vendredi 30 mars 2018

SpaceX - Iridium-5 Mission

SpaceX - Falcon 9 / Iridium-5 Mission patch.

March 30, 2018

Falcon 9 carrying 10 Iridium satellites launch

On Friday, March 30 at 7:13 a.m. PDT, SpaceX successfully launched the Iridium-5 mission from Space Launch Complex 4E (SLC-4E) at Vandenberg Air Force Base in California.

SpaceX - Iridium-5 Mission

This was the fifth set of 10 satellites in a series of 75 total satellites that SpaceX will launch for Iridium’s next generation global satellite constellation, Iridium® NEXT. The satellites were deployed about an hour after launch.

Iridium Next satellite

Falcon 9’s first stage for the Iridium-5 mission previously supported the Iridium-3 mission from SLC-4E in October 2017. SpaceX did not attempt to recover Falcon 9’s first stage after launch.

For more information about Iridium Next, visit:

For more information about SpaceX, visit:

Images, Video, Text, Credits: SpaceX/Iridium.


jeudi 29 mars 2018

Experienced Spacewalkers Wrap Up Station Maintenance Excursion

ISS - Expedition 55 Mission patch / EVA - Extra Vehicular Activities patch.

March 29, 2018

Images above: Spacewalker helmet camera view's during today spacewalk, images 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 29, 2018.

Expedition 55 Flight Engineers Drew Feustel and Ricky Arnold of NASA completed the fourth spacewalk this year at 3:43 p.m. EDT, lasting 6 hours, 10 minutes. The two astronauts installed wireless communications antennas on the Tranquility module, replaced a camera system on the port truss and removed suspect hoses from a cooling system.

Image above: There have been 209 spacewalks at the International Space Station since December 1998. Image Credit: NASA.

Spacewalkers have now spent a total of 54 days and 10 hours working outside the station in support of assembly and maintenance of the orbiting laboratory.

Related links:

Expedition 55:

International Space Station (ISS):

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

Best regards,

CASC - Long March 3B launches two Beidou-3 MEO satellites

CASC - China Aerospace Science and Technology Corporation logo / Beidou Navigation System logo.

March 29, 2018

Long March 3B carrying pair of Beidou-3 MEO satellites lift off.Image Credit: CNS

A Long March-3B/YZ-1 has orbited a new pair of navigation satellites in what was China’s ninth launch of the year. The launch of Beidou-3MEO5 (or Beidou-30) and Beidou-3MEO6 (or Beidou-31) took place at 17:56 UTC from the LC2 Launch Complex of the Xichang Satellite Launch Center, Sichuan province. It will take over four hours to complete the mission.

The MEO satellites are the Medium Earth Orbit component of the third phase of the Chinese Beidou (Compass) satellite navigation system. The satellites are part of a fleet that will expand the system to a global navigation coverage.

Beidou-3 navigation satellites launched by Long March-3B

The satellites are using a new bus that features a phased array antenna for navigation signals and a laser retroreflector, with a launch mass 1,014 kg. Spacecraft dimensions are noted to be 2.25 by 1.0 by 1.22 meters. Usually, the satellites reside in a 21,500 – 21,400 km nominal orbit at 55.5 degrees.

BeDou-3 satellite. Image Credit: J. Huart

The Beidou Phase III system includes the migration of its civil Beidou 1 or B1 signal from 1561.098 MHz to a frequency centered at 1575.42 MHz – the same as the GPS L1 and Galileo E1 civil signals – and its transformation from a quadrature phase shift keying (QPSK) modulation to a multiplexed binary offset carrier (MBOC) modulation similar to the future GPS L1C and Galileo’s E1.

For more information about China Aerospace Science and Technology Corporation (CASC), visit:

Images (mentioned), Video, Text, Credits: SciNews/NASA C. Barbosa.


Soyuz 2-1v Rocket Launch EMKA “Experimental Small Satellite”


March 29, 2018

Image above: File Image of a Soyuz 2-1v Rocket blasting off from Plesetsk. Image Credit: Russian MOD.

Russia conducted a secretive launch out of the country’s primary military spaceport on Thursday, involving what is officially only known as a Small Experimental Satellite going by the acronym EMKA and suspected to be a former remote-sensing satellite design turned into a black project by the Russian Ministry of Defence.

EMKA lifted off atop the fourth Soyuz 2-1v rocket at 17:38 UTC according to multiple Russian news outlets citing officials within Russia’s Space Forces that control military missions out of the Plesetsk Cosmodrome. Navigational warnings indicated the vehicle was heading north on a flight path consistent with a mission to Sun Synchronous Orbit or another type of polar orbit – the preferred orbital vantage point for imaging satellites of all types.

Soyuz 2-1v Rocket. Image Credit: TsKB Progress

Confirmation of successful orbital insertion was provided around 16 minutes after the evening liftoff and tracking data collected by the U.S. revealed the satellite and the rocket’s upper stage in an extraordinarily low Sun Synchronous Orbit of 316 x 318 Kilometers, 96.64°.

Soyuz 2-1v – developed as a light-lifter to take over after the limited supply of Rockot boosters runs out – has conducted four launches to date, debuting in December 2013 as the third member of the Soyuz 2 family.

Since then, Soyuz 2-1v has exclusively launched missions of a military or intelligence-gathering nature, lifting the ill-fated Kanopus-ST mission in 2015 and launching the still-mysterious three-satellite mission around Kosmos-2519 in June 2017.

Kanopus Satellite. Image Credit: VNIIEM

The designation “EMKA” first showed up in late November through insurance filings made for the satellite’s air transport to the Plesetsk Cosmodrome which in turn tied the project to Roscosmos subsidiary VNIIEM that is responsible for a number of satellite projects including the Kanopus, Meteor and Resurs-O remote sensing and weather satellites.

Images (mentioned), Text, Credits: Spaceflight101/ Aerospace.


ISRO - GSLV Successfully Launches GSAT-6A Satellite

ISRO - Indian Space Research Organisation logo.

Mar 29, 2018

GSLV-F08/GSAT-6A lift off

India's Geosynchronous Satellite Launch Vehicle (GSLV-F08) successfully launched GSAT-6A Satellite into Geosynchronous Transfer Orbit (GTO) today (March 29, 2018). Today’s launch of GSLV was its twelfth and took place from the Second Launch Pad at Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota, the spaceport of India. This is the fifth consecutive success achieved by GSLV carrying indigenously developed Cryogenic Upper Stage.

In its oval shaped GTO, GSAT-6A is now orbiting the Earth with a perigee (nearest point to Earth) of 169.4 km and an apogee (farthest point to Earth) of 36,692.5 km with an orbital inclination of 20.64 deg with respect to the equator.

GSLV-F08 Liftoff and Onboard Camera Video

Few seconds before the launch countdown reached zero, the four liquid propellant strap-on motors of GSLV-F08, each with nearly 43 tons of liquid propellants, were ignited. At count zero and after confirming the normal performance of all the four  strap-on motors, the 139 ton solid propellant first stage core motor was ignited and GSLV lifted off at 16:56 IST, as scheduled. The major phases of the flight occurred as intended.  About seventeen and a half minutes after lift-off, GSAT-6A was successfully placed in GTO.                                       .

Soon after separation from GSLV, the two solar arrays of GSAT-6A were automatically deployed in quick succession and the Master Control Facility (MCF) at Hassan in Karnataka assumed control of the satellite.

GSAT-6A Satellite

GSAT-6A is a communication satellite built by ISRO to provide mobile communication services through multi beam coverage.  For this, it is equipped with S and C band transponders.

In the coming days, the orbit of GSAT-6A will be raised from its present GTO to the final circular Geostationary Orbit (GSO) by firing the satellite's Liquid Apogee Motor (LAM) in stages. The Satellite will be commissioned into service after the completion of orbit raising operations and its positioning in the designated slot in GSO following in-orbit testing of its payloads.

GSLV-F08  is the 12th flight of Geosynchronous Satellite Launch Vehicle (GSLV) and Sixth flight with indigenous Cryogenic Stage. The Launch of GSLV-F08 carrying GSAT-6A took place from the Second Launch Pad (SLP) in Satish Dhawan Space Centre SHAR, Sriharikota.

GSAT-6A, similar to GSAT-6 is a high power S-band communication satellite configured around I-2K bus. The mission life of spacecraft planned is about 10 years. The satellite will also provide a platform for developing technologies such as demonstration of 6 m S-Band Unfurlable Antenna, handheld ground terminals and network management techniques that could be useful in satellite based mobile communication applications.

GSLV F08-GSAT6A Brochure:

For more information about Indian Space Research Organisation (ISRO), visit:

Images, Video, Text, Credit: ISRO.

Best regards,

mercredi 28 mars 2018

Space Station Science Highlights: Week of Mar 19, 2018

ISS - Expedition 55 Mission patch.

March 28, 2018

International Space Station (ISS). Image Credits: NASA/STS-134

The crew members aboard the International Space Station were busy last week with many hours of scientific operations as they awaited the arrival of three new crew members and planned for an upcoming spacewalk.

NASA’s Ricky Arnold, Drew Feustel and Oleg Artemyev, a cosmonaut out of Roscosmos, arrived to the space station after launching inside the Soyuz MS-08 spacecraft Wednesday March 21 from the Baikonur Cosmodrome in Kazakhstan. They joined the rest of the Expedition 55 crew, who have been living and working aboard the space station since Dec. 19.

Image above: Mizuna and Green Lettuce growing within plant pillows as a part of the Veg-03 investigation. Image Credit: NASA.

Take a look at some of the science that happened this week aboard your orbiting laboratory:

Investigation tests adjustable lighting options to encourage better sleep

The hazards of lost sleep can range from on-the-job errors to chronic disease. People all around the world experience disruptions in circadian rhythm, or the body’s natural regulator for sleep and wake cycles based on a 24-hour schedule, every day. This instinctual process can be disrupted by abnormal work schedules, extensive traveling between time zones, and by daily life for space crew members, who could experience 16 sunrises a day.

The Testing Solid State Lighting Countermeasures to Improve Circadian Adaptation, Sleep, and Performance During High Fidelity Analog and Flight Studies for the International Space Station (Lighting Effects) investigation studies the impact of the change from fluorescent light bulbs to solid-state light-emitting diodes (LEDs) with adjustable intensity and color and aims to determine if the new lights can improve crew circadian rhythms, sleep, and cognitive performance.

Animation above: The Advanced Combustion Microgravity Experiment (ACME) investigation is a set of studies of gaseous flames to be conducted in the Combustion Integration Rack (CIR), one of which being Electric-Field Effects on Laminar Diffusion Flames (E-FIELD Flames). In E-FIELD Flames, an electric field with voltages as high as 10,000 volts is established between the burner and a mesh electrode. Animation Credit: NASA.

Last week, crew members completed daily sleep logs, noting sleep patterns and periods of wakefulness. Information collected during this investigation will be used to develop more efficient lighting both in space and on Earth. Learn more about adjusting to sleep disruptions here.

Instrument starts collection of data

NASA's Total and Spectral Solar Irradiance Sensor, or TSIS-1, measures the sun's energy input to Earth. Various satellites have captured a continuous record of this solar energy input to Earth since 1978. TSIS-1 sensors advance previous measurements with three times the accuracy, enabling scientists to study the sun’s natural influence on Earth’s ozone layer, atmospheric circulation, clouds, and ecosystems. These observations are essential for a scientific understanding of the effects of solar variability on the Earth system.

Last week marks the completion of the check-out process of the TSIS instrument since its arrival on the SpaceX CRS-13 and the start of the five-year data collection process.

Sensors track astronaut sleeping habits

In addition to studying alternative lighting options to improve sleeping habits in space, researchers are also examining changes in in circadian rhythms in humans during long-term spaceflight. The Circadian Rhythms investigation provides important insight into adaptations of the human autonomic nervous system in space over time and helps to improve physical exercise plans, rest- and work shifts and fosters adequate workplace illumination during future spaceflight.

Animation above: JAXA astronaut Norishige Kanai conducts maintenance on the Fluid Integration Rack (FIR). Animation Credit: NASA.

Last week, a crew member began the experiment by donning the Thermolab Double sensors, a wearable sensor, and then removing it 36 hours later.

Camera records full Earth rotation for television series

The space station offers vantage points not available from any other location on Earth. The National Geographic Channel–Virtual Reality Educational Video for Television Series–"One Strange Rock" (One Strange Rock Virtual Reality) investigation brings the space station into homes by capturing day-in-the-life style footage of the crew aboard the station. Each episode in the series will feature a different crew member and address different natural history and solar system topics, raising awareness of the space program and the Earth as a life-support system.

Last week, the crew opened all Cupola Window shutters and deployed the NanoRacks Vuze Camera to record views for one full Earth rotation, including sunrise and sunset.

Space to Ground: Night Launch: 03/23/2018

Video Credit: NASA Johnson.

Other work was done on these investigations: Crew Earth Observations, Veg-03,  MagVector (supporting WiseNet), Space Headaches, Transparent Alloys, DOSIS-3D, EIISS,  VESSEL ID, ACME E-FIELD Flames, Two Phase Flow, Fluids Integrated Rack (FIR), Manufacturing Device, Rodent Research-6, and Tropical Cyclone.

Related links:

Lighting Effects:

Total and Spectral Solar Irradiance Sensor (TSIS-1):

SpaceX CRS-13:

Circadian Rhythms:

One Strange Rock Virtual Reality:


Crew Earth Observations:



Space Headaches:

Transparent Alloys:





Two Phase Flow:

Manufacturing Device:

Rodent Research-6:

Tropical Cyclone:

Expedition 55:

Space Station Research and Technology:

International Space Station (ISS):

Images (mentioned), Animations (mentioned), Video (mentioned), Text, Credits: NASA/Erling Holm/Yuri Guinart-Ramirez, Lead Increment Scientist Expeditions 55 & 56.


Cargo Ship Departs, Emergency Reviews Day Before Spacewalk Begins

ISS - Expedition 55 Mission patch.

March 28, 2018

Image above: Russia’s Progress 68 resupply ship is pictured docked to the Pirs docking compartment as the International Space Station orbited over the Atlantic Ocean south of the island of Bermuda. Image Credit: NASA.

A Russian cargo craft departed the International Space Station this morning after completing a six-month stay at the Pirs docking compartment. Meanwhile, the Expedition 55 crew is less than a day away from beginning the fourth spacewalk this the year for orbital lab maintenance.

Russia’s Progress 68 (68P) resupply ship flawlessly undocked from Pirs this morning at 9:50 a.m. EDT. It will orbit Earth for a month where Russian ground controllers will conduct a series of engineering tests on the 68P. The cargo ship will then reenter the atmosphere April 25 loaded with trash and discarded items for a fiery but safe demise over the Pacific Ocean.

Image above: Flying over South Atlantic Ocean seen by EarthCam on ISS, speed: 27'604 Km/h, altitude: 406,23 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 28, 2018 at 16:40 UTC.

While a pair of astronauts are finalizing spacewalk preparations today, the six Expedition 55 crew members spent an hour today reviewing emergency roles and responsibilities. The four astronauts and two cosmonauts practiced communication procedures with each other and mission controllers on the ground. The crew also checked the location of safety gear and followed escape routes to their Soyuz vehicles in the unlikely event a crisis would require evacuating the station.

Finally, spacewalkers Ricky Arnold and Drew Feustel have their tools and suits ready for Thursday’s excursion to install antennas and replace a camera assembly outside the space station. The duo wrapped up final reviews today with Flight Engineers Scott Tingle and Norishige Kanai who will assist the spacewalkers in and out of their spacesuits. The spacewalk is expected to start at 8:10 a.m. tomorrow with NASA TV beginning its live coverage at 6:30 a.m.

Related links:


SpaceX Dragon:

Expedition 55:

International Space Station (ISS):

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

Best regards,

CERN experiment sees hints of a rare kaon decay

CERN - European Organization for Nuclear Research logo.

March 28, 2018

Image above: NA62 experiment in CERN's North Area. (Image: NA62/CERN).

What if the odds of an event occurring were about one in ten billion? This is the case for the decay of a positively charged particle known as a kaon into another positively charged particle called a pion and a neutrino–antineutrino pair. Yet, such a rare event, which has never been observed with certainty, is something that particle physicists really want to get their hands on. The reason? The Standard Model predicts such one-in-ten-billion odds with an uncertainty of less than ten percent. A deviation from this prediction, revealed by a precise measurement of the decay, could therefore be a clear indicator of physics beyond the Standard Model.

In a seminar taking place today at CERN, the NA62 collaboration reports a candidate event of this ultra-rare kaon decay found using a new “in-flight decay” approach. While this single event cannot be used to probe beyond-Standard-Model physics, it demonstrates that the approach works well and can be applied to catch more events in the next run of data-taking, which kicks off in mid-April. The result was also presented earlier this month at the Rencontres de Moriond conference in La Thuile, Italy.

To look for kaon decays, the NA62 team first makes beams rich in kaons by firing high-energy protons from the Super Proton Synchrotron (SPS) accelerator into a beryllium target. The collision creates a beam of nearly one billion particles per second, only about 6% of which are kaons. Next, the team sends the beam through a Cherenkov detector, which positively identifies the kaons from the Cherenkov radiation that they produce. A silicon-pixel detector then determines the momentum of the kaons with a time resolution of 100 picoseconds (1 picosecond is one trillionth of a second). A device called a straw tracker, placed inside the vacuum tank, in turn measures the momentum of the charged daughter particles into which the kaons decay, and another Cherenkov detector called RICH determines the particles’ type. Other devices known as calorimeters reject unwanted background events with photons and muons.

In their analysis of data taken over the course of 2016, the NA62 team identified a candidate event of the decay of a positively charged kaon into a positively charged pion and a neutrino–antineutrino pair that escapes undetected. The result allowed the researchers to put an upper limit on the relative frequency, or “branching fraction”, of the decay of 14 in 10 billion. The result is compatible with the Standard-Model prediction, which is 8.4 in 100 billion (with an uncertainty of 1), but more data is needed to probe beyond-Standard-Model theories, which predict deviations from the Standard-Model value.

Graphic above: NA62’s candidate event of a rare kaon decay. Octagons show hits in the RICH detector. Circles show predicted “Cherenkov rings” for positively charged pion (π+), positively charged muon (μ+) and antielectron (e+) decay particles. (Image: NA62/CERN).

This is not the first time that hints of this decay have been observed. Several candidate events have been previously reported by the E949 experiment and its predecessor E787 at Brookhaven National Laboratory in Long Island, New York. These candidate events have been used to infer a branching fraction of 17.3 in 100 billion (with an uncertainty of about 11), which is consistent, within large errors, with the Standard-Model prediction.

But there is a difference between the Brookhaven experiments and NA62: whereas the former observed the kaon decays with the particles at rest in a target, NA62 observes them while the particles are in flight within the vacuum tank. This new in-flight approach has advantages because it provides much more room for detection and background-event immunity.

The NA62 team expects to identify more events of the rare kaon decay in the ongoing analysis of a twenty-fold-larger dataset taken in 2017, and it will begin taking data again in mid-April for a record number of 218 days. If all goes to plan, the collaboration should be able to measure the branching fraction of the decay with a small enough uncertainty to make a precise test of the Standard Model.


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.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Related links:

Standard Model:


Rencontres de Moriond conference:

Super Proton Synchrotron (SPS):

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

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

Best regards,

‘Marsquakes’ Could Shake Up Planetary Science

NASA - InSight Mission logo.

March 28, 2018

Starting next year, scientists will get their first look deep below the surface of Mars.

That's when NASA will send the first robotic lander dedicated to exploring the planet's subsurface. InSight, which stands for Interior Exploration using Seismic Investigations, will study marsquakes to learn about the Martian crust, mantle and core.

Doing so could help answer a big question: how are planets born?

Seismology, the study of quakes, has already revealed some of the answers here on Earth, said Bruce Banerdt, Insight's principal investigator at NASA's Jet Propulsion Laboratory, Pasadena, California. But Earth has been churning its geologic record for billions of years, hiding its most ancient history. Mars, at half the size of Earth, churns far less: it's a fossil planet, preserving the history of its early birth.

Mars in a Minute: Are There Quakes on Mars?

Video above: Are there earthquakes on Mars? Or rather, "marsquakes?" And what could they teach us about the Red Planet? Video Credits: NASA/JPL-Caltech.

"During formation, this ball of featureless rock metamorphosed into a diverse and fascinating planet, almost like caterpillar to a butterfly," Banerdt said. "We want to use seismology to learn why Mars formed the way it did, and how planets take shape in general."

A Planetary CT Scan

When rocks crack or shift, they give off seismic waves that bounce throughout a planet. These waves, better known as quakes, travel at different speeds depending on the geologic material they travel through.

Seismometers, like InSight's SEIS instrument, measure the size, frequency and speed of these quakes, offering scientists a snapshot of the material they pass through.

"A seismometer is like a camera that takes an image of a planet's interior," Banerdt said. "It's a bit like taking a CT scan of a planet."

Image above: An artist’s rendition of the InSight lander operating on the surface of Mars. Image Credits: NASA/JPL-Caltech.

Mars' geologic record includes lighter rocks and minerals -- which rose from the planet’s interior to form the Martian crust -- and heavier rocks and minerals that sank to form the Martian mantle and core. By learning about the layering of these materials, scientists can explain why some rocky planets turn into an "Earth" rather than a "Mars" or "Venus" -- a factor that is essential to understanding where life can appear in the universe.

A Fuzzy Picture

Each time a quake happens on Mars, it will give InSight a "snapshot" of the planet's interior. The InSight team estimates the spacecraft will see between a couple dozen to several hundred quakes over the course of the mission. Small meteorites, which pass through the thin Martian atmosphere on a regular basis, will also serve as seismic "snapshots."

"It will be a fuzzy picture at first, but the more quakes we see, the sharper it will get," Banerdt said.

One challenge will be getting a complete look at Mars using only one location. Most seismology on Earth takes measurements from multiple stations. InSight will have the planet's only seismometer, requiring scientists to parse the data in creative ways.

"We have to get clever," Banerdt said. "We can measure how various waves from the same quake bounce off things and hit the station at different times."

Moonquakes and Marsquakes

InSight won't be the first NASA mission to do seismology.

The Apollo missions included four seismometers for the Moon. Astronauts exploded mortar rounds to create vibrations, offering a peek about 328 feet (100 meters) under the surface. They crashed the upper stages of rockets into the Moon, producing waves that enabled them to probe its crust. They also detected thousands of genuine moonquakes and meteorite impacts.

The Viking landers attempted to conduct seismology on Mars in the late 1970s. But those seismometers were located on top of the landers, which swayed in the wind on legs equipped with shock absorbers.

"It was a handicapped experiment," Banerdt said. "I joke that we didn't do seismology on Mars -- we did it three feet above Mars."

Image above: Artist’s rendition showing the inner structure of Mars. The topmost layer is known as the crust, underneath it is the mantle, which rests on an inner core. Image Credits: NASA/JPL-Caltech.

InSight will measure more than seismology. The Doppler shift from a radio signal on the lander can reveal whether the planet's core is still molten; a self-burrowing probe is designed to measure heat from the interior. Wind, pressure and temperature sensors will allow scientists to subtract vibrational "noise" caused by weather. Combining all this data will give us the most complete picture of Mars yet.

JPL, a division of Caltech in Pasadena, manages the InSight Project for NASA's Science Mission Directorate, Washington. Lockheed Martin Space in Denver, Colorado, built and tested the spacecraft. InSight is part of NASA's Discovery Program, which is managed by NASA's Marshall Space Flight Center in Huntsville, Alabama.

For more information about InSight:

Related link:

InSight's SEIS instrument:

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


Dark Matter Goes Missing in Oddball Galaxy

NASA - Hubble Space Telescope patch.

March 28, 2018

Galaxies and dark matter go together like peanut butter and jelly. You typically don't find one without the other.

Therefore, researchers were surprised when they uncovered a galaxy that is missing most, if not all, of its dark matter. An invisible substance, dark matter is the underlying scaffolding upon which galaxies are built. It's the glue that holds the visible matter in galaxies — stars and gas — together.

"We thought that every galaxy had dark matter and that dark matter is how a galaxy begins," said Pieter van Dokkum of Yale University in New Haven, Connecticut, lead researcher of the Hubble observations. "This invisible, mysterious substance is the most dominant aspect of any galaxy. So finding a galaxy without it is unexpected. It challenges the standard ideas of how we think galaxies work, and it shows that dark matter is real: it has its own separate existence apart from other components of galaxies. This result also suggests that there may be more than one way to form a galaxy."

Hubble Views Galaxy Lacking Dark Matter

Video above: NASA's Hubble Space Telescope took an image of a bizarre, ghostly looking galaxy called NGC 1052-DF2 that astronomers calculate to have little to no dark matter. This is the first galaxy astronomers have discovered to be so lacking in dark matter, which is thought to comprise 85% of our universe's mass.
Video Credits: NASA's Goddard Space Flight Center/Scientific Visualization Studio.

The unique galaxy, called NGC 1052-DF2, contains at most 1/400th the amount of dark matter that astronomers had expected. The galaxy is as large as our Milky Way, but it had escaped attention because it contains only 1/200th the number of stars. Given the object's large size and faint appearance, astronomers classify NGC 1052-DF2 as an ultra-diffuse galaxy. A 2015 survey of the Coma galaxy cluster showed these large, faint objects to be surprisingly common.

But none of the ultra-diffuse galaxies discovered so far have been found to be lacking in dark matter. So even among this unusual class of galaxy, NGC 1052-DF2 is an oddball.

Van Dokkum and his team spotted the galaxy with the Dragonfly Telephoto Array, a custom-built telescope in New Mexico they designed to find these ghostly galaxies. They then used the W.M. Keck Observatory in Hawaii to measure the motions of 10 giant groupings of stars called globular clusters in the galaxy. Keck revealed that the globular clusters were moving at relatively low speeds, less than 23,000 miles per hour. Stars and clusters in the outskirts of galaxies containing dark matter move at least three times faster. From those measurements, the team calculated the galaxy's mass. "If there is any dark matter at all, it's very little," van Dokkum explained. "The stars in the galaxy can account for all the mass, and there doesn't seem to be any room for dark matter."

The researchers next used NASA's Hubble Space Telescope and the Gemini Observatory in Hawaii to uncover more details about the unique galaxy. Gemini revealed that the galaxy does not show signs of an interaction with another galaxy. Hubble helped them better identify the globular clusters and measure an accurate distance to the galaxy.

Image above: This large, fuzzy-looking galaxy is so diffuse that astronomers call it a “see-through” galaxy because they can clearly see distant galaxies behind it. The ghostly object, catalogued as NGC 1052-DF2, doesn’t have a noticeable central region, or even spiral arms and a disk, typical features of a spiral galaxy. But it doesn’t look like an elliptical galaxy, either. Even its globular clusters are oddballs: they are twice as large as typical stellar groupings seen in other galaxies. All of these oddities pale in comparison to the weirdest aspect of this galaxy: NGC 1052-DF2 is missing most, if not all, of its dark matter. Image Credits: NASA, ESA, and P. van Dokkum (Yale University).

The Hubble images also revealed the galaxy's unusual appearance. "I spent an hour just staring at the Hubble image," van Dokkum recalled. "It's so rare, particularly these days after so many years of Hubble, that you get an image of something and you say, 'I've never seen that before.' This thing is astonishing: a gigantic blob that you can look through. It's so sparse that you see all of the galaxies behind it. It is literally a see-through galaxy."

The ghostly galaxy doesn't have a noticeable central region, or even spiral arms and a disk, typical features of a spiral galaxy. But it doesn't look like an elliptical galaxy, either. The galaxy also shows no evidence that it houses a central black hole. Based on the colors of its globular clusters, the galaxy is about 10 billion years old. Even the globular clusters are oddballs: they are twice as large as typical stellar groupings seen in other galaxies.

"It's like you take a galaxy and you only have the stellar halo and globular clusters, and it somehow forgot to make everything else," van Dokkum said. "There is no theory that predicted these types of galaxies. The galaxy is a complete mystery, as everything about it is strange. How you actually go about forming one of these things is completely unknown."

But the researchers do have some ideas. NGC 1052-DF2 resides about 65 million light-years away in a collection of galaxies that is dominated by the giant elliptical galaxy NGC 1052. Galaxy formation is turbulent and violent, and van Dokkum suggests that the growth of the fledgling massive galaxy billions of years ago perhaps played a role in NGC 1052-DF2's dark-matter deficiency.

Another idea is that gas moving toward the giant elliptical NGC 1052 may have fragmented and formed NGC 1052-DF2. The formation of NGC 1052-DF2 may have been helped by powerful winds emanating from the young black hole that was growing in the center of NGC 1052. These possibilities are speculative, however, and don't explain all of the characteristics of the observed galaxy, the researchers said.

Hubble Space Telescope (HST). Animation Credits: NASA/ESA

The team is already hunting for more dark-matter deficient galaxies. They are analyzing Hubble images of 23 other diffuse galaxies. Three of them appear similar to NGC 1052-DF2.

"Every galaxy we knew about before has dark matter, and they all fall in familiar categories like spiral or elliptical galaxies," van Dokkum said. "But what would you get if there were no dark matter at all? Maybe this is what you would get."

The team's results will appear in the March 29, 2018, issue of the journal Nature.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

For images and more information about galaxy NGC 1052-DF2 and Hubble, visit:

NASA's Hubble Portal:

The science paper:

HubbleSite link:

Image (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/Karl Hille/Space Telescope Science Institute/Donna Weaver/Ray Villard/Yale University/Pieter van Dokkum.

Best regards,

mardi 27 mars 2018

The Chinese space station will fall from the sky like Easter eggs

CASC - Tiangong-1 Mission patch.

March 27, 2018

The end of Tiangong-1, the Chinese station out of control since the end of 2016, is near. It should hit the ground between March 29th and April 3rd.


According to legend, at Easter, eggs made of sugar or chocolate would fall bells for the delight of little gourmands.

This year, in addition to treats, it's a space station that will fall from the sky. Indeed, it has been several months since Tiangong-1, owned by the Chinese space agency, began its descent on earth. The only problem, since the end of 2016 the "Heaven Palace", its English name, is out of control.

Video above: World exlcusive higly topical radar image video of Tiangong-1 based on data recorded today! Altitude: 200,5 km perigee, Rotation speed has increased, now 2,2 °/s -> 2:23 min per one turn. Video Credit: Fraunhofer FHR.

If we mentioned southern Europe as an impact point, it seems risky to say exactly where the machine will land. However, we know more or less when. Last Thursday, the National Center for Space Studies (Cnes, France) and the European Space Agency (Esa) raised a window between March 29 and April 3. Probably March 31, according to experts. Precisions should be further refined in the coming weeks, says the daily Sud Ouest.

Not enough to panic

Tiangong-1 radar images

As for the location of the impact, the uncertainty will be up to the last 24 hours preceding the entry into the atmosphere of the space station. "The inclination of the orbit of the Chinese station is about 42.8 degrees, explains South West Stéphane Christy, expert at the National Center for Space Studies of Toulouse. This means that if we project this orbit on a planisphere, the land area on which the object will fall is a band between latitudes - 42.8 ° and + 42.8 °.

Tiangong-1 radar images

Although Tiangong-1 is a big cylinder of about 10 meters long for 8.5 tons, there is nothing to worry about. Citing a NASA report from 2011, the French newspaper recalls in particular that the probability that space debris affects a human being to about 1 in 3,200.

Related articles:

Chinese space station risks crashing in France

Uncontrolled crash on Earth of a Chinese space station

Related link:

Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR:

Images , Video (mentioned), Text, Credits: DRI/CASC/Fraunhofer FHR/ Aerospace/Roland Berga.


Expedition 55 Focuses on Spacewalk and Dragon Delivery

ISS - Expedition 55 Mission patch.

March 27, 2018

International Space Station (ISS). Animation Credit: NASA

The Expedition 55 crew is ramping up for Thursday’s spacewalk and training for next week’s arrival of the SpaceX Dragon resupply ship.

