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Erika 

@ExploreCosmos_ • 53,970 subscribers

Canadian astrophysicist focused on extragalactic astronomy & early-universe galaxies. Seeking mountain peaks. Writing through the chaos; riding away from it.

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When a spacecraft leaves Earth, it doesn’t just fire its engines and head straight to its destination. In many missions, especially those going beyond low Earth orbit, there’s a more subtle and elegant strategy at play, one that uses gravity itself as part of the navigation system. This is often called a gravity assist, or a slingshot maneuver. But in the case of missions like #Artemis II, what’s being used is a closely related idea known as a free-return trajectory. At first glance, it might sound simple: the spacecraft goes to the Moon, loops around it, and comes back. But the physics behind it is anything but simple. Instead of relying on continuous propulsion, the spacecraft follows a carefully calculated path through the gravitational field of the Earth–Moon system. It is launched with just the right speed and direction so that, as it approaches the Moon, the Moon’s gravity bends its trajectory. The spacecraft is effectively flung around the Moon, redirected onto a path that naturally brings it back toward Earth. No major engine burn is needed for the return. Small trajectory corrections may still be required, but gravity does the heavy lifting. That’s the key. This kind of trajectory is not just efficient, it’s also safe. If something goes wrong with the spacecraft’s engines or onboard systems, gravity itself ensures the return. It’s an inherent backup plan, built into the trajectory from the very beginning. The same fundamental idea appears in gravity assists used across the Solar System. When a spacecraft flies past a planet, it can gain or lose speed by exchanging momentum with that planet. From the spacecraft’s point of view, it’s as if it has been accelerated without using fuel. In reality, it has borrowed a tiny amount of orbital energy from the planet itself. That’s how missions like Voyager reached the outer planets, and how probes continue to explore regions far beyond what their onboard fuel alone would allow. But there’s an important distinction. An interplanetary gravity assist is typically used to change speed and direction, often increasing the spacecraft’s energy. A free-return trajectory, like the one used in Artemis II, is designed for something more specific: a path that naturally loops back to Earth without requiring additional propulsion. It’s less about gaining energy, and more about shaping a trajectory that guarantees a return. To understand why this works, it helps to stop thinking in straight lines. In space, motion follows curves defined by gravity. The spacecraft is constantly falling, first toward Earth, then toward the Moon, and then back toward Earth again. What looks like a loop is really a continuous free fall through a changing gravitational landscape. This way of navigating space reveals something deeper. We tend to think of engines as the drivers of motion, but once a spacecraft is on its way, gravity does most of the work. The art of spaceflight is not just about thrust. It’s about knowing when not to use it. #GoodLuck #Artemis NASA Artemis

When a spacecraft leaves Earth, it doesn’t just fire its engines and head straight to its destination. In many missions, especially those going beyond low Earth orbit, there’s a more subtle and elegant strategy at play, one that uses gravity itself as part of the navigation system. This is often called a gravity assist, or a slingshot maneuver. But in the case of missions like #Artemis II, what’s being used is a closely related idea known as a free-return trajectory. At first glance, it might sound simple: the spacecraft goes to the Moon, loops around it, and comes back. But the physics behind it is anything but simple. Instead of relying on continuous propulsion, the spacecraft follows a carefully calculated path through the gravitational field of the Earth–Moon system. It is launched with just the right speed and direction so that, as it approaches the Moon, the Moon’s gravity bends its trajectory. The spacecraft is effectively flung around the Moon, redirected onto a path that naturally brings it back toward Earth. No major engine burn is needed for the return. Small trajectory corrections may still be required, but gravity does the heavy lifting. That’s the key. This kind of trajectory is not just efficient, it’s also safe. If something goes wrong with the spacecraft’s engines or onboard systems, gravity itself ensures the return. It’s an inherent backup plan, built into the trajectory from the very beginning. The same fundamental idea appears in gravity assists used across the Solar System. When a spacecraft flies past a planet, it can gain or lose speed by exchanging momentum with that planet. From the spacecraft’s point of view, it’s as if it has been accelerated without using fuel. In reality, it has borrowed a tiny amount of orbital energy from the planet itself. That’s how missions like Voyager reached the outer planets, and how probes continue to explore regions far beyond what their onboard fuel alone would allow. But there’s an important distinction. An interplanetary gravity assist is typically used to change speed and direction, often increasing the spacecraft’s energy. A free-return trajectory, like the one used in Artemis II, is designed for something more specific: a path that naturally loops back to Earth without requiring additional propulsion. It’s less about gaining energy, and more about shaping a trajectory that guarantees a return. To understand why this works, it helps to stop thinking in straight lines. In space, motion follows curves defined by gravity. The spacecraft is constantly falling, first toward Earth, then toward the Moon, and then back toward Earth again. What looks like a loop is really a continuous free fall through a changing gravitational landscape. This way of navigating space reveals something deeper. We tend to think of engines as the drivers of motion, but once a spacecraft is on its way, gravity does most of the work. The art of spaceflight is not just about thrust. It’s about knowing when not to use it. #GoodLuck #Artemis NASA Artemis

