It took me a while to understand from 5:08 to 5:30. I'll break it up for the one's who are facing the same problem as I did. 1) At Aphelion, Mercury's angular rotational speed is faster than it's angular orbital speed, so the Sun moves rapidly to the west side in the sky. 2) Four days before Perihelion, the angular orbital velocity of Mercury is equal to the angular rotational velocity, so the Sun appears to stop in the sky. 3) While now at Perihelion, the angular orbital velocity of Mercury is more than the angular rotational velocity, so the Sun appears to move eastwards. 4) Now as the Mercury is pulled away from the Sun i.e. it leaves it Perihelion position, again it moves westwards as the angular rotational velocity dominates over the angular orbital velocity.
Thanks, that clears it up a bit...can you explain what angular rotational speed, angular orbital speed, and angular rotational velocity are? That would be great, thanks!
@@amritha.yelleti put very simply, when mercury is farthest away from the sun, it's spinning faster than it orbits, so the sun appears to move fast across the sky. When it's closest to the sun, it's actually orbiting faster than it spins for a little bit, making the sun appear to move backwards to the east. As the orbit moves further away from the sun, the orbit speed slows, causing the sun to appear to move west again.
Also, I say we adopt the phrase "I had a Mercury's day" to describe a day when it feels as if everything was chaotic and the end of your day never seemed to arrive.
This video actually corrected a misconception that I had about Mercury. I remember reading that Mercury was tidally locked in the same way that the Moon was so that its year was the same as its day. I always believed that Mercury had a permanent light side and dark side, and that the light side was always really hot and the dark side was extremely cold. I think I got this impression from a children's book I had while growing up which might have been using out of date information.
The best thing about Thursday is more Crash Course Astronomy, where I get to learn some stuff I didn't know, get reminded of some stuff I did know, and I get to hear Phil's one-liners, which are awful in all the right ways.
Little bonus fact, even though it is the closest planet to the sun, Venus is hotter, this is because the atmosphere on Venus keeps the heat in. Because Mercury has almost no atmosphere to retain heat, Mercury's surface experiences the greatest temperature variation of the planets in the Solar System, ranging from 100 K (−173 °C; −280 °F) at night to 700 K (427 °C; 800 °F) during the day at some equatorial regions.
All the craters are named with surnames, not first names. Unfortunately, there is no "Mercury" crater, considering there _is_ a "Lennon" crater, named after John Lennon, so it's not just classical musicians. But I suppose it would be awkward having a crater Mercury on Mercury. They could still name one "Bulsara" since that was his real name, but no one knows him by that name.
sheepwshotguns Right? I was waiting for CC Astronomy to get to the good stuff, because I really like the host. He's not quite as entertaining as John, but compared to the CC Politics guy...
I get so excited every time an Astronomy crash course shows up on my subscription list, seriously how come we never learn any of this fascinating stuff in school?
PajamaMan According to the "Kurzgesagt" video on the moon Triton (great channel btw) there are 4 tectonic active objects in the solar system. Earth, Triton, Io and Enceladus. Though there is still a lot of speculation involved.
«In 1639, the Italian astronomer Giovanni Zupi discovered that it undergoes a complete cycle of phases, just like the Moon does. The only way that can happen is if Mercury orbits the Sun and not the Earth....» But Phil, the Moon undergoes a complete cycle of phases - which is why you use it for comparison - but it orbits the Earth, and not the Sun.... Henri
Mr plait, thank you for taking time in your life to teach us about this ever expanding universe and the celestial bodies that move in it. I look forward to watch your videos to escape my depressing days
Seems sriontube isn't counting the Asteroid Belt, Ceres, the Galilean Moons or Saturn's moons/rings as potential episodes in his equation (though, it's possible he counted one of them... or accidentally counted Earth.) One could also fill out an entire episode about the discoveries of Uranus, Neptune and Pluto before making episodes about the planets themselves.
This video told me a lot about Mercury that I didn't know, but it didn't answer the question I had - about the anomaly of Mercury's orbit that had to be explained through Relativity. I have looked in other places, where the anomaly seems to be its precession - but I don't think relativity is needed to explain that. I'm guessing that when precession is taken into account, the orbit is still not exactly what it is expected to be. The answer must be out there somewhere - but the Internet is a big place!
