00:00This is a metal planet baked by the Sun. Surface temperatures can melt lead and tin.
00:06Yet, incredibly, it still has polar ice caps. This is Mercury.
00:12Mercury is the smallest planet in our solar system. Its diameter is just 4,879 kilometers.
00:20That's smaller than some moons of Jupiter and Saturn. Its average distance from the Sun?
00:25Only 58 million kilometers. This close proximity creates extreme temperatures.
00:32Mercury's Sun-facing side reaches 427 degrees Celsius. The dark side plunges to negative 179
00:40degrees Celsius. The day-night temperature difference? Over 600 degrees Celsius.
00:46Despite being such a hellish world, humans explored it. We've launched three groundbreaking missions,
00:52Mariner 10 in 1974, Messenger in 2004, and Bepi Colombo in 2018. Here in 2025,
01:02Bepi Colombo is still exploring Mercury. Today, let's dive into Mercury's complete story.
01:09Friends, what's the birth of Mercury? About 4.5 billion years ago, our solar system began
01:18forming. It started as a rotating disk of gas and dust. We call this a protoplanetary disk.
01:25This disk contained hydrogen, helium, and heavier elements. These came from supernova explosions and
01:32stellar evolution. Tiny dust particles gradually clumped together. They used electrostatic forces in
01:39collisions. Particles grew larger and larger. Then, they became kilometer-sized bodies called
01:46planetesimals. Over time, planetesimals attracted each other. Gravity pulled them together. They merged
01:53into even larger bodies called proto-planets. This is how Mercury slowly formed. It experienced
02:01violent impacts and melting processes. These increased its mass and caused core differentiation.
02:07Mercury formed as one of the innermost planets. The Sun's intense gravity and radiation influenced it
02:13heavily. Being so close to the Sun created extreme heat. This heat caused hydrogen to evaporate and
02:20escape. Volatile materials also escaped. This is why Mercury has such a massive metallic core.
02:27The core comprises over one-third of the planet. That's about 42% of Mercury's total mass. Earth's core is
02:36only 19% by comparison. Mercury's core is primarily iron and nickel. This gives it a magnetic field.
02:44Despite being tiny, Mercury has enough magnetism. It can protect its surface from solar wind. It even
02:51maintains an extremely thin atmosphere. Ancient Observations
02:56Ancient Babylonians observed Mercury as early as 3000 BCE. They called it Nabu. Through careful
03:04observation, they tracked its periodic motion. They could accurately predict when Mercury would appear.
03:10They also predicted where it would show up. Historical records of Mercury go way back.
03:15Ancient astronomical texts mention it frequently. Mercury stays close to the Sun in our sky. It's only
03:22visible from Earth briefly at dawn or dusk. Mercury's unique rotation
03:28Modern scientists made an interesting discovery. Mercury's rotation period is about 58.6 Earth days.
03:36Its orbital period is about 88 Earth days. Mercury's rotation is two-thirds of its orbital period.
03:43This means something fascinating happens. Mercury rotates three times while orbiting twice.
03:50This relationship is called orbital resonance. It results from the Sun's tidal forces.
03:55These forces interact with Mercury's internal structure. Due to this special resonance, something
04:00amazing occurs. One solar day on Mercury lasts 176 Earth days. That means one Mercury day equals two
04:10Mercury years. Scientists aren't entirely sure why Mercury rotates so slowly, but they suspect it's been this
04:17way since birth. The Mariner 10 mission. On November 3, 1973, NASA launched Mariner 10.
04:26It was the final probe in the Mariner series. More importantly, it was humanity's first Mercury explorer.
04:32Its primary mission was to study Venus and Mercury. It was also the first spacecraft to use gravity assist.
04:38Using Venus's gravity, Mariner 10 reached Mercury. It first flew by Mercury on March 29, 1974.
04:47Then, it made two more passes. September 21, 1974 and March 16, 1975. The closest approach came within 700
04:58kilometers.
04:59Key Discoveries
05:01Photography
05:03Mariner 10 captured over 2,700 images. These were high-resolution shots of Mercury's surface.
05:09They covered 45% of Mercury's total surface area.
05:14Here's a fun quiz, friends. Can you guess which photo shows Mercury and which one shows our Moon?
05:21Surprise! Both of those were actually the Moon. This is Mercury. Mercury and the Moon's surfaces look
05:29incredibly similar. Magnetic field. Data revealed something unexpected. Mercury has a magnetic field.
05:38It's about 1% as strong as Earth's. This surprised scientists completely. They didn't expect such a
05:44small planet to have magnetism. Thin atmosphere. Mercury has an extremely thin atmosphere. It's composed
05:53mainly of helium, hydrogen, oxygen, and sodium. Thanks to its large metallic core,
05:58it resists solar wind. It can maintain this wispy atmosphere.
06:04Massive core. Gravitational measurements confirmed it. Mercury has an enormous metallic core.
06:10We explained the reasons earlier. Mariner 10 was powered by two large solar panels.
06:15But after its final solar orbit in March 1975, disaster struck. It suddenly lost contact with Earth.
06:23It might still be orbiting the Sun today. The Messenger mission NASA wanted to explore Mercury further.
