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Rogue planets: hunting the galaxy's most mysterious worlds – Phys.org

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Most known planets orbit a star. These planets, including Earth, benefit from the star’s warmth and light. And it is the light emitted from these stars which makes it possible for us to see them. But there are also “invisible” planets, hidden from our gaze, which float, abandoned, through the cosmos. These dark, lonely worlds have no star to orbit, no light in which to bask, no warmth to be radiated by. They are the “rogue” planets—and astronomers have just found a new one, roughly the same size as Earth.

Planets are made from the debris left over after the birth of a star. These circle the young star in a thin disc of grains and gas and grow when these small particles stick and pull each other together until they clear their immediate surroundings. Things are chaotic in this world and collisions between planetary embryos, or proto-planets, are common. Stars tend not to form alone, but in clusters of hundreds or thousands at once, and encounters between their nascent planetary systems cause further havoc.

Young Earth is thought to have been hit by a Mars-sized body, knocking out enough material to form the Moon. But some planets faced a darker future: they were knocked out altogether, destined for a life in the vast coldness of space between the stars. These are the free-floating “rogue planets”.

When planets are still very young, say just a few million years old (Earth is more than 4.5bn years old) they are still warm from their formation and from the energy released by their continued gravitational contraction and radio activity in their cores. Large examples of such young but free-floating planets (think of a baby Jupiter) have been seen directly in regions where stars had just formed. But finding smaller rogue planets proved almost impossible until “lensing” was discovered.

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Gravitational lensing

Anything with mass bends space and causes light to deflect from a straight path. The result is that an object with mass focuses the light from a source behind it—amplifying it like a huge magnifying glass. This is called . It was predicted by Einstein’s general theory of relativity and was first verified when stars were seen to be displaced from their usual positions when viewed close to the Sun while it was perfectly eclipsed by the Moon in 1919.

The effect of gravitational lensing has been observed in galaxies made up of trillions of stars, caused by the vast amounts of stuff in between galaxies and by stars lining up with other in the background. One observation was caused by a black hole in a “nearby” massive galaxy called Messier 87, in 2019. So even an “invisible” rogue planet could act as a gravitational lens—or micro-lens, as they can be so small.

One such “micro-lensing” event was attributed to the new rogue planet, called OGLE-2016-BLG-1928. The sighting of the amplification of the light from an inconspicuous star in the dense inner regions of the Milky Way galaxy only lasted 42 minutes.

This meant it had to be a small object and the estimated mass left no doubt that it had to be a planet not much different in size from Earth. The lensing planet was not found to be associated with a star. Lensing rogue planets have been found before, but this is one of the most convincing cases. As well as being the one most akin to Earth, OGLE-2016-BLG-1928 is also the smallest rogue ever found.

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Could Earth go rogue?

Large numbers of rogue planets criss-crossing our galaxy raise intriguing questions. Could life have formed and survived, or settled on such worlds? Perhaps technologically advanced civilisations could overcome the inconveniences of eternal darkness and an ice age with no comparison in Earth’s long and varied history? Maybe they harnessed nuclear power or became entirely non-biological?

That may sound like science fiction, but what are the chances of Earth running into such a planet by chance? This is not inconceivable. Only in the last couple of years, rogue asteroids such as Oumuamua and rogue comets such as Borisov whizzed through our solar system. It is unlikely a rogue planet would pass by us that close up. But it’s not beyond the realms of probability.

Earth has so far escaped banishment from the Sun. But one day, in about 4bn years, Earth too could go rogue. Because as the Sun ages, swells up and blows half of itself into space, Earth will either be swallowed by it, or be forced away. But it is unlikely to escape its gravitational attraction altogether. So as the dead Sun is degraded to a smouldering white dwarf, the Earth will face a similar fate to those other dark, cold worlds. Not entirely alone, but far away from the once warm and bright orbit of its star.


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An Earth-sized rogue planet discovered in the Milky Way


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Midday fireball, boom thrill gazers from Ontario to Virginia – Humboldt Journal

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SYRACUSE, N.Y. — A noontime boom that was heard and felt from southern Ontario to Virginia was likely caused by a disintegrating meteor, according to an organization in western New York that keeps track of such phenomena.

Witnesses across the area reported hearing the boom or seeing a fireball in the sky shortly after noon on Wednesday, said Robert Lunsford of the American Meteor Society in Geneseo. By 5 p.m., the organization had recorded 90 reports of the fireball seen in Maryland, Michigan, New York, Ontario, Pennsylvania and Virginia.

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Police agencies and fire departments around central New York received 911 calls reporting a boom that shook windows, but clouds prevented sightings in much of the area. Since most reports of the boom were around Syracuse, that’s likely where the meteor blew to bits, Lunsford said.

On the society’s website, an observer in western New York reported the fireball was bright white with shades of yellow. An observer in Hagerstown, Maryland reported a fireball with red and orange sparks, smoke and a persistent train. A report from Welland, Ontario, described a long, bright green train.

“Sunny day so it looked like a gold metallic flash against the blue sky,” said a report from Winchester, Virginia.

“Astonishing, amazing, still get goosebumps talking about it,” wrote an observer in Port Dover, Ontario. “The train was flaming white, wide and long, no smoke.”

“We tend to notice fireballs more at night because they stand out better, but it’s not terribly unusual for very bright ones to be noticed during the day. It happens several times a year over populated areas,” said Margaret Campbell-Brown, a member of the Meteor Physics Group at Western University in London, Ontario.

All fireballs, which are bright meteors, produce sound waves, sometimes detectable only by sensitive microphones, Campbell-Brown said by email. A large one may produce a thunderlike sonic boom with possible extra bangs from fragmentation, she said.

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Science on the back roads could help us prepare for solar storms (5 images) – ElliotLakeToday.com

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There is science on the back roads and the new Solar Cycle 25 has begun.

The potential upswing in space weather will impact our lives and technology on Earth, as well as astronauts in space and a line of towers near Kapuskasing will play a role in understanding the effects.

The satellite-based economy is here and now, nearly all international banking, internet, television and communications are done by satellite.

Beyond the beauty of the Northern Lights, the space environment is extremely dangerous for the delicate electronic systems on every satellite. Conditions are particularly threatening during “magnetic storms” when astronauts are required to take shelter in the International Space Station and transpolar airline flights are diverted to avoid the dangerous radiation from space. These are storms that originate from the Sun and occur in space near Earth or in the Earth’s atmosphere

With the rising sophistication of our technologies and the number of people that use technology, vulnerability to space weather events has increased dramatically.

This unassuming bank of radar towers, located on Sylvain Road in Kitigan, 10 km east of Kapuskasing, are part of SuperDARN which stands for Super Dual Aurora Radar Network, it is a global program, with 35 radar sites around the globe, managed by sixteen institutes in ten countries. The SuperDARN radar outside provides valuable data over central Canada that promotes understanding of ionosphere processes and phenomena.

Researchers are looking forward to the radar contributing to the upcoming solar maximum during the new solar cycle that just started in early September.

Space Weather

“Extreme solar storms pose a threat to all forms of high-technology,” said Dr. J. Michael Ruohoniemi Associate Professor, Bradley Department of Computer and Electrical Engineering, Virginia Tech (Virginia Polytechnic Institute and State University).

He is the ‘Principle Investigator’ for the Kapusakasing (Kap) radar station as well as Goose Bay, and some others in the U.S.

“They begin with an explosion, a “solar flare”—in the magnetic canopy of a sunspot. X-rays and extreme UV radiation reach Earth at light speed, ionizing the upper layers of our atmosphere; side effects include radio blackouts and GPS navigation errors.”

Minutes to hours later, the energetic particles arrive, moving only slightly slower than light itself. Electrons and protons accelerated by the blast can electrify satellites and damage their electronics.

SuperDARN is a large international collaboration and the operation of the radar in Kapuskasing is funded by the U.S. National Science Foundation (NSF) through an award to Virginia Tech. A large group at the University of Saskatchewan operates five radars including three in the high arctic (‘PolarDARN’).

“Kap was built in 1993 and the site was selected because it has a good geometry with the radar at Saskatoon,” Ruohiniemi. “This means the fields-of-view of the two radars overlap substantially, making it possible to observe the same volume from two directions which is useful if you are trying to measure velocity. We also selected Kap because it is a substantial town with good facilities.”

He also has a personal connection to the town. “My father was born there and I visited my grandparents often as a kid and teenager. When we were looking at potential sites in northern Ontario I thought of the Experimental farm. We wound up going to the other side of town but it was a good start.”