Yes, we're getting somewhere! In the first episodes of Astronomy CC, nothing was said that I haven't known since I was 8 y.o. But here I learned several new things!
thank you for quick speaking style. easier to get information that way. but you emphasized important parts clearly. thank you also for using kilometers. class course!
Mercury has a comet like tail, water ice in craters, measurable magnetic field? and it's weird tidal locking pattern with Sun... wow.. the solar system never ceases to amaze me.
Thank you very much for making this video, Phil Plait, _Though Café_ and the rest of _CrashCourse_ Astronomy! It was fascinating to learn about Mercury, surely one of the weirdest planets in our solar system. I have a question for you: you said that Mercury stated out as a very big planet and than got small do to a collision with something. A few episodes back, you talked about the moon and how it was formed by a collision between Earth and the planet Theia. Is it possible that Mercury was Theia all along? Is the Moon a child of Earth and Mercury? What do the space geologists say?
Oooh, we're on planets now! Nice :) I'm using this mostly as interesting revision of basic concepts for my Astrophysics course, and it hasn't failed to deliver so far (you even mentioned the sodium tail, and magnetosphere!)
CrashCourse @1:06"it undergoes a complete cycle of phases just like the Moon does - the only way that can happen is if Mercury orbits the Sun and not the Earth - another check mark in the column for heliocentrism" *How did that prove heliocentrism?... If its orbit was "just like the Moon" - because the Moon orbits the Earth not the Sun. I'm not arguing against heliocentrism - I just find Phil's phrasing and logic confusing in his explanation.
8:20 There's an error: the actual reason impacts on Mercury have a higher energy is not because its orbital speed, but because asteroids move faster the closer they get to the Sun due to its gravitational pull.
The speed of the planet definitely contributes. Kinetic energy is quadratic in the velocity so even if it is a small relative increase in velocity, it can be a big increase in energy.
He, and many astronomy sites use "Mercury days" in two ways and it's very confusing. At 3:25 it says Mercury's Day: 58.65 Earth Days, and then at 4:13 it says in the diagram that 0.50 Mercury Days =88 Earth Days. These two cannot go together. It is either that one rotation on its axis is equal to one day, or that one "Sun cycle" is equal to one day.
sense John Green is no longer doing World History, he should do Crash Course Wars, where he goes in dept look at the tactics, strategies, and weapons of different wars. Sense he did not do so in World History
There's also the thing about how Mercury helped to prove General Relativity. IIRC the precession of Mercury's perihelion was slightly different to the value predicted by Newtonian orbital dynamics, and that turned out to be because it's deep enough in the Sun's gravity well for relativistic effects to be measurable. But I don't really know the details - so I'd love to see Phil (or possibly SciShow Space) cover this at some point!
Hey I think you guys have a small error around the 1:10 mark. You say that, because Mercury exhibits a full cycle of phases, it could only orbit the sun and not the earth. But the moon orbits the earth and we see its full cycle of phases! If an object shows a full cycle of phases, it must either orbit the earth or orbit the sun CLOSER THAN the earth. If we never see the full cycle of phases, it must orbit further from the sun than the earth. For example, we can never see Mars, Jupiter, Saturn, etc. as crescents because they are never between the earth and sun. :) Also: Your animation at 3:56 was confusing. The way the audio synced up with the three points in the orbit made it seem like there are three perihelions per orbit
With the craters being cold enough for water ice, could it be plausible to have some sort of life happening in there? Somewhere between the surface that's too hot and the deep section of the crater where it's too cold?
ceebee27sts I don't think the Goldilocks zones are consistent and large enough to sustain an environment suitable for spontaneous evolution of life. The statistical probability of something like amino acids forming in the optimal conditions gets higher over time, but so does the likelihood of an asteroid striking the spot where that was happening. So, in conclusion; very very unlikely.
It better be some ultra-resistant little fella. Radiation would absolutely destroy any Earthlike cells living there. It'd need cells walls made of lead instead of phosphates.
ceebee27sts That what I was wondering. The craters seemingly have been that low temperature for millions of years so one would expect the crater walls to have decent "weather" enabling liquid water.
