If Proxima Centauri goes supernova will it negatively affect the Earth?

If Proxima Centauri goes supernova will it negatively affect the Earth?

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Proxima Centauri is the closest star to the Earth (besides our Sun). If it went supernova, would such an event negatively affect the Earth? Can Proxima Centauri negatively affect the Earth in some other fashion?

First thing, Proxima Centauri cannot go supernova. It is only $0.12 M_odot$, while core-collapse supernovae can only be triggered by stars that are more massive than $8 M_odot$. Now the only exception here is if it undergoes a type Ia supernova, but this is very unrealistic because Proxima won't become a white dwarf in trillions of years and is not part of a binary system that is close enough to engage in mass transfer.

To answer your second question, the answer is also no. To affect the Earth significantly, it needs to pass very close (less than 100-1000 AU), which is virtually impossible. Proxima will not approach closer than 3 light years from our Sun in the near future, so it absolutely has no effect on the Solar System. See my answer regarding stellar collisions.

Could recent supernovae be responsible for mass extinctions?

The ultraviolet radiation from a nearby supernova may have resulted in changes in life on Earth. Credit: David Aguilar (CfA)

Two nearby supernovae that exploded about 2.5 and eight million years ago could have resulted in a staggered depletion of Earth's ozone layer, leading to a variety of repercussions for life on Earth.

In particular, two-and-a-half million years ago the Earth was changing dramatically. The Pliocene, which was a hot and balmy epoch, was ending and the Pleistocene, an era of repeated glaciation known as the Ice Age, was beginning. Natural variations in Earth's orbit and wobble likely accounted for the change in climate, but the simultaneous event of a supernova could provide insight on the diversification of life during this epoch.

This supernova is thought to have occurred between 163 and 326 light years away (50–100 parsecs) from Earth. For perspective, our closest stellar neighbor, Proxima Centauri, is 4.2 light years away.

Consequences for Earth

Supernovae can sterilize any nearby inhabited planets that happen to be in the path of their harmful ionizing radiation. Could nearby supernovae wreak havoc on the existing biology of our planet? One researcher wanted to find out. Dr. Brian Thomas, an astrophysicist at Washburn University in Kansas, USA, modeled the biological impacts at the Earth's surface, based on geologic evidence of nearby supernovae 2.5 million and 8 million years ago. In his latest paper, Thomas investigated cosmic rays from the supernovae as they propagated through our atmosphere to the surface, to understand their effect on living organisms.

Looking at the fossil record during the Pliocene–Pleistocene boundary (2.5 million years ago), we see a dramatic change in the fossil record and in land cover globally. Thomas tells Astrobiology Magazinethat "there were changes, especially in Africa, which went from being more forested to more grassland." During this time the geologic record shows an elevated global concentration of iron-60 (60Fe), which is a radioactive isotope produced during a supernova.

The globally averaged change in ozone density, as a percent difference at 100 years, 300 years, and 1000 years after a nearby supernova explosion. Credit: Brian Thomas

"We are interested in how exploding stars affect life on Earth, and it turns out a few million years ago there were changesin the things that were living at the time," says Thomas. "It might have been connected to this supernova."

For example, there was a change in the abundance of species during the Pliocene–Pleistocene boundary. Although no major mass extinctions happened, there was a higher rate of extinction in general, more speciation and a change in vegetation.

How would a nearby supernova affect life on Earth? Thomas laments that supernovae often are exemplified as "supernova goes off and everything dies", but that is not quite the case. The answer lies in the atmosphere. Beyond sunscreen, the ozone layer protects all biology from harmful, genetically altering ultraviolet (UV) radiation. Thomas used global climate models, recent atmospheric chemistry models and radiative transfer (the propagation of radiation through the layers of the atmosphere) to better understand how the flux of cosmic rays from supernovae would alter Earth's atmosphere, specifically the ozone layer.

One thing to note is that cosmic rays from supernovae would not blast everything in their paths all at once. The intergalactic medium acts as a kind of sieve, slowing down the arrival of cosmic rays and "radioactive iron rain" (60Fe) over hundreds of thousands of years, Thomastells Astrobiology Magazine. Higher energetic particles will reach Earth first and interact with our atmosphere differently than lower energy particles arriving later. Thomas's study modeled the depletion in ozone 100, 300, and 1,000 years after the initial particles from a supernovabegan penetrating our atmosphere. Interestingly, depletion peaked (at roughly 26 percent) for the 300-year case, beating out the 100-year case.

The high-energy cosmic rays in the 100-year case would zip right through the stratosphere and deposit their energy below the ozone layer, depleting it less, while the less energetic cosmic rays arriving during the 300-year interval would deposit more energy in the stratosphere, depleting ozone significantly.

One of the the last supernovae known to have exploded in our Milky Way Galaxy was the star that left behind the Cassiopeia A supernova remnant over 300 years ago, which is 11,000 light years away – much too far to have affected Earth. Credit: NASA/JPL-Caltech/O. Krause (Steward Observatory)

A decrease in ozone could be a concern for life on the surface. "This work is an important step towards understanding the impact of nearby supernovae on our biosphere," says Dr. Dimitra Atri, a computational physicist at the Blue Marble Space Institute of Science in Seattle, USA.

Thomas examined several possible biologically-damaging effects (erythema, skin cancer, cataracts, marine phytoplankton photosynthesis inhibition and plant damage) at different latitudes as a result of increased UV radiation resulting from a depleted ozone layer. They showed heightened damage across the board, generally increasing with latitude, which makes sense given the changes we see in the fossil record. However, the effects aren't equally detrimental to all organisms. Plankton, the primary producers of oxygen, seemed to be minimally affected. The results also suggested a small increase in the risk of sunburn and skin cancer among humans.

So, do nearby supernovae result in mass extinctions? It depends, says Thomas. "There is a subtler shift instead of a 'wipe-out everything', some [organisms] are better off and some are worse off." For example some plants showed increase yield, like soybean and wheat, while other plants showed reduced productivity. "It fits," Thomas states, referring to the change in species in the fossil record.

In the future, Thomas hopes to expand on this work and examine possible linkages between human evolution and supernovae.