Concern and Awareness

“Definitely the public should know about the potential dangers,” said Ruohoniemi. “The largest source of error on GPS measurements, for example, is space weather in the ionosphere. If GPS is being used to land aircraft this is a serious concern. “

There was a spectacular occurrence in 1859, known as the Carrington event, that interrupted telegraph systems.

“If we had an event of that magnitude again everyone would be aware of the damage to all the electrical systems in use today. The threat is cyclical with the 11-year sunspot cycle with more intense storms happening at the peak and declining phases. There was a near-miss due to a solar superstorm in 2012 – a really big flare went off but just missed Earth. We are in a quiet phase right now. I don’t want to sound alarmist, but yes, we should be paying attention to the danger posed by solar storms.”

The NOAA Space Weather Prediction Center issues a continuous forecast of the weather in Earth’s near-space environment. Solar flares cause impacts that can make the evening news such as the severe geomagnetic storm in 1989; an aurora was seen as far south as Texas and knocked out the Quebec power grid.

“By combining the data from all the radars we get an image of plasma flows in the ionosphere (above 100 km altitude) that looks a lot like a typical weather map with atmospheric winds,” Ruohoniemi said. “The radars, in effect, see something like a radio wave version of the visual aurora and we can use the Doppler shift on the signal coming back to estimate plasma flow velocity.”

How it Works

“Village Media readers may be familiar with Ham radio, people who have a tall antenna by their house and a little room crammed with equipment to send and receive High Frequency (HF) radio signal. Because this signal bounces off the ionosphere at heights of 100-300 km, it can be received by other Hams a great distance away. The ionosphere is highly variable because of solar storms and sometimes the Hams can make amazing connections with people on the other side of the world but can’t connect to each other a few hundred kilometres apart. Our radar works basically like a Ham radio except that we have many antennas (16) and we are interested in how the signal bounces off the ionosphere and what that tells us about the space environment, not in communicating with other people (although we could). Not very much power is required and the radars operate continuously under computer control with connections to research labs in Canada, the U.S., and other countries.”

SuperDARN has shown how the circulation of plasma in the ionosphere (‘plasma winds’) at high latitudes is tightly controlled by the solar wind. The plasma consists of ions and electrons and can move at speeds greater than 1 km per second, so these winds are incredibly fast compared to the wind that blows in the atmosphere at ground level. “When viewed from well above the North Pole, you can see the winds forming giant cells of circulation similar to atmospheric winds. When the solar wind changes, especially when its magnetic field reverses direction, the pattern of circulation can flip in a matter of minutes. By combining data from multiple SuperDARN radars we are able to image these changes as they happen and to study the physics of the sun-earth connection, which is the basis for space weather.”

The back roads hold a lot of oddities.

This bank of radar towers doesn’t appear to be anything special but when the physics behind this space weather interaction is understood it can be seen in a different light. Scientists working on predictive models will one-day forecast space weather much like meteorologists forecast weather on Earth.

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Science on the back roads could help us prepare for solar storms (5 images) – TimminsToday

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There is science on the back roads and the new Solar Cycle 25 has begun.

The potential upswing in space weather will impact our lives and technology on Earth, as well as astronauts in space and a line of towers near Kapuskasing will play a role in understanding the effects.

The satellite-based economy is here and now, nearly all international banking, internet, television and communications are done by satellite.

Beyond the beauty of the Northern Lights, the space environment is extremely dangerous for the delicate electronic systems on every satellite. Conditions are particularly threatening during “magnetic storms” when astronauts are required to take shelter in the International Space Station and transpolar airline flights are diverted to avoid the dangerous radiation from space. These are storms that originate from the Sun and occur in space near Earth or in the Earth’s atmosphere

With the rising sophistication of our technologies and the number of people that use technology, vulnerability to space weather events has increased dramatically.

This unassuming bank of radar towers, located on Sylvain Road in Kitigan, 10 km east of Kapuskasing, are part of SuperDARN which stands for Super Dual Aurora Radar Network, it is a global program, with 35 radar sites around the globe, managed by sixteen institutes in ten countries. The SuperDARN radar outside provides valuable data over central Canada that promotes understanding of ionosphere processes and phenomena.

Researchers are looking forward to the radar contributing to the upcoming solar maximum during the new solar cycle that just started in early September.

Space Weather

“Extreme solar storms pose a threat to all forms of high-technology,” said Dr. J. Michael Ruohoniemi Associate Professor, Bradley Department of Computer and Electrical Engineering, Virginia Tech (Virginia Polytechnic Institute and State University).

He is the ‘Principle Investigator’ for the Kapusakasing (Kap) radar station as well as Goose Bay, and some others in the U.S.

“They begin with an explosion, a “solar flare”—in the magnetic canopy of a sunspot. X-rays and extreme UV radiation reach Earth at light speed, ionizing the upper layers of our atmosphere; side effects include radio blackouts and GPS navigation errors.”

Minutes to hours later, the energetic particles arrive, moving only slightly slower than light itself. Electrons and protons accelerated by the blast can electrify satellites and damage their electronics.

SuperDARN is a large international collaboration and the operation of the radar in Kapuskasing is funded by the U.S. National Science Foundation (NSF) through an award to Virginia Tech. A large group at the University of Saskatchewan operates five radars including three in the high arctic (‘PolarDARN’).

“Kap was built in 1993 and the site was selected because it has a good geometry with the radar at Saskatoon,” Ruohiniemi. “This means the fields-of-view of the two radars overlap substantially, making it possible to observe the same volume from two directions which is useful if you are trying to measure velocity. We also selected Kap because it is a substantial town with good facilities.”

He also has a personal connection to the town. “My father was born there and I visited my grandparents often as a kid and teenager. When we were looking at potential sites in northern Ontario I thought of the Experimental farm. We wound up going to the other side of town but it was a good start.”

Concern and Awareness

“Definitely the public should know about the potential dangers,” said Ruohoniemi. “The largest source of error on GPS measurements, for example, is space weather in the ionosphere. If GPS is being used to land aircraft this is a serious concern. “

There was a spectacular occurrence in 1859, known as the Carrington event, that interrupted telegraph systems.

“If we had an event of that magnitude again everyone would be aware of the damage to all the electrical systems in use today. The threat is cyclical with the 11-year sunspot cycle with more intense storms happening at the peak and declining phases. There was a near-miss due to a solar superstorm in 2012 – a really big flare went off but just missed Earth. We are in a quiet phase right now. I don’t want to sound alarmist, but yes, we should be paying attention to the danger posed by solar storms.”

The NOAA Space Weather Prediction Center issues a continuous forecast of the weather in Earth’s near-space environment. Solar flares cause impacts that can make the evening news such as the severe geomagnetic storm in 1989; an aurora was seen as far south as Texas and knocked out the Quebec power grid.

“By combining the data from all the radars we get an image of plasma flows in the ionosphere (above 100 km altitude) that looks a lot like a typical weather map with atmospheric winds,” Ruohoniemi said. “The radars, in effect, see something like a radio wave version of the visual aurora and we can use the Doppler shift on the signal coming back to estimate plasma flow velocity.”

How it Works

“Village Media readers may be familiar with Ham radio, people who have a tall antenna by their house and a little room crammed with equipment to send and receive High Frequency (HF) radio signal. Because this signal bounces off the ionosphere at heights of 100-300 km, it can be received by other Hams a great distance away. The ionosphere is highly variable because of solar storms and sometimes the Hams can make amazing connections with people on the other side of the world but can’t connect to each other a few hundred kilometres apart. Our radar works basically like a Ham radio except that we have many antennas (16) and we are interested in how the signal bounces off the ionosphere and what that tells us about the space environment, not in communicating with other people (although we could). Not very much power is required and the radars operate continuously under computer control with connections to research labs in Canada, the U.S., and other countries.”

SuperDARN has shown how the circulation of plasma in the ionosphere (‘plasma winds’) at high latitudes is tightly controlled by the solar wind. The plasma consists of ions and electrons and can move at speeds greater than 1 km per second, so these winds are incredibly fast compared to the wind that blows in the atmosphere at ground level. “When viewed from well above the North Pole, you can see the winds forming giant cells of circulation similar to atmospheric winds. When the solar wind changes, especially when its magnetic field reverses direction, the pattern of circulation can flip in a matter of minutes. By combining data from multiple SuperDARN radars we are able to image these changes as they happen and to study the physics of the sun-earth connection, which is the basis for space weather.”

The back roads hold a lot of oddities.

This bank of radar towers doesn’t appear to be anything special but when the physics behind this space weather interaction is understood it can be seen in a different light. Scientists working on predictive models will one-day forecast space weather much like meteorologists forecast weather on Earth.

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