James Caswell Enough though the temperatures may be appropriate, liquid water still cant exist there. The relative lack of an atmosphere fails to provide the necessary pressure. And without sunlight, lifeforms would have a very limited source of food. This would prevent them from blossoming into any kind of complexity.
It took me a while to understand from 5:08 to 5:30. I'll break it up for the one's who are facing the same problem as I did.
1) At Aphelion, Mercury's angular rotational speed is faster than it's angular orbital speed, so the Sun moves rapidly to the west side in the sky.
2) Four days before Perihelion, the angular orbital velocity of Mercury is equal to the angular rotational velocity, so the Sun appears to stop in the sky.
3) While now at Perihelion, the angular orbital velocity of Mercury is more than the angular rotational velocity, so the Sun appears to move eastwards.
4) Now as the Mercury is pulled away from the Sun i.e. it leaves it Perihelion position, again it moves westwards as the angular rotational velocity dominates over the angular orbital velocity.
Thanks, that clears it up a bit...can you explain what angular rotational speed, angular orbital speed, and angular rotational velocity are? That would be great, thanks!
@@amritha.yelleti put very simply, when mercury is farthest away from the sun, it's spinning faster than it orbits, so the sun appears to move fast across the sky.
When it's closest to the sun, it's actually orbiting faster than it spins for a little bit, making the sun appear to move backwards to the east. As the orbit moves further away from the sun, the orbit speed slows, causing the sun to appear to move west again.
i dont get how a day equals two years.I couldn't relate the motion of mercury around sun and its day duration.Could you please explain?
Also, I say we adopt the phrase "I had a Mercury's day" to describe a day when it feels as if everything was chaotic and the end of your day never seemed to arrive.
This video actually corrected a misconception that I had about Mercury. I remember reading that Mercury was tidally locked in the same way that the Moon was so that its year was the same as its day. I always believed that Mercury had a permanent light side and dark side, and that the light side was always really hot and the dark side was extremely cold. I think I got this impression from a children's book I had while growing up which might have been using out of date information.
Phlebas same here!
I LOVE listening to this guy! Something aabout the way he talks just makes me want to listen.
not a 2am!
I feel like I just had 2 cups of coffee and did a line of coke!
brother?
lol I love the fssst sound he made when he talks about the water
KL Havoc/Pyrex92 Everybody knows that's the sound of evaporation!
KL Havoc/Pyrex92 The sizzle sound effect.
KL Havoc/Pyrex92 I read this comment the moment I heard him make the sound :D
KL Havoc/Pyrex92 you can buy the sound effect on amazon i think
I like the fact that came along with it aswell
The best thing about Thursday is more Crash Course Astronomy, where I get to learn some stuff I didn't know, get reminded of some stuff I did know, and I get to hear Phil's one-liners, which are awful in all the right ways.
Being both really hot and really cold, Mercury must be really having some *first world problems*
Nice XD
These videos always provide some interesting facts.
Mark B well, they're spozed to! ;-)
Little bonus fact, even though it is the closest planet to the sun, Venus is hotter, this is because the atmosphere on Venus keeps the heat in.
Because Mercury has almost no atmosphere to retain heat, Mercury's surface experiences the greatest temperature variation of the planets in the Solar System, ranging from 100 K (−173 °C; −280 °F) at night to 700 K (427 °C; 800 °F) during the day at some equatorial regions.
***** numbers lol nerd
***** thanks dude! interesting stuff :)
***** Hey you're spoiling the next CC astronomy!
***** obviously this also explains the whole ice thing :D
do you people really not know that...? Have you people never taken a class on science?
"of course in the harsh heat, that water just goes fsstttttt" LOL
made my day
There'd better be a crater named after Freddie in that planet
lmAO RIGHT Because his last name is Mercury, that's perfect!
All the craters are named with surnames, not first names. Unfortunately, there is no "Mercury" crater, considering there _is_ a "Lennon" crater, named after John Lennon, so it's not just classical musicians. But I suppose it would be awkward having a crater Mercury on Mercury. They could still name one "Bulsara" since that was his real name, but no one knows him by that name.
@@pasijutaulietuviuesas9174 is that a 'fun' fact?
@@unclefreddieDied No, I'm explaining why there could not be a crater "Freddie".
Haha!!
can we appreciate the fact that Phil broke out of prison just to deliver us this episode?