234,687 görüntüleme

When a nuclear reactor is switched on for the first time, an intense, almost hypnotic blue glow appears in the water surrounding the reactor core. This light is neither fire nor heat; it is Cherenkov radiation, a physical phenomenon that occurs when charged particles, such as high-energy electrons produced during nuclear fission, travel through a transparent medium faster than light can propagate within that same medium. While nothing can exceed the speed of light in a vacuum, light travels more slowly in materials like water. When a charged particle surpasses this reduced speed, it emits a coherent shock-like electromagnetic wave, often described as an optical analogue of a sonic boom. This radiation produces the distinctive blue glow. The colour arises because Cherenkov radiation is strongest at shorter wavelengths, which are dominated by blue and ultraviolet light. The phenomenon was first observed experimentally in 1934 and later explained theoretically, work that led to the Nobel Prize in Physics in 1958. Its explanation confirmed how relativity and electromagnetism operate in material media. Today, this deep blue light is both a warning and a scientific tool. It signals the presence of intense ionising radiation, while also being exploited in particle detectors, nuclear reactors, and neutrino observatories. It provides a rare, visible manifestation of subatomic processes that are otherwise hidden from direct human perception. #GottaLovePhysics #Physics

When a nuclear reactor is switched on for the first time, an intense, almost hypnotic blue glow appears in the water surrounding the reactor core. This light is neither fire nor heat; it is Cherenkov radiation, a physical phenomenon that occurs when charged particles, such as high-energy electrons produced during nuclear fission, travel through a transparent medium faster than light can propagate within that same medium. While nothing can exceed the speed of light in a vacuum, light travels more slowly in materials like water. When a charged particle surpasses this reduced speed, it emits a coherent shock-like electromagnetic wave, often described as an optical analogue of a sonic boom. This radiation produces the distinctive blue glow. The colour arises because Cherenkov radiation is strongest at shorter wavelengths, which are dominated by blue and ultraviolet light. The phenomenon was first observed experimentally in 1934 and later explained theoretically, work that led to the Nobel Prize in Physics in 1958. Its explanation confirmed how relativity and electromagnetism operate in material media. Today, this deep blue light is both a warning and a scientific tool. It signals the presence of intense ionising radiation, while also being exploited in particle detectors, nuclear reactors, and neutrino observatories. It provides a rare, visible manifestation of subatomic processes that are otherwise hidden from direct human perception. #GottaLovePhysics #Physics

275,451 görüntüleme

The three-body problem is a classic and notoriously difficult question in physics and mathematics. It asks: How do three objects, such as stars, planets, or moons, move under the influence of each other’s gravity? Unlike the simpler two-body problem, which has precise and predictable analytical solutions (like the Earth orbiting the Sun in an ellipse), the three-body problem quickly becomes chaotic and unpredictable. This complexity arises because each object's motion constantly affects, and is affected by, the other two. These gravitational interactions form a tangled and unstable system. In fact, there's no general formula that can solve all three-body scenarios exactly. This was first demonstrated in the 19th century by Henri Poincaré, whose work laid the foundations for chaos theory. While exact solutions remain elusive, scientists have discovered certain special cases where the motion is stable or periodic. One well-known example is the Lagrange points, where three bodies can maintain a stable triangular configuration. However, such neat solutions are rare. Today, thanks to powerful computers, researchers can simulate three-body systems with remarkable accuracy, helping us study triple-star systems, exoplanets, and asteroid dynamics. Yet even small changes in the starting conditions can lead to dramatically different outcomes, highlighting the sensitive dependence on initial conditions that defines chaotic systems. The three-body problem is actually a specific case of the broader n-body problem, where n can be any number of interacting bodies. As n increases, the complexity and unpredictability rise even further. The three-body problem serves as a vivid example of how simple laws of nature, like Newton’s law of gravity, can produce behavior that is intricate, unexpected, and profoundly difficult to predict.

