jeudi 24 décembre 2020

When light and atoms share a common vibe


Ecole Polytechnique Fédérale de Lausanne logo.

Dec. 24, 2020

Scientists from EPFL, MIT, and CEA Saclay demonstrate a state of vibration that exists simultaneously at two different times. They evidence this quantum superposition by measuring the strongest class of quantum correlations between light beams that interact with the vibration.

When light and atoms share a common vibe

An especially counter-intuitive feature of quantum mechanics is that a single event can exist in a state of superposition – happening both here and there, or both today and tomorrow.

Such superpositions are hard to create, as they are destroyed if any kind of information about the place and time of the event leaks into the surrounding – and even if nobody actually records this information. But when superpositions do occur, they lead to observations that are very different from that of classical physics, questioning down to our very understanding of space and time.

Scientists from EPFL, MIT, and CEA Saclay, publishing in Science Advances, demonstrate a state of vibration that exists simultaneously at two different times, and evidence this quantum superposition by measuring the strongest class of quantum correlations between light beams that interact with the vibration.

The researchers used a very short laser-pulse to trigger a specific pattern of vibration inside a diamond crystal. Each pair of neighboring atoms oscillated like two masses linked by a spring, and this oscillation was synchronous across the entire illuminated region. To conserve energy during this process, a light of a new color is emitted, shifted toward the red of the spectrum.

This classical picture, however, is inconsistent with the experiments. Instead, both light and vibration should be described as particles, or quanta: light energy is quantized into discrete photons while vibrational energy is quantized into discrete phonons (named after the ancient Greek “photo = light” and “phono = sound”).

The process described above should therefore be seen as the fission of an incoming photon from the laser into a pair of photon and phonon – akin to nuclear fission of an atom into two smaller pieces.

But it is not the only shortcoming of classical physics. In quantum mechanics, particles can exist in a superposition state, like the famous Schrödinger cat being alive and dead at the same time.

Even more counterintuitive: two particles can become entangled, losing their individuality. The only information that can be collected about them concerns their common correlations. Because both particles are described by a common state (the wavefunction), these correlations are stronger than what is possible in classical physics. It can be demonstrated by performing appropriate measurements on the two particles. If the results violate a classical limit, one can be sure they were entangled.

 When light and atoms share a common vibe

In the new study, EPFL researchers managed to entangle the photon and the phonon (i.e., light and vibration) produced in the fission of an incoming laser photon inside the crystal. To do so, the scientists designed an experiment in which the photon-phonon pair could be created at two different instants. Classically, it would result in a situation where the pair is created at time t1 with 50% probability, or at a later time t2 with 50% probability.

But here comes the “trick” played by the researchers to generate an entangled state. By a precise arrangement of the experiment, they ensured that not even the faintest trace of the light-vibration pair creation time (t1 vs. t2) was left in the universe. In other words, they erased information about t1 and t2. Quantum mechanics then predicts that the phonon-photon pair becomes entangled, and exists in a superposition of time t1 and t2. This prediction was beautifully confirmed by the measurements, which yielded results incompatible with the classical probabilistic theory.

By showing entanglement between light and vibration in a crystal that one could hold in their finger during the experiment, the new study creates a bridge between our daily experience and the fascinating realm of quantum mechanics.

“Quantum technologies are heralded as the next technological revolution in computing, communication, sensing, says Christophe Galland, head of the Laboratory for Quantum and Nano-Optics at EPFL and one of the study’s main authors. “They are currently being developed by top universities and large companies worldwide, but the challenge is daunting. Such technologies rely on very fragile quantum effects surviving only at extremely cold temperatures or under high vacuum. Our study demonstrates that even a common material at ambient conditions can sustain the delicate quantum properties required for quantum technologies. There is a price to pay, though: the quantum correlations sustained by atomic vibrations in the crystal are lost after only 4 picoseconds — i.e., 0.000000000004 of a second! This short time scale is, however, also an opportunity for developing ultrafast quantum technologies. But much research lies ahead to transform our experiment into a useful device — a job for future quantum engineers.”


Swiss National Science Foundation

European Research Council’s (ERC) Horizon 2020 Research and Innovation programme

Army Research Laboratory Center for Distributed Quantum Information (SciNet)


Santiago Tarrago Velez, Vivishek Sudhir, Nicolas Sangouard, Christophe Galland. Bell correlations between light and vibration at ambient conditions. Science Advances 18 December 2020, 6: eabb0260.

Ecole Polytechnique Fédérale de Lausanne (EPFL):

Image, Video, Text, Credits: EPFL/Christophe Galland, Nik Papageorgiou.

Best regards,

Space Station 20th: Celebrating the Holidays in Space


ISS - 20 Years on the International Space Station patch.

Dec. 24, 2020

Happy holidays. Animation Credit: NASA

The Christmas, Hanukkah, and New Year’s holidays are typically joyful events spent with family and friends. Astronauts and cosmonauts who happen to be in space during the holidays have found their own unique ways to celebrate the occasions. In the early years of the space program, holidays spent in space were relatively rare events, such as the flight of Apollo 8 around the Moon during Christmas 1968, making them perhaps more memorable. As missions became longer and more frequent, holidays in space became less rare occasions. For the past 20 years, holidays spent aboard the International Space Station (ISS) have become annual, if not entirely routine, events.

Above: The famous Earthrise photograph, taken by the Apollo 8 crew in lunar orbit.
Below: Video of the Apollo 8 crew of Frank Borman, James A. Lovell,
and William A. Anders reading from Genesis.

The first crew to spend Christmas in space, Apollo 8 astronauts Frank Borman, James A. Lovell, and William A. Anders, spent the holiday while circling the Moon in December 1968, the first humans to have left Earth orbit. They immortalized the event on Christmas Eve by taking turns reading the opening verses from the Bible’s book of Genesis as they broadcast scenes of the Moon gliding by below. An estimated one billion people in 64 countries tuned in to their Christmas Eve broadcast. As they left lunar orbit, Lovell radioed back to Earth, where it was already Christmas Day, “Please be informed there is a Santa Claus!”

Above: The makeshift Christmas tree aboard Skylab in 1973. Below: Skylab 4 astronauts
Gerald P. Carr, left, and Edward G. Gibson trimming their homemade Christmas tree.

During their 84-day record-setting mission aboard the Skylab space station in 1973 and 1974, Skylab 4 astronauts Gerald P. Carr, William R. Pogue, and Edward G. Gibson celebrated Thanksgiving, Christmas, and New Year’s in space. They were the first crew to spend Thanksgiving and New Year’s in orbit. Carr and Pogue spent seven hours on a Christmas Day spacewalk to change out film canisters and observe the passing Comet Kohoutek. They had built a homemade Christmas tree from leftover food containers, used colored decals as decorations, and topped it with a cardboard cutout in the shape of a comet. Once back inside the station, they enjoyed a Christmas dinner complete with fruitcake, talked to their families, and opened presents. They even had visitors of sorts, as Soviet cosmonauts Pyotr I. Klimuk and Valentin V. Lebedev were in orbit aboard Soyuz 13 between Dec. 18 and 26, marking the first time that astronauts and cosmonauts were in space at the same time (and at five, the largest number of people in space up to that time).

Above: Aboard Salyut-6, Georgi M. Grechko, Below, and Yuri V. Romanenko, toast to celebrate
the new year in space, the first Russian cosmonauts to do so.
Credits: RKK Energiya.

In the more secular Soviet era, the New Year’s holiday had more significance than the Jan. 7 observance of Russian Orthodox Christmas. The first cosmonauts to ring in a new year in orbit were Yuri V. Romanenko and Georgi M. Grechko, during their 96-day record-setting mission in 1977 and 1978, aboard the Salyut-6 space station. They toasted the new year during a TV broadcast with the ground. The exact nature of the beverage consumed for the occasion has not been passed down to posterity.