Just four days after moving into their new home NASA astronauts Ricky Arnold and Drew Feustel are getting their suits and gear ready for a spacewalk on Thursday. The duo filled spacesuit tanks and cooling garments with water and reviewed checklists and warning systems today.

They will work outside for about 6.5 hours to install communications antennas on the Tranquility module. The pair will also replace a camera assembly on the Port 1 truss structure. Arnold and Feustel are expected to set their spacesuits to battery power at 8:10 a.m. signifying the official start of Thursday’s spacewalk. NASA TV will begin its live coverage of the spacewalk at 6:30 a.m. ET.

Image above: NASA astronaut Andrew Feustel is pictured during a spacewalk in May of 2011 at the International Space Station. Feustel was a mission specialist for STS-134 who last visited the station aboard space shuttle Endeavour. Image Credit: NASA.

Meanwhile, Flight Engineers Norishige Kanai and Scott Tingle continue training for next week’s capture of the Dragon cargo craft with the Canadarm2 robotic arm. Kanai will be at the robotics controls inside the cupola as Tingle monitors Dragon’s approach and rendezvous.

Dragon is set to launch Monday at 4:30 p.m. and arrive Wednesday just ten meters away from the station where Kanai will robotically capture it at 7 a.m. The commercial cargo craft will deliver over 5,800 pounds of crew supplies, science gear, spacewalking equipment and other station hardware. NASA TV will broadcast both events live.

The Progress 68 (68P) cargo craft will undock from the Pirs docking compartment Wednesday at 9:50 a.m. loaded with trash and old gear. It will reenter Earth’s atmosphere April 25 for a fiery demise over the Pacific Ocean. The 68P has been attached to the station since Oct. 16.

Related links:


SpaceX Dragon:

Expedition 55:

International Space Station (ISS):

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

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New Study Shows What Interstellar Visitor ‘Oumuamua Can Teach Us

Asteroid Watch logo.

March 27, 2018

The first interstellar object ever seen in our solar system, named ‘Oumuamua, is giving scientists a fresh perspective on the development of planetary systems. A new study by a team including astrophysicists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, calculated how this visitor from outside our solar system fits into what we know about how planets, asteroids and comets form.

On Oct. 19, 2017, astronomers working with the NASA-funded Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1) at the University of Hawaii spotted an object zipping through our solar system at a very high speed. Scientists at the Minor Planet Center, funded by NASA’s Near-Earth Object Observations Program, confirmed it was the first object of interstellar origin that we’ve seen. The team dubbed it ‘Oumuamua (pronounced oh-MOO-ah-MOO-ah), which means “a messenger from afar arriving first” in Hawaiian — and it’s already living up to its name.

“This object was likely ejected from a distant star system,” said Elisa Quintana, an astrophysicist at Goddard. “What’s interesting is that just this one object flying by so quickly can help us constrain some of our planet formation models.”

Image above: An illustration of ‘Oumuamua, the first object we’ve ever seen pass through our own solar system that has interstellar origins. Image Credits: European Southern Observatory/M. Kornmesser.

On Sept. 19, ‘Oumuamua sped past the Sun at about 196,000 mph (315,400 km/h), fast enough to escape the Sun’s gravitational pull and break free of the solar system, never to return. Usually, an object traveling at a similar speed would be a comet falling sunward from the outer solar system. Comets are icy objects that range between house-sized to many miles across. But they usually shed gas and dust as they approach the Sun and warm up. ‘Oumuamua didn’t. Some scientists interpreted this to mean that ‘Oumuamua was a dry asteroid.

Planets and planetesimals, smaller objects that include comets and asteroids, condense out of disks of dust, gas and ice around young stars. Smaller objects that form closer to their stars are too hot to have stable surface ice and become asteroids. Those that form farther away use ice as a building block and become comets. The region where asteroids develop is relatively small.

“The total real estate that’s hot enough for that is almost zero,” said lead author Sean Raymond, an astrophysicist at the French National Center for Scientific Research and the University of Bordeaux. “It’s these tiny little circular regions around stars. It’s harder for that stuff to get ejected because it’s more gravitationally bound to the star. It’s hard to imagine how ‘Oumuamua could have gotten kicked out of its system if it started off as an asteroid.”

The distance from a star beyond which water stays ice, even if it’s exposed to sunlight, is called the snow line or ice line. In our own solar system, for example, objects that developed within three times the distance between the Sun and Earth would have been so hot that they lost all their water. That snow line contracted a little as the Sun shrank and cooled over time, but our main belt asteroids are located within or near our snow line — close enough to the Sun that it would be difficult to be ejected.

“If we understand planet formation correctly, ejected material like ‘Oumuamua should be predominantly icy,” said Thomas Barclay, an astrophysicist at Goddard and the University of Maryland, Baltimore County. “If we see populations of these objects that are predominantly rocky, it tells us we’ve got something wrong in our models.”

Scientists suspect most ejected planetesimals come from systems with giant gas planets. The gravitational pull of these massive planets can fling objects out of their system and into interstellar space. Systems with giant planets in unstable orbits are the most efficient at ejecting these smaller bodies because as the giants shift around, they come into contact with more material. Systems that do not form giant planets rarely eject material.

Using simulations from previous research, Raymond and colleagues showed that a small percentage of objects get so close to gas giants as they’re ejected that they should be torn into pieces. The researchers believe the strong gravitational stretching that occurs in these scenarios could explain ‘Oumuamua’s long, thin cigar-like shape.

The researchers calculated the number of interstellar objects we should see, based on estimates that a star system likely ejects a couple of Earth-masses of material during planet formation. They estimated that a few large planetesimals will hold most of that mass but will be outnumbered by smaller fragments like ‘Oumuamua. The results were published March 27 in the journal Monthly Notices of the Royal Astronomical Society.

The findings have already been partially confirmed by observations of the object’s color. Other studies have also noted that star systems like our own would be more likely to eject comets than asteroids. Future observatories like the National Science Foundation-funded Large Synoptic Survey Telescope could help scientists spot more of these objects and improve our statistical understanding of planet and planetesimal formation — even beyond our solar system.

“Even though this object was flying through our solar system, it does have implications for extrasolar planets and finding other Earths,” Quintana said.

Related articles:

Solar System’s First Interstellar Visitor Dazzles Scientists

ESO Observations Show First Interstellar Asteroid is Like Nothing Seen Before

Related links:

Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1):

Large Synoptic Survey Telescope:

Monthly Notices of the Royal Astronomical Society:

Other studies:

Image (mentioned), Text, Credits: NASA/Rob Garner/Goddard Space Flight Center, by Jeanette Kazmierczak.


lundi 26 mars 2018

New Station Astronauts March into Spacewalk Preparations

ISS - Expedition 55 Mission patch.

March 26, 2018

Three new Expedition 55 crew members are beginning their first full workweek aboard the International Space Station. They and the rest of the crew are getting ready for a spacewalk on Thursday and next week’s arrival of the SpaceX Dragon cargo craft.

Image above: Flying over Austral Ocean seen by EarthCam on ISS, speed: 27'576 Km/h, altitude: 418,29 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 26, 2018 at 11:56 UTC.

NASA astronauts Ricky Arnold and Drew Feustel are preparing for a spacewalk just six days after arriving at their new home in space. The duo reviewed their spacewalk procedures today with fellow astronauts Scott Tingle and Norishige Kanai. The veteran spacewalkers will install communications antennas and replace a camera assembly during the excursion set to begin Thursday at 8:10 a.m. EDT. NASA TV broadcast the spacewalk activities live beginning at 7 a.m.

Expedition 55 Commander Anton Shkaplerov has been packing a Russian resupply ship with trash and old gear readying it for its departure on Wednesday. The Progress 68 (68P) cargo craft will undock from the Pirs docking compartment Wednesday at 9:50 a.m. It will reenter Earth’s atmosphere April 25 for a fiery demise over the Pacific Ocean. The 68P has been attached to the station since Oct. 16.

Image above: NASA astronaut Scott Tingle is inside the International Space Station’s window to the world, the seven-windowed cupola, where astronauts operate the Canadarm2 robotic arm to capture visiting vehicles such as the SpaceX Dragon, the Orbital ATK Cygnus and Japan’s H-II Transfer Vehicle. Image Credit: NASA.

The next cargo craft due to resupply the station is the SpaceX Dragon. After its launch April 2 at 4:30 p.m. Dragon will take a two-day flight to the station. The commercial cargo craft will be robotically captured and installed next Wednesday at 6 a.m. to the Earth-facing port of the Harmony module.

Kanai and Tingle will be at the robotics controls inside the cupola when they capture Dragon with the Canadarm2 robotic arm. The duo practiced the Dragon rendezvous and capture procedures today. The crew has also been configuring the orbital lab for the new science experiments Dragon is delivering next week.

Related links:


SpaceX Dragon:

Expedition 55:

International Space Station (ISS):

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

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Kepler Beyond Planets: Finding Exploding Stars

NASA - Kepler Space Telescope patch.

March 26, 2018

Image above: A new study describes the most extreme known example of a "fast-evolving luminous transient" (FELT) supernova.Image Credits: NASA/JPL-Caltech.

Fast Facts:

- The Kepler space telescope, famous for finding exoplanets, has also been valuable in tracking exploding stars known as supernovae

- Supernovae forge heavy elements -- materials that make up the world in which we live -- and distribute them

- Through creative engineering, Kepler has had a second life in finding both exoplanets and other astrophysical phenomena

- Kepler's current observing campaign is a rare opportunity to coordinate with ground-based telescopes to look for supernovae

Astronomer Ed Shaya was in his office looking at data from NASA's Kepler space telescope in 2012 when he noticed something unusual: The light from a galaxy had quickly brightened by 10 percent. The sudden bump in light got Shaya instantly excited, but also nervous. The effect could be explained by the massive explosion of a star -- a supernova! -- or, more troublingly, a computer error.

"I just remember on that day, not knowing whether I should believe it or not," he remembers. Rather than celebrate, he thought, "Did I make a mistake? Am I doing this all wrong?"

Felt Supernova

Video above: This animation shows a kind of stellar explosion called a Fast-Evolving Luminous Transient. In this case, a giant star "burps" out a shell of gas and dust about a year before exploding. Most of the energy from the supernova turns into light when it hits this previously ejected material, resulting in a short, but brilliant burst of radiation. Video Credits: NASA/JPL-Caltech.

Stellar explosions forge and distribute materials that make up the world in which we live, and also hold clues to how fast the universe is expanding. By understanding supernovae, scientists can unlock mysteries that are key to what we are made of and the fate of our universe. But to get the full picture, scientists must observe supernovae from a variety of perspectives, especially in the first moments of the explosion. That's really difficult -- there's no telling when or where a supernova might happen next.

A small group of astronomers, including Shaya, realized Kepler could offer a new technique for supernova-hunting. Launched in 2009, Kepler is best known for having discovered thousands of exoplanets. But as a telescope that stares at single patches of space for long periods of time, it can capture a vast trove of other cosmic treasures --especially the kind that change rapidly or pop in and out of view, like supernovae.

"Kepler opened up a new way of looking at the sky," said Jessie Dotson, Kepler's project scientist, based at NASA's Ames Research Center in California's Silicon Valley. "It was designed to do one thing really well, which was to find planets around other stars. In order to do that, it had to deliver high-precision, continuous data, which has been valuable for other areas of astronomy."

Originally, Shaya and colleagues were looking for active galactic nuclei in their Kepler data. An active galactic nucleus is an extremely bright area at the center of a galaxy where a voracious black hole is surrounded by a disk of hot gas. They had thought about searching for supernovae, but since supernovae are such rare events, they didn't mention it in their proposal. "It was too iffy," Shaya said.

Unsure if the supernova signal he found was real, Shaya and his University of Maryland colleague Robert Olling spent months developing software to better calibrate Kepler data, taking into account variations in temperature and pointing of the instrument. Still, the supernova signal persisted. In fact, they found five more supernovae in their Kepler sample of more than 400 galaxies. When Olling showed one of the signals to Armin Rest, who is now an astronomer at the Space Telescope Science Institute in Baltlimore, Rest's jaw dropped. "I started to drool," he said. The door had opened to a new way of tracking and understanding stellar explosions.

Today, these astronomers are part of the Kepler Extra-Galactic Survey, a collaboration between seven scientists in the United States, Australia and Chile looking for supernovae and active galactic nuclei to explore the physics of our universe. To date, they have found more than 20 supernovae using data from the Kepler spacecraft, including an exotic type reported by Rest in a new study in Nature Astronomy. Many more are currently being recorded by Kepler's ongoing observations.

"We have some of the best-understood supernovae," said Brad Tucker, astronomer at the Mt. Stromlo Observatory at the Australian National University, who is part of the Kepler Extra-Galactic Survey.