The three-body problem is a classic and notoriously difficult question in physics and mathematics. It asks: How do three objects, such as stars, planets, or moons, move under the influence of each other’s gravity? Unlike the simpler two-body problem, which has precise and predictable analytical solutions (like the Earth orbiting the Sun in an ellipse), the three-body problem quickly becomes chaotic and unpredictable. This complexity arises because each object's motion constantly affects, and is affected by, the other two. These gravitational interactions form a tangled and unstable system. In fact, there's no general formula that can solve all three-body scenarios exactly. This was first demonstrated in the 19th century by Henri Poincaré, whose work laid the foundations for chaos theory. While exact solutions remain elusive, scientists have discovered certain special cases where the motion is stable or periodic. One well-known example is the Lagrange points, where three bodies can maintain a stable triangular configuration. However, such neat solutions are rare. Today, thanks to powerful computers, researchers can simulate three-body systems with remarkable accuracy, helping us study triple-star systems, exoplanets, and asteroid dynamics. Yet even small changes in the starting conditions can lead to dramatically different outcomes, highlighting the sensitive dependence on initial conditions that defines chaotic systems. The three-body problem is actually a specific case of the broader n-body problem, where n can be any number of interacting bodies. As n increases, the complexity and unpredictability rise even further. The three-body problem serves as a vivid example of how simple laws of nature, like Newton’s law of gravity, can produce behavior that is intricate, unexpected, and profoundly difficult to predict.

213,292 görüntüleme

Asteroid Apophis is coming back. Apophis stands out as the most dangerous asteroid that passes close to our planet. In March 2021, it had a close encounter with Earth, and it's poised to return in 2029. During its 2029 closest approach, Apophis will pass within.... 1/

Asteroid Apophis is coming back. Apophis stands out as the most dangerous asteroid that passes close to our planet. In March 2021, it had a close encounter with Earth, and it's poised to return in 2029. During its 2029 closest approach, Apophis will pass within.... 1/

353,658 görüntüleme

Researchers at Northwestern University captured the formation of nanoscale water bubbles as hydrogen and oxygen combined in real-time. Using a new method involving nanoreactors and electron microscopes, the team observed how palladium helps generate water from these gases. This breakthrough has potential implications for water production, especially in space travel, where it could help astronauts create water from gases without extreme conditions. 👉

Researchers at Northwestern University captured the formation of nanoscale water bubbles as hydrogen and oxygen combined in real-time. Using a new method involving nanoreactors and electron microscopes, the team observed how palladium helps generate water from these gases. This breakthrough has potential implications for water production, especially in space travel, where it could help astronauts create water from gases without extreme conditions. 👉

64,849 görüntüleme

Get ready!! A rare planetary parade will occur from January 21, 2025, lasting about four weeks. Venus, Mars, Jupiter, and Saturn will be visible to the naked eye, while Neptune and Uranus will require a telescope. Mercury will join later, briefly aligning all seven planets. The best viewing time is around 8:30 PM after sunset, and it will be visible in regions like India, North America, Mexico, and Canada.

Get ready!! A rare planetary parade will occur from January 21, 2025, lasting about four weeks. Venus, Mars, Jupiter, and Saturn will be visible to the naked eye, while Neptune and Uranus will require a telescope. Mercury will join later, briefly aligning all seven planets. The best viewing time is around 8:30 PM after sunset, and it will be visible in regions like India, North America, Mexico, and Canada.