Above:: STS-61 mission specialist Jeffrey Hoffman with a dreidel during Hanukkah in 1993.
Below: Video of Hoffman describing how he celebrated Hanukkah aboard
space shuttle Endeavour.

The Jewish holiday of Hanukkah, also known as the Festival of Lights, is an eight-day celebration of the recapture of Jerusalem and rededication of the Second Temple in 164 B.C.E. It is celebrated in the month of Kislev in the lunar Hebrew calendar, which can fall between late November to late December in the Gregorian calendar. NASA astronaut Jeffrey A. Hoffman celebrated the first Hanukkah in space during the STS-61 Hubble Space Telescope repair mission in 1993. Hanukkah that year began on the evening of Dec. 9, after Hoffman completed his third spacewalk of the mission. He celebrated with a traveling menorah, unlit of course, and by spinning a dreidel.

The STS-103 crew of Claude Nicollier, left front, Scott J. Kelly,
John M. Grunsfeld; Steven L. Smith, left rear, C. Michael Foale,
Curtis L. Brown, and Jean- François A. Clervoy, showing off their
Santa hats on the flight deck of space shuttle Discovery in 1999.

The crew of another Hubble Space Telescope repair mission celebrated the first space shuttle Christmas in 1999 aboard Discovery. For Christmas dinner, Curtis L. Brown, Scott J. Kelly, Steven L. Smith, Jean- François A. Clervoy, John M. Grunsfeld, C. Michael Foale, and Claude Nicollier enjoyed duck foie gras on Mexican tortillas, cassoulet, and salted pork with lentils. Smith and Grunsfeld completed repairs on the telescope during a Christmas Eve spacewalk.

Above: Russian cosmonaut and Mir Expedition 17 flight engineer Elena V. Kondakova
with a bottle of champagne to celebrate New Year’s Eve 1994. elow: Video of Kondakova
demonstrating the behavior of champagne in weightlessness aboard Mir.

Between 1987 and 1998, 12 Mir expedition crews spent their holidays aboard the ever-expanding orbital outpost. Two crews included NASA astronauts John E. Blaha and David A. Wolf, aboard the Russian space station as part of the Shuttle-Mir Program.

Above: Video of Mir Expedition 22 flight engineer and NASA astronaut John E. Blaha’s 1996
Christmas message from Mir. Below: Mir Expedition 24 flight engineer and NASA astronaut
David A. Wolf with his menorah and dreidel to celebrate Hanukkah in 1997.  

The last two New Year’s Eve messages from Mir. Above: Mir 24 crew of Pavel V. Vinogradov,
left, David A. Wolf, and Anatoli Y. Solovyev in 1997. Below: Mir 26 crew of Sergei V. Avdeyev,
left, and Gennadi I. Padalka in 1998. It was the third time Avdeyev rang in the
new year in space.

The arrival of Expedition 1 crew members William M. Shepherd, Yuri P. Gidzenko, and Sergei K. Krikalev aboard the ISS on Nov. 2, 2000, marked the beginning of a permanent human presence aboard the orbiting facility. They were the first to celebrate Christmas and ring in the new year aboard the orbiting laboratory and began a tradition of reading a goodwill message to people back on Earth. Shepherd honored a naval tradition of writing a poem as the first entry of the new year in the ship’s log.

Above: Video of Expedition 1 crew members Yuri P. Gidzenko, left, William M. Shepherd,
and Sergei K. Krikalev reading their Christmas message in December 2000 – this
marked Krikalev’s third holiday season spent in orbit. Below: The ISS as it
appeared in December 2000.

Expedition 1 commander and NASA astronaut William M. Shepherd’s
poem, written for the New Year’s Day 2001 entry in the International
Space Station’s log, in keeping with naval tradition.

 Above: A brief video selection of how some expedition crews celebrated Christmas aboard ISS.
Below: From 2019, the Christmas message from the Expedition 61 crew members.
Enjoy the following selection of photographs of international crews as they celebrated Hanukkah and Christmas, and rang in the new year over the past 20 years aboard the ISS.

