略過至播放器跳至主內容
Ever heard of a planet that rolls on its side, glows blue-green, and is colder than anywhere else in the solar system? 🌌 That’s Uranus — the oddball giant in our cosmic backyard. Stick around and I’ll even show you how to spot it from here in Australia!#Uranus #planet Uranus #solar system #seventh planet #ice giant #William Herschel #coldest planet #Voyager 2 #planet discovery #Uranus rings #Uranus moons #blue green planet #methane atmosphere #axial tilt #planet rotation #Uranus facts #space exploration #astronomy #Titania moon #Oberon moon #magnetic field #diamond rain #planetary science #telescope observation #planet atmosphere #Uranus temperature #wind speed #Hubble telescope #Pleiades #Taurus constellation
文字稿
00:00what if i told you there's a planet rolling through space on its side wearing a blue green glow and
00:05colder than anywhere else in the solar system that's uranus i reckon many of you have heard
00:10the name but don't really know much about it today let's explore the seventh planet from
00:14the sun together stick around till the end i'll show you how to spot uranus with your own eyes
00:20so buckle up we're going full throttle straight to uranus let's go the discovery of uranus is
00:26legendary stuff in 1781 british astronomer william herschel spotted this planet using a telescope he
00:33built himself it was also the first planet in human history discovered through a telescope
00:38before this ancient people could only see mercury venus mars jupiter and saturn with the naked eye
00:45uranus completely changed how we understood our solar system and the universe suddenly we realized
00:50the universe was massive there was actually another planet beyond saturn that we couldn't even see
00:56uranus sits about 2.87 billion kilometers from the sun that's about 19 times farther from the sun than
01:03earth so far that sunlight takes nearly three hours to get there its orbital period is a whopping 84 years
01:10meaning uranus takes one trip around the sun while earth completes 84 orbits its volume is roughly 63 times
01:18earths but its mass is only about 14.5 times heavier its density ranges between 1.27 to 1.3
01:27just slightly heavier than the human body uranus has a truly unique color it appears blue green
01:33because its atmosphere contains about two percent methane that two percent methane acts like an optical filter
01:40it absorbs red light and some green light from the sun then scatters and reflects blue light plus the remaining
01:45green light this atmospheric chemistry creates that distinctive blue green appearance we see
01:51besides methane uranus's atmosphere is mainly 83 hydrogen and 15 helium the atmosphere is incredibly
01:59thick with a complex structure thanks to the hubble telescope and voyager 2 we discovered that uranus
02:04spins ridiculously fast one rotation takes just 17 hours and 14 minutes much faster than earth
02:12this high speed rotation combined with its extreme axial tilt creates fierce storms in uranus's atmosphere
02:18wind speeds can hit 900 kilometers per hour for comparison earth's highest recorded tornado wind speed
02:25was 513 kilometers per hour in oklahoma back in 1999 while natural wind speeds max out around 372 kilometers
02:33per hour here's where uranus gets really weird it's the only planet among the eight that's literally lying on its side
02:40why do i say lying down most planets have slightly tilted rotation axis earth's is 23.5 degrees
02:49but uranus a massive 97.8 degrees almost parallel to its orbital plane basically uranus is rolling through
02:57the solar system like a ball this bizarre orientation creates extreme seasonal changes each pole experiences
03:0442 years of continuous daylight followed by 42 years of darkness that's downright mind-boