The supermassive black hole at the centre of the Milky Way triggered a “cataclysmic” explosion recently enough to occur as our earliest ancestors walked the Earth, scientists believe.
While astronomers have suspected such an event took place for years, new research dates the blast to just 3.5 million years ago – 63 million years after an asteroid wiped out the dinosaurs.
Two cone-shaped nuclear flares sliced through the Milky Way in opposite directions for at least 200,000 light years, bursting out into deep space and impacting the trail of gas partially circling the galaxy known as the Magellanic Stream.
Scientists allege such a powerful blast could only have been caused by nuclear activity associated with Sagittarius A, the black hole at the centre of our galaxy, which is 4.2 million times larger than the sun.
“These results dramatically change our understanding of the Milky Way,” said the study’s co-author Dr Magda Guglielmo, of the University of Sydney. “We always thought about our galaxy as an inactive galaxy, with a not so bright centre.
1/9 Soap bubble structures showing light interference colours and patterning
Bubbles want to optimise space and minimise their surface area for a given volume of air. This unique phenomenon makes them a reliable, useful tool in many areas of research. In particular, materials science and ‘packing’ – how things fit together. Bubble walls drain under gravity, thin at the top, thick at the bottom and interferes with travelling lightwaves to create bands of colour. Black spots show the wall is too thin for interference colours, indicating the bubble is about to burst! – Kym Cox
Kym Cox/RPS
2/9 Upside down Jelly fish, Cassiopea xamachana
Instead of swimming, this species spends its time pulsing up and down in the water. Their diet is sea plankton and their coloration comes from the uptake of algae in the water. Some jellyfish species have been documented eating plastics in the ocean. One theory suggests that algae grows on the plastic. As it breaks down, the algae creates the odor of dimethyl sulfide that attracts hungry animals. – Mary Anne Chilton
Mary Anne Chilton/RPS
3/9 Tribolium confusum. Confused flour beetle.
This small beetle is a pest in stored grain and flour products. Scanning electron micrograph, coloured in Photoshop. – David Spears
David Spears/RPS
4/9 NGC7000 North American Nebula
The North America Nebula, NGC7000, is an emission nebula in the constellation Cygnus, close to Deneb. The remarkable shape of the nebula resembles that of the continent of North America, complete with a prominent Gulf of Mexico. The Cygnus Wall, a term for the “Mexico and Central America part” of the North America Nebula, exhibits the most concentrated star formations in the nebula. – Dave Watson
Dave Watson/RPS
5/9 Safety Corona
A safety pin is connected to a high tension AC generator. The pin ionizes the air around it. When the electrons fall back on an atom, the excess energy is emitted as a photon, which generate the corona glow around the pin. The fuzziness of the pin is because the camera did not actually capture light reflected on the pin but rather the light emitted by the ionized light around it. – Richard Germain
Richard Germain/RPS
6/9 Calmness of Eternity
Himalayas mountains, Nepal. Gosaikunda high-mountain lake. Point of shooting – 4400m. The Milky Way is the galaxy that contains the Solar System, with the name describing the galaxy’s appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The Milky Way is a barred spiral galaxy with a diameter between 150,000 and 200,000 light-years. It is estimated to contain 100‚ 400 billion stars
Yevhen Samuchenko
Yevhen Samuchenko/RPS
7/9 Stag beetle
Stag beetle. Light microscopy. Magnification 5x. – Viktor Sykora
Viktor Sykora/RPS
8/9 Mapping1_OxygenIb_PEM
Final Major Project for an MA Photography Falmouth University. Project: Mapping 1, Post Exertional Malaise. Mapping 1, focuses on discovering the research behind Myalgic Encephalomyelitis. Through exploration of perspective, complexities, and scientific multidisciplinary collaborations, I create imagery that explains, reveals and connects us consciously to the ambiguous and unknown. – Yasmin Crawford
Yasmin Crawford/RPS
9/9 Lovell Telescope Series 1c
I have always been fascinated with the Lovell Telescope at Jodrell Bank since I went on a school trip as a child. Here, I wanted to take a series of closer, more detailed and more honest shots than we often see. Exploring the multitude of shapes and exposing the wear of the telescope, each photo in the series stands alone or can be viewed collectively, either way, they present a powerful portrayal of machine that helps humankind in their endeavours to understand space and time. – Marge Bradshaw
Marge Bradshaw/RPS
1/9 Soap bubble structures showing light interference colours and patterning
Bubbles want to optimise space and minimise their surface area for a given volume of air. This unique phenomenon makes them a reliable, useful tool in many areas of research. In particular, materials science and ‘packing’ – how things fit together. Bubble walls drain under gravity, thin at the top, thick at the bottom and interferes with travelling lightwaves to create bands of colour. Black spots show the wall is too thin for interference colours, indicating the bubble is about to burst! – Kym Cox
Kym Cox/RPS
2/9 Upside down Jelly fish, Cassiopea xamachana
Instead of swimming, this species spends its time pulsing up and down in the water. Their diet is sea plankton and their coloration comes from the uptake of algae in the water. Some jellyfish species have been documented eating plastics in the ocean. One theory suggests that algae grows on the plastic. As it breaks down, the algae creates the odor of dimethyl sulfide that attracts hungry animals. – Mary Anne Chilton
Mary Anne Chilton/RPS
3/9 Tribolium confusum. Confused flour beetle.