 Above: The Expedition 4 crew of Daniel W. Bursch, left, Yuri I. Onufriyenko, and Carl E. Walz pose
for their Christmas photo in 2001. Middle: C. Michael Foale, left, and Aleksandr Y. Kaleri of Expedition 8
celebrate Christmas in 2003. Below: The Expedition 10 crew of Salizhan S. Sharipov, left, and Leroy Chiao
festooned for New Year’s Eve 2004.

 Above: Valeri I. Tokarev, left, and William S. McArthur of Expedition 12 pose with Christmas stockings
in 2005. Middle: The Expedition 14 crew of Mikhail V. Tyurin, left, Michael E. Lopez-Alegria, and
Sunita L. Williams pose wearing Santa hats for Christmas 2006. Below: Posing with their Christmas
stockings and presents are Expedition 16 crew members Yuri I. Malenchenko, left, Peggy A. Whitson,
and Daniel M. Tani, in 2007.
 Above: The Expedition 18 crew of E. Michael Fincke, left, Sandra H. Magnus, and Yuri V. Lonchakov enjoy
their Christmas dinner in 2008. Middle: The five-member Expedition 22 crew of Soichi Noguchi, left,
Maksim V. Surayev, Oleg V. Kotov, Timothy J. Creamer, and Jeffrey N. Williams around the Christmas
dinner table in 2009. Below: The Expedition 26 crew of Oleg I. Skripochka, left, Paolo A. Nespoli,
Dmitri Y. Kondratyev, Catherine G. “Cady” Coleman, Aleksandr Y. Kaleri, and Scott J. Kelly celebrate
New Year’s Eve 2010. This marked Kaleri’s third holiday season spent in space.
 Above:  The Expedition 30 crew of Donald R. Pettit, left, Anatoli A. Ivanishin, Oleg D. Kononenko,
André Kuipers, Daniel C. Burbank, and Anton N. Shkaplerov pose for their Christmas photo in 2011.
Middle: Christmas 2012 photograph of Expedition 34 crew members Thomas H. Marshburn, left,
Roman Y. Romanenko, Oleg V. Novitski, Yevgeni I. Tarelkin, Kevin A. Ford, and Chris A. Hadfield.
Below: For Christmas in 2013, the Expedition 42 crew left milk and cookies for Santa and hung
their stockings using the Joint Airlock as a makeshift chimney.
 Above: Expedition 50 crew members Sergei N. Ryzhikov, left, R. Shane Kimbrough, Andrei I. Borisenko,
Oleg V. Novitski, Peggy A. Whitson, and Thomas G. Pesquet celebrating New Year’s Eve in style in 2016.
Middle: Expedition 54 crew member Mark T. Vande Hei strikes a pose as an Elf on the Shelf for Christmas
2017. Below: The Expedition 58 crew of David Saint-Jacques, left, Anne C. McClain, and Oleg D. Kononenko
inspect their Christmas stockings for presents in 2018.

Three scenes from the 2019 holiday season aboard the ISS. Above: Expedition 61 flight engineer
Jessica U. Meir shows off her Hanukkah-themed socks in the Cupola. Middle: Expedition 61 crew
members Andrew R. Morgan, left, Christina H. Koch, Luca S. Parmitano, and Meir share their
Christmas messages. Below: Expedition 61 crew members Koch, left, Morgan, Oleg I. Skripochka,
Meir, Aleksandr A. Skvortsov, and Parmitano ring in the new year with harmonicas.

We hope you enjoyed these stories and photographs from holiday celebrations in space. We would like to wish everyone here on the ground and the seven-member crew of Expedition 64 aboard the ISS the happiest of holidays!

Related links:

Historic Missions:

International Space Station (ISS):

Animation (mentioned), Images, Videos, Text, Credits: ROSCOSMOSNASA/Kelli Mars/JSC/John Uri.

