Gamma Ray Burst 2 Billion Light-Years Away Impacted Earth's Atmosphere as Strongly as a Solar Flare
Introduction
Last year, on October 9, humanity on Earth bore witness to
the most awe-inspiring celestial phenomenon ever recorded. It manifested as a
gamma ray burst (GRB) that surpassed any other known example in luminosity by
at least tenfold. Moreover, its duration exceeded that of any previously
documented GRB by a staggering factor of seventy. This event represents the
most colossal explosion ever observed within the vast expanse of our Universe.
From our vantage point on Earth, estimations suggest that such an event occurs
only once every 10,000 years.
The initial inkling of an extraordinary occurrence came from
various sources, including NASA's Earth-orbiting THEMIS probes, the
GRB-monitoring Swift Observatory, and ESA/NASA's Solar Orbiter. Numerous satellites
and ground telescopes swiftly detected it as well. It did not take long for
astronomers to realize that this phenomenon far surpassed anything they had
ever encountered before. It was promptly designated GRB221009A, denoting a
Gamma Ray Burst occurring on October 9, 2022, marking a significant milestone
in scientific exploration.
Upon learning of this disruptive event, Laura Hayes of ESA
sought to investigate its potential impact on the atmosphere. To accomplish
this, she turned to SuperSID, a ground-based receiver in Ireland responsible
for monitoring very-low-frequency (VLF) radio signals. VLF signals are
deliberately emitted by various terrestrial stations but also occur naturally
as a result of lightning and other atmospheric phenomena.
Such VLF signals traverse the space between Earth's surface
and the lower region of the ionosphere, located approximately 40 miles above
the surface. If the electrical conductivity or effective depth of the
ionosphere experiences any alterations, these changes will be reflected in the
received VLF signal by a recording device situated at a distance from the
transmitter.
The presence of an ionosphere is primarily attributable to
the Sun's radiation, comprising X-rays and ultraviolet rays, which dislodges
electrons from their atoms, giving rise to ions - charged particles. Initially
neutral atoms become positively charged, while negatively charged electrons
roam freely. During nighttime, a considerable number of charged particles
reunite, resulting in a lower ion count on the night side compared to the day
side. This day-night cycle exhibits remarkable stability, allowing us to
anticipate the behavior of the ionosphere. However, occasional disruptions may
occur, triggering deviations from the norm. The most frequent cause of such
disturbances is solar flares, wherein the Sun emits excessive ionizing
radiation, leading to an increased number of free electrons in the ionosphere.
Consequently, some of these electrons may descend below their customary
altitude. These deviations are readily detectable by VLF detectors scattered
across Earth, enabling the approximate mapping of the affected regions.
Outer space-originating GRBs can also induce these
disruptions on rare occasions. GRBs can emerge from the collapse of stars into
neutron stars or supernovae, or during the merging of two stars. Nevertheless,
the mechanisms responsible for generating the most potent GRBs remain somewhat
enigmatic. How do these extreme events achieve such incredible magnitudes?
Contrary to solar flares, once GRBs reach Earth, they tend to be considerably
weaker owing to their greater distance from our planet compared to the Sun.
Consequently, the overwhelming majority of GRBs have an insubstantial impact on
the atmosphere that is scarcely detectable.
Disturbances in the lower ionosphere can be detected by a change in amplitude and phase of waves coming from a very-low-frequency trasmitter. These waves bounce off of Earth’s surface and the bottom of the ionosphere
Nevertheless, when Hayes examined the VLF data from
SuperSID, she identified a notable disturbance over northern Europe that
aligned perfectly with the emergence of the GRB. Based on this correspondence,
she concluded that despite originating from a location two billion light-years
away, the GRB had affected Earth's lower ionosphere at a level comparable to a
significant solar flare. Undoubtedly, this event must have entailed an extraordinary
explosion!
Subsequently, further studies were conducted, yielding two
enlightening papers published on November 15. Nature Communications hosted a
comprehensive analysis by a team of Italian researchers, delving deeper into
the substantial effects of this exceedingly distant blast on Earth's atmosphere
as a whole. Simultaneously, Science Advances featured a study conducted by
researchers at the Large High-Altitude Air Shower Observatory (LHAASO) in
China. Their research quantified the sheer magnitude of the explosion, shedding
light on the monumental energy it must have discharged.
The Italian researchers revealed that the gamma-ray
illumination reached its focal point along India's west coast. However, its
radiance extended across Europe, Africa, Asia, and Australia, enveloping vast
regions of these continents.
The structure and depth of the ionosphere is different during the day and night, because the ionosphere is formed by the Sun’s radiation
Moreover, they provided an unprecedented account of the first-ever measurement of a GRB's influence on the upper region of the ionosphere, situated roughly 300 miles above Earth's surface. Prior to their research, no means existed to measure this phenomenon accurately. Fortunately, the Chinese satellite named CSES, designed to monitor the upper ionosphere until the end of 2023, fortuitously captured the disturbance during its passage over Europe, firmly establishing that this upper ionosphere disturbance originated solely from the GRB. Consequently, it can be inferred that the entirety of the ionosphere experienced the repercussions of this colossal event.
The LHAASO group detected approximately 5,000 high-energy
gamma rays within a thirty-minute timespan during the disturbance. LHAASO
comprises three detectors, one of which, known as the Kilometer Squared Array
(KM2A), covers an area of 1.3 square kilometers and is specifically designed
for detecting very high-energy gamma rays exceeding 3 teraelectron-volts (TeV).