48,953 görüntüleme

.NASA, NOAA , and the Solar Cycle Prediction Panel have officially declared that the solar maximum has begun. This marks the peak of the Sun's 11-year activity cycle, characterized by frequent sunspots, solar flares, and coronal mass ejections. The solar maximum brings increased solar activity, which can cause geomagnetic storms affecting Earth’s power grids, communications, and satellites but also leads to beautiful auroras. Scientists cannot predict the exact timing or strength of solar cycles with precision. The Sun's magnetic poles will eventually switch places, and the activity will decrease, but the exact peak of this cycle may not be known for months or years. Although this cycle is stronger than initial predictions, it remains within normal limits. The most powerful flare of this cycle occurred on October 4, 2024, but wasn't the strongest ever recorded. 👉

.NASA, NOAA , and the Solar Cycle Prediction Panel have officially declared that the solar maximum has begun. This marks the peak of the Sun's 11-year activity cycle, characterized by frequent sunspots, solar flares, and coronal mass ejections. The solar maximum brings increased solar activity, which can cause geomagnetic storms affecting Earth’s power grids, communications, and satellites but also leads to beautiful auroras. Scientists cannot predict the exact timing or strength of solar cycles with precision. The Sun's magnetic poles will eventually switch places, and the activity will decrease, but the exact peak of this cycle may not be known for months or years. Although this cycle is stronger than initial predictions, it remains within normal limits. The most powerful flare of this cycle occurred on October 4, 2024, but wasn't the strongest ever recorded. 👉

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Just in case this wasn't obvious... 😋 The Moon is visible at night (and day) due to sunlight reflecting off its surface. Our position on Earth and the Moon's location in its orbit around our planet determine its phase. 1/

Just in case this wasn't obvious... 😋 The Moon is visible at night (and day) due to sunlight reflecting off its surface. Our position on Earth and the Moon's location in its orbit around our planet determine its phase. 1/

30,228 görüntüleme

How the Ancient Greeks calculated the circumference of the Earth. The ancient Greek mathematician, Eratosthenes, accurately calculated Earth's circumference around 240 BCE. He knew that at noon on the summer solstice in the city of Syene, the sun was directly overhead. 1/

How the Ancient Greeks calculated the circumference of the Earth. The ancient Greek mathematician, Eratosthenes, accurately calculated Earth's circumference around 240 BCE. He knew that at noon on the summer solstice in the city of Syene, the sun was directly overhead. 1/

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The sun has an atmosphere structured similar to Earth's, with three distinct regions: the photosphere, the chromosphere & corona. According to ©️ NASA's SDO, there may be as many as 10,000 magnetic solar tornadoes visible on the surface of the sun at any given moment. 🤯

The sun has an atmosphere structured similar to Earth's, with three distinct regions: the photosphere, the chromosphere & corona. According to ©️ NASA's SDO, there may be as many as 10,000 magnetic solar tornadoes visible on the surface of the sun at any given moment. 🤯

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Photographer Aaron Jenkin, traveled thousands of miles to the darkest place on Earth, in Aoraki Mount Cook National Park in New Zealand, to shoot the night sky. 👉 #MilkyWay #Astrophotography #NaturePhotograhpy #Astronomy

Photographer Aaron Jenkin, traveled thousands of miles to the darkest place on Earth, in Aoraki Mount Cook National Park in New Zealand, to shoot the night sky. 👉 #MilkyWay #Astrophotography #NaturePhotograhpy #Astronomy

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4 billion years ago vs now.

4 billion years ago vs now.

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Astronomers recorded the Comet C/2023 A3 Tsuchinshan ATLAS' path for an entire week using the SOHO space observatory. The comet's nucleus is clearly visible, surrounded by a dusty coma and trailing an impressively long tail. SOHO sees the large dust tail edge-on, curving in on itself as it is pushed outward by solar wind. ©️ European Space Agency / NASA

Astronomers recorded the Comet C/2023 A3 Tsuchinshan ATLAS' path for an entire week using the SOHO space observatory. The comet's nucleus is clearly visible, surrounded by a dusty coma and trailing an impressively long tail. SOHO sees the large dust tail edge-on, curving in on itself as it is pushed outward by solar wind. ©️ European Space Agency / NASA

15,191 görüntüleme

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About 1300 years ago, an unexplained cosmic storm hit our planet. It left its imprints in the tree rings across the globe and the ice cores of Antarctica. Then, after 200 years, the event repeated, but this time it was 60% as strong. 1/ #Thread #SpaceWeather
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About 1300 years ago, an unexplained cosmic storm hit our planet. It left its imprints in the tree rings across the globe and the ice cores of Antarctica. Then, after 200 years, the event repeated, but this time it was 60% as strong. 1/ #Thread #SpaceWeather

Erika 

1,618,725 görüntüleme • 2 yıl önce

Researchers at Tokamak Energy have captured for the first time a real-time, high-speed video of plasma behaviour inside their ST40 spherical tokamak, tracking visible green and red light emissions as the fusion process occurs. This visual insight comes via a camera operating at thousands of frames per second, offering unprecedented detail of how the plasma evolves, interacts with the surrounding lithium blanket and outer regions, and ultimately radiates energy. The imaging enables scientists to observe how the ultra-hot core transitions outward into cooler zones, how magnetic confinement shapes the plasma behaviour, and how impurities or outer-region interactions influence the process. By giving a ‘star-in-a-donut’ view of fusion in action, this breakthrough adds a new diagnostic tool to the development of fusion energy, helping engineers refine the magnetic confinement, optimise plasma stability and better understand the heat and light flows at play. It was slowed down by 100x. All this was for 0.3s A tokamak is one of the most advanced devices ever created to achieve controlled nuclear fusion, the same process that powers the Sun. Its goal is simple in principle but incredibly challenging in practice: heat a gas until it becomes plasma, raise that plasma to over 100 million degrees, and confine it long enough for hydrogen nuclei to fuse and release energy. Because no material container can survive such temperatures, a tokamak uses powerful magnetic fields to hold and shape the plasma like an invisible cage. The device has a distinctive doughnut-shaped (toroidal) chamber surrounded by magnetic coils. When the machine is switched on, electric currents and external magnets work together to create helical magnetic fields that trap the plasma and keep it away from the walls. As the plasma spirals around these magnetic lines, it heats up dramatically. Additional heating comes from methods like radio-frequency waves and neutral-beam injection, pushing the plasma toward the extreme temperatures needed for fusion. Inside this tightly controlled environment, hydrogen isotopes such as deuterium and tritium can collide and fuse, releasing fast neutrons and a burst of energy. The goal of tokamak research is to reach a point where the fusion reactions produce more energy than the system consumes, a milestone known as “net energy gain.” Modern machines like ITER, JET, and Tokamak Energy’s ST40 are bringing this vision closer, using advanced diagnostics, superconducting magnets, and increasingly stable plasma control. 👉
0:33
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Researchers at Tokamak Energy have captured for the first time a real-time, high-speed video of plasma behaviour inside their ST40 spherical tokamak, tracking visible green and red light emissions as the fusion process occurs. This visual insight comes via a camera operating at thousands of frames per second, offering unprecedented detail of how the plasma evolves, interacts with the surrounding lithium blanket and outer regions, and ultimately radiates energy. The imaging enables scientists to observe how the ultra-hot core transitions outward into cooler zones, how magnetic confinement shapes the plasma behaviour, and how impurities or outer-region interactions influence the process. By giving a ‘star-in-a-donut’ view of fusion in action, this breakthrough adds a new diagnostic tool to the development of fusion energy, helping engineers refine the magnetic confinement, optimise plasma stability and better understand the heat and light flows at play. It was slowed down by 100x. All this was for 0.3s A tokamak is one of the most advanced devices ever created to achieve controlled nuclear fusion, the same process that powers the Sun. Its goal is simple in principle but incredibly challenging in practice: heat a gas until it becomes plasma, raise that plasma to over 100 million degrees, and confine it long enough for hydrogen nuclei to fuse and release energy. Because no material container can survive such temperatures, a tokamak uses powerful magnetic fields to hold and shape the plasma like an invisible cage. The device has a distinctive doughnut-shaped (toroidal) chamber surrounded by magnetic coils. When the machine is switched on, electric currents and external magnets work together to create helical magnetic fields that trap the plasma and keep it away from the walls. As the plasma spirals around these magnetic lines, it heats up dramatically. Additional heating comes from methods like radio-frequency waves and neutral-beam injection, pushing the plasma toward the extreme temperatures needed for fusion. Inside this tightly controlled environment, hydrogen isotopes such as deuterium and tritium can collide and fuse, releasing fast neutrons and a burst of energy. The goal of tokamak research is to reach a point where the fusion reactions produce more energy than the system consumes, a milestone known as “net energy gain.” Modern machines like ITER, JET, and Tokamak Energy’s ST40 are bringing this vision closer, using advanced diagnostics, superconducting magnets, and increasingly stable plasma control. 👉