This small beetle is a pest in stored grain and flour products. Scanning electron micrograph, coloured in Photoshop. – David Spears
David Spears/RPS
4/9 NGC7000 North American Nebula
The North America Nebula, NGC7000, is an emission nebula in the constellation Cygnus, close to Deneb. The remarkable shape of the nebula resembles that of the continent of North America, complete with a prominent Gulf of Mexico. The Cygnus Wall, a term for the “Mexico and Central America part” of the North America Nebula, exhibits the most concentrated star formations in the nebula. – Dave Watson
Dave Watson/RPS
5/9 Safety Corona
A safety pin is connected to a high tension AC generator. The pin ionizes the air around it. When the electrons fall back on an atom, the excess energy is emitted as a photon, which generate the corona glow around the pin. The fuzziness of the pin is because the camera did not actually capture light reflected on the pin but rather the light emitted by the ionized light around it. – Richard Germain
Richard Germain/RPS
6/9 Calmness of Eternity
Himalayas mountains, Nepal. Gosaikunda high-mountain lake. Point of shooting – 4400m. The Milky Way is the galaxy that contains the Solar System, with the name describing the galaxy’s appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The Milky Way is a barred spiral galaxy with a diameter between 150,000 and 200,000 light-years. It is estimated to contain 100‚ 400 billion stars
Yevhen Samuchenko
Yevhen Samuchenko/RPS
7/9 Stag beetle
Stag beetle. Light microscopy. Magnification 5x. – Viktor Sykora
Viktor Sykora/RPS
8/9 Mapping1_OxygenIb_PEM
Final Major Project for an MA Photography Falmouth University. Project: Mapping 1, Post Exertional Malaise. Mapping 1, focuses on discovering the research behind Myalgic Encephalomyelitis. Through exploration of perspective, complexities, and scientific multidisciplinary collaborations, I create imagery that explains, reveals and connects us consciously to the ambiguous and unknown. – Yasmin Crawford
Yasmin Crawford/RPS
9/9 Lovell Telescope Series 1c
I have always been fascinated with the Lovell Telescope at Jodrell Bank since I went on a school trip as a child. Here, I wanted to take a series of closer, more detailed and more honest shots than we often see. Exploring the multitude of shapes and exposing the wear of the telescope, each photo in the series stands alone or can be viewed collectively, either way, they present a powerful portrayal of machine that helps humankind in their endeavours to understand space and time. – Marge Bradshaw
Marge Bradshaw/RPS
“These new results instead open the possibility of a complete reinterpretation of its evolution and nature. The flare event … was so powerful it had consequences on the surrounding of our galaxy. We are the witness to the awakening of the sleeping beauty.”
Sagittarius A tends to be a relatively stable “sleeping dragon”, researchers said.
But the study suggests the black hole woke up dramatically as our ancient ancestors, the ape-like Australopithecines, were already afoot in Africa, releasing a burst known as a Seyfert flare.
Study leader Professor Joss Bland-Hawthorn, of the University of Sydney, said: “The flare must have been a bit like a lighthouse beam.
“Imagine darkness, and then someone switches on a lighthouse beacon for a brief period of time.”
His team at Australia’s ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) described it as a “titanic, expanding beam of energy”.
Professor Lisa Kewley, director of ASTRO 3D, said: “This is a dramatic event that happened a few million years ago in the Milky Way’s history.
“A massive blast of energy and radiation came right out of the galactic centre and into the surrounding material.
“This shows that the centre of the Milky Way is a much more dynamic place than we had previously thought. It is lucky we’re not residing there.”
In 1996, astronomers became aware of a strange glow radiating from the Magellanic Stream. Scientists began to hunt for a cause and Sagittarius A became the prime suspect.
The team first described the evidence of this explosion in 2013, when they identified the black hole as the cause.
Their latest work, published in the Astrophysical Journal, builds upon and reinforces their previous findings.
Based on a recent analysis of the data gathered by the Hubble Space Telescope, the researchers calculated the massive explosion took place 3.5 million years ago and lasted around 300,000 years.
The question of how black holes evolve, influence and interact with galaxies “is an outstanding problem in astrophysics”, the researchers added.
Black holes are places where matter is compressed by gravity to a point where the normal laws of physics break down, bending and distorting space and time.
By definition, they cannot be seen in the conventional sense, making them hard to study. Their presence is inferred from radiation emitted as gas and debris swirl around them.
In another contrast to its “sleepy” persona, last month researchers discovered Sagittarius A was “growing hungrier”, eating far more interstellar gas and dust than it had ever been seen doing before.
Additional reporting by agencies