I love this guy, he seems to be so interested and passionate about what he's talking about. Always makes for an interesting video.
oh this is fantastic. we're really starting to get some meat and potatoes with this crash course.
sheepwshotguns Right? I was waiting for CC Astronomy to get to the good stuff, because I really like the host. He's not quite as entertaining as John, but compared to the CC Politics guy...
Diana Peña Shut up and eat your chicken.
Planets and Suns and potential life on other planets is amazing!
The moon is boring as sht.
sheepwshotguns Why did you have to talk about meat and potatoes, now I'm hungry. Apart from that I agree.
sheepwshotguns exactly what I thought, first few episode disapointed me a little but this one was great!
Love how he does the lesson recap at the end to focus on the key points in the lesson. AMAAZIIIINGGG
Hi Mr phil thaks for your videos
Hello Qscience you're welcome. :)
Took me a little while but I was absolutely stoked to notice Jeb, Bill and Bob on the shelf in the background.
I love the fact you have your own book on the top of the stack of books in front of you Phill
I get so excited every time an Astronomy crash course shows up on my subscription list, seriously how come we never learn any of this fascinating stuff in school?
Phil, even when making bad puns, you're so classy, just keep up the great work :D
I love this series, and I loved the fact about craters being named after artists.
Do any other planets have tectonic plates?
PajamaMan You better watch out kid
PajamaMan Venus might. Mars & Mercury not. Of course, the gas giants don't have a crust.
I'm willing to be a few geologically active moons do, as well. Not ours, of course, but the gas giants.'
PajamaMan Mainly moons
PajamaMan According to the "Kurzgesagt" video on the moon Triton (great channel btw) there are 4 tectonic active objects in the solar system. Earth, Triton, Io and Enceladus. Though there is still a lot of speculation involved.
Solid Ice On Mercury, a planet like Mercury. This Facts gives me Goose Bumps. Biggest Surprise Of My Astronomy Learning Career...
Huhhhh, That is really really bizarre...
"Solid Ice On Mercury, a planet like Mercury. " What?
Having the Kerbal figurines in the background is a nice touch.
Crash Course Astronomy has become my favorite show on your channel. Thank you guys.
CrashCourse I had no idea that some craters had a lot of water in them.
Thanks for the Upload CC :)
Remember to watch this year's Mercury transit 9th May 2016.
Note: don't do it without proper eye protection.
teubert2 I just covered my hands with my eyes..........wait
lolol
I become so overwhelmed with excitement when I see a new Crash Course Astronomy episode!
is there a crater called Freddie?
«In 1639, the Italian astronomer Giovanni Zupi discovered that it undergoes a complete cycle of phases, just like the Moon does. The only way that can happen is if Mercury orbits the Sun and not the Earth....» But Phil, the Moon undergoes a complete cycle of phases - which is why you use it for comparison - but it orbits the Earth, and not the Sun....
Henri
Mr plait, thank you for taking time in your life to teach us about this ever expanding universe and the celestial bodies that move in it. I look forward to watch your videos to escape my depressing days
i know what are the next 8 episodes of Crash Course Astronomy...so do you.
sriontube I see you putting that thinking cap on... but we might pull a bit of a plot twist on you, so stay tuned, friend. ;)
-Nicole
Seems sriontube isn't counting the Asteroid Belt, Ceres, the Galilean Moons or Saturn's moons/rings as potential episodes in his equation (though, it's possible he counted one of them... or accidentally counted Earth.) One could also fill out an entire episode about the discoveries of Uranus, Neptune and Pluto before making episodes about the planets themselves.
i can't wait for saturn, favorite not Earth planet
Recon WB Neptune's winds will literally blow the Saturn episode away
with saturn's mass, maybe in a few billion years ;)
I friggin' love this Crash Course series. Phil's the man.
Before watching this video, I didn't care about Mercury.
Now I love it ! Thanks Phil. :)
This video told me a lot about Mercury that I didn't know, but it didn't answer the question I had - about the anomaly of Mercury's orbit that had to be explained through Relativity. I have looked in other places, where the anomaly seems to be its precession - but I don't think relativity is needed to explain that. I'm guessing that when precession is taken into account, the orbit is still not exactly what it is expected to be. The answer must be out there somewhere - but the Internet is a big place!
