vendredi 8 mars 2019

“Goldilocks” Stars May Be “Just Right” for Finding Habitable Worlds

NASA - Goddard Space Flight Center logo.

March 8, 2019

Scientists looking for signs of life beyond our solar system face major challenges, one of which is that there are hundreds of billions of stars in our galaxy alone to consider. To narrow the search, they must figure out: What kinds of stars are most likely to host habitable planets?

A new study finds a particular class of stars called K stars, which are dimmer than the Sun but brighter than the faintest stars, may be particularly promising targets for searching for signs of life.

Image above: This is an artist's concept of a planet orbiting in the habitable zone of a K star. Image Credits: NASA Ames/JPL-Caltech/Tim Pyle.

Why? First, K stars live a very long time — 17 billion to 70 billion years, compared to 10 billion years for the Sun — giving plenty of time for life to evolve. Also, K stars have less extreme activity in their youth than the universe’s dimmest stars, called M stars or “red dwarfs.”

M stars do offer some advantages for in the search for habitable planets. They are the most common star type in the galaxy, comprising about 75 percent of all the stars in the universe. They are also frugal with their fuel, and could shine on for over a trillion years. One example of an M star, TRAPPIST-1, is known to host seven Earth-size rocky planets.

But the turbulent youth of M stars presents problems for potential life. Stellar flares – explosive releases of magnetic energy – are much more frequent and energetic from young M stars than young Sun-like stars. M stars are also much brighter when they are young, for up to a billion years after they form, with energy that could boil off oceans on any planets that might someday be in the habitable zone.

“I like to think that K stars are in a ‘sweet spot’ between Sun-analog stars and M stars,” said Giada Arney of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Arney wanted to find out what biosignatures, or signs of life, might look like on a hypothetical planet orbiting a K star. Her analysis is published in the Astrophysical Journal Letters.

Scientists consider the simultaneous presence of oxygen and methane in a planet’s atmosphere to be a strong biosignature because these gases like to react with each other, destroying each other. So, if you see them present in an atmosphere together, that implies something is producing them both quickly, quite possibly life, according to Arney.

However, because planets around other stars (exoplanets) are so remote, there needs to be significant amounts of oxygen and methane in an exoplanet’s atmosphere for it to be seen by observatories at Earth. Arney’s analysis found that the oxygen-methane biosignature is likely to be stronger around a K star than a Sun-like star.

Arney used a computer model that simulates the chemistry and temperature of a planetary atmosphere, and how that atmosphere responds to different host stars. These synthetic atmospheres were then run through a model that simulates the planet’s spectrum to show what it might look like to future telescopes.

“When you put the planet around a K star, the oxygen does not destroy the methane as rapidly, so more of it can build up in the atmosphere,” said Arney. “This is because the K star’s ultraviolet light does not generate highly reactive oxygen gases that destroy methane as readily as a Sun-like star.”

This stronger oxygen-methane signal has also been predicted for planets around M stars, but their high activity levels might make M stars unable to host habitable worlds. K stars can offer the advantage of a higher probability of simultaneous oxygen-methane detection compared to Sun-like stars without the disadvantages that come along with an M star host.

Additionally, exoplanets around K stars will be easier to see than those around Sun-like stars simply because K stars are dimmer. “The Sun is 10 billion times brighter than an Earthlike planet around it, so that’s a lot of light you have to suppress if you want to see an orbiting planet. A K star might be ‘only’ a billion times brighter than an Earth around it,” said Arney.

Arney’s research also includes discussion of which of the nearby K stars may be the best targets for future observations. Since we don’t have the ability to travel to planets around other stars due to their enormous distances from us, we are limited to analyzing the light from these planets to search for a signal that life might be present. By separating this light into its component colors, or spectrum, scientists can identify the constituents of a planet’s atmosphere, since different compounds emit and absorb distinct colors of light.

“I find that certain nearby K stars like 61 Cyg A/B, Epsilon Indi, Groombridge 1618, and HD 156026 may be particularly good targets for future biosignature searches,” said Arney.

Related links:


Goddard Space Flight Center (GSFC):

Image (mentioned), Text, Credits: NASA/Goddard Space Flight Center, Bill Steigerwald.


Hubble’s Dazzling Display of 2 Colliding Galaxies

NASA - Hubble Space Telescope patch.

March 8, 2019

Located in the constellation of Hercules, about 230 million light-years away, NGC 6052 is a pair of colliding galaxies. They were first discovered in 1784 by William Herschel and were originally classified as a single irregular galaxy because of their odd shape. However, we now know that NGC 6052 actually consists of two galaxies that are in the process of colliding. This particular image of NGC 6052 was taken using the Wide Field Camera 3 on the NASA/ESA Hubble Space Telescope.

A long time ago gravity drew the two galaxies together into the chaotic state we now observe. Stars from within both of the original galaxies now follow new trajectories caused by the new gravitational effects. However, actual collisions between stars themselves are very rare as stars are very small relative to the distances between them (most of a galaxy is empty space). Eventually the galaxies will fully merge to form a single, stable galaxy.

Our own galaxy, the Milky Way, will undergo a similar collision in the future with our nearest galactic neighbor, the Andromeda galaxy. However, this is not expected to happen for around 4 billion years.

This object was previously observed by Hubble with its old Wide Field and Planetary Camera 2 (WFPC2). That image was released in 2015.

Hubble Space Telescope (HST)

For more information about Hubble, visit:

Image, Animation, Credits: ESA/Hubble & NASA, A. Adamo et al./Text Credits: ESA (European Space Agency)//NASA/Rob Garner.


SpaceX Crew Dragon Undock from ISS and Splashes Down in Atlantic Ocean

SpaceX - COTS C-1 Mission patch.

March 8, 2019

Image above: The uncrewed SpaceX Crew Dragon spacecraft just moments after undocking from the International Space Station. Image Credit: NASA TV.

SpaceX’s Crew Dragon returned to Earth with a splash in the Atlantic Ocean off Florida’s eastern shore at 8:45 a.m. EST, completing an end-to-end flight test to demonstrate most of the capabilities of its crew transportation system to the International Space Station as part of NASA’s Commercial Crew Program.

Crew Dragon undocking and departure

The mission, known as Demo-1, is a critical step for NASA and SpaceX to demonstrate the ability to safely fly missions with NASA astronauts to the orbital laboratory.

Image above: Crew Dragon spacecraft on it’s way back to Earth after undocking from the International Space Station at 2:32 am EST on March 8, 2019. Image Credit: NASA TV.

The Crew Dragon launched March 2 from NASA’s Kennedy Space Center in Florida. It was the first commercially-built and operated American crew spacecraft and rocket to launch from American soil on a mission to the space station and autonomously dock to the station. To complete the docking, both the station and Crew Dragon’s adapters used the new international docking standard.

Crew Dragon deorbit and splashdown in the Atlantic Ocean

Crew Dragon is returning to Earth some critical research samples from science investigations conducted to enable human exploration farther into space and develop and demonstrate in the U.S. ISS National Laboratory new technologies, treatments, and products for improving life on Earth.

Also traveling aboard the spacecraft is an anthropomorphic test device named Ripley outfitted with sensors to provide data about potential effects on humans traveling in Crew Dragon.

Image above: SpaceX’s Crew Dragon splashes down in the Atlantic Ocean after successful Demo-1 flight on March 8, 2019. Image Credit: NASA TV.

SpaceX’s recovery ship, Go Searcher, is equipped with a crane to lift Crew Dragon out of the water and onto the main deck of the ship within an hour after splashdown.

NASA and SpaceX still have work to do to review the systems and flight data to validate the spacecraft’s performance and prepare it to fly astronauts. Already planned upgrades, additional qualification testing, and an in-flight abort test will occur before NASA astronauts Bob Behnken and Doug Hurley will climb aboard for Demo-2, the crewed flight test to the International Space Station that is necessary to certify Crew Dragon for routine operational missions.

Crew Dragon’s splashdown in the Atlantic was almost 50 years after the return of Apollo 9 on March 13, 1969, the last human spacecraft to return to the waters off the East Coast.

Related article:

Crew Dragon Set for Friday Splashdown Amid Space Physics Research

Related links:

Expedition 58:

SpaceX Crew Dragon:

Commercial Crew Program:

Space Station Research and Technology:

International Space Station (ISS):

Images (mentioned), Video, Text, Credits: NASA/Norah Moran/NASA TV/SciNews.

Best regards,

jeudi 7 mars 2019

Ultima Thule in 3D

NASA - New Horizons Mission patch.

March 7, 2019

Cross your eyes and break out the 3D glasses! NASA’s New Horizons team has created new stereo views of the Kuiper Belt object nicknamed Ultima Thule – the target of the New Horizons spacecraft’s historic New Year’s 2019 flyby, four billion miles from Earth – and the images are as cool and captivating as they are scientifically valuable.

Animation above: Flicker: Just watch and enjoy! Animation Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/National Optical Astronomy Observatory.

The 3D effects come from pairing or combining images taken at slightly different viewing angles, creating a “binocular” effect, just as the slight separation of our eyes allows us to see three-dimensionally. For the images on this page, the New Horizons team paired sets of processed images taken by the spacecraft’s Long-Range Reconnaissance Imager (LORRI) at 5:01 and 5:26 Universal Time on Jan. 1, from respective distances of 17,400 miles (28,000 kilometers) and 4,100 miles (6,600 kilometers), offering respective original scales of about 430 feet (130 meters) and 110 feet (33 meters) per pixel.

Image above: View with 3D Glasses: This image of Ultima Thule can be viewed with red-blue stereo glasses to reveal the Kuiper Belt object's three-dimensional shape.
Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/National Optical Astronomy Observatory.

The viewing direction for the earlier sequence was slightly different than the later set, which consists of the highest-resolution images obtained with LORRI. The closer view offers about four times higher resolution per pixel but, because of shorter exposure time, lower image quality. The combination, however, creates a stereo view of the object (officially named 2014 MU69) better than the team could previously create.

Artist's view of New Horizons flyby Ultima Thule. Image Credits: NASA/JHUAPL

“These views provide a clearer picture of Ultima Thule’s overall shape,” said mission Principal Investigator Alan Stern, from Southwest Research Institute (SwRI) in Boulder, Colorado, “including the flattened shape of the large lobe, as well as the shape of individual topographic features such as the "neck" connecting the two lobes, the large depression on the smaller lobe, and hills and valleys on the larger lobe.”

Image above: Parallel: For this view, change your focus from the image by looking "through" it (and the screen) and into the distance. This will create the effect of a third image in the middle; try setting your focus on that third image. Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/National Optical Astronomy Observatory.

"We have been looking forward to this high-quality stereo view since long before the flyby,” added John Spencer, New Horizons deputy project scientist from SwRI. “Now we can use this rich, three-dimensional view to help us understand how Ultima Thule came to have its extraordinary shape." 

Image above: Cross-Eyed: For this view, cross your eyes until the pair of images merges into one. It might help to place your finger or a pen just a couple of inches from your eyes, and focus on it. When the background image comes into focus, remove the closer object and concentrate on the image. Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/National Optical Astronomy Observatory.

The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, designed, built and operates the New Horizons spacecraft, and manages the mission for NASA's Science Mission Directorate. The MSFC Planetary Management Office provides the NASA oversight for the New Horizons. Southwest Research Institute, based in San Antonio, directs the mission via Principal Investigator Stern, and leads the science team, payload operations and encounter science planning. New Horizons is part of the New Frontiers Program managed by NASA's Marshall Space Flight Center in Huntsville, Alabama.

New Horizons:

Images (mentioned), Text, Credits: MASA/Tricia Talbert.

Best regards,

Crew Dragon Set for Friday Splashdown Amid Space Physics Research

ISS - Expedition 58 Mission patch.

March 7, 2019

The SpaceX Crew Dragon’s hatch is closed and the stage is set for the Commercial Crew Program’s first undocking and return to Earth Friday. As NASA and SpaceX get ready for Friday’s splashdown, the Expedition 58 crew continued exploring a variety of space physics phenomena aboard the International Space Station.

The uncrewed SpaceX DM-1 mission has one final milestone and that is the safe return to Earth with a splashdown in the Atlantic Ocean around 8:45 a.m. EST Friday. The Crew Dragon will undock Friday at 2:31 a.m. from the Harmony module’s international docking adapter. NASA TV will broadcast the departure and return activities live.

Image above: The uncrewed SpaceX Crew Dragon spacecraft is the first Commercial Crew vehicle to visit the International Space Station. Here it is pictured with its nose cone open revealing its docking mechanism while approaching the station’s Harmony module on March 3, 2019. Image Credit: NASA.

The first commercial crew vehicle from SpaceX will be bringing back over 330 pounds of science gear, crew supplies and station hardware. It delivered almost 450 pounds of materials to resupply the station crew on March 3.

Science took precedence as usual aboard the orbital lab today as SpaceX prepares to welcome its Crew Dragon back on Earth.

International Space Station (ISS). Image Credit: NASA

NASA astronaut Anne McClain spent Thursday morning setting up hardware to explore ways to improve the production of higher-quality semiconductor crystals. Afterward, she relocated the Alpha Magnetic Spectrometer laptop computer that researches cosmic rays and antimatter from the Columbus lab module to the Destiny lab module.

Commander Oleg Kononenko worked throughout the day on a Russian-European experiment researching plasma physics. The Plasma Krystal-4 study observes plasma crystal formation that could inform future research and spacecraft designs.

Related links:

Expedition 58:

SpaceX Crew Dragon:

Commercial Crew Program:

Harmony module:

Higher-quality semiconductor crystals:

Alpha Magnetic Spectrometer:

Columbus lab module:

Destiny lab module:

Plasma Krystal-4:

Space Station Research and Technology:

International Space Station (ISS):

Images (mentioned), Text, Credits: NASA/Norah Moran.

Best regards,

The Slow Charm of Brain Terrain

NASA - Mars Reconnaissance Orbiter (MRO) patch.

March 7, 2019

You are staring at one of the unsolved mysteries on Mars. This surface texture of interconnected ridges and troughs, referred to as "brain terrain" is found throughout the mid-latitude regions of Mars. (This image is in Protonilus Mensae.)

This bizarrely textured terrain may be directly related to the water ice that lies beneath the surface. One hypothesis is that when the buried water ice sublimates (changes from a solid to a gas), it forms the troughs in the ice. The formation of these features might be an active process that is slowly occurring since HiRISE has yet to detect significant changes in these terrains.

The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. (The original image scale is 29.6 centimeters [11.7 inches] per pixel [with 1 x 1 binning] to 59.3 centimeters [23.3 inches] per pixel [with 2 x 2 binning].) North is up.

The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.

Mars Reconnaissance Orbiter (MRO):

Image, Text, Credits:  NASA/Tony Greicius/JPL-Caltech/University of Arizona.


Hubble & Gaia accurately weigh the Milky Way

ESA - Hubble Space Telescope logo.

7 March 2019

Globular clusters surrounding the Milky Way (artist’s impression)

In a striking example of multi-mission astronomy, measurements from the NASA/ESA Hubble Space Telescope and the ESA Gaia mission have been combined to improve the estimate of the mass of our home galaxy the Milky Way: 1.5 trillion solar masses.

The mass of the Milky Way is one of the most fundamental measurements astronomers can make about our galactic home. However, despite decades of intense effort, even the best available estimates of the Milky Way’s mass disagree wildly. Now, by combining new data from the European Space Agency (ESA) Gaia mission with observations made with the NASA/ESA Hubble Space Telescope, astronomers have found that the Milky Way weighs in at about 1.5 trillion solar masses within a radius of 129 000 light-years from the galactic centre.

Previous estimates of the mass of the Milky Way ranged from 500 billion to 3 trillion times the mass of the Sun. This huge uncertainty arose primarily from the different methods used for measuring the distribution of dark matter — which makes up about 90% of the mass of the galaxy.

ESA’s Gaia satellite

“We just can’t detect dark matter directly,” explains Laura Watkins (European Southern Observatory, Germany), who led the team performing the analysis. “That’s what leads to the present uncertainty in the Milky Way’s mass — you can’t measure accurately what you can’t see!”

Given the elusive nature of the dark matter, the team had to use a clever method to weigh the Milky Way, which relied on measuring the velocities of globular clusters — dense star clusters that orbit the spiral disc of the galaxy at great distances [1].

“The more massive a galaxy, the faster its clusters move under the pull of its gravity” explains N. Wyn Evans (University of Cambridge, UK). “Most previous measurements have found the speed at which a cluster is approaching or receding from Earth, that is the velocity along our line of sight. However, we were able to also measure the sideways motion of the clusters, from which the total velocity, and consequently the galactic mass, can be calculated.” [2]

Globular cluster NGC 4147

The group used Gaia’s second data release as a basis for their study. Gaia was designed to create a precise three-dimensional map of astronomical objects throughout the Milky Way and to track their motions. Its second data release includes measurements of globular clusters as far as 65 000 light-years from Earth.

"Global clusters extend out to a great distance, so they are considered the best tracers astronomers use to measure the mass of our galaxy" said Tony Sohn (Space Telescope Science Institute, USA), who led the Hubble measurements.

The team combined these data with Hubble’s unparalleled sensitivity and observational legacy. Observations from Hubble allowed faint and distant globular clusters, as far as 130 000 light-years from Earth, to be added to the study. As Hubble has been observing some of these objects for a decade, it was possible to accurately track the velocities of these clusters as well.

Globular clusters surrounding the Milky Way (artist’s impression)

“We were lucky to have such a great combination of data,” explained Roeland P. van der Marel (Space Telescope Science Institute, USA). “By combining Gaia’s measurements of 34 globular clusters with measurements of 12 more distant clusters from Hubble, we could pin down the Milky Way’s mass in a way that would be impossible without these two space telescopes.”

Until now, not knowing the precise mass of the Milky Way has presented a problem for attempts to answer a lot of cosmological questions. The dark matter content of a galaxy and its distribution are intrinsically linked to the formation and growth of structures in the Universe. Accurately determining the mass for the Milky Way gives us a clearer understanding of where our galaxy sits in a cosmological context.

Hubble Space Telescope (HST)


[1] Globular clusters formed prior to the construction of the Milky Way’s spiral disk, where our Sun and the Solar System later formed. Because of their great distances, globular star clusters allow astronomers to trace the mass of the vast envelope of dark matter surrounding our galaxy far beyond the spiral disk.

[2] The total velocity of an object is made up of three motions — a radial motion plus two defining the sideway motions. However, in astronomy most often only line-of-sight velocities are available. With only one component of the velocity available, the estimated masses depend very strongly on the assumptions for the sideway motions. Therefore measuring the sideway motions directly significantly reduces the size of the error bars for the mass.

More information

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

ESA's Gaia satellite was launched in 2013 to create the most precise three-dimensional map of more than one billion stars in the Milky Way. The mission has release two lots of data thus far: Gaia Data Release 1 in 2016 and Gaia Data Release 2 in 2018. More releases will follow in the coming years.

The study was presented in the paper “Evidence for an Intermediate-Mass Milky Way from Gaia DR2 Halo Globular Cluster Motions”, which will be published in The Astrophysical Journal.

The international team of astronomers in this study consists of Laura L. Watkins (European Southern Observatory, Germany), Roeland P. van der Marel (Space Telescope Science Institute, USA, and Johns Hopkins University Center for Astrophysical Sciences, USA), Sangmo T. Sohn (Space Telescope Science Institute, USA), and N. Wyn Evans (University of Cambridge, UK).

Related article:

Rethinking everything we thought we knew about star clusters

Related Links:

Hubblecast 117 Light: Hubble & Gaia weigh the Milky Way:

Gaia Data Release 1:

Gaia Data Release 2:

Hubblesite release:

Science paper:

Gaia mission page:

NASA/ESA Hubble Space Telescope:

Images, Animations, Text, Credits: ESA/Hubble, L. Watkins, L. Calçada/ESA/Bethany Downer/Space Telescope Science Institute/Roeland P. van der Marel/University of Cambridge/N. Wyn Evans/ESO/Laura Watkins/ATG medialab/Hubble & NASA, T. Sohn et al./Video Credits:
ESA/Hubble, NASA, L. Calçada, M.Kormesser.


mercredi 6 mars 2019

Vice President (USA) Calls Station, Crew Dragon Packed for Friday Return

ISS - Expedition 58 Mission patch.

March 6, 2019

Vice President Mike Pence and NASA Administrator Jim Bridenstine called up to the Expedition 58 crew today. Astronauts Anne McClain and David Saint-Jacques were on hand to talk about their mission success and the arrival of the first Commercial Crew vehicle, the SpaceX Crew Dragon.

The Crew Dragon is being packed and readied for its return to Earth on Friday. In the midst of NASA’s first Commercial Crew mission, the crew members continued more space research and practiced an emergency drill today.

Image above: Vice President Mike Pence and NASA Administrator Jim Bridenstine called up to the Expedition 58 crew today from NASA Headquarters Space Operations Center in Washington, D.C.. Image Credit: NASA TV.

Saint-Jacques of the Canadian Space Agency transferred cargo in and out of the Crew Dragon today. Over 300 pounds of science gear, crew supplies and station hardware will be retrieved from Dragon after it returns to Earth.

The Crew Dragon will undock Friday at 2:31 a.m. EST from the Harmony module’s international docking adapter. It will parachute to a splashdown in the Atlantic Ocean around 8:45 a.m. EST. NASA TV will cover all the activities live.

Image above: Astronauts David Saint-Jacques (left) and Anne McClain talk to the Vice President and NASA Administrator about their mission success and the arrival of the SpaceX Crew Dragon. Image Credit: NASA TV.

McClain from NASA worked in the Destiny laboratory module today stowing science hardware after working on the Microgravity Sciences Glovebox. She then began collecting and readying more experiment hardware that will test ways to improve the production of higher-quality semiconductor crystals.

Both astronauts then joined Commander Oleg Kononenko from Roscosmos to practice an emergency evacuation of the International Space Station. The trio wore breathing masks, entered the docked Soyuz spacecraft and prepared for a return to Earth in the unlikely event of a critical emergency aboard the orbital complex.

Related links:

Expedition 58:

Commercial Crew:

SpaceX Crew Dragon:

Harmony module:


Destiny laboratory module:

Microgravity Sciences Glovebox:

Higher-quality semiconductor crystals:

Space Station Research and Technology:

International Space Station (ISS):

Images (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards,

Space Station Science Highlights: Week of February 25, 2019

ISS - Expedition 58 Mission patch.

March 6, 2019

The members of Expedition 58 aboard the International Space Station continued preparing for several spacewalks planned for the near future and conducted a number of science experiments. The crew also prepared for the arrival of SpaceX Demo-1 flight test which launched from Kennedy Space Center at 2:49 a.m. EST Saturday, March 2, and docked the next day.

Here are details about some of the science conducted last week:

The brain on microgravity

Crew members performed both the strapped-in and free-floating body configurations for NeuroMapping, an investigation into whether long-duration spaceflight causes changes to brain structure and function, motor control and multi-tasking abilities. The investigation also measures how long it takes for the brain and body to recover from such changes. Previous research and anecdotal evidence from astronauts suggests microgravity can affect movement control and cognition.

Studying gaseous flames and flammability

Image above: Astronaut David Saint-Jacques of the Canadian Space Agency is inside the U.S. Destiny laboratory module working on the Combustion Integrated Rack. Saint-Jacques replaced fuel flow controllers inside the device for the Advanced Combustion via Microgravity Experiments which are a set of five independent studies of gaseous flames. Image Credit: NASA.

Following replacement of an ACME fuel flow controller, which allows observation of different flow conditions, the crew documented its final configuration with photographs. The ACME series performed in the Combustion Integrated Rack (CIR) includes five independent studies of gaseous flames. The current experiment, Burning Rate Emulator (BRE), focuses on spacecraft fire prevention, specifically improving understanding of materials flammability and assessing existing flammability test methods in low and partial-gravity environments.

Managing satellite traffic jams

SPHERES. Image Credit: NASA

The crew set up and performed a SPHERES SmoothNav test session. This investigation develops an algorithm to collect measurements of distances between multiple small spacecraft, including those operating with different instruments, and estimates their most probable relative positions and velocities. It works with different satellite platforms and onboard sensors, which makes it adaptable if one or more satellites become inoperable, and it can use delayed measurements or those received at different frequencies.

Figuring out up from down in microgravity

Animation above: NASA astronaut Anne McClain conducts a session for the VECTION investigation, which evaluates how microgravity may disrupt an astronaut’s visual interpretation of motion, orientation, and distance. Image Credit: NASA.

VECTION determines to what extent microgravity may disrupt an astronaut’s visual interpretation of motion, orientation, and distance as well as how that interpretation may adapt in space and then again upon return to Earth. The crew deployed support hardware, including the free-float restraint system, and performed experiment sessions. These sessions are broken into three tasks: Orientation Perception, Relative Height (Motion Processing), and Depth Perception (Vection). Multiple experimental time points inflight and upon return to Earth allows for investigation of the adaptation and recovery process.

Other investigations on which the crew performed work:

- The Actiwatch waterproof, nonintrusive, sleep-wake activity monitor worn on the wrist of a crewmember. The data it collects helps determine if space travel has an impact on the sleep-wake patterns of crewmembers:

- A virtual reality film documenting daily life aboard the space station, ISS Experience educates a variety of audiences about life aboard the orbiting lab and science conducted there:

- The Sally Ride EarthKAM program allows students to remotely control a digital camera mounted on the space station and use it to take photographs of coastlines, mountain ranges and other features and phenomena. The images are posted online, where the public and participating classrooms can view Earth from the station’s unique vantage point:

- The Team Task Switching investigation examines whether crew members have difficulty switching tasks and determines the effects of these switches in order to both reduce any negative consequences and improve individual and team motivation and effectiveness:

Space to Ground: An American Dawn: 03/01/2019

Related links:

Expedition 58:


SpaceX Demo-1 flight test:



Combustion Integrated Rack (CIR):

Burning Rate Emulator (BRE):


Space Station Research and Technology:

International Space Station (ISS):

Images (mentioned), Animation (mentioned), Video (NASA), Text, Credits: NASA/Michael Johnson/Vic Cooley, Lead Increment Scientist Expeditions 57/58.

Best regards,

Hubble’s Advanced Camera for Surveys Resumes Operations

NASA - Hubble Space Telescope patch.

March 6, 2019

NASA has recovered the Hubble Space Telescope’s Advanced Camera for Surveys instrument, which suspended operations on Thursday, Feb. 28. The final tests were conducted and the instrument was brought back to its operational mode on March 6.

At 8:31 p.m. EST on Feb. 28, the Advanced Camera for Surveys aboard NASA’s Hubble Space Telescope suspended operations after an error was detected as the instrument was performing a routine boot procedure. The error indicated that software inside the camera had not loaded correctly in a small section of computer memory. The Hubble operations team ran repeated tests to reload the memory and check the entire process. No errors have been detected since the initial incident, and it appears that all circuits, computer memory and processors that are part of that boot process are now operating normally. The instrument has now been brought back to its standard operating mode for normal operations.

Hubble Space Telescope. Image Credit: NASA

The Advanced Camera for Surveys was installed in 2002 and repaired during the last servicing mission to Hubble back in 2009 after a power supply failure. More than 5,500 peer-reviewed scientific papers have been published from its data, and it is credited with some of Hubble’s most iconic images, including the Hubble Ultra Deep Field, the farthest look into the universe at that time.

Hubble itself is in its 29th year of operations, well surpassing its original 15-year lifetime. With its primary and backup systems, it is expected that Hubble will operate simultaneously with the upcoming James Webb Space Telescope to obtain multiwavelength observations of astronomical objects. Scheduled to launch in 2021, the James Webb Space Telescope is designed to see near- and mid-infrared light while Hubble is optimized for ultraviolet and visible light.

Related article:

Advanced Camera for Surveys Anomaly on Hubble Space Telescope

For more information about Hubble, visit:

Hubble Ultra Deep Field:

Image (mentioned), Text, Credits: NASA/Rob Garner/Elizabeth Landau/GSFC/Claire Saravia Andreoli.


NASA Captures First Air-to-Air Images of Supersonic Shockwave Interaction in Flight

NASA - Armstrong Flight Research Center patch.

March 6, 2019

“We never dreamt that it would be this clear, this beautiful.”

Physical Scientist J.T. Heineck of NASA’s Ames Research Center in Mountain View, California gets his first glimpse at a set of long-awaited images, and takes a moment to reflect on more than 10 years of technique development – an effort that has led to a milestone for NASA’s Aeronautics Research Mission Directorate.

NASA has successfully tested an advanced air-to-air photographic technology in flight, capturing the first-ever images of the interaction of shockwaves from two supersonic aircraft in flight.

Image above: One of the greatest challenges of the flight series was timing. In order to acquire this image, originally monochromatic and shown here as a colorized composite image, NASA flew a B-200, outfitted with an updated imaging system, at around 30,000 feet while the pair of T-38s were required to not only remain in formation, but to fly at supersonic speeds at the precise moment they were directly beneath the B-200. The images were captured as a result of all three aircraft being in the exact right place at the exact right time designated by NASA’s operations team. Image Credit: NASA Photo.

“I am ecstatic about how these images turned out,” said Heineck. “With this upgraded system, we have, by an order of magnitude, improved both the speed and quality of our imagery from previous research.”

The images were captured during the fourth phase of Air-to-Air Background Oriented Schlieren flights, or AirBOS, which took place at NASA’s Armstrong Flight Research Center in Edwards, California. The flight series saw successful testing of an upgraded imaging system capable of capturing high-quality images of shockwaves, rapid pressure changes which are produced when an aircraft flies faster than the speed of sound, or supersonic. Shockwaves produced by aircraft merge together as they travel through the atmosphere and are responsible for what is heard on the ground as a sonic boom.

The system will be used to capture data crucial to confirming the design of the agency’s X-59 Quiet SuperSonic Technology X-plane, or X-59 QueSST, which will fly supersonic, but will produce shockwaves in such a way that, instead of a loud sonic boom, only a quiet rumble may be heard. The ability to fly supersonic without a sonic boom may one day result in lifting current restrictions on supersonic flight over land.

Image above: When aircraft fly faster than the speed of sound, shockwaves travel away from the vehicle, and are heard on the ground as a sonic boom. NASA researchers use this imagery to study these shockwaves as part of the effort to make sonic booms quieter, which may open the future to possible supersonic flight over land. The updated camera system used in the AirBOS flight series enabled the supersonic T-38 to be photographed from much closer, approximately 2,000 feet away, resulting in a much clearer image compared to previous flight series. Image Credit: NASA Photo.

The images feature a pair of T-38s from the U.S. Air Force Test Pilot School at Edwards Air Force Base, flying in formation at supersonic speeds. The T-38s are flying approximately 30 feet away from each other, with the trailing aircraft flying about 10 feet lower than the leading T-38. With exceptional clarity, the flow of the shock waves from both aircraft is seen, and for the first time, the interaction of the shocks can be seen in flight.

“We’re looking at a supersonic flow, which is why we’re getting these shockwaves,” said Neal Smith, a research engineer with AerospaceComputing Inc. at NASA Ames’ fluid mechanics laboratory.

“What’s interesting is, if you look at the rear T-38, you see these shocks kind of interact in a curve,” he said. “This is because the trailing T-38 is flying in the wake of the leading aircraft, so the shocks are going to be shaped differently. This data is really going to help us advance our understanding of how these shocks interact.”

The study of how shockwaves interact with each other, as well as with the exhaust plume of an aircraft, has been a topic of interest among researchers. Previous, subscale schlieren research in Ames’ wind tunnel, revealed distortion of the shocks, leading to further efforts to expand this research to full-scale flight testing.

While the acquisition of these images for research marked one of the goals of AirBOS, one of the primary objectives was to flight test advanced equipment capable of high quality air-to-air schlieren imagery, to have ready for X-59’s Low-Boom Flight Demonstration, a mission that will use the X-59 to provide regulators with statistically valid data needed for potential regulation changes to enable quiet commercial supersonic flight over land.

While NASA has previously used the schlieren photography technique to study shockwaves, the AirBOS 4 flights featured an upgraded version of the previous airborne schlieren systems, allowing researchers to capture three times the amount of data in the same amount of time.

“We’re seeing a level of physical detail here that I don’t think anybody has ever seen before,” said Dan Banks, senior research engineer at NASA Armstrong. “Just looking at the data for the first time, I think things worked out better than we’d imagined. This is a very big step.”

Image above: The X-59 Quiet SuperSonic Technology X-plane, or QueSST, will test its quiet supersonic technologies by flying over communities in the United States. X-59 is designed so that when flying supersonic, people on the ground will hear nothing more than a quiet sonic thump – if anything at all. The scientifically valid data gathered from these community overflights will be presented to U.S. and international regulators, who will use the information to help them come up with rules based on noise levels that enable new commercial markets for supersonic flight over land. Image Credits: NASA Image.

Additional images included a “knife-edge” shot of a single T-38 in supersonic flight, as well as a slow-speed T-34 aircraft, to test the feasibility of visualizing an aircraft’s wing and flap vortices using the AirBOS system.

The images were captured from a NASA B-200 King Air, using an upgraded camera system to increase image quality. The upgraded system included the addition of a camera able to capture data with a wider field of view. This improved spatial awareness allowed for more accurate positioning of the aircraft. The system also included a memory upgrade for the cameras, permitting researchers to increase the frame rate to 1400 frames per second, making it easier to capture a larger number of samples. Finally, the system received an upgraded connection to data storage computers, which allowed for a much higher rate of data download. This also contributed to the team being able to capture more data per pass, boosting the quality of the images.

In addition to a recent avionics upgrade for the King Air, which improved the ability of the aircraft to be in the exact right place at the exact right time, the team also developed a new installation system for the cameras, drastically reducing the time it took to integrate them with the aircraft.

“With previous iterations of AirBOS, it took up to a week or more to integrate the camera system onto the aircraft and get it working. This time we were able to get it in and functioning within a day,” said Tiffany Titus, flight operations engineer. “That’s time the research team can use to go out and fly, and get that data.”

While the updated camera system and avionics upgrade on the B-200 greatly improved the ability to conduct these flights more efficiently than in previous series, obtaining the images still required a great deal of skill and coordination from engineers, mission controllers, and pilots from both NASA and Edwards’ U.S. Air Force Test Pilot School.

Image above: Using the schlieren photography technique, NASA was able to capture the first air-to-air images of the interaction of shockwaves from two supersonic aircraft flying in formation. These two U.S. Air Force Test Pilot School T-38 aircraft are flying in formation, approximately 30 feet apart, at supersonic speeds, or faster than the speed of sound, producing shockwaves that are typically heard on the ground as a sonic boom. The images, originally monochromatic and shown here as colorized composite images, were captured during a supersonic flight series flown, in part, to better understand how shocks interact with aircraft plumes, as well as with each other. Image Credit: NASA Photo.

In order to capture these images, the King Air, flying a pattern around 30,000 feet, had to arrive in a precise position as the pair of T-38s passed at supersonic speeds approximately 2,000 feet below. Meanwhile, the cameras, able to record for a total of three seconds, had to begin recording at the exact moment the supersonic T-38s came into frame.

“The biggest challenge was trying to get the timing correct to make sure we could get these images,” said Heather Maliska, AirBOS sub-project manager. “I’m absolutely happy with how the team was able to pull this off. Our operations team has done this type of maneuver before. They know how to get the maneuver lined up, and our NASA pilots and the Air Force pilots did a great job being where they needed to be.”

“They were rock stars.”

The data from the AirBOS flights will continue to undergo analysis, helping NASA refine the techniques for these tests to improve data further, with future flights potentially taking place at higher altitudes. These efforts will help advance knowledge of the characteristics of shockwaves as NASA progresses toward quiet supersonic research flights with the X-59, and closer toward a major milestone in aviation.

AirBOS was flown as a sub-project under NASA’s Commercial Supersonic Technology project.

Related article:

The future "Concorde" will have to be silent

Related links:

Aeronautics Research Mission Directorate:

NASA’s Commercial Supersonic Technology project:

Low-Boom Flight Demonstration (LBFD):


Images (mentioned), Text, Credits: NASA/Monroe Conner/Armstrong Flight Research Center/Matt Kamlet.

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Discovery Alert! Kepler's First Planet Candidate Confirmed, 10 Years Later

NASA - Kepler Mission patch.

March 6, 2019

Planet: Kepler-1658b

Discovered by: Chontos et al. using NASA’s Kepler telescope

Date: February 2019

Key Facts: This newly-confirmed exoplanet is a massive hot Jupiter that whips around its star every 3.85 days. From the surface, the star would appear 60 times larger in diameter than the Sun as seen from Earth.

Image above: An artist's concept of the Kepler-1658 system. Sound waves propagating through the stellar interior were used to characterize the star and the planet. Kepler-1658b, orbiting with a period of just 3.8 days, was the first exoplanet candidate discovered by Kepler nearly 10 years ago. Image Credit: Gabriel Perez Diaz/Instituto de Astrofísica de Canarias.

Details: Despite being the very first planet candidate discovered by NASA’s Kepler space telescope, Kepler-1658b had a rocky road to confirmation. The initial estimate of the planet’s host star was off, so the sizes of both the star and Kepler-1658b were vastly underestimated. It was later marked as a false positive — that is, scientists thought the data did not really point to a planet — when the numbers didn’t quite add up for the effects seen on its star for a body of that size. Kepler-1658b moved from planet candidate to false positive and back until new software was used to refine the data and reclassify it, changing it from a data anomaly to possible planet.

Fortuitously, a team at the University of Hawaii was poised to step in at just the right time. As part of her first year research project, lead author Ashley Chontos, a graduate student with the university’s Institute for Astronomy, went back through Kepler data looking for targets to reanalyze in 2017.

“Our new analysis, which uses stellar sound waves observed in the Kepler data to characterize the star, demonstrated that the star is in fact three times larger than previously thought. This in turn means that the planet is three times larger, revealing that Kepler-1658b is actually a hot Jupiter,” Chontos said. With this refined analysis, everything pointed to it being a real planet. Next came confirmation.

Kepler Space Telescope. Image Credits: NASA/JPL

“We alerted Dave Latham (a senior astronomer at the Smithsonian Astrophysical Observatory, and co-author on the paper) and his team collected the necessary spectroscopic data to unambiguously show that Kepler-1658b is a planet,” said Dan Huber, co-author and astronomer at the University of Hawaii. “As one of the pioneers of exoplanet science and a key figure behind the Kepler mission, it was particularly fitting to have Dave be part of this confirmation.”

What’s new: Kepler-1658b is one of the closest known planets orbiting a future version of our Sun, and revealed new constraints on the complex physical interactions that cause planets to spiral into their host stars. "Kepler-1658 is a perfect example of why a better understanding of host stars of exoplanets is so important," Chontos said. "It also tells us that there are many treasures left to be found in the Kepler data."

Read the paper: The Curious Case of KOI 4: Confirming Kepler’s First Exoplanet Detection:

Kepler and K2:

Images (mentioned), Text, Credits: NASA/Rick Chen.


mardi 5 mars 2019

AEgIS makes positronium for antimatter gravity experiments

CERN - European Organization for Nuclear Research logo.

5 March, 2019

The AEgIS collaboration at CERN has found a new way of making long-lived positronium atoms for antimatter gravity experiments 

Image above: The experimental set-up used by the AEgIS collaboration to make long-lived positronium (Image: Ruggero Caravita/CERN).

The universe is almost devoid of antimatter, and physicists haven’t yet figured out why. Discovering any slight difference between the behaviour of antimatter and matter in Earth’s gravitational field could shed light on this question. Positronium atoms, which consist of an electron and a positron, are one type of atimatter atoms being considered to test whether antimatter falls at the same rate as matter in Earth’s gravitational field. But they are short-lived, lasting a mere 142 nanoseconds – too little to perform an antimatter gravity experiment. Researchers are therefore actively seeking tricks to make sources of positronium atoms that live longer. In a paper published today in the journal Physical Review A, the AEgIS collaboration at CERN describes a new way of making long-lived positronium.

To be useful for antimatter gravity experiments, a source of positronium atoms needs to produce long-lived atoms in large numbers, and with known velocities that can be controlled and are unaffected by disturbances such as electric and magnetic fields. The new AEgIS source ticks all of these boxes, producing some 80 000 positronium atoms per minute that last 1140 nanoseconds each and have a known velocity (between 70 and 120 kilometres per second) that can be controlled with a high precision (10 kilometres per second).

The trick? Using a special positron-to-positronium converter to produce the atoms and a single flash of ultraviolet laser light that kills two birds with one stone. The laser brings the atoms from the lowest-energy electronic state to a long-lived higher-energy state and can select among all of the atoms only those with a certain velocity.

This is not the first time that researchers have produced a source of long-lived positronium atoms. There are other techniques that do so, including one that involves bringing the atoms to electronic states called Rydberg states, and which could also be used to perform gravity experiments with positronium. But all of these are very sensitive to electric and magnetic fields, which influence the atoms’ velocity and would need to be factored into future gravity measurements. The new method devised by AEgIS is “cleaner”, in that it is almost insensitive to these fields.