Season Greetings, Roland Berga (Aka

mercredi 23 décembre 2020

Astronauts Studying Vision, Genetic Changes and Heart Conditions Today


ISS - Expedition 64 Mission patch.

Dec. 23, 2020

The seven Expedition 64 residents living aboard the International Space Station will be going into the Christmas holiday focusing intensely on space biology. The entire crew will be off duty on Christmas day relaxing following an increased pace of microgravity research.

Rodent research will be the highlight through Christmas eve as the astronauts explore how living in space affects eyesight and bones. Scientists are observing mice launched to the orbiting lab earlier this month to understand why 40 percent of crew members living in space have reported vision impairment. A combination of factors, such as headward fluid shifts and space radiation, is suspected of impacting eyesight off the Earth.

Image above: NASA astronaut Shannon Walker unpacks hardware inside the Quest airlock where U.S. spacewalks are staged. Image Credit: NASA.

Another group of mice is being analyzed for space-caused genetic changes in bone tissue. The study is exploring the molecular mechanisms of tissue degeneration that may provide preventative therapies for astronauts in space and humans on Earth.

The mice from both biomedical studies will be returned to Earth aboard the SpaceX Cargo Dragon resupply ship in January for analysis by scientists in Florida. The Cargo Dragon completes its mission on January 11 when it undocks from the Harmony module and splashes down in the Atlantic Ocean. It will be packed with finalized science experiments and space station hardware for servicing.

The Nanoracks Bishop Airlock was installed on the International Space Station

Heart research continued today with Flight Engineer Kate Rubins exploring engineered heart tissues to gain insights into aging and weakening heart muscles. The cardiovascular study was activated shortly after its arrival aboard the Cargo Dragon and may improve treatments for heart conditions on and off Earth.

Microbes are also being examined for the risk they pose to spacecraft systems and astronaut health. The experiment may provide insight into better ways to control their growth and disinfect surfaces on Earth and in space.

Related links:

Expedition 64:

Vision impairment:

Space-caused genetic changes in bone tissue:

Harmony module:

Engineered heart tissues:


Space Station Research and Technology:

International Space Station (ISS):

Image (mentioned), Video, Text, Credits: NASA/Mark Garcia/NASA/Kim Shiflett/Glenn Benson/SciNews/Music: Lunar Landing by Silent Partner courtesy of YouTube Audio Library.

Best regards,

A-68A iceberg thinning at 2.5 cm per day


ESA - CRYOSAT Mission logo.

Dec. 23, 2020

Latest images reveal that the A-68A iceberg has shattered into multiple pieces, with two large fragments of ice breaking off from the main berg and floating away in the open ocean. Scientists using satellite data have not only been monitoring the iceberg’s journey across the South Atlantic Ocean, but have been studying the iceberg’s ever-changing shape.

The colossal A-68A iceberg – one of the largest bergs of all time – has drifted slowly northwards since it broke free from the Larsen-C ice shelf in July 2017, and has been floating perilously close to South Georgia for the past month.

Marine scientists are concerned that its presence will harm the fragile ecosystem that thrives around the island, either through scraping of the iceberg’s keel on the seabed or through the massive release of cold freshwater into the surrounding ocean. Just how close the berg will reach depends on how deep its keel is, but only with measurements of the berg’s changing shape, this has been impossible to determine with confidence.

A-68A’s journey

Using data from four different satellites, scientists from the Centre for Polar Observation and Modelling at the University of Leeds have produced the first assessment of the iceberg's changing shape.

The team first built a map of the icebergs initial thickness from measurements recorded by ESA’s CryoSat satellite radar altimeter in the 12 months before it calved. This detailed map reveals that A-68 was originally, on average, 232 m thick, and 285 m at its thickest point. The berg has 30 m deep channels oriented parallel to its narrow side following the direction Larsen ice shelf was flowing out to sea before it snapped – a common feature related to ocean melting.