Stellar Flares With a Chance of Radio Bursts: Space Weather Discovery Puts “Habitable Planets” at Risk

A discovery that links stellar flares with radio-burst signatures will make it easier for astronomers to detect space weather around nearby stars outside the Solar System. Unfortunately, the first weather reports from our nearest neighbor, Proxima Centauri, are not promising for finding life as we know it.

“Astronomers have recently found there are two ‘Earth-like’ rocky planets around Proxima Centauri, one within the ‘habitable zone’ where any water could be in liquid form,” said Andrew Zic from the University of Sydney.

Proxima Centauri is just 4.2 light years from Earth.

“But given Proxima Centauri is a cool, small red-dwarf star, it means this habitable zone is very close to the star much closer in than Mercury is to our Sun,” he said.

“What our research shows is that this makes the planets very vulnerable to dangerous ionizing radiation that could effectively sterilize the planets.”

Lead author Andrew Zic at the GMRT radio telescope in India. Credit: University of Sydney/supplied

Led by Mr. Zic, astronomers have for the first time shown a definitive link between optical flares and radio bursts on a star that is not the Sun. The finding, published today (December 9, 2020) in The Astrophysical Journal, is an important step to using radio signals from distant stars to effectively produce space weather reports.

“Our own Sun regularly emits hot clouds of ionized particles during what we call ‘coronal mass ejections’. But given the Sun is much hotter than Proxima Centauri and other red-dwarf stars, our ‘habitable zone’ is far from the Sun’s surface, meaning the Earth is a relatively long way from these events,” Mr. Zic said.

“Further, the Earth has a very powerful planetary magnetic field that shields us from these intense blasts of solar plasma.”

The research was done in collaboration with CSIRO, the University of Western Australia, University of Wisconsin-Milwaukee, University of Colorado and Curtin University. There were contributions from the ARC Centre for Gravitational Waves and University of California Berkeley.

The study formed part of Mr. Zic’s doctoral studies at the Sydney Institute for Astronomy under the supervision of Professor Tara Murphy, deputy head of the School of Physics at the University of Sydney. Mr. Zic has now taken a joint position at Macquarie University and CSIRO.

He said: “M-dwarf radio bursts might happen for different reasons than on the Sun, where they are usually associated with coronal mass ejections. But it’s highly likely that there are similar events associated with the stellar flares and radio bursts we have seen in this study.”

Coronal mass ejections are hugely energetic expulsions of ionised plasma and radiation leaving the stellar atmosphere.

“This is probably bad news on the space weather front. It seems likely that the galaxy’s most common stars – red dwarfs – won’t be great places to find life as we know it,” Mr Zic said.

In the past decade, there has been a renaissance in the discovery of planets orbiting stars outside our Solar System. There are now more than 4000 known exoplanets.

This has boosted hopes of finding ‘Earth-like’ conditions on exoplanets. Recent research says that about half the Sun-like stars in the Milky Way could be home to such planets. However, Sun-like stars only make up 7 percent of the galaxy’s stellar objects. By contrast, M-type red dwarfs like Proxima Centauri make up about 70 percent of stars in the Milky Way.

The findings strongly suggest planets around these stars are likely to be showered with stellar flares and plasma ejections.


The Proxima Centauri observations were taken with the CSIRO’s Australian Square Kilometer Array Pathfinder (ASKAP) telescope in Western Australia, the Zadko Telescope at the University of Western Australia and a suite of other instruments.

University of Western Australia scientist Dr. Bruce Gendre, from the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), said the research helps understand the dramatic effects of space weather on solar systems beyond our own.

Supervising research lead Professor Tara Murphy from the Sydney Institute for Astronomy and School of Physics at the University of Sydney. Credit: University of Sydney

“Understanding space weather is critical for understanding how our own planet biosphere evolved – but also for what the future is,” Dr. Gendre said.

Professor Murphy said: “This is an exciting result from ASKAP. The incredible data quality allowed us to view the stellar flare from Proxima Centauri over its full evolution in amazing detail.

“Most importantly, we can see polarized light, which is a signature of these events. It’s a bit like looking at the star with sunglasses on. Once ASKAP is operating in full survey mode we should be able to observe many more events on nearby stars.”

This will give us much greater insights to the space weather around nearby stars.

Other facilities, including NASA’s planet-hunting Transiting Exoplanet Survey Satellite and the Zadko Telescope observed simultaneously with ASKAP providing the crucial link between the radio bursts and powerful optical flares observed.

Mr. Zic said: “The probability that the observed solar flare and received radio signal from our neighbor were not connected is much less than one chance in 128,000.”

The research shows that planets around Proxima Centauri may suffer strong atmospheric erosion, leaving them exposed to very intense X-rays and ultraviolet radiation.

But could there be magnetic fields protecting these planets?

Mr. Zic said: “This remains an open question. How many exoplanets have magnetic fields like ours?”

So far there have been no observations of magnetic fields around exoplanets and finding these could prove tricky. Mr. Zic said one potential way to identify distant magnetic fields would be to look for aurorae, like those around Earth and also witnessed on Jupiter.

“But even if there were magnetic fields, given the stellar proximity of habitable zone planets around M-dwarf stars, this might not be enough to protect them,” Mr. Zic said.

Reference: “A Flare-type IV Burst Event from Proxima Centauri and Implications for Space Weather” by Andrew Zic, Tara Murphy, Christene Lynch, George Heald, Emil Lenc, David L. Kaplan, Iver H. Cairns, David Coward, Bruce Gendre, Helen Johnston, Meredith MacGregor, Danny C. Price and Michael S. Wheatland, 9 December 2020, Astrophysical Journal.
DOI: 10.3847/1538-4357/abca90

Funding: Andrew Zic was funded by an Australian Government Research Training Program Scholarship. Tara Murphy acknowledges the support of the Australian Research Council. Parts of this research were conducted by the Australian Research Council Centre of Excellence

Is Betelgeuse about to go Supernova?

Although it would probably look spectacular, I'd hate to see Betelgeuse go if for no other reason than I love the name.

Seriously, it's one of the most recognizable stars in our sky.

