’s Venus Express spacecraft.

Venus has a very choppy and fast-moving atmosphere – although wind speeds are sluggish at the surface, they reach dizzying speeds of around 400 km/h at the altitude of the cloud tops, some 70 km above the surface. At this altitude, Venus’ atmosphere spins round some 60 times faster than the planet itself. This is very rapid; even Earth’s fastest winds move at most about 30% of our planet’s rotation speed. Quick-moving Venusian winds can complete a full lap of the planet in just four Earth days.

Polar vortices form because heated air from equatorial latitudes rises and spirals towards the poles, carried by the fast winds. As the air converges on the pole and then sinks, it creates a vortex much like that found above the plughole of a bath. In 1979, the Pioneer Venus orbiter spotted a huge hourglass-shaped depression in the clouds, some 2000 km across, at the centre of the north polar vortex. However, other than brief glimpses from the Pioneer Venus and Mariner 10 missions in the 1970s, Venus’ south pole had not been seen in detail until ESA’s Venus Express first entered orbit in April 2006.

Visiting Venus

One of Venus Express’ first discoveries, made during its very first orbit, was confirming the existence of a huge atmospheric vortex circulation at the south pole with a shape matching the one glimpsed at the north pole.

This south polar vortex is a turbulent mix of warming and cooling gases, all surrounded by a ‘collar’ of cool air. Follow-up Venus Express observations in 2007, including this image, showed that the core of the vortex changes shape on a daily basis. Just four hours after this image the vortex looked very different and a day later it had morphed into a squashed shape unrecognisable from the eye-like structure here.

A video of the vortex, made from 10 images taken over a period of five hours, can be seen bellow. The vortex rotates with a period of around 44 hours.

Close-up view of south polar vortex

The swirling region shown in this VIRTIS image is about 60 km above the planet’s surface. Venus’ south pole is located just up and to the left of the image centre, slightly above the wispy ‘eye’ itself.

This image was obtained on 7 April 2007 at a wavelength of 5.02 micrometres. It shows thermal-infrared emission from the cloud tops; brighter regions like the ‘eye’ of the vortex are at lower altitude and therefore hotter.

For more information about Venus Express mission, visit: http://www.esa.int/Our_Activities/Space_Science/Venus_Express

Images, Animation, Text, Credits: ESA/VIRTIS/INAF-IASF/Obs. de Paris-LESIA/Univ. Oxford/MPS/DLR/IDA, M. Pérez-Ayúcar & C. Wilson.

Best regards, Orbiter.ch