Wednesday, April 30, 2014

Volcanic Plume Over Southern Atlantic Ocean Revealed Through False-Colour Imagery

Image Credit: Jeff Schmaltz /MODIS Land Rapid Response Team, NASA GSFC

The South Sandwich Islands, in the far southern Atlantic Ocean, are often shrouded with thick cloud, making it difficult to view the region from space.

Sometimes, however, the use of false-colour imagery can be used to reveal events that would otherwise be obscured under cloud cover.

The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite flew over the South Sandwich Islands on April 19, 2014 and acquired this false-colour image of the cloudy scene.

This false-colour image uses a combination of non-visible (middle infrared and infrared) and visible (red) light captured in bands 7, 2, and 1, respectively, to distinguish clouds from snow and ice.

Here the ice-covered islands appear bright turquoise, the clouds light turquoise and the water in the ocean appears deep black.

Because the volcanic plume is a moist mixture of gas and ash, it reflects all three forms of light relatively well, so it appears nearly white.

In the north of this image, a thin plume of white rises from the volcano on Zavodovski island, the northernmost of the South Sandwich Islands and streams to the northeast.

Further south, a wider white plume can be seen blowing across the Atlantic Ocean.

This plume rises from the Mount Michael volcano, which is a young and frequently active stratovolcano located on Saunders Island, near the center of the South Sandwich Island chain.

The white plume from Mount Michael forms a chain of swirling eddies as it blows to the northeast.

To the south, similar eddies can be seen behind three other islands. These are known as Von Kármán vortices.

These vortices can form nearly anywhere that fluid flow is disturbed by an object. Because the atmosphere behaves like a fluid, when streaming air hits a blunt object, such as a mountain peak, the wind is forced around the object.

The disturbance in the flow of the wind propagates downstream in a double row of vortices that alternate their direction of rotation, much like the eddies seen behind a pier in a river as water rushes past.

ESA Vega VV03 Launch: DZZ-HR satellite Payload

Vega liftoff on flight VV03. 

Credit: Arianespace

The third launch by Europe's new small launcher, Vega, has delivered Kazakhstan's first satellite for high-resolution Earth observation into its planned orbit.

Liftoff of flight VV03 from Europe's Spaceport in Kourou, French Guiana came at 01:35 GMT on 30 April (03:35 CEST; 22:35 local time on 29 April).

The DZZ-HR satellite was released into the target Sun-synchronous circular orbit at 750 km altitude and an inclination of 98.54º precisely 55 minutes and 29 seconds after launch.

This satellite feeds a complete range of civilian applications for the Republic of Kazakhstan. The high-resolution images will be used for mapping, monitoring natural and agricultural resources, and search and rescue during natural disasters.

KazEOSat-2, as it will be named once in its operational orbit, was built by EADS Airbus Defence and Space and is expected to operate for more than 7 years.

Vega's payload mass for this launch was 918 kg, of which 830 kg was the satellite.

Vega is a 30 m-high, four-stage vehicle designed to accommodate between 300 kg and 2.5 tonnes of payload depending on the orbit and altitude.

A flawless maiden flight in February 2012 was followed in May 2013 by the first of the 'Verta' flights to prove the system's flexibility.

Vega flight VV03 liftoff replay. Credit: ESA/CNES/Arianespace

On its second mission, Vega delivered three satellites into two different orbits and then, to help keep space clean, safely disposed of the upper stage to burn up high in the atmosphere over the ocean, a complex mission sequence made possible by the flexibility of the upper stage and the Vespa multisatellite adapter.

Through this launch, Vega has entered into commercial exploitation and is being operated in conjunction with the heavy-lift Ariane 5 and medium-lift Soyuz rockets at Europe's Spaceport to provide a full range of services meeting the varied demands of the launchers market.

ESA: Phobos Occults

Credit: ESA/DLR/FU Berlin (G. Neukum)

Mars' moon Phobos has already been extensively observed – this image is just one example, taken in 2009 – so its occultation of ESA Mars Express on 28 April 2014 is not expected to yield dramatic discoveries.

But science lies in the smallest things – like obtaining a 'snapshot in time' of continuous change.

The occultation meant that, for a brief time, Phobos passed between ESA Mars Express and Earth, blocking the spacecraft's radio signal.

The break in the signal was small – about nine seconds – but the precise start and end times are valuable information.

These will allow scientists to calculate the orbit of Phobos with great precision – specifically the mean distance from Mars, which is notoriously difficult to pin down because Phobos' natural motion around the planet changes over time.

Phobos and sister moon Deimos are formidable scientific enigmas.