The only problem ?
If Betelgeuse goes supernovae , it has the Earth laser sighted.
"Turn out the lights , the party's over"
ETA : 600+ years later

It would take 640 years for the impact to reach Earth though, right?

It would take 640 years for the impact to reach Earth though, right?

Not an expert but I think it would take longer than that.
The shock wave or whatever it’s called wouldn’t travel at the speed of light.
Maybe someone more knowledgeable can comment.

The only problem ?
If Betelgeuse goes supernovae , it has the Earth laser sighted.
"Turn out the lights , the party's over"
ETA : 600+ years later

If it's that far away it would have already gone 640 years ago, we would just now be seeing it

We see light from stars as they were in the past. Not as they are now

It would take 640 years for the impact to reach Earth though, right?

Depending on the range of the scope used .
And , it is not an "impact"
Theoretically , it would burn away the Van Allen Belt and strip the Earth's atmosphere.
But , on a lighter note , Beetlejuice is not the correct type of star.
Red Dwarf , doesn't contain enough heavy metals , and is shrinking.
As much as we know.

It would take 640 years for the impact to reach Earth though, right?

Not an expert but I think it would take longer than that.
The shock wave or whatever it’s called wouldn’t travel at the speed of light.
Maybe someone more knowledgeable can comment.
Uhhh , it is not a "shock wave"
It is most likely a gamma ray burst. A HUGE one . That usually travels at the speed of light.

The only problem ?
If Betelgeuse goes supernovae , it has the Earth laser sighted.
"Turn out the lights , the party's over"
ETA : 600+ years later

If it's that far away it would have already gone 640 years ago, we would just now be seeing it

We see light from stars as they were in the past. Not as they are now
Uhh, no.
Like I stated on the other post , depends on the range of the scope

Betelgeuse could have already exploded up to 640 years ago and we wouldn't know it until we see it.

IF (big if, see below) its explosion caused bursts of gamma rays or bursts of x-rays, those dangerous rays would already be heading to Earth at the speed of light and get to Earth at the same time as the light -- since those things are part of the light. Gamma rays and x-rays, just like visible light, are EM radiation they are part of the overall "light."

HOWEVER, according to this article by Phil Plait (the Bad Astronomy guy) linked below, Betelgeuse is not the type of star whose explosion would be harmful to us at the distance it is from us. We would NOT have our atmosphere torn away or have harmful radiation searing us from Betelgeuse.

Edit to add excerpt from article:

It would take 640 years for the impact to reach Earth though, right?

Not an expert but I think it would take longer than that.
The shock wave or whatever it’s called wouldn’t travel at the speed of light.
Maybe someone more knowledgeable can comment.
Uhhh , it is not a "shock wave"
It is most likely a gamma ray burst. A HUGE one . That usually travels at the speed of light.

Ok not a shock wave.
Betelgeuse is 640 light years away and if we see it go supernova tomorrow, it actually happened 640 years ago.
So what you are saying is the gamma ray burst with reach us at the exact same time we see the star explode?

originally posted by: Soylent Green Is People
Betelgeuse could have already exploded up to 640 years ago and we wouldn't know it until we see it.

IF (big if, see below) its explosion caused bursts of gamma rays or bursts of x-rays, those dangerous rays would already be heading to Earth at the speed of light and get to Earth at the same time as the light -- since those things are part of the light Gamma rays and x-rays are, just like light, EM radiation.

HOWEVER, according to this article by Phil Plait (the Bad Astronomy guy) linked below, Betelgeuse is not the type of star whose explosion would be harmful to us at the distance it is from us. We would NOT have our atmosphere torn away or have harmful radiation searing us from Betelgeuse.

Betelgeuse is the exact wrong type of star to cause a "gamma-ray burst" and its axis is not even pointed at the earth so I wouldn't worry about a stellar apocalypse from that direction.

The name "Betelgeuse" would exist as part of our common language for centuries. First as "The Betelgeuse event" (which would be as bright as the moon for weeks or months), and then as the Betelgeuse nebula. Unlike the star itself the name, Betelgeuse isn't going anywhere any time "soon"*.

*where soon can be defined as a range between now(ish) and hundreds of thousands of years.

and its axis is not even pointed at the earth

It would take 640 years for the impact to reach Earth though, right?

If we see it tomorrow, then . yes.

originally posted by: Soylent Green Is People
Betelgeuse could have already exploded up to 640 years ago and we wouldn't know it until we see it.

IF (big if, see below) its explosion caused bursts of gamma rays or bursts of x-rays, those dangerous rays would already be heading to Earth at the speed of light and get to Earth at the same time as the light -- since those things are part of the light Gamma rays and x-rays are, just like light, EM radiation.

HOWEVER, according to this article by Phil Plait (the Bad Astronomy guy) linked below, Betelgeuse is not the type of star whose explosion would be harmful to us at the distance it is from us. We would NOT have our atmosphere torn away or have harmful radiation searing us from Betelgeuse.

How is that relevant to the time frame?

Gamma bursts, X rays, etc. travel the same speed as photons, do they not?

I've been looking up at the skies since this anomaly became known. As someone who is a stargazer, it is easy to tell that Betelguise has gotten significantly dimmer. Now it's not only at an unprecedented dimmness, it is also lasting much longer than any previous observed cycles.(It is a variable star so it dims and brightens in what usually is a predictable cycle both time and magnitude).

It would be awesome to see it go supernova in our lifetime. I can't imagine the Constellation Orion without it.

If it's about to blow, the timing is something to note, given the unrest the world is facing, some might say we are on the verge of another World War when they would be one hell of an omen.

I think our solar system is at a safe enough distance that even if it does go Nova it should not cause any significant harm though there was something I read that suggested the magnetic waves from the dying star could actually somehow affect our own stars core causing it to reduce activity and actually cool for a period, I think this is probably bunk but the theory was interesting enough and the guy that wrote the article seemed intelligence enough that it deserves mention.

Also the star while about 20 times the mass of our own sun is unlikely to become a black hole as it is probably too small for that but it could leave a white dwarf behind when it goes, the first indication even before the light reaches us though probably only a fraction of a second before the light would be a sudden wave of high energy neutrino's that would be detected in some of our neutrino detecting underground observatory's.