Type Ia Supernova When a White Dwarf Steals Material from Companion

Video above: This animation shows the explosion of a white dwarf, an extremely dense remnant of a star that can no longer burn nuclear fuel at its core. In this "type Ia" supernova, white dwarf's gravity steals material away from a nearby stellar companion. When the white dwarf reaches an estimated 1.4 times the current mass of the Sun, it can no longer sustain its own weight, and blows up. Video Credits: NASA/JPL-Caltech.

Why do we care about supernovae?

A longstanding mystery in astrophysics is how and why stars explode in different ways. One kind of supernova happens when a dense, dead star called a white dwarf explodes. A second kind happens when a single gigantic star nears the end of its life, and its core can no longer withstand the gravitational forces acting on it. The details of these general categories are still being worked out.

The first kind, called "type Ia" (pronounced as "one a") is special because the intrinsic brightness of each of these supernovae is almost the same. Astronomers have used this standard property to measure the expansion of the universe and found the more distant supernovae were less bright than expected. This indicated they were farther away than scientists had thought, as the light had become stretched out over expanding space. This proved that the universe is expanding at an accelerating rate and earned those researchers the Nobel Prize in 2011. The leading theory is that a mysterious force called "dark energy" is pushing everything in the universe apart from everything else, faster and faster.

But as astronomers find more and more examples of type Ia explosions, including with Kepler, they realize not all are created equal. While some of these supernovae happen when a white dwarf robs its companion of too much matter, others are the result of two white dwarfs merging. In fact, the white dwarf mergers may be more common. More supernova research with Kepler will help astronomers on a quest to find out if different type Ia mechanisms result in some supernovae being brighter than others -- which would throw a wrench into how they are used to measure the universe's expansion.

"To get a better idea of constraining dark energy, we have to understand better how these type Ia supernovae are formed," Rest said.

Type Ia Supernova from a White Dwarf Merger

Video above: This animation shows the merger of two white dwarfs. A white dwarf is an extremely dense remnant of a star that can no longer burn nuclear fuel at its core. This is another way that a "type Ia" supernova occurs. Video Credits: NASA/JPL-Caltech.

Another kind of supernova, the "core collapse" variety, happens when a massive star ends its life in an explosion. This includes "Type II" supernovae. These supernovae have a characteristic shockwave called the "shock breakout," which was captured for the first time in optical light by Kepler. The Kepler Extra-Galactic Survey team, led by team member Peter Garnavich, an astrophysics professor at the University of Notre Dame in Indiana, spotted this shock breakout in 2011 Kepler data from a supernova called KSN 2011d, an explosion from a star roughly 500 times the size of our Sun. Surprisingly, the team did not find a shock breakout in a smaller type II supernova called KSN 2011a, whose star was 300 times the size of the Sun -- but instead found the supernova nestled in a layer of dust, suggesting that there is diversity in type II stellar explosions, too.

Kepler data have revealed other mysteries about supernovae. The new study led by Rest in Nature Astronomy describes a supernova from data captured by Kepler's extended mission, called K2, that reaches its peak brightness in just a little over two days, about 10 times less than others take. It is the most extreme known example of a "fast-evolving luminous transient" (FELT) supernova. FELTs are about as bright as the type Ia variety, but rise in less than 10 days and fade in about 30. It is possible that the star spewed out a dense shell of gas about a year before the explosion, and when the supernova happened, ejected material hit the shell. The energy released in that collision would explain the quick brightening.

Why Kepler?

Telescopes on Earth offer a lot of information about exploding stars, but only over short periods of time -- and only when the Sun goes down and the sky is clear - so it's hard to document the "before" and "after" effects of these explosions. Kepler, on the other hand, offers astronomers the rare opportunity to monitor single patches of sky continuously for months, like a car's dashboard camera that is always recording. In fact, the primary Kepler mission, which ran from 2009 to 2013, delivered four years of observations of the same field of view, snapping a picture about every 30 minutes. In the extended K2 mission, the telescope is holding its gaze steady for up to about three months.

Core Collapse Supernova

Video above: This animation shows a gigantic star exploding in a "core collapse" supernova. As molecules fuse inside the star, eventually the star can't support its own weight anymore. Gravity makes the star collapse on itself. Core collapse supernovae are called type Ib, Ic, or II depending on the chemical elements present. Video Credits: NASA/JPL-Caltech.

With ground-based telescopes, astronomers can tell the supernova's color and how it changes with time, which lets them figure out what chemicals are present in the explosion. The supernova's composition helps determine the type of star that exploded. Kepler, on the other hand, reveals how and why the star explodes, and the details of how the explosion progresses. Using the two datasets together, astronomers can get fuller pictures of supernovae behavior than ever before.

Kepler mission planners revived the telescope in 2013, after the malfunction of the second of its four reaction wheels -- devices that help control the orientation of the spacecraft. In the configuration called K2, it needs to rotate every three months or so -- marking observing "campaigns." Members of the Kepler Extra-Galactic Survey made the case that in the K2 mission, Kepler could still monitor supernovae and other exotic, distant astrophysical objects, in addition to exoplanets.

The possibilities were so exciting that the Kepler team devised two K2 observing campaigns especially useful for coordinating supernovae studies with ground-based telescopes. Campaign 16, which began on Dec. 7, 2017, and ended Feb. 25, 2018,included 9,000 galaxies. There are about 14,000 in Campaign 17, which is just beginning now. In both campaigns, Kepler faces in the direction of Earth so that observers on the ground can see the same patch of sky as the spacecraft. The campaigns have excited a community of researchers who can advantage of this rare coordination between Kepler and telescopes on the ground.

A recent possible sighting got astronomers riled up on Super Bowl Sunday this year, even if they weren't into the game. On that "super" day, the All Sky Automated Survey for SuperNovae (ASASSN) reported a supernova in the same nearby galaxy Kepler was monitoring. This is just one of many candidate events that scientists are excited to follow up on and perhaps use to better understand the secrets of the universe.

A few more supernovae may come from NASA's Transiting Exoplanet Survey Satellite, (TESS) which is expected to launch on April 16. In the meantime, scientists will have a lot of work ahead of them once they receive the full dataset from K2's supernova-focused campaigns.

"It will be a treasure trove of supernova information for years to come," Tucker said.

Ames manages the Kepler and K2 missions for NASA's Science Mission Directorate. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

Related link:

Hubble observations:

For more information about the Kepler mission, visit:

Images (mentioned), Videos (mentioned), Text, Credits: NASA/Ames Research Center/Alison Hawkes/JPL/Calla Cofield/NASA's Exoplanet Exploration Program, written by Elizabeth Landau.