There is no confirmed theory of their origin that offers a satisfactory explanation for their current orbits and appearances.

They could be excellent targets for future robotic landings.

ESA experts analysed yesterday's data from the tracking station and found the occultation to have started just before 01:08:24 GMT, lasting until shortly before 01:08:33 GMT.

Now, we'll know the orbit of Phobos with just a little more precision, at least for a while.

ESA Herschel Observatory: Researchers discover young galaxies not behaving as predicted

The young galaxy SDSS090122.37+181432.3. It is distorted because of gravitational lensing. 

Credit: NASA/STScI; S. Allam and team; and the Master Lens Database (, L. A. Moustakas, K. Stewart, et al (2014).

New Herschel Space Observatory findings have given scientists a remarkable insight into the internal dynamics of two young galaxies.

Surprisingly, they have shown that just a few billion years after the big bang, some galaxies were rotating in a mature way, seemingly having completed the accumulation of their gas reservoirs.

When galaxies form, they accumulate mass by gravitationally attracting vast, external gas clouds. As the gas clouds are consumed by the galaxy, they fall into haphazard orbits.

These disordered paths cause turbulence in the host galaxies, which can drive star formation.

James Rhoads
To investigate the internal conditions of forming galaxies, James Rhoads and Sangeeta Malhotra, both from Arizona State University, and colleagues targeted two young galaxies, known as SDSS0901 and the Clone.

The light from both galaxies has taken 10 billion years to reach us across space. Thus, we are seeing them when they were comparatively young.

Rhoads studies galaxy formation, galaxy evolution and the reionization of intergalactic hydrogen by early galaxies.

Malhotra's research ranges from properties of dust and gas in the (relatively nearby) interstellar medium to some of the farthest known galaxies.

Sangeeta Malhotra
In recent years they have also collaborated on finding and characterizing galaxies in the cosmic dawn, when the universe was less than a billion years old.

The current project focuses on a somewhat later time, the high noon of star formation in the universe – a time when the universe was about 3 billion years old, and when star birth in galaxies was much more active than it is today.

"The purpose of this project is to study the physical conditions of gas in those galaxies. We wanted to know: 'Are they similar to the galaxies around us, or is there some difference in their physical conditions?'" says Rhoads.

The two galaxies they choose to study are average galaxies for that time in cosmic history. This means that they are about 10 to 20 percent the size of our Milky Way, which is considered an average galaxy in the present-day universe.

Studying galaxies so far away is usually challenging because they appear too dim to study effectively, but in this case, the researchers were helped by a cosmic mirage known as a gravitational lens.

The two galaxies both sit behind intervening groups of galaxies, whose gravity warps space.

As described by Albert Einstein's General Theory of Relativity, this warping acts like a lens.

Although it distorts the images of the young galaxies, it helps by magnifying their light, thus bringing them within reach of ESA Herschel's HIFI instrument.

Read the full article here

Cosmic Web Imager: Observes 'dim matter'

This is a comparison of the Lyman alpha blob observed with the Cosmic Web Imager and a simulation of the cosmic web based on theoretical predictions. 

Credit: Christopher Martin, Robert Hurt

Caltech astronomers have taken unprecedented images of the intergalactic medium (IGM), the diffuse gas that connects galaxies throughout the universe, with the Cosmic Web Imager, an instrument designed and built at Caltech.

Until now, the structure of the IGM has mostly been a matter for theoretical speculation.

However, with observations from the Cosmic Web Imager, deployed on the Hale 200-inch telescope at Palomar Observatory, astronomers are obtaining our first three-dimensional pictures of the IGM.

The Cosmic Web Imager will make possible a new understanding of galactic and intergalactic dynamics, and it has already detected one possible spiral-galaxy-in-the-making that is three times the size of our Milky Way.

Chris Martin
The Cosmic Web Imager was conceived and developed by Caltech professor of physics Christopher Martin.

"I've been thinking about the intergalactic medium since I was a graduate student," says Martin. "Not only does it comprise most of the normal matter in the universe, it is also the medium in which galaxies form and grow."

Since the late 1980s and early 1990s, theoreticians have predicted that primordial gas from the Big Bang is not spread uniformly throughout space, but is instead distributed in channels that span galaxies and flow between them.

This "cosmic web"(IGM) is a network of smaller and larger filaments crisscrossing one another across the vastness of space and back through time to an era when galaxies were first forming and stars were being produced at a rapid rate.

Martin describes the diffuse gas of the IGM as "dim matter," to distinguish it from the bright matter of stars and galaxies, and the dark matter and energy that compose most of the universe.