The next step on the long path to measuring the effect of gravity on positronium with the new AEgIS source (the AEgIS team and other CERN collaborations mainly plan to take measurements with antihydrogen atoms) will be to confirm that the atoms produced are electrically neutral. CERN’s accelerator complex is currently shut down for a major two-year upgrade programme, so most experiments at the Laboratory, which require a beam of protons, have ceased to operate during this period. An advantage of this positronium experiment is that it doesn’t require protons, so it can continue to be operated during the shutdown.


CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Related article:

New antimatter gravity experiments begin at CERN

Related links:


Physical Review:

For more information about European Organization for Nuclear Research (CERN), Visit:

Image (mentioned), Text, Credits: CERN/Ana Lopes.

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Crew Resumes Normal Ops Before Crew Dragon Leaves Friday

ISS - Expedition 58 Mission patch.

March 5, 2019

The three Expedition 58 crew members are back to normal operations today with the newest SpaceX Crew Dragon spaceship integrated to the International Space Station. Dragon will leave the station Friday as the next crew prepares to launch on March 14.

Astronauts Anne McClain and David Saint-Jacques called down to mission controllers today to discuss Crew Dragon operations. The duo also linked up with SpaceX personnel throughout the United States describing life on orbit and their impressions of the new crew vehicle.

Image above: Astronauts (from left) Anne McClain and David Saint Jacques are pictured in between a pair of spacesuits that are stowed and serviced inside the Quest airlock where U.S. spacewalks are staged. Image Credit: NASA.

McClain started today resizing U.S. spacesuits ahead of a set of spacewalks planned for March and April. She later worked on life support systems and plumbing maintenance in the Unity and Tranquility modules.

Saint-Jacques collected station water samples for microbial analysis. He then inspected tethers the astronauts will use to stay attached to the station during the upcoming spacewalks.

Image above: "The dawn of a new era in human spaceflight." — Astronaut Anne McClain. McClain had an unparalleled view from orbit of SpaceX's Crew Dragon spacecraft as it approached the International Space Station on Sunday, March 3, 2019. The Crew Dragon docked autonomously to the orbiting laboratory, a historic first for a commercially built and operated American crew spacecraft. This uncrewed test flight is providing valuable information to help verify that Crew Dragon will provide astronauts a safe, comfortable and enjoyable ride to space. Image Credit: NASA.

Commander Oleg Kononenko replaced fuel bottles used during experiment operations inside the Combustion Integrated Rack. The veteran cosmonaut also explored low temperature gas mixtures for the Plasma Krysyall-4 experiment collaboration between Europe and Russia.

The SpaceX Crew Dragon undocks Friday at 2:31 a.m. EST. Splashdown in the Atlantic Ocean is scheduled around 8:45 a.m. EST. NASA TV will cover all the activities live after closing the hatch Thursday.

Image above: Sunrise over Okhotsk Sea, seen by EarthCam on ISS, speed: 27'617 Km/h, altitude: 411,98 Km, image captured by Roland Berga (on Earth in Switzerland) from International Space Station (ISS) using ISS-HD Live application with EarthCam's from ISS on March 5, 2019 at 20:36 UTC. Image Credits: Aerospace/Roland Berga.

On the other side of the world in Kazakhstan, three new Expedition 59 crew members are in final training awaiting their launch to the station. Commander Alexey Ovchinin and Flight Engineers Nick Hague and Christina Koch are set to blastoff March 14 at 3:14 p.m. and dock less than six hours later to their new home in space.

Related links:

Expedition 58:

Expedition 59:


Unity module:

Tranquility module:

Combustion Integrated Rack:

Plasma Krysyall-4:

Space Station Research and Technology:

International Space Station (ISS):

Images (mentioned), Text, Credits: NASA/Mark Garcia/ Aerospace/Roland Berga.

Best regards,

Mars InSight Lander's 'Mole' Pauses Digging

NASA - InSight Mission patch.

March 5, 2019

NASA's Mars InSight lander has a probe designed to dig up to 16 feet (5 meters) below the surface and measure heat coming from inside the planet. After beginning to hammer itself into the soil on Thursday, Feb. 28, the 16-inch-long (40-centimeter-long) probe — part of an instrument called the Heat and Physical Properties Package, or HP3 — got about three-fourths of the way out of its housing structure before stopping. No significant progress was seen after a second bout of hammering on Saturday, March 2. Data suggests the probe, known as a "mole," is at a 15-degree tilt.

Scientists suspect it hit a rock or some gravel. The team had hoped there would be relatively few rocks below ground, given how few appear on the surface beside the lander. Even so, the mole was designed to push small rocks aside or wend its way around them. The instrument, which was provided for InSight by the German Aerospace Center (DLR), did so repeatedly during testing before InSight launched.

Image above: NASA's InSight lander set its heat probe, called the Heat and Physical Properties Package (HP3), on the Martian surface on Feb. 12. Image Credits: NASA/JPL-Caltech/DLR.

"The team has decided to pause the hammering for now to allow the situation to be analyzed more closely and jointly come up with strategies for overcoming the obstacle," HP3 Principal Investigator Tilman Spohn of DLR wrote in a blog post. He added that the team wants to hold off from further hammering for about two weeks.

Data show that the probe itself continues to function as expected: After heating by 50 degrees Fahrenheit (28 degrees Celsius), it measures how quickly that heat dissipates in the soil. This property, known as thermal conductivity, helps calibrate sensors embedded in a tether trailing from the back of the mole. Once the mole is deep enough, these tether sensors can measure Mars' natural heat coming from inside the planet, which is generated by radioactive materials decaying and energy left over from Mars' formation.

The team will be conducting further heating tests this week to measure the thermal conductivity of the upper surface. They will also use a radiometer on InSight's deck to measure temperature changes on the surface. Mars' moon Phobos will pass in front of the Sun several times this week; like a cloud passing overhead, the eclipse will darken and cool the ground around InSight.

For more details, visit DLR's blog:

For more information about InSight, visit:

Heat and Physical Properties Package (HP3):

Image (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Andrew Good.