Your videos contain much more information than i expected from a "crashcourse". Cool!
the intro killed me xD
"One thing we've learned about nature, that it has a lot of imaginations than we do"- brilliant quote. Should go into books of philosophy
Yes, we're getting somewhere! In the first episodes of Astronomy CC, nothing was said that I haven't known since I was 8 y.o. But here I learned several new things!
I love how there's 3,185 thumbs up and 10 thumbs down. That, my friends, is the ratio of a master youtuber. :)
I think I like this episode best so far. This is the first one to really surprise me with new and very interesting information. :)
Wonderful, wonderful episode. I learned more new stuff in this one than in possibly the whole series leading up to it. Can't wait to see more.
LOVE the sound effect of water going FSHZZZ on the surface at 9:10
I can't believe how much time did i waste without knowing about you guys
You are amazing
I seriously hope that astronomers DO NOT name a newly discovered crater on mercury Beiber.
I feel you...!
I don't know why they would, since they only name craters after artists
princess of spades
It makes me sad that when you think of an artist you think of Bieber.
Same as you
thank you for quick speaking style. easier to get information that way. but you emphasized important parts clearly. thank you also for using kilometers. class course!
I clicked on this by accident but couldn't click away as the none stop facts drew me in. Nicely done guys
U speak very nicely clearly n a little bit slowly which makes us understand easily.. Thanks!! :)
How am I always here so early????
Anywho
crash course philosophy
Salomon Flamenco yess^^^
Salomon Flamenco Yes please.
You say this on every crash course video shut up
Crash course physics
Salomon Flamenco nice
Love this show!
Mercury has a comet like tail, water ice in craters, measurable magnetic field? and it's weird tidal locking pattern with Sun... wow.. the solar system never ceases to amaze me.
Loving this channel.
What a great description of the Sun's path in Mercury's sky!
Id vote yes on a crash course tax. Just so this guy can keep making videos and have nothing else in life to worry about
I freaking love this series so much!! That's all.
Ahh loved this episode! Can't wait for the next :)
I love all your videos so much.. Amazing information educational and fun to study.. Thank you for everything 🙏
thoroughly enjoy watching these videos after a long day ... thanks guys! keep it up :)
I loved this one! I learned so much about how they make discoveries about bodies in the solar system. I've always wondered. Thanks!
The strange planet is mercury 🖤 I love you Mercury , and I can feel your weirdness
I love this series please keep the videos coming!
also. I never comment but I want to say that I love your videos and listen to them often.
This show is so interesting. Definitely the highlight of my Thursdays.
I love these videos, never stop!
Get you a man that talks about you as excited as this guy talks about mercury
Thank you very much for making this video, Phil Plait, _Though Café_ and the rest of _CrashCourse_ Astronomy! It was fascinating to learn about Mercury, surely one of the weirdest planets in our solar system.
I have a question for you: you said that Mercury stated out as a very big planet and than got small do to a collision with something. A few episodes back, you talked about the moon and how it was formed by a collision between Earth and the planet Theia. Is it possible that Mercury was Theia all along? Is the Moon a child of Earth and Mercury? What do the space geologists say?
wait until you learned about Venus
Nope
Fantastic series Phil.!!!
I didn't know about the relationship between Mercury's days and years - that's so interesting! Thanks for the great video!
Another fantastic video. Thank you guys so much.
I love how each planet has its own special characteristics that give them their unique "personality" :-)
Excellent crash course. Thx for sharing
WOW! Never thought Mercury could have ice... LOL! Thanks for that, Phil and PBS!
Great episode, thanks for doing what you do!
Oooh, we're on planets now! Nice :)
I'm using this mostly as interesting revision of basic concepts for my Astrophysics course, and it hasn't failed to deliver so far (you even mentioned the sodium tail, and magnetosphere!)
l love the way this guy explains things,make it more interesting
loved it phil! nice job
man this vids are awesome
CrashCourse @1:06"it undergoes a complete cycle of phases just like the Moon does - the only way that can happen is if Mercury orbits the Sun and not the Earth - another check mark in the column for heliocentrism" *How did that prove heliocentrism?... If its orbit was "just like the Moon" - because the Moon orbits the Earth not the Sun. I'm not arguing against heliocentrism - I just find Phil's phrasing and logic confusing in his explanation.