Though you might not think so on a bright sunny day or even a starlit night, fully 96 percent of the mass and energy in the universe is dark energy and dark matter (first inferred by Caltech's Fritz Zwicky in the 1930s), whose existence we know of only due to its effects on the remaining 4 percent that we can see: normal matter.

Of this 4 percent that is normal matter, only one-quarter is made up of stars and galaxies, the bright objects that light our night sky. The remainder, which amounts to only about 3 percent of everything in the universe, is the IGM.

As Martin's name for the IGM suggests, "dim matter" is hard to see. Prior to the development of the Cosmic Web Imager, the IGM was observed primarily via foreground absorption of light—indicating the presence of matter—occurring between Earth and a distant object such as a quasar (the nucleus of a young galaxy).

"When you look at the gas between us and a quasar, you have only one line of sight," explains Martin. "You know that there's some gas farther away, there's some gas closer in, and there's some gas in the middle, but there's no information about how that gas is distributed across three dimensions."

Observation of quasar (QSO 1549+19) taken with Caltech's Cosmic Web Imager. Blue shows hydrogen gas surrounding and inflowing to quasar. 

Credit: Christopher Martin, Robert Hurt

The integral field unit of the Cosmic Web Imager. 

Credit: Matt Matuszewski

More information: Paper 1. Paper 2.

NASA Mars Curiosity Rover: MAHLI Captures a mosaic of Mars

A mosaic of MSL MAHLI images acquired on Sol 613. CLICK on the photo to see the full image

Credit: NASA /JPL-Caltech /MSSS

This is Curiosity's latest "selfie," a mosaic made up of about a dozen images acquired with the rover's Mars Hand Lens Imager (MAHLI) instrument on April 27-28, 2014 (Sol 613).

The 5.5-km-high Mount Sharp (Aeolis Mons) rising in the background.

There are plenty of discrepancies in the mosaic tiling but, some say, it imparts some character to Curiosity.

Visible in the mosaic are Curiosity's cylindrical RUHF antenna and a bit of her Radioisotope Thermoelectric Generator (RTG) visible in the lower center.

Tuesday, April 29, 2014

Possible meteor shower May 23-24 as Earth passes through dust trail of 209P/LINEAR

Composite photo of Lyrid meteor shower and non-Lyrids taken with a NASA all-sky camera April 21-23, 2012. 

A new meteor shower emanating from Camelopardalids near the North Star is expected to light up the skies the morning May 24 around 2 a.m. CDT (7 UT). 

Credit: NASA /MSFC /Danielle Moser

On Friday night/early Saturday May 23-24 skywatchers across the U.S. and southern Canada may witness the birth of a brand new meteor shower.

If predictions hold true, Earth will pass through multiple tendrils of dust and pebbly bits left behind by comet 209P/LINEAR, firing up a celestial display on par with the strongest showers of the year. Or better.

Earlier predictions called for a zenithal hourly rate or ZHR of 1,000 per hour, pushing this shower into the 'storm' category.

ZHR is an idealized number based on the shower radiant located at the zenith under ideal skies.

The actual number is lower depending on how far the radiant is removed from the zenith and how much light pollution or moonlight is present.

Peter Jenniskens
Meteor expert Peter Jenniskens of NASA's SETI Institute and Finland's Esko Lyytinen first saw the possibility of a comet-spawned meteor storm and presented their results in Jenniskens' 2006 book Meteor Showers and Their Parent Comets.

Esko Lyytinen
Quanzhi Ye and Paul Wiegert (University of Western Ontario) predict a weaker shower because of a decline in the comet's dust production rate based on observations made during its last return in 2009. They estimate a rate of ~200 per hour.

On the bright side, their simulations show that the comet sheds larger particles than usual, which could mean a shower rich in fireballs. Other researchers predict rates between 200 and 40o per hour.

At the very least, the Camelopardalids – the constellation from which the meteors will appear to originate – promise to rival the Perseids and Geminids, the year's richest showers.

Approximate location of the radiant (blue) of the 209P/LINEAR shower at the peak of the brief maximum around 2 a.m. CDT May 24. 

Between 100-400 meteors may radiate from the dim constellation of Camelopardalids near the North Star. 

This map shows the sky from the central U.S. 

Created with Stellarium

Comet 209P/LINEAR, discovered in Feb. 2004 by the automated Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) sky survey, orbits the sun every 5.04 years with an aphelion (most distant point from the sun) near Jupiter.

The OSIRIS-REx spacecraft with its sample-collecting arm resembles a standing heron and inspired Michael Toler Puzio’s inventive name for the asteroid that the OSIRIS-REx space mission will visit. 