Other than that many people would regard it as a sign some seeing it as a good sign and other's as a bad one, people are superstitious and religious like that but I would find it saddening that a great star had lived out it's life cycle, our own sun is expected to live for about another 4 to 5 billion years then to swell into a red giant before it too end's it life cycle but if our descendant's by that time have left our solar system they may well be living around stars such as Proxima Centauri a tiny red dwarf star that will live for maybe a hundred time's as long as our own sun, despite being smaller these smaller stars have much slower rates of fusion and so despite having less material one of the perversity's of the star life cycle is that they last so much longer, generally the larger the star the shorter it's life span.

Some interesting size comparison's.

Hopefully that great star will be around for a long time and future generations can enjoy it's constant presence but many of the great stars listed in the first video may be already long, long gone and it is only there ghost light we are seeing so long after there passing.

Now if it had the potential to become a Neutron star and it's emission to pass our way THEN I would be worried but that is also unlikely to occur.

Earth-like planet near Proxima Centauri

At a distance of just over four light years, Proxima Centauri is the nearest star outside our solar system, and has thus long been a favourite of science fiction writers. The latter may now be getting fresh inspiration: astronomers have discovered a planet that orbits Proxima Centauri once every 11.2 days at a distance of seven million kilometres - within an area where there may just be the right conditions for the emergence of life. The mass of the celestial body called Proxima Centauri b is estimated to amount to 1.3 Earth masses.

Glimpse of a new world: artist's impression of the newly discovered planet orbiting Proxima Centauri, at a distance of 4.24 light-years the fixed star nearest to Earth.

© Ricardo Ramirez & James Jenkins (Department of Astronomy, Universidad de Chile)

Glimpse of a new world: artist's impression of the newly discovered planet orbiting Proxima Centauri, at a distance of 4.24 light-years the fixed star nearest to Earth.

The planet may not necessarily possess habitable conditions. But in spite of the close proximity to its host star, the object is located in the region astronomers call the &aposhabitable zone&apos. Planets in the habitable zone around the host star could potentially have surface temperatures that would principally permit liquid water - a crucial prerequisite for life as we know it from our Earth.

Proxima Centauri is a red dwarf star spectral type M5.5Ve, and as such significantly lighter and dimmer than our Sun. For example, Proxima has just 12% of the Sun’s mass, and merely 0.17% of the Sun’s overall brightness. Red dwarfs account for 70-80% of all stars in the solar neighbourhood, and with some probability for the same fraction of stars within our home galaxy as a whole.

On the other hand, the close proximity of Proxima Centauri b to its host star makes it very likely that the planet is in bound rotation. This means that one side of the planet would always be oriented towards the star, resulting in perpetual day, the other side would be in perpetual night. It is unclear how life could evolve under such adverse conditions.

Red dwarf stars with one third the Sun’s mass or less are fully convective: their matter is in constant motion, similar to the way that in a boiling pot, water is constantly moving around, each portion of water mixing with all other portions. A significant fraction of red dwarfs has a comparatively strong magnetic field, and shows substantial stellar activity, and Proxima Centauri is no exception.

One consequence is the occurrence of flares: sudden releases of magnetic energy that lead to marked, but short-lived increases in the star’s brightness. The activity of the host star also creates high-energy particles and X-rays regularly hitting the planet – which would make conditions for possible life on Proxima Centauri b considerably more difficult.

And while a possible detection of life, or at least of chemical properties suggestive of the presence of life, is likely to be some decades off, these observations provide opportunities to learn about a planet around the most common type of star in our galaxy – with lessons that are interesting in their own right, for astronomers seeking a systematic understanding of planet formation in our home galaxy.

Astronomers have found nearly 3500 such planets around stars other than the Sun. Most of the exoplanet discoveries are due to NASA’s space telescope Kepler, which is able to monitor the brightness of many different stars with high accuracy. Planets whose orbits take them between their host star and an observer on Earth periodically obscure some of the host star’s light.

This allows them to be detected as astronomers monitor the host star’s brightness for tell- tale, systematic dips. While Proxima has been monitored for such dips in the past, none have so far been found. This did not preclude the existence of a planet – only of a suitably large planet whose orbit happened to be aligned in exactly the right way.

More recently, the close passage of Proxima Cen in front of two other stars, in October 2014 and February 2016, opened up the possibility for an unusual detection method known as microlensing.

Had there been a planet of Proxima that had passed directly in front of one of these stars, its mass would have deflected and intensified the more distant star’s light. This would have created a fleeting increase in brightness based on effects of Einstein’s theory of general relativity.

But again, the absence of these detections did not rule out the existence of a planet. It merely showed that such a planet was not in the right place at the right time.

Data of a planet: radial velocity measurements phase folded at the 11.2 day period of the planet candidate for 16 years of observations. Different symbols are used for data from the Pale Red Dot (PRD) campaign, HARPS data taken before 2016, and the earlier data from UVES. The solid line depicts the best fitting Keplerian orbit to the data.

© Guillem Anglada-Escudé et al., School of Physics and Astronomy, Queen Mary University of London, UK / Max Planck Institutw for Astronomy

This left a third standard method for detecting exoplanets: the radial velocity method, which measures tiny wobbles of a star as both the star and the planet orbit their common centre of mass, bound by mutual gravitational attraction. Similar to the way that the siren of a fire truck or police car changes pitch as the car passes you by, light from a star will be slightly shifted in frequency towards the blue end of the spectrum if the star approaches you, and towards the red end if the star is moving away.

Stellar spectra – the rainbow-like decomposition of the star’s light into myriads of different shades of colour, or wavelengths – contain characteristic patterns of thousands of narrow, dark lines. Precision measurements of how these lines shift are redshifted and blueshifted over time can help uncover a tiny, planet-caused wobble, and thus yield indirect evidence of the presence of a planet around the star.

Several searches using this method targeted Proxima Centauri over the past decades, but no planet was discovered. Proxima Centauri b with its comparatively small mass causes a tiny wobble that is close to the limit of what can be detected with today’s astronomical instruments. In particular, a detection takes a long series of measurements, and a stable spectrograph that can deliver precise and consistent high quality measurements over the course of years.