Since it has been drifting in the ocean, the iceberg's position and shape have been captured in a sequence of 11 images taken by two different satellites – the Copernicus Sentinel-1 mission, which has an all-weather and year-round imaging radar, and NASA’s MODIS, which records images that are visible to the naked eye.

Depth of the A-68A iceberg

The imagery shows that the iceberg has halved in size from an initial area of 5664 sq km to its present extent of just 2606 sq km. A large proportion of this loss has been through the creation of smaller bergs, some of which are still afloat.

Profiles of the iceberg’s height have also been recorded on eight separate occasions as it has drifted and rotated in the ocean by CryoSat and by NASA’s ICESat-2 laser altimeter, which has been in orbit since September 2018. The coincident satellite imagery made it possible to orientate the altimeter height profiles relative to the icebergs initial position and calculate its change in thickness over time.

On average, the iceberg has thinned by 32 m, and by over 50 m in places – around a quarter of its initial thickness. When combined, the change in thickness and area amount to a 64% reduction in the iceberg’s volume from 1467 to 526 cubic kilometres.

Area, thickness and volume of A-68A

The iceberg's future trajectory depends on how deep its keel is relative to the surrounding ocean. Although South Georgia lies in a remote spot of the South Atlantic Ocean, it is surrounded by relatively shallow shelf waters that extend tens of kilometres beyond its coastline.

At its thickest section, the A-68A iceberg currently has a 206 m deep keel, and so the main section is unlikely to travel much closer to the island until it thins or breaks apart. However, two relatively large fragments which broke away on 21 December are considerably thinner, with keels that are up to 50 m shallower, and so these pose the greatest immediate threat.

Since it broke free, the average melting rate of A-68 has been 2.5 centimetres per day and the berg is now shedding 767 cubic metres of freshwater per second into the surrounding ocean – equivalent to 12 times the outflow of the River Thames.

The team will continue to monitor A-68A and its remnant parts as part of their ongoing assessment of Earth’s polar regions.

A-68A iceberg breaks off

Anne Brackmann-Folgmann, PhD student at the University of Leeds, said, “Icebergs can have major environmental impacts, including disturbing ocean circulation, marine ecosystems, and could block the route between penguin colonies and their feeding grounds during the breeding season. Thanks to CryoSat, we can track changes in their thickness, providing advance warning of when and where they might run aground.”

Jamie Izzard, postgraduate researcher at the University of Leeds, said, “Satellite altimeters allow us to measure iceberg terrain with incredible precision, allowing us to detect subtle features like the shallow surface depression above the basal channel which was the line of weakness along which the latest bergs calved.”


ESA’s CryoSat Mission Manager, Tommaso Parrinello, said, “It’s fantastic to know that even in the remotest parts of our planet, satellites like CryoSat are able to shed light on events like this and help us to monitor our environment and thanks to the recent change of CryoSat orbit to sync with ICESat-2, we will see more results in the future coming from the combination of the two satellite measurements.”

Related links:


Copernicus Sentinel-1 mission:

Animations, Images, Text, Credits: ESA/University of Leeds/Contains modified Copernicus Sentinel data (2020), processed by ESA; Antarctic Iceberg Tracking Database.


mardi 22 décembre 2020

Crew Studies Immunology, Genetic Expression and Space Manufacturing


ISS - Expedition 64 Mission patch.

Dec. 22, 2020

The seven-member Expedition 64 crew, consisting of five astronauts and two cosmonauts, will spend the rest of the year conducting valuable space research aboard the International Space Station.

Tuesday’s slate of science investigations explored a range of space biology and physics phenomena to benefit human health and manufacturing. Results from these microgravity studies could also boost the commercialization of space.

Image above: This image from International Space Station as it was flying 261 miles over Iran looks southeast across the Persian Gulf and the Gulf of Oman. Image Credit: NASA.

The crew has been looking at tiny organisms including microbes and fruit flies today to gain insights into immunology and genetic expression. These experiments will return to Earth on Jan. 11 for analysis when the SpaceX Cargo Dragon undocks from the Harmony module and splashes down in the Atlantic Ocean.