Pron and Cone Table
| Pron | Cone |
|---|---|
| A cosmic blast seared Earth's atmosphere from 2 billion light-years away. | The burst occurred at a vast distance, with gamma rays traveling about two billion light-years. |
| Earth experienced an enormous burst of gamma rays from a source 2 billion light-years away. | This event is considered the brightest gamma-ray burst ever seen, impacting Earth's upper ionosphere. |
| The impact on Earth's atmosphere was as strong as a solar flare, with the burst being the brightest ever recorded]. | The burst, known as BOAT (Brightest Of All Time), is believed to have originated from a massive star explosion more than 2 billion light-years away. |
| The burst disrupted Earth's upper atmosphere, creating significant disturbances. | This gamma-ray burst managed to scramble Earth's upper atmosphere, reaching the ionosphere and impacting ozone levels. |
Given the immense distance, the number of gamma rays
reaching Earth from such an event is relatively small. This is because Earth
occupies a minuscule portion of the sky where the event occurred, resulting in
limited direct exposure. Nonetheless, individual gamma rays, as long as they do
not collide with other objects, retain their energy throughout the billions of
years it takes for them to reach us, apart from the slight energy loss caused
by the expansion of space.
Consequently, the gamma rays detected by LHAASO's KM2A
detector maintain a near equivalent level of energy to when they originated
from the highly extraordinary event that generated them. The most energetic
gamma rays detected by LHAASO carried an astonishing 13 TeV of energy. It is
worth noting that in 2021, LHAASO also captured photons with energy levels
ranging from 100 to 1000 TeV — the most energetically intense radiation ever
observed, although these were probably a result of peculiar naturally occurring
particle acceleration phenomena rather than direct explosions.
What does it mean to possess gamma rays with an energy of 13
TeV? The prefix "tera-" signifies "trillion," so 13
trillion electron-volts certainly sounds like a substantial value. But how
powerful is it really?
Let us consider a scenario where we have a flashlight
emitting 10 watts of power. In this case, nothing significant would happen.
Absolutely nothing.
One of the reasons for writing this is due to a recent
increase in peculiar high-energy events occurring in space, or at least a
heightened awareness of such phenomena. Just last month, gamma rays measuring
20 TeV were recorded emanating from a pulsar within the Vela constellation,
marking the highest-energy pulsar radiation ever detected. Additionally, on
November 15, Nature reported an extraordinary explosion known as the 'Tasmanian
devil' that was a hundred times brighter than a typical supernova and sustained
peak brightness over several months. What is happening out there?!
On a different note, Italian researchers point out that if
an event like GRB221009A were to occur within the Milky Way, it would
obliterate our ozone layer and expose all the plants and animals on Earth to
the full intensity of UV rays from the Sun, most likely resulting in their
extinction, along with our own.
Fortunately, these occurrences appear to be exceedingly
rare, but it raises the question of whether these events hinder the development
of advanced lifeforms often enough to counterbalance the comparatively
infrequent emergence of intelligent life.
However, it is conceivable that life may be concealed within
the oceans beneath the surfaces of celestial bodies such as Enceladus, Europa,
or even Pluto, thereby shielding them from such radiative assaults. If we want
to discover life of that nature — and we certainly will make the attempt — we
will likely need to focus our search within our own Solar System.
The current challenge before us, with numerous theories
waiting to be considered, is to fully elucidate the nature of the event capable
of generating an explosion of such indescribably immense power. Indeed, the
Universe has become quite turbulent.
Gamma-Ray Bursts vs. Solar Flares: Key Differences
While similarities exist, key differences distinguish gamma-ray bursts from solar flares. Understanding these disparities is crucial in comprehending the diverse cosmic processes at play and their unique impacts on our solar system.
Challenges in Studying Distant Events
Observing events from such vast distances presents challenges. However, advancements in technology continue to enhance our observational capabilities, allowing astronomers to peer deeper into the cosmos. What are the current limitations, and how are scientists overcoming them?
Implications for Earth's Future
Exploring the potential long-term effects of such cosmic events on Earth opens avenues for discussion. How resilient is our planet, and what measures can we take to prepare for or mitigate the impact of similar events in the future?
Public Interest and Awareness
Communicating complex cosmic events to the general public requires effective science communication. How can we bridge the gap between scientific discoveries and public understanding? What role does the media play in shaping public interest and perceptions?
Scientists' Perspectives
Gaining insights from astrophysicists and researchers involved in studying these phenomena is crucial. What do experts in the field have to say about the significance of this gamma-ray burst and its implications for our understanding of the universe?
Future Research and Exploration
The recent gamma-ray burst sparks curiosity and prompts further exploration. How does this event pave the way for future research, and what missions or studies are on the horizon to delve deeper into the mysteries of cosmic phenomena?
Conclusion
In conclusion, the impact of a gamma-ray burst 2 billion light-years away on Earth's atmosphere raises intriguing questions and provides a unique glimpse into the cosmic forces shaping our universe. As we continue to explore these phenomena, our understanding of the vast and complex cosmos expands, paving the way for new discoveries and revelations.
FAQs About Gamma-Ray Bursts and Their Impact
Are gamma-ray bursts dangerous to Earth?
- Addressing common misconceptions and clarifying the potential risks associated with gamma-ray bursts.
How do scientists detect and study gamma-ray bursts?
- Explaining the tools and techniques astronomers use to observe and analyze these distant cosmic events.
Can gamma-ray bursts affect our technology?
- Discussing the potential impact of gamma-ray bursts on Earth's technological infrastructure.
What is the difference between gamma-ray bursts and supernovae?
- Distinguishing between these cosmic phenomena and their respective implications for the universe.
Are there any ongoing missions focused on studying gamma-ray bursts?
- Providing information on current and upcoming space missions dedicated to exploring gamma-ray bursts and related celestial events.
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