The first ingredient of the present discovery was the spectrograph HARPS at the 3.6 m telescope of the European Southern Observatory (ESO) at La Silla Observatory in Chile, which was designed for precisely this kind of planet-hunting work and has been delivering reliable and accurate radial velocities since 2003.

In 2013, Guillem Anglada-Escudé, then at the University of Göttingen, Germany, and colleagues observed Proxima Centauri using HARPS, and found some indication of the possible presence of a planet with a period of 11.2 days, or, less likely, 13.6 days or 18.3 days.

The data was not sufficiently conclusive to allow for the discovery of such a planet. The astronomers could not exclude that these were false alarms: the presence of a planet, mimicked by the ever-present noise in the observations. The data was sufficient, on the other hand, to convince Anglada-Escudé to organize a systematic search campaign, dubbed "Pale Red Dot", which would involve extensive additional measurements with the HARPS spectrograph as well as regular luminosity measurements using smaller telescopes, which would allow the astronomers to better take into account the influence of stellar activity. The HARPS measurements were performed on 54 nights between Jan 18th and March 30th, 2016.

Anglada-Escudé, by then at Queen Mary University of London, had also added an outreach component to the campaign, the &aposPale Red Dot&apos websites, with scientists involved in the measurements writing regular blog articles and charting the campaign’s progress on social media.

The measurements began to show stronger and stronger signs of the presence of a planet. Guillem Anglada-Escudé says: "The first 10 days were promising, the first 20 were consistent with expectations, and at 30 days the result was pretty much definitive, so we started drafting the paper!"

Interpreting the data, however, was difficult. Because the red dwarf Proxima Centauri is active and has a strong magnetic field, astronomers expect that the star’s atmosphere will frequently feature dark, cooler spots: the red dwarf version of the sunspots visible on the surface of our Sun through a (suitably shielded) telescope. Such spots affect the radial velocity measurements, as well: Such star spots show up in the star’s spectrum, and can mimic the presence of a planet where no planet exists.

In order for a detection to be solid, such effects need to be taken into account. In fact, the Alpha Centauri system, a double star system very close to Proxima, and which might even include Proxima as a third component, is the subject of a cautionary tale: The discovery of what was thought between 2012 and about 2015 to be the closest planet outside our Solar system, Alpha Centauri Bb orbiting the star Alpha Centauri B, is now widely regarded as the artefact of a flawed analysis demonstrating the difficulty of extracting weak radial velocity signals from among the various noise sources present in such observations, which prominently includes the effects of stellar spots.

What clinched the detection were older observations taken by Martin Kürster from the Max Planck Institute for Astronomy and his former PhD student Michael Endl (now at the University of Texas at Austin) and analysed jointly with his former PhD student Mathias Zechmeister (now at the University of Göttingen) during a systematic search for companions of M stars, taken with the UVES spectrograph at ESO’s Very Large Telescope (VLT) during a period of seven years from 2000 to 2007.

Martin Kürster says: "In our earlier measurements, the signal for the planet with a period of 11.2 days is visible." But with this data alone there was no way of telling whether the signal indicates the presence of a planet or is the result of random fluctuations.

Kürsters continues: "When combined with the new measurements, on the other hand, the earlier signal is a strong indication that what the Pale Red Dot campaign discovered is a real planet. False signals due to stellar activity would not have remained stable over the past 17 years.”

Betelgeuse Interesting Facts

Credit & Copyright: Rogelio Bernal Andreo at

Located In Orion Constellation

Betelgeuse is a red supergiant star located 640 light-years away in the constellation of Orion. This distinctive star is found in the upper-left corner of Orion and marks the hunter’s right shoulder.

Name Means ‘Hand Of The Central One’

The name Betelgeuse is derived from the Arabic ‘yad al-jawza’ meaning ‘hand of the central one’ However, in medieval times the “y” was mistranslated as a “b” hence the star’s unusual name. Interestingly, Arab astronomers initially saw the central one (‘Jauza’) as the nearby constellation of Gemini, but after studying Greek astronomy switched its name to refer to the constellation of Orion.

1,000 Times Bigger Than Our Sun

Betelgeuse is a huge variable star that fluctuates in size from between 700 times to 1,000 bigger than the Sun. If it replaced the sun in our own solar system it would reach the Asteroid Belt, and extend to the orbit of Jupiter.

Fluctuates In Brightness

Being an irregular variable Betelgeuse also fluctuates in brightness and although it has a luminosity around 13,000 times that of the sun, its brightness ranges between 0.2 and 1.2 magnitude in the night sky. Consequently, despite being the 8th brightest star in the celestial heavens there are periods when it outshines even Orion’s brightest star Rigel, while at other times it appears fainter than the 19th brightest star Deneb in the constellation Cygnus.

A Red Supergiant Star

Stars change color throughout their life-cycle from the hottest blue types to the older, cooler red types depending on which phase of its stellar evolution has been reached. Betelgeuse is old for a supergiant and has a low surface temperature of 6000 F, making it appear orange-red in colour. Interestingly, the Greek astronomer Ptolemy (90AD – 168AD) observed its colour as “ruddiness,” but three centuries earlier Chinese astronomers described Betelgeuse as appearing yellow, perhaps suggesting Betelgeuse may have been a yellow supergiant just a couple of thousand years ago.

Just 10 Million Years Old

A peculiar fact about massive stars is that they burn through their fuel much faster than other stars and are extremely short-lived. At just 10 million years of age, Betelgeuse is already quite old for a supergiant and near the end of its life. In contrast, our sun is a yellow dwarf star 4.5 billion years old which is expected to last another 6 billion years.

Betelgeuse Could Go Supernova

As a star gets older it quickly burns out its hydrogen fuel, and then switches to helium and other elements. During this expanding and cooling stage the star is called a giant, but during fusion heavier and heavier atoms are created until its core is iron, at which point it runs out of fuel. If that star is sufficiently massive, like Betelgeuse, the entire star collapses and explode as a supernova. In fact, it is possible Betelgeuse has already gone supernova, and that the light will not reach Earth for centuries as Betelgeuse is located 640 light-years away.