8:20 There's an error: the actual reason impacts on Mercury have a higher energy is not because its orbital speed, but because asteroids move faster the closer they get to the Sun due to its gravitational pull.
The speed of the planet definitely contributes. Kinetic energy is quadratic in the velocity so even if it is a small relative increase in velocity, it can be a big increase in energy.
BosonCollider Yes, but the speed of the planet tends to be perpendicular to the speed of the impactor.
Kilgore Trout The relative velocities still add using the cosine theorem. The contribution from the planet's motion is substantial.
BosonCollider uhh.... You're both right. Both of your points are factors and none is negligible.
Kilgore Trout The planet's speed adds to that huge speed.
And by the way, some asteroids are actually near to Mercury.... at least in the past.
Thank you so much for these super interesting videos!!!
Great watch
One of the best channels (one...)
Phil is such a great host!
I could just listen to you talk about the stars all day.
He, and many astronomy sites use "Mercury days" in two ways and it's very confusing. At 3:25 it says Mercury's Day: 58.65 Earth Days, and then at 4:13 it says in the diagram that 0.50 Mercury Days =88 Earth Days. These two cannot go together. It is either that one rotation on its axis is equal to one day, or that one "Sun cycle" is equal to one day.
You made my least favorite planet interesting. I knew I could count on you Crash Course!
loving this series :D and i must say Phil is such a great host ! :D
sense John Green is no longer doing World History, he should do Crash Course Wars, where he goes in dept look at the tactics, strategies, and weapons of different wars. Sense he did not do so in World History
It's the illmatier
rewatching my fav episodes. i miss this series so much :'(
There's also the thing about how Mercury helped to prove General Relativity. IIRC the precession of Mercury's perihelion was slightly different to the value predicted by Newtonian orbital dynamics, and that turned out to be because it's deep enough in the Sun's gravity well for relativistic effects to be measurable. But I don't really know the details - so I'd love to see Phil (or possibly SciShow Space) cover this at some point!
Hey I think you guys have a small error around the 1:10 mark. You say that, because Mercury exhibits a full cycle of phases, it could only orbit the sun and not the earth. But the moon orbits the earth and we see its full cycle of phases!
If an object shows a full cycle of phases, it must either orbit the earth or orbit the sun CLOSER THAN the earth. If we never see the full cycle of phases, it must orbit further from the sun than the earth. For example, we can never see Mars, Jupiter, Saturn, etc. as crescents because they are never between the earth and sun.
:)
Also: Your animation at 3:56 was confusing. The way the audio synced up with the three points in the orbit made it seem like there are three perihelions per orbit
best show on youtube
I really enjoyed this video!
the beat at the end and beginning is dope if you have headphones with a lot of bass.
Wasn't expecting that stuff about ice in such a place. How can a "ball" heat up so much and still have unbelievably cold spots?
So freaking amazing! It's wonderful how astronomy can surprise us. :D
Mr Phil, you are a really good host!
With the craters being cold enough for water ice, could it be plausible to have some sort of life happening in there? Somewhere between the surface that's too hot and the deep section of the crater where it's too cold?
ceebee27sts I don't think the Goldilocks zones are consistent and large enough to sustain an environment suitable for spontaneous evolution of life. The statistical probability of something like amino acids forming in the optimal conditions gets higher over time, but so does the likelihood of an asteroid striking the spot where that was happening. So, in conclusion; very very unlikely.
It better be some ultra-resistant little fella. Radiation would absolutely destroy any Earthlike cells living there. It'd need cells walls made of lead instead of phosphates.
I'm guessing because Venus has clouds of sulfuric acid and extremely high surface pressure and temperature.
ceebee27sts That what I was wondering. The craters seemingly have been that low temperature for millions of years so one would expect the crater walls to have decent "weather" enabling liquid water.
James Caswell Enough though the temperatures may be appropriate, liquid water still cant exist there. The relative lack of an atmosphere fails to provide the necessary pressure. And without sunlight, lifeforms would have a very limited source of food. This would prevent them from blossoming into any kind of complexity.
The Kerbals on the shelf are a nice touch.
Very good sir. The solar system is so interesting.