06:29So they launched Messenger on August 3, 2004. This mission had ambitious goals. Study Mercury's
06:36chemical composition in detail. Analyze its geological activity and magnetic field sources.
06:42The plan included long-term orbital observation.
06:45Messenger successfully reached Mercury orbit. This happened on March 18, 2011. During its mission,
06:53it captured 289,000 photos. This gave NASA the first complete surface imagery. They created nearly
07:01complete color maps. Major discoveries. Polar ice. Messenger discovered ice caps at Mercury's poles.
07:08It also found giant impact craters there. Surface chemistry. Analysis revealed interesting compositions.
07:16Mercury's surface contains 46% oxygen, 12% magnesium, 26% silicon, 7% aluminum, and 4% calcium.
07:26Surprisingly, it found abundant sulfur, but very little iron on the surface. Volcanic activity.
07:34This created a surface composition puzzle. Why so little surface iron, but a massive iron core?
07:41Messenger solved this when it photographed ancient volcanoes. Scientists concluded Mercury
07:47experienced intense volcanism. The entire planet was possibly covered in lava. During this geological
07:54activity, heavy elements sank down. Elements like iron moved toward the core. Solar wind blew away
08:02volatile and lighter elements. Only small amounts remained in the atmosphere. Water discovery.
08:08Despite extreme heat on the sun-facing side, Messenger found ice caps in polar regions.
08:14These areas aren't directly illuminated by sunlight. The ice deposits are tens of meters thick.
08:20There might be ice-water mixtures at the bottom. This increased speculation about underground water.
08:25In April, 2015, Messenger's fuel ran low. It had flown for nearly 10 years. Scientists decided to crash it
08:35into Mercury. They wanted one final data collection. Messenger transmitted its last data set. Then,
08:42it impacted Mercury's surface, BepiColombo mission. In 2018, a joint mission launched. The European Space
08:51Agency and Japan teamed up. They launched BepiColombo for close-range reconnaissance. This mission focuses
08:57on several key areas. Mercury's surface, magnetic field, and polar ice caps. It also studies Mercury's
09:05interactions with the sun. The spacecraft is expected to reach Mercury orbit in 2025. We're writing this in
09:12April 2025. No specific progress updates have been released yet. Most likely, the probe is still
09:19traveling to Mercury. Let's eagerly await what secrets it will reveal. Mercury's surface.
09:27Features. Let's examine what Mariner 10 and Messenger discovered. Mercury's surface is almost
09:32entirely covered with impact craters. Some areas have smooth planes, though. This indicates Mercury was
09:38heavily bombarded after cooling. Currently, 567 confirmed craters have been identified. NASA named each
09:46one after historical figures. Scientists classify craters into two types based on morphology.
09:53Simple craters. Usually 1 to 14 kilometers in diameter. They're less than 11 kilometers deep.
09:59These make up the majority of craters. They're mainly concentrated in the southern hemisphere.
10:04Complex craters. Generally 16 to 270 kilometers in diameter. They're over 11 kilometers deep.
10:11Their distinctive feature is a central peak. This peak forms from rebound after impact.
10:17Mercury has the most complex craters in the solar system. About 110 complex craters exist there.
10:24Our moon has only 17 by comparison. The largest craters are better called basins.
10:30Mercury has famous basins like Caloris and Rembrandt. Caloris Basin.
10:35This is Mercury's largest crater. It's 1,550 kilometers in diameter.
10:42Photos suggest it was likely covered by lava. This gives it a smooth, bowl-like appearance.
10:48Rembrandt Basin. This is Mercury's second largest crater. It's about half the size of Caloris.
10:56Among all craters, scientists found the oldest basin. It's possibly over 4 billion years old.
11:01Thick volcanic ash covers its surface. It might hide secrets from our solar system's formation.
11:07Bonus discovery. Mercury's dust ring. Here's a final surprise for you guys.
11:12Around 2010, scientists made an accidental discovery. They were studying dust distribution
11:19near Mercury's orbit. They discovered a cosmic dust ring around Mercury. This ring is about 15 million
11:26kilometers in diameter. It consists mainly of fragmented asteroids. Cometary debris from solar
11:32system formation is also present. This discovery shattered previous theories. Scientists thought
11:38Mercury was too small for dust rings. They also thought it was too close to the Sun. This ring is
11:44incredibly thin. Scientists can only detect it through data analysis. Unlike Saturn and Jupiter's rings,
11:51Mercury's works differently. Its ring maintenance mechanism is more complex. Scientists speculate
11:57about undiscovered asteroid groups. Special gravitational effects might be involved too. These could
12:03counteract the Sun's dispersive forces. This discovery challenges traditional understanding. It reveals new
12:10possibilities for small body interactions. Its existence provides direct observational samples. We can study
12:17material remnants from early planetary formation. Wrapping up you guys who love space exploration.
12:24This one's for you. Unsolved mysteries and cosmic stories await. Support Cosmic Canvas with likes and
12:30subscriptions. Your comments and subscriptions mean everything. They're the biggest support for Starweaver.
12:36That's all for today's show. See you next time. Bye bye.
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