640 Light-years Distant

When Betelgeuse does finally go supernova, it will present a truly spectacular sight from Earth and could resemble the picture above. The blast of light will appear as bright as the full Moon and be visible in daylight for many months. However, it’s radiation is unlikely to affect the Earth as to be harmful a supernova would have to be no further than 25 light years away, and Betelgeuse is a safe 640 light-years distant from us.

Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science

Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if. ", "How will the future. ", "If all the rules for 'X' were different. ", "Why does my. ".

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Are wormholes theoretically possible? In terms of reaching other galaxies.

*please bear with my wording if it's a little off.

They were actually conceptualized theoretically. Theoretically they are possible, but there has never been any evidence or way to prove it other than (technically) quantum tunneling, which, to make it sound fun, is when an electron doesn't have enough energy to pass through a barrier, so it kinda just teleports to where it was going to go

Yes, they are absolutely theoretically possible, and maybe a way of getting to other galaxies as you suggest. Their scientific name is Einstein-Rosen bridge. According to the Einstein-Cartan-Sciama-Kibble theory of gravity, black holes are really sorts of intergalactic bridges. They are created when the force of gravity causes a star (or any matter) to collapse past the "Schwarzschild radius". Still, the matter doesn't reach infinite density, and rebounds to create the other half of the bridge apparently.

Now as for the actual ability to travel through these strange space tunnels with current technology, something like in interstellar, this is an entirely different question. Just because they could exist in theory doesn't mean we'll ever be able to actually use them as a means of travel. The main reason being it could close on the travellers at any moment, causing what would be their surefire deaths.

This is why the Nolan's got Kip Thorne to work as a scientific consultant for the movie, because he was actually the person Carl Sagan went to when he was trying to come up with a super sci-fi idea for his book Contact (another great movie about wormholes). "Although Schwarzschild wormholes are not traversable in both directions , their existence inspired Kip Thorne to imagine traversable wormholes created by holding the "throat" of a Schwarzschild wormhole open with exotic matter (material that has negative mass/energy)." From Wikipedia article on wormholes. Thorne goes into a lot of detail about this interesting fact in his famous book on black holes, as well as his companion book on the science behind interstellar.

[Quantum Physics] When a pair of virtual particles annihilate, do they cause gravitational waves?

It's possible in theory, but it doesn't ever happen. Gravitational waves are caused by a spin-down of massive objects most virtual particles don't survive long enough to form such stable orbits, and instead directly annihilate transferring all of their angular momentum and energy into the photons that are released.

Why are most fruits spherical or oval? And what about bananas?

Original bananas before human agriculture got hold of them were more oval-shaped.

What else could they be? Cubic or pyramidal?

I think that mainly has to do with equal distribution of weight, which is favorable for fruits, since they often hang in trees and such.

Current cosmological experiments have shown that the curvature of the universe is either very close or exactly 0. This means that the universe is flat, like a piece of paper that extends infinitely in every direction.

The idea that you would return to your initial point is true only for universes with positive curvature (sphere-like). This is unlikely as if the universe does deviate from flatness, the current measurements make it more likely to have negative curvature (saddle shaped).

It is highly unlikely. To be able to do this you would have a highly eccentric orbit, know exactly when it was captured, and be able to measure the precession of the orbit. Even then you're going to have to hope that it came from a fairly low-density region to be able to tell which of those systems the planet came from since they will have moved in the mean time as well.

not really from the orbit alone. To actually start orbiting the sun it would have to interact with a third body. This interaction then determines the final orbit. But if we see it approaching we could determine where it came from, or at least suggest some likely candidates.
But anyway a rogue planet appearing in our solar system is extremely unlikely.

Does the rotation of the earth affect g? (Force due to gravity).

From my understanding, as the earth rotates it exerts a centripetal force towards the core but at the same time we are moving with it. So I was wondering if for example the earth rotated not once per day (1/24hrs) but twice the frequency (1/12hrs) how would this affect g? Double? Non at all?

I've checked all over the internet but always get conflicting answers :/

The rotation of the earth doesn't change the gravitational acceleration itself, but rather introduces a second force that counteracts part of it. It results in an apparent outward force that varies from 0 at the poles to a maximum at the equator. This force reduces the apparent gravity at the equator by

If the moon had a surface temperature of 5000K, would it heat up Earth as much as the Sun does?

The equilibrium temperature for a secondary body receiving light from a primary is given by:

Where D is the separation between them, [R_p] is the radius of the primary, and [T_p ,,< m and>,, T_s] are the temperatures of the primary and secondary respectively. Using the numbers for the moon, and the proposed surface temperature that would make earth's equilibrium surface temperature around 236 K or around -37 o C.

What is our most advanced engine for space travel and realistically how far are we away from reaching Proxima Centauri (or any other viable destination)?

The most advanced engine is a complicated question that has to do a lot with what you want, and what engines you would say we have. Essentially with any engine in space there is a trade off between thrust and specific impulse. Higher thrusts mean larger accelerations, but it consumes a lot of fuel very quickly - think chemical rockets like the ones used to launch spacecraft. On the other end things like Ion Engines have very low thrust but high specific impulse, they can provide just a little acceleration for a very very long time. In the end the Ion thruster will actually allow for higher speeds, but only over very long trips and with no outside forces, which is why Chemical rockets are still used to lift off of earth as they must overcome Earth's gravity.

There are lots of variations of Electromagnetic propulsion drives that are currently in development, and if any of them become commercially viable they would easily be the most advanced, but again would be used for in-space propulsion, not for lift off.

As for how far are we from reaching another star, that's a complicated affair. We could send something there now, but it would take a long time. The Voyager 2 spacecraft is the furthest into deep space of any man made device. It was launched in the 70's and only just reached the edge of the solar system a few years ago.

Beyond just the tech, no one is going to fund a mission like that. It would be hugely expensive to launch a craft that could get there with decades or more before any payoff would come, and even then its unclear how or if we could retrieve that information. Centauri is too far away beam the information by radio, which means, having the craft physically turn around and come back is the only way, but that makes it insanely expensive to have to escape both our System, and the Proxima system.