Weightlessness has the potential to increase the virulence of microbes and the Micro-14A study seeks to understand why. The astronauts are looking at the opportunistic pathogen Candida albicans in a human cell host to see how it adapts to space. Results could help doctors quantify the health risk to space crews and formulate countermeasures.

The Genes in Space-7 investigation examines the central nervous system of fruit flies for space-caused changes in genetic expression. The lack of a day-night cycle in space can create cognitive changes to molecular pathways that scientists want to track. Monitoring the changes to neural systems in space will help scientists understand how the biological clock adapts to long-term space missions.

ISS - A Space Lab flying over the Earth. Animation Credit: NASA

A pair of physics studies is under way aboard the station seeking to promote the manufacturing of high-quality fiber optics that only microgravity can provide. Optical fiber samples were swapped out inside the Microgravity Science Glovebox today for the Fiber Optic Production study that is testing commercial production on the station. A secondary experiment, Space Fibers-2, explores a custom fiber fabrication method that operates autonomously inside its own specialized device that can be examined back on Earth.

The 2,400-pound NanoRacks Bishop research airlock is now part of the orbiting lab’s Tranquility module and will be activated and pressurized for operations at a later date. Bishop will increase the station’s capacity for private and public research and also enable the release of larger satellites and the transfer of cargo inside and outside the station.

Related links:

Expedition 64:

Harmony module:


Genes in Space-7:

Microgravity Science Glovebox:

Fiber Optic Production:

Space Fibers-2:

Tranquility module:

Space Station Research and Technology:

International Space Station (ISS):

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

Best regards,

Asteroids - Next Five Close Approaches


Asteroid Watch logo.

Dec. 22, 2020

Each day one or more asteroids pass near the Earth. They are of different size, from the largest to the smallest they are all potentially dangerous if they cross the orbit of the Earth (impact).

Artist's view of  Asteroid approaching the Earth

In order to prevent us from such a risk, it is necessary to continue to be vigilant and to invest in means of fight such as several programs such as Hera from ESA or Dart from NASA.

Amateur or professional astronomers also play a role of vigilance throughout the world, thank you to them.

You can also be informed directly by a very powerful and easy to use application:

Asteroid Alert (Smartphone & tablet application for Android)

This is a scientific application that simulates the solar system dynamics using the information provided by the NASA NEO Program. The Near Earth objects and objects close to other planets will be reported in real time. The advanced graphical interface allows you to monitor the orbits of celestial bodies as a function of the elapsed time.

X rays and protons emitted by Sun are also notified to have a complete view of the dangers from space. Notification of near-Earth objects, notifications of high level emissions coming from the sun (X ray and protons) and more. Not available for Apple devices.

Center for Near Earth Object Studies (CNEOS)

Click on the image for enlarge (screen capture)

A division of Caltech in Pasadena, JPL hosts CNEOS for NASA's Near-Earth Object Observations Program in NASA's Planetary Defense Coordination Office. More information about CNEOS, asteroids and near-Earth objects can be found at:

Center for Near Earth Object Studies (CNEOS):

Next Five Close Approaches

 (Screen capture)

Average distance between Earth and the moon is about 239,000 miles (385,000 kilometers).

The Asteroid Watch Widget tracks asteroids and comets that will make relatively close approaches to Earth. The Widget displays the date of closest approach, approximate object diameter, relative size and distance from Earth for each encounter. The object's name is displayed by hovering over its encounter date. Clicking on the encounter date will display a Web page with details about that object.

NASA Asteroid Watch:

The Widget displays the next five Earth approaches to within 4.6 million miles (7.5 million kilometers or 19.5 times the distance to the moon); an object larger than about 150 meters that can approach the Earth to within this distance is termed a potentially hazardous object.

For more information about NASA's Planetary Defense Coordination Office, visit:

Images, Text, Credits: NASA/JPL/ Aerospace/Roland Berga.