Erika 

162,019 görüntüleme • 6 ay önce

The final parsec problem presents a significant challenge in astrophysics, particularly in the study of the coalescence of binary black hole systems. This problem arises from the inefficiency of gravitational wave emission in driving the black holes together once ... 1/
0:53
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The final parsec problem presents a significant challenge in astrophysics, particularly in the study of the coalescence of binary black hole systems. This problem arises from the inefficiency of gravitational wave emission in driving the black holes together once ... 1/

Erika 

454,600 görüntüleme • 2 yıl önce

I'm not crying 🥲 #Auroraborealis #AuroraBoreal
0:37
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I'm not crying 🥲 #Auroraborealis #AuroraBoreal

Erika 

411,597 görüntüleme • 2 yıl önce

Gotta love geometry 💚 This dodecagon can be split into pieces and put back together as three equal squares, each one using the radius as its side. That works because its 12 sides are all the same length and repeat in a perfect pattern. Ancient mathematicians, like Euclid, discovered that some shapes can be “taken apart” and “put back together” to show their area in a simpler way. So in the end, the area of a dodecagon is basically like combining three squares made from its radius. #Math #Geometry
0:58
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Gotta love geometry 💚 This dodecagon can be split into pieces and put back together as three equal squares, each one using the radius as its side. That works because its 12 sides are all the same length and repeat in a perfect pattern. Ancient mathematicians, like Euclid, discovered that some shapes can be “taken apart” and “put back together” to show their area in a simpler way. So in the end, the area of a dodecagon is basically like combining three squares made from its radius. #Math #Geometry

Erika 

110,501 görüntüleme • 6 ay önce

The Milky Way is nothing else, but a mass of innumerable stars planted together in clusters. ~Galileo Galilei~ The planets orbit the Sun, roughly in the same plane. The Solar System moves through the galaxy with about a 60° angle between the galactic... 1/2 ©️ YT / DjSadhu
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The Milky Way is nothing else, but a mass of innumerable stars planted together in clusters. ~Galileo Galilei~ The planets orbit the Sun, roughly in the same plane. The Solar System moves through the galaxy with about a 60° angle between the galactic... 1/2 ©️ YT / DjSadhu

Erika 

297,762 görüntüleme • 2 yıl önce

Earth is approaching a stream of debris from Halley's Comet, source of the Orionid meteor shower. Forecasters expect the shower to peak on Sun, Oct. 22nd, with 15/20 meteors/h. The best time to look is during the dark hours before sunrise when Orion the Hunter is high in the sky.
0:23
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Earth is approaching a stream of debris from Halley's Comet, source of the Orionid meteor shower. Forecasters expect the shower to peak on Sun, Oct. 22nd, with 15/20 meteors/h. The best time to look is during the dark hours before sunrise when Orion the Hunter is high in the sky.

Erika 

185,799 görüntüleme • 2 yıl önce

Distance to some galaxies from the Milky Way. 1 light year = 9.5 trillion km.
0:48
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Distance to some galaxies from the Milky Way. 1 light year = 9.5 trillion km.

Erika 

83,052 görüntüleme • 1 yıl önce

Betelgeuse, nestled on Orion's shoulder, has experienced a sudden increase in its brightness surging by over 50 percent above its typical luminosity. At the beginning of the year, Betelgeuse was the 10th brightest star in our night sky. 1/ #Thread #Update
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Betelgeuse, nestled on Orion's shoulder, has experienced a sudden increase in its brightness surging by over 50 percent above its typical luminosity. At the beginning of the year, Betelgeuse was the 10th brightest star in our night sky. 1/ #Thread #Update

Erika 

178,486 görüntüleme • 3 yıl önce

Planning is underway for NASA's next big flagship space telescope. Enter the Habitable Worlds Observatory (HWO) 👉
2:10
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Planning is underway for NASA's next big flagship space telescope. Enter the Habitable Worlds Observatory (HWO) 👉

Erika 

145,454 görüntüleme • 2 yıl önce

I don't know what you think, but for me, The Parker Solar Probe, "touching" the sun, has been one of the great achievements of our time. But, why didn't it melt? 1/ #Thread
0:34
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I don't know what you think, but for me, The Parker Solar Probe, "touching" the sun, has been one of the great achievements of our time. But, why didn't it melt? 1/ #Thread

Erika 

147,471 görüntüleme • 2 yıl önce

A new study has provided compelling evidence that Earth, shortly after its formation, was initially dry and lifeless, lacking the essential building blocks for life, such as water and organic compounds. Using precise measurements of the radioactive decay of manganese-53 into chromium-53 in meteorites and terrestrial rocks, the researchers determined that Earth's basic chemical composition was established within roughly three million years after the Solar System formed. This finding supports the Giant Impact Hypothesis: Earth’s Moon formed when a Mars-sized body, dubbed Theia, collided with our planet about 4.5 billion years ago. Crucially, Theia appears to have originated farther out in the Solar System and carried volatile elements, including water and carbon-rich compounds, that Earth lacked at the time. Therefore, it seems that Earth’s habitability, and ultimately the emergence of life, was not a straightforward outcome of gradual development but rather hinged on this dramatic, chance impact. 👉
1:42
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A new study has provided compelling evidence that Earth, shortly after its formation, was initially dry and lifeless, lacking the essential building blocks for life, such as water and organic compounds. Using precise measurements of the radioactive decay of manganese-53 into chromium-53 in meteorites and terrestrial rocks, the researchers determined that Earth's basic chemical composition was established within roughly three million years after the Solar System formed. This finding supports the Giant Impact Hypothesis: Earth’s Moon formed when a Mars-sized body, dubbed Theia, collided with our planet about 4.5 billion years ago. Crucially, Theia appears to have originated farther out in the Solar System and carried volatile elements, including water and carbon-rich compounds, that Earth lacked at the time. Therefore, it seems that Earth’s habitability, and ultimately the emergence of life, was not a straightforward outcome of gradual development but rather hinged on this dramatic, chance impact. 👉

Erika 

44,915 görüntüleme • 8 ay önce

Astrophotographer Mark Johnston Azastroguy captured a mesmerizing scene on October 20, 2025, from Willow Springs Lake in Arizona, showing a fiery filament of hydrogen plasma dancing above the Sun’s limb. Suspended by the Sun’s magnetic field, this structure twists and shimmers in a 6.5-second time-lapse video that condenses 75 minutes of real solar activity. Using a TEC 160FL refractor equipped with specialized solar filters, including a 0.3 Å hydrogen-alpha etalon, Johnston revealed an extraordinary level of detail in the solar prominence, a glowing loop of magnetized gas rising from the photosphere into the corona. The footage captures the intricate motion of plasma arcing hundreds of thousands of kilometers across the Sun’s surface, sometimes lasting for days or even weeks. Beyond its beauty, the video serves as a reminder of the Sun’s dynamic magnetism and the importance of using certified solar filters, since observing the Sun without protection can cause permanent eye damage.
0:45
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Astrophotographer Mark Johnston Azastroguy captured a mesmerizing scene on October 20, 2025, from Willow Springs Lake in Arizona, showing a fiery filament of hydrogen plasma dancing above the Sun’s limb. Suspended by the Sun’s magnetic field, this structure twists and shimmers in a 6.5-second time-lapse video that condenses 75 minutes of real solar activity. Using a TEC 160FL refractor equipped with specialized solar filters, including a 0.3 Å hydrogen-alpha etalon, Johnston revealed an extraordinary level of detail in the solar prominence, a glowing loop of magnetized gas rising from the photosphere into the corona. The footage captures the intricate motion of plasma arcing hundreds of thousands of kilometers across the Sun’s surface, sometimes lasting for days or even weeks. Beyond its beauty, the video serves as a reminder of the Sun’s dynamic magnetism and the importance of using certified solar filters, since observing the Sun without protection can cause permanent eye damage.

Erika 

37,014 görüntüleme • 7 ay önce

This astonishing Crater on Mars was captured by NASA Opportunity Rover (Sol 117-123). The audio was recorded by Perseverance Rover in 2021. #Mars
0:56
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This astonishing Crater on Mars was captured by NASA Opportunity Rover (Sol 117-123). The audio was recorded by Perseverance Rover in 2021. #Mars

Erika 

80,099 görüntüleme • 1 yıl önce

The Lagrange points, named after the French mathematician Joseph-Louis Lagrange, are unique locations in space where gravitational forces create a delicate equilibrium btw the gravitational pull of 2 large celestial bodies, such as a planet & its moon or a planet & the sun. 1/
1:09
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The Lagrange points, named after the French mathematician Joseph-Louis Lagrange, are unique locations in space where gravitational forces create a delicate equilibrium btw the gravitational pull of 2 large celestial bodies, such as a planet & its moon or a planet & the sun. 1/