What force is created before supernova explosion?

I think he means an outward force so big that the whole star expands.

And in that case it is produced in every single star in the universe other than brown and red dwarfs(brown and red dwarfs just gradually die off like how a battery gradually dies off so no outward force other than the one produced by fusion is involved) from small ones like our sun that will never supernova to large ones like betelgeuse that will definetely supernova within the next 10,000 years.

Ah you lost me here, what is this outward force you are referring to ?

Also, do you have a reference to the fact that Betelgeuse will go supernova in the next 10,000 years ? This seems extremely precise, I wonder how we can get such accuracy ?

OK I see - pressure is nothing one would call antigravity, but also, as I understand it this is not what causes a supernova explosion. On the contrary, if I recall correctly, it is insufficient pressure to counteract gravity that provokes a collapse, and the explosion is the resulting rebound. Describing this as antigravity seems very weird, if anything the force causing the explosion is gravity.

Regarding Betelgeuse, I found this article, which is reporting on : Evolutionary tracks for Betelgeuse (Michelle M. Dolan, Grant J. Mathews, Doan Duc Lam, Nguyen Quynh Lan, Gregory J. Herczeg, David S. P. Dearborn). They estimate

100k years, which seems quite precise already. Very interesting stuff.

Below is a good brief description of what goes on in a red supergiant just before supernova-

I suppose you could say that it is the mass of the original star that results in there being a supernova or not. A star with an original mass of up to 8 sol will result in a white dwarf, a star with an original mass of between 8 and 18 sol will result in a supernova & neutron star, and a star with an original mass of more than 18 sol will result in a supernova & black hole.

You were misinformed somewhere. Gravity doesn't "collapse" during the microseconds preceding the supernova event.

If anything, once fusion stops in the core of the star, gravity is able to cause the core to compress to a tiny fraction of its original size, since there is nothing, no force, which counteracts it.

You should read something about supernova formation, to get the correct idea about the sequence of events:

Right. That mechanism says that if there is net heat loss, gravity will slightly exceed pressure. It is a misconception to say that the heat loss ever causes temperature drop, however-- the temperature can rise monotonically everywhere, throughout the process. The key is that the slight excess of gravity is always causing contraction, allowing gravity to do work that pumps kinetic energy into the system-- usually at a rate twice as large as the net heat loss that is driving the whole business. Thus the excess kinetic energy piles up and causes the continuing temperature rise, but even though the temperature is steadily rising, the rising gravity continues to slightly exceed the pressure.

Anything that short-circuits the net heat loss will stop this process, and either fusion or degeneracy can do that-- fusion by replacing lost heat, degeneracy by preventing heat loss in the first place.

That is certainly a standard way to describe the situation, but I am pointing out the potential for that language to lead to misconceptions. In strict terms, the only gross macroscopic effect of degeneracy is the inhibition of heat loss, and as such it does not "cause" an outward force. (It also inhibits internal collisions, so it conducts heat very efficiently, but that just redistributes excess heat, most of the internal kinetic energy is still insulated against any heat loss.)

Admittedly, what constitutes a "cause" is not necessarily cut-and-dried in science, but let me offer this analogy. Take a hot ball of self-gravitating ideal gas, say a protostar, prior to any fusion. Now surround it with a big mirror, so no heat can escape. That protostar will quickly cease contracting. Would we say that the mirror is causing the outward force in that star, that prevents it from collapsing? The role of degeneracy in a white dwarf or neutron star is quite similar to that mirror-- it is the reason there is no further contraction, but it is not the cause of the outward force. The cause of the outward force is the internal kinetic energy of the particles, and nothing else.

So what happens in bigger stars? The neutrons go relativistic. It turns out that relativistic kinetic energy is never good at producing pressure that can resist gravitational contraction, because then gravitational contraction only supplies an equal amount of energy as needed for the increasing pressure to keep pace with the increasing gravity (so continues to lag behind if out of balance), rather than providing twice that amount as happens in nonrelativistic gas (so causes the pressure to eventually rise up and exceed gravity, as happens in a core bounce). That fact has nothing to do with degeneracy, degeneracy only tells you if heat loss will be stopped before the gas goes relativistic. If the gas has already gone relativistic, degeneracy is of no importance.

The Earth IS Spinning Faster, After All!

The Earth is spinning faster than it has at any time in the last 50 years, careful study of our planet reveals. Each of the 28 shortest days ever measured came in 2020.

It is possible this may require shortening the standard time on which much of our technological systems are based.

“The Earth is spinning faster now than at any time in the last 50 years. It’s quite possible that a negative leap second will be needed if the Earth’s rotation rate increases further, but it’s too early to say if this is likely to happen,” Peter Whibberley of the National Physical Laboratory said.

Does Anyone Have the Time?

The FOCS-1 atomic clock in Switzerland, seen here, is one of the most accurate timekeeping devices in the world, accurate to one second every 30 million years. Public domain image.

Atomic clocks make it possible to measure the length of a day with unprecedented accuracy. Since their development in the 1960’s, researchers have understood that the rotational rate of the Earth changes over time. Due to these variations, leap seconds have been added 28 times over the last 48 years.

However, or the first time ever, scientists are now talking about the possible need for a negative leap second — officially removing a second this year, making up for the increased rotational speed of Earth.

So why is the Earth is spinning faster than normal?

Official measurements of time derive from comparing the time from a network of 400 hundred atomic clocks, to the position of stars in the sky. (Interestingly, stars produce a different measurement of the length of a day, known as sidereal time. But, astronomers convert as needed).

Atomic clocks reveal that the time it takes for Earth to rotate through a complete day changes regularly, driven by atmospheric and oceanic currents, movements in the molten core of our planet, and even changes in atmospheric pressure.

Due to these effects, Coordinated Universal Time (UTC) — the standard by which all clocks are set — needs to occasionally be updated. In 2016, an extra leap second was added to the UTC time to make up for this difference. Since 1972, leap seconds have been added 28 times, usually at the end of June or December.