Credit: NASA/Goddard Flight Center/University of Arizona.

In 2012, during a relatively close pass of that planet, Jupiter perturbed its orbit, bringing it to within 280,000 miles (450,000 km) of Earth's orbit.

That set up a remarkably close encounter with our planet on May 29 when 209P/LINEAR will cruise just 5 million miles (8 million km) from Earth to become the 9th closest comet ever observed.

Multiple debris trails shed by the comet as long ago as the 18th century will intersect our planet's path 5 days earlier, providing the material for the upcoming meteor shower/storm.

Read the full article here

Experiment on Earth demonstrates effect observed in space

Streaming jets of high-speed matter produce some of the most stunning objects seen in space.

Astronomers have seen them shooting out of young stars just being formed, X-ray binary stars and even the supermassive black holes at the centers of large galaxies.

Theoretical explanations for what causes those beam-like jets have been around for years, but now an experiment by French and American researchers using extremely high-powered lasers offers experimental verification of one proposed mechanism for creating them.

"This research is an example of how laboratory experiments can be used to test mechanisms that may produce what we observe in space," said Eric Blackman, professor of physics and astronomy at the University of Rochester and one of the co-authors.

Blackman explains that he and his collaborators wanted to recreate conditions in the lab that lead to jets in space becoming collimated, parallel beam-like, rather than diverging.

Theory and computational simulations had suggested the possibility that jets might be created by "shock focused inertial confinement."

Blackman adds that the experiment "confirms that this particular mechanism is viable, even though other effects are likely to also be taking place."

In their results, the researchers show evidence of the "shocks" predicted by theory, and which give the mechanism its name.

These shocks are surfaces in space where there is a sudden change in the density, speed, and direction of a flow.

According to theory, which is consistent with the new experiment, they are what cause the beam-like nature of the jets to form.

In the paper published in Physical Review Letters, and highlighted as an editor's suggestion, the researchers explain how they used the laser laboratory facility (LULI), at the Ecole Polytechnique in France, to recreate these space jets.

Collaborators at the University of Chicago supplied a sophisticated computer code FLASH that they developed and adapted to help analyze the results.

"We have focused a very energetic laser beam on a tiny iron target – a little thinner than a human hair," explains Alessandra Ravasio, who led the experiment.

"In this way we can create a supersonic plasma flow."

With nothing to prevent the resulting iron plasma from spreading out, it would flow quasi-spherically from the target. In order to see the effects of a surrounding wind, the researchers generated another lighter, supersonic plasma from a plastic ring surrounding the central target.

"The novelty of this experiment is in the way we spatially distribute the laser energy, with a central dot generating the iron flow and a outer ring incident on the plastic," adds Ravasio.

"In this way we could create a nested geometry and study the interaction between the two flows."

The researchers found that the interaction of the two plasmas sharply collimates the iron plasma flow. That is, rather than spreading out in all directions, the iron flow emanates primarily along a single direction.

The experimental data showed that a shock wave is generated in this interaction, which helps the momentum and inertia of the plastic outer wind to collimate the inner iron flow into a jet.

The experiment is an example of laboratory astrophysics, a rapidly growing area of high energy density physics that requires the collaboration of astrophysicists, experimental plasma physicists and computational physicists.

More information: Paper:

NASA RFI: External Concepts for mission to Europa - the oceanic Jovian moon

This image shows two views of the trailing hemisphere of Jupiter's ice-covered satellite, Europa

The left image shows the approximate natural colour appearance of Europa

The image on the right is a false-color composite version combining violet, green and infrared images to enhance colour differences in the predominantly water-ice crust of Europa


NASA has issued a Request for Information (RFI) to science and engineering communities for ideas for a mission to Europa that could address fundamental questions of the enigmatic moon and the search for life beyond Earth.

The RFI's focus is for concepts for a mission to Europa that costs less than $1 billion, excluding the launch vehicle that can meet as many of the science priorities as possible recommended by the National Research Council's 2011 Planetary Science Decadal Survey for the study of Europa.

"This is an opportunity to hear from those creative teams that have ideas on how we can achieve the most science at minimum cost," said John Grunsfeld, associate administrator for the NASA Science Mission Directorate at the agency's headquarters in Washington.

"Europa is one of the most interesting sites in our solar system in the search for life beyond Earth. The drive to explore Europa has stimulated not only scientific interest but also the ingenuity of engineers and scientists with innovative concepts."

NASA has studied a variety of mission designs and concepts in previous years and currently is funding the development of technologies that will be needed for the science instruments for a Europa mission.