Erika 

106,766 görüntüleme • 2 yıl önce

It is already known that the configuration of our Solar System, a single star with planets around it, is something that is not really a standard in our Galaxy. A lot of Systems have two Stars, for example, a binary system, and there are even weirder ones with many stars. In Comparison, our System seems boring. 🥱 📹 morn1415
3:01
ExploreCosmos_'s profile picture

It is already known that the configuration of our Solar System, a single star with planets around it, is something that is not really a standard in our Galaxy. A lot of Systems have two Stars, for example, a binary system, and there are even weirder ones with many stars. In Comparison, our System seems boring. 🥱 📹 morn1415

Erika 

80,474 görüntüleme • 1 yıl önce

Mars sometimes appears to move backward in the night sky due to retrograde motion, an optical illusion. This happens when faster-orbiting Earth overtakes Mars. As Earth passes, Mars seems to slow, stop, and move westward, although it's still moving forward in space. This "backward" motion occurs roughly every 26 months. The last one started on December 6, 2024 and finished on February 23, 2025. The next one is from January 25, 2027 to April 7, 2027. Retrograde motion puzzled ancient astronomers, who thought Earth was the center of the universe. It wasn’t until the heliocentric model (with the Sun at the center) that this illusion was correctly explained. All outer planets show retrograde motion when Earth passes them.
0:50
ExploreCosmos_'s profile picture

Mars sometimes appears to move backward in the night sky due to retrograde motion, an optical illusion. This happens when faster-orbiting Earth overtakes Mars. As Earth passes, Mars seems to slow, stop, and move westward, although it's still moving forward in space. This "backward" motion occurs roughly every 26 months. The last one started on December 6, 2024 and finished on February 23, 2025. The next one is from January 25, 2027 to April 7, 2027. Retrograde motion puzzled ancient astronomers, who thought Earth was the center of the universe. It wasn’t until the heliocentric model (with the Sun at the center) that this illusion was correctly explained. All outer planets show retrograde motion when Earth passes them.

Erika 

50,137 görüntüleme • 1 yıl önce

No, the cubes aren't moving. 😵‍💫😵‍💫
0:22
ExploreCosmos_'s profile picture

No, the cubes aren't moving. 😵‍💫😵‍💫

Erika 

85,132 görüntüleme • 2 yıl önce

Sun vs. the Blue Supergiant. * Rigel, the supergiant blue star, dwarfs everything around it, including our Sun. * In this video, the focus of this visual is on their diameters - giving you a stunning scale comparison. But more than that, it's about what type of star each one is, and what that means: * The Sun is a stable main-sequence yellow dwarf, the kind of star that can host life-bearing planets like Earth. * Vega is a main-sequence white star, hotter, brighter, and spinning much faster than our Sun. * Arcturus is a cooler red giant, showing what stars like our Sun become in their later life stages. * Rigel is a massive, luminous blue supergiant, a short-lived giant destined to end in a spectacular supernova. * I've taken care to reflect not just size and color, but also realistic rotation speeds: * Vega rotates in just 0.7 days. * Rigel spins around in roughly 1.2 days. * While our Sun takes about 25 days to complete one rotation at the equator."
0:56
ExploreCosmos_'s profile picture

Sun vs. the Blue Supergiant. * Rigel, the supergiant blue star, dwarfs everything around it, including our Sun. * In this video, the focus of this visual is on their diameters - giving you a stunning scale comparison. But more than that, it's about what type of star each one is, and what that means: * The Sun is a stable main-sequence yellow dwarf, the kind of star that can host life-bearing planets like Earth. * Vega is a main-sequence white star, hotter, brighter, and spinning much faster than our Sun. * Arcturus is a cooler red giant, showing what stars like our Sun become in their later life stages. * Rigel is a massive, luminous blue supergiant, a short-lived giant destined to end in a spectacular supernova. * I've taken care to reflect not just size and color, but also realistic rotation speeds: * Vega rotates in just 0.7 days. * Rigel spins around in roughly 1.2 days. * While our Sun takes about 25 days to complete one rotation at the equator."

Erika 

49,020 görüntüleme • 1 yıl önce