“Before UTC was introduced as the world time standard in 1972, GMT was a solar time standard that also acted as a reference point to determine local times worldwide. Today, GMT is a common time zone deriving its local time from UTC,” Konstantin Bikos explains for

Strangely, 2020 Didn’t Seem to Go By Quickly at All…

However (believe it or not), 2020 was actually the shortest year on record. Each day was roughly 1/20th of a millisecond shorter than normal. That difference, accumulated over the course of 2021, would result in clocks drifting roughly 1/50 of a second off of the rotational period of Earth.

“…[A]n average day in 2021 will be 0.05 ms shorter than 86,400 seconds. Over the course of the entire year, atomic clocks will have accumulated a lag of about 19 ms… In fact, the year 2021 is predicted to be the shortest in decades. The last time that an average day was less than 86,400 seconds across a full year was in 1937,” Graham Jones and Konstantin Bikos report for

And, if the Earth is spinning faster than previous years, even this seemingly small error can play havoc with electronic systems, including GPS, critical to cars, airplanes, and satellites.

Why do we need atomic clocks? A discussion on what makes these instruments so critical. Video credit: Nova PBS

Normally, it takes Earth 86,400 seconds to complete one rotation around its axis — referred to as a mean solar day. (There are other ways of measuring a day, but the principle of time drifting remains the same).

July 5, 2020 ended 1.0516 milliseconds faster than the standard day. Two weeks later, July 14 was the shortest day of the day, lasting 1.4602 milliseconds less than normal.

“Before this year began, the shortest day since 1973 was July 5, 2005, when the Earth’s rotation took 1.0516 milliseconds less than 86,400 seconds,” explains Graham Jones of

Incidentally, the longest day of 2020 was April 8, which lasted 1.61 milliseconds longer than a standard day.

When do we Go from Here?

“Tracked you down with this. This is my timey-wimey detector. It goes ding when there’s stuff. Also, it can boil an egg at 30 paces, whether you want it to or not, actually, so I’ve learned to stay away from hens. It’s not pretty when they blow.” — Doctor Who

Louis Essen and J. V. L. Parry stand next to the world’s first Cesium-133 atomic clock. Image credit: UK National Physical Laboratory

Atomic clocks measure the length of a second based on the time it takes for atoms of cesium-133 to oscillate between a pair of energy levels (which happens 9,192,631,770 times a second when atoms are held at a temperature of absolute zero).

“Atomic clocks are designed to detect this frequency, most of them today using atomic fountains a cloud of atoms that is tossed upwards by lasers in the Earth’s gravitational field. If one could see an atomic fountain, it would resemble a water fountain,” Bikos and Anne Buckle explain.

Next-generation clocks could use light to measure atomic fluctuations, making timekeeping 50,000 times more accurate than today’s most advanced instruments.

Options to correct for the recent hasty rotation of our home world currently being considered by The International Earth Rotation and Reference Systems Service (IERS) in Paris, France includes subtracting a second from 2021, or possibly putting aside leap seconds altogether until the time difference adds up to an hour.

In that case, astronomers would need to constantly adjust their observations to correct for an increasingly inaccurate standard time. Then, everyone would lose an hour of time, in much the same way as springing ahead during daylight savings time.

James Maynard

James Maynard is the founder and publisher of The Cosmic Companion. He is a New England native turned desert rat in Tucson, where he lives with his lovely wife, Nicole, and Max the Cat.

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6 thoughts on &ldquo The Earth IS Spinning Faster, After All! &rdquo

Quick, everyone start running east!

Where’s Superman when you need him?

If zi understand and comprahend for the last 48 years have there Earth orbit been 28 sec shorter.

Upcoming Guests

June 29 (s4/e26): Alyssa Mills, Graduate intern at JPL, talks about the largest moon in the Solar System, Ganymede.

July 6 (s5/e1): SEASON FIVE PREMERE! New York Times bestselling author Earl Swift, author of Across the Airless Wilds, the first major history of NASA’s lunar buggy.

July 13 (s5/e2):

Stella Kafka, CEO of The American Association of Variable Star Observers, talking about Betelgeuse.

July 20 (s5/e3):

Geoff Notkin, host of Meteorite Men on the Science Channel and president of the National Space Society, talks meteorites.

July 27 (s5/e4):

CHIME member Kaitlyn Shin, MIT grad student, explains fast radio bursts (FRBs)

August 3 (s5/e5):

Teaching science to children with Stephanie Ryan, author of “Let’s Learn Chemistry.”

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Supernova Radioisotopes Show Sun Was Born In Star Cluster, Scientists Say

The death of a massive nearby star billions of years ago offers evidence the sun was born in a star cluster, say astronomers at the University of Illinois at Urbana-Champaign. Rather than being an only child, the sun could have hundreds or thousands of celestial siblings, now dispersed across the heavens.

In a paper accepted for publication in the Astrophysical Journal, astronomy professors Leslie W. Looney and Brian D. Fields, and undergraduate student John J. Tobin take a close look at short-lived radioactive isotopes once present in primitive meteorites. The researchers' conclusions could reshape current theories on how, when and where planets form around stars.

Short-lived radioactive isotopes are created when massive stars end their lives in spectacular explosions called supernovas. Blown outward, bits of this radioactive material mix with nebular gas and dust in the process of condensing into stars and planets. When the solar system was forming, some of this material hardened into rocks and later fell to Earth as meteorites.

The radioisotopes have long since vanished from meteorites found on Earth, but they left their signatures in daughter species. By examining the abundances of those daughter species, the researchers could calculate how far away the supernova was, in both distance and time.

"The supernova was stunningly close much closer to the sun than any star is today," Fields said. "Our solar system was still in the process of forming when the supernova occurred."

The massive star that exploded was formed in a group or cluster of stars with perhaps hundreds, or even thousands, of low-mass stars like the sun, Fields said. Because the stars were not gravitationally bound to one another, the sun's siblings wandered away millennia ago.

Our solar system, rather than being the exception, could be the rule, the astronomers said. Planetary system formation should be understood in this context.

"We know that the majority of stars in our galaxy were born in star clusters," Looney said. "Now we also know that the newborn solar system not only arose in such a cluster, but also survived the impact of an exploding star. This suggests that planetary systems are impressively rugged, and may be common even in the most tumultuous stellar nurseries."