Congress appropriated $80 million for this work in Fiscal Year 2014, and the Fiscal Year 2015 budget proposal requests an additional $15 million.

Previous scientific findings point to the existence of a liquid water ocean located under the moon's icy crust. This ocean covers Europa entirely and contains more liquid water than all of Earth's oceans combined.

The Decadal Survey deemed a mission to the Jupiter moon as among the highest priority scientific pursuits for NASA.

It lists five key science objectives in priority order that are necessary to improve our understanding of this potentially habitable moon.

The mission will need to:

  • Characterise the extent of the ocean and its relation to the deeper interior
  • Characterise the ice shell and any subsurface water, including their heterogeneity, and the nature of surface-ice-ocean exchange
  • Determine global surface, compositions and chemistry, especially as related to habitability
  • Understand the formation of surface features, including sites of recent or current activity, identify and characterise candidate sites for future detailed exploration
  • Understand Europa's space environment and interaction with the magnetosphere.

Although Europa and Jupiter's other moons have been visited by other spacecraft, they were each limited to a single distant flyby of these satellites.

NASA's Galileo spacecraft, launched in 1989 by the space shuttle, was the only mission to make repeated visits to Europa, passing close by the moon fewer than a dozen times.

In December 2013, ESA /NASA's Hubble Space Telescope observed water vapor above the moon's frigid south polar region.

This provided the first strong evidence of water plumes erupting off the moon's surface, although researchers are still working to verify the existence of these plumes.

Any mission to Europa must take into account the harsh radiation environment that would require unique protection of the spacecraft and instruments.

In addition, spacecraft must meet planetary protection requirements intended to protect Europa's potentially habitable ocean.

These requirements are very strict and involve ensuring that a viable Earth organism is not introduced into the Europa ocean.

The RFI is not a request for proposal or formal procurement and therefore is not a solicitation or commitment by the government. Deadline to submit the mission concepts is May 30.

Monday, April 28, 2014

USAF Boeing X-37B: 500 days in orbit and more speculation

The highly extended mission hints that there's more than mundane testing on this flight. Perhaps components that were undergoing testing on previous flights are now on a true operational mission. 

Or perhaps we are witnessing a long endurance run to prove that certain critical satellite parts can work reliably for a long-duration spy satellite. Both theories are plausible.

With more than 500 days in orbit, the third mission of the mysterious X-37B spaceplane is not only longer than any previous flight, but also much stranger.

The X-37B is a robotic spacecraft launched by the US Air Force on a secret mission that has generally eluded boffins and analysts.

It's not unusual for nations to launch secret spacecraft, but it's often the case that their true missions can be deduced.

The size of the rocket, the orbit and other factors can give analysts clues that a certain satellite is an optical spy satellite, a radar observation satellite or a classified communications satellite.

Knowing that the secrecy is sometimes just a formality, some missions have patches that hint at their true missions, like owl's eyes and large mesh arrays with the motto "We own the night".

Suspicions that this was a radar observation satellite that could see targets in the dark were confirmed.

No such clues have been dropped for X-37B. Part of its mission is known, thanks to US Air Force statements and the fact that X-37B was once a civilian project operated by NASA.

This is an experimental spaceplane designed to test new technologies, ranging from "robot pilot" avionics to an advanced heatshield system.

Photography of the exterior of this spaceplane has been extensive, both before and after landing.

There's more mystery surrounding what lies inside. X-37B features a small shuttle-like payload bay in its middle, with clamshell doors that open in space.

We know that there's a solar panel inside that unfurls from a mast once the X-37B is in orbit but there's room for other items too.

Exactly what else is inside, and what it's doing, has confounded the media and the space community.

This analyst has suggested that X-37B is conducting mundane but critical tests of electromechanical components intended for future US national security satellites.

The parts are operated in open space for long periods then returned to Earth for study.

Other analysts have suggested that the vehicle is conducting a semi-operational mission that involves the use of sensors for Earth observation.

EADS E-Fan and E-Thrust Battery-powered plane takes to the skies - Video

We’ve already got electric cars and bikes, but they could soon be joined by aircraft if a bold new concept from Airbus gets off the ground.

The aircraft manufacturer has unveiled its ideas at an E-Aircraft Day including previews of E-Fan and E-Thrust planes that are powered by batteries.

A highlight was the first public flight of the electric E-Fan experimental aircraft pictured here.

The impressive creation is a training plane that comes packed with innovative technology and the maiden voyage represents a significant step forward in the development of electric aircraft.

Airbus is currently putting together plans that will see a production facility built close to Bordeaux.

Adding to the expansion is a plan to produce a four-seater version E-Fan 4.0, which will be a training and general aviation aircraft and could feature a combustion engine within the fuselage to provide an extended range or endurance.

The experimental E-Fan plane will be used as a test bed for Airbus and its move towards electric and hybrid engines in the future.

It was first shown off at the 2013 Paris Airshow and features a cutting-edge design that makes uses of composite materials, which means less weight and better durability.

The more motors allow the plane to remain nimble and easy to maneuver, making it an ideal craft for pilot training.

Although the aircraft is still in development, its lithium-ion polymer batteries can keep the plane in the air for around 30 minutes.

As Airbus increases development of both the plane and the batteries it hopes to take that flying time up to around an hour. Airbus bosses reckon that the E-Fan could be turned into a production model by 2017.

“The E-Fan project and Airbus Group’s commitment to the field of electric and hybrid research show our vision of future technological developments."

"It will not only lead to a further reduction in aircraft emissions and noise to support our environmental goals but will also lead to more economic and efficient aircraft technology in the long run."

"Our focus is to develop innovations that will help define what tomorrow’s aerospace industry will look like,” said Airbus Group Chief Technical Officer Jean Botti.

NASA WISE Discovers Coldest Brown Dwarf Neighbour of the Sun

This artist's conception shows a newfound object named WISE J085510.83-071442.5, the coldest known brown dwarf. 

Credit: Penn State University/NASA/JPL-Caltech

A brown dwarf as cold as the North Pole has been discovered lurking remarkably close to our solar system, and it appears to be the coldest of its kind yet found, scientists say.

Using NASA's Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescope, astronomers discovered the dim, "failed star" lurking just 7.2 light-years away, making it the fourth closest system to our sun.

"It's very exciting to discover a new neighbor of our solar system that is so close," Kevin Luhman, an astronomer at Pennsylvania State University's Center for Exoplanets and Habitable Worlds, said in a statement.

"And given its extreme temperature, it should tell us a lot about the atmospheres of planets, which often have similarly cold temperatures."

This diagram illustrates the locations of the star systems closest to the sun. 

Credit: Penn State University

Brown dwarfs are sometimes called failed stars because they have many of the elements of that make up stars, but they lack the huge mass needed to kick off nuclear fusion in their core.

As a result, these objects don't radiate starlight and they sometimes resemble planets.

Some are even cool enough to have atmospheres much like gas giants.

While brown dwarfs are hidden in images taken in the visible spectrum, infrared telescopes like WISE can pick up the meager glow of brown dwarfs.

Luhman and colleagues first spotted the object in WISE data. It appeared to be moving quite fast, hinting that it was close by.

The team then investigated the object using Spitzer and the Gemini South telescope on Cerro Pachon in Chile to measure its distance and temperature.

"It is remarkable that even after many decades of studying the sky, we still do not have a complete inventory of the sun's nearest neighbours," Michael Werner, the project scientist for Spitzer at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement.

Dubbed WISE J085510.83-071442.5, our newfound neighbor is now the record-holder for the coldest brown dwarf, with a temperature between minus 54 and 9 degrees Fahrenheit (minus 48 to minus 13 degrees Celsius), Luhman and colleagues say.

The previous record holders were more tepid, chilling only to room temperature.

At 3 to 10 times the mass of Jupiter, the object also may be one of the least massive brown dwarfs ever found, the astronomers say.

Because it is so small, the scientists say it's possible that the body is actually a planet ejected from its star system, but brown dwarfs are known to be quite common cosmic objects.

The findings were described April 21 in The Astrophysical Journal.

NOAA GOES-East Image: Captures weather system that spawned tornadoes

This NOAA GOES-East satellite image from Monday, Apr. 28, 2014 at 13:01 UTC/9:01 a.m. EDT shows the same storm system that generated the severe weather outbreak yesterday, has moved to the east. 

Credit: NASA /NOAA GOES Project

NASA has just released an animation of visible and infrared satellite data from NOAA's GOES-East satellite that shows the development and movement of the weather system that spawned tornadoes affecting seven central and southern U.S. states on April 27-28, 2014.

NASA's Aqua satellite captured infrared data on the system that revealed powerful storms, high into the troposphere.

This storm system generated reports of tornadoes from Nebraska, Kansas, Iowa, Oklahoma, Arkansas, Louisiana, and Mississippi.

Coupled with local weather observations, soundings, and computer models, data from satellites like NOAA's Geostationary Operational Environmental Satellite (GOES-East or GOES-13) gives forecasters information about developing weather situations.

In real-time, the NOAA's GOES-East satellite data in animated form showed forecasters how the area of severe weather was developing and moving.

NOAA's GOES-East satellite sits in a fixed orbit in space capturing visible and infrared imagery of weather over the eastern U.S. and Atlantic Ocean.

The GOES-East satellite is operated by the National Oceanic and Atmospheric Administration.

NASA/NOAA's GOES Project at the NASA Goddard Space Flight Center in Greenbelt, Md. created the animation of GOES-East satellite data that covered the period during the tornado outbreak.

The GOES-East animation of visible and infrared imagery runs 31 seconds. The animation begins on April 27 at 00:15 UTC (April 26 at 8:15 p.m. EDT) and runs through April 28 at 14:15 UTC/10:15 a.m. EDT.

By 14:45 UTC/10:45 a.m. EDT on April 27 the animation shows the squall line of thunderstorms developing.

This animation of NOAA's GOES-East satellite data shows the development and movement of the weather system that spawned tornadoes affecting seven central and southern U.S. states on April 27-28, 2014. 

Credit: NASA/NOAA GOES Project

To create the video and imagery, NASA/NOAA's GOES Project takes the cloud data from NOAA's GOES-East satellite and overlays it on a true-color image of land and ocean created by data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument that flies aboard NASA's Aqua and Terra satellites.

Together, those data created the entire picture of the storm system and show its movement.

A NASA satellite also captured an image of the storm, collecting infrared data on it as it passed overhead on April 27.

At NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. a false-colored image was created of the storm system using data gathered by the Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite on April 27 at 18:59 UTC (1:59 p.m. CDT).

The AIRS image showed very cold cloud top temperatures indicating that the thunderstorms had strong uplift that pushed cloud tops to the top of the troposphere.

Some of those thunderstorms had cloud tops as cold as 200 kelvin (-99.6 F/-73.1C). Temperatures drop to just under 220 degrees kelvin at the top of the troposphere (and where the tropopause begins).

This false-colored infrared image from the AIRS instrument aboard NASA's Aqua satellite shows the cold cloud top temperatures associated with the severe thunderstorms that brought severe weather to seven states on Apr. 27. 

Credit: NASA/JPL, Ed Olsen

Leaving Exoplanets aside, Exomoons may harbour life too

Shooting for the exomoon. 

Credit: CBC11, CC BY-SA

In the Star Wars universe, everyone's favourite furry aliens, the Ewoks, famously lived on the "forest moon of Endor".

In scientific terms, the Ewok's home world would be referred to as an exomoon, which is simply a moon that orbits an exoplanet, any planet that orbits a star other than our sun.

Although more than 1,000 exoplanets have been discovered since the first one was found in 1995, only a handful of those are thought to be habitable, at least by life as we know it.

New research shows that exomoons, too, could provide habitable environments. Although we are yet to find exomoons, we have good reasons to believe that there should be many, even more than exoplanets.

Goldilocks zone
Perhaps the most habitable planet found to date is the recently announced Kepler-186f.

This is one of five exoplanets discovered by NASA's Kepler satellite, all orbiting a small, faint, red dwarf star, 500 light years away in the constellation of Cygnus.

Kepler-186f is an Earth-sized planet that orbits its star in only 130 days and is about as distant from its star as Mercury is from the Sun. But, because the red dwarf is much dimmer than the Sun, Kepler-186f receives only about one-third of the energy that the Earth does.

As a result, Kepler-186f lies at the outer edge of its star's "habitable zone".

This is the hypothetical region of space surrounding a star in which liquid water may conceivably exist on the surface of any exoplanets.

In our own solar system, Venus lies too close to the Sun and is too hot.

Mars lies too far from the Sun and is too cold.

But Earth, of course, lies within the critical "Goldilocks zone", where the temperature is just right.

Simply residing in the habitable zone, though, is no guarantee that an exoplanet has water oceans.

The climate of a planet is much more complicated than we can capture with a simple calculation based on the distance of a planet from a star.

We know that Mars probably had running water on its surface in the past, but now it is a frozen desert. Earth, meanwhile, was probably in a completely frozen "snowball" state about 650m years ago.

Duncan Forgan
Recent research by Duncan Forgan and Vergil Yotov at the University of Edinburgh highlights the various factors that may make an exomoon more or less habitable.

They investigate how the climate of an exomoon will be affected by tidal stresses which provide a source of internal heating for the exomoon as it is stretched and deformed by the gravitational pull of its planet.

They also investigated how light reflected from the exoplanet, and eclipses by the exoplanet, can also subtly alter the exomoon's climate.

The researchers lump theoretical exomoons into a number of classifications: "habitable", "hot", "snowball" or "transient".

Those in the first class have more than 10% of their surface at a temperature between the freezing and boiling points of water, with only a small fluctuation around the average temperature value.

Those in the second class have average temperatures above 100°C at all times, whereas those in the third class are permanently frozen, in both cases less than 10% of the surface is habitable.

Exomoons in the fourth, transient class are on average habitable, but the amount of habitable surface area varies widely with time.

Overall, this research shows that exomoon climates are rather more complex than previous research has supposed.

As yet, no exomoons have been discovered, but there are various techniques proposed for finding them.

One way is by studying the effects that an exomoon will have on the exoplanet it is orbiting – their gravitational connection means there will be a to-and-fro tugging between them.

This will cause variations in the times at which the planet transits in front of its star and in the durations of these transits, which we are able to measure.

These time variations will only be a few seconds at most, so very accurate measurements of the transits must be made to reveal the exomoon's presence.

If variations are detected then, in principle, both the mass and orbit of the exomoon may be calculated from the measurements.

It surely is only a matter of time before the first exomoon is discovered and the probability of finding one in the habitable zone of a star is reasonably high.

We may not find any Ewoks, but habitable exomoons may indeed offer the best prospect for hosting alien life.

NASA's Curiosity Mars Rover Inspects new Drill Site - Windjana

The team operating NASA's Curiosity Mars rover is telling the rover to use several tools this weekend to inspect a sandstone slab being evaluated as a possible drilling target.

If this target meets criteria set by engineers and scientists, it could become the mission's third drilled rock, and the first that is not mudstone.

The team calls it "Windjana," after a gorge in Western Australia.

The planned inspection, designed to aid a decision on whether to drill at Windjana, includes observations with the camera and X-ray spectrometer at the end of the rover's arm, use of a brush to remove dust from a patch on the rock, and readings of composition at various points on the rock with an instrument that fires laser shots from the rover's mast.

Curiosity's hammering drill collects powdered sample material from the interior of a rock, and then the rover prepares and delivers portions of the sample to onboard laboratory instruments.

The first two Martian rocks drilled and analyzed this way were mudstone slabs neighboring each other in Yellowknife Bay, about 2.5 miles (4 kilometers) northeast of the rover's current location at a waypoint called "the Kimberley."

Those two rocks yielded evidence of an ancient lakebed environment with key chemical elements and a chemical energy source that provided conditions billions of years ago favourable for microbial life.

From planned drilling at Windjana or some nearby location on sandstone at the Kimberley, Curiosity's science team hopes to analyze the cement that holds together the sand-size grains in the rock.

"We want to learn more about the wet process that turned sand deposits into sandstone here," said Curiosity Project Scientist John Grotzinger, of the California Institute of Technology in Pasadena.

"What was the composition of the fluids that bound the grains together?

That aqueous chemistry is part of the habitability story we're investigating."

The view is an excerpt from an April 11, 2014, observation by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. 

A larger scene from the same observation can be found here.

In the image's enhanced colour, Curiosity itself appears as the bright blue object at the two-o'clock position relative to the butte in the lower center of the scene.

That butte is called "Mount Remarkable" and stands about 16 feet (5 meters) high.

The rover subsequently drove to within its robotic arm's reach of Windjana. For scale, the distance between the parallel wheel tracks visible in the image is about 9 feet (2.7 meters).

Sunday, April 27, 2014

NASA's Curiosity rover captures images of asteroids Ceres and Vesta

For the first time, NASA's Curiosity rover has captured images of an asteroid from the surface of Mars -- two of them, in fact.

The imagery recorded by Curiosity and beamed back to Earth feature Ceres and Vesta, two of the largest asteroids in the asteroid belt that runs between between Mars and Jupiter.

This Curiosity first was also a bit of a coincidence, as the SUV-sized rover had aimed its cameras at the Martian sky in order to snap shots of the Red Planet's two moons, not hunt for asteroids whizzing by.

"This imaging was part of an experiment checking the opacity of the atmosphere at night in Curiosity's location on Mars, where water-ice clouds and hazes develop during this season," camera team member Mark Lemmon, of Texas A&M University, explained in a statement.

"The two Martian moons were the main targets that night, but we chose a time when one of the moons was near Ceres and Vesta in the sky."

Mark Lemmon
NASA is currently on its way to get an even closer look at this two giant space rocks.

NASA's Dawn spacecraft orbited the 350-mile-wide Vesta asteroid in 2011 and 2012, and it is preparing to orbit the 590-mile-wide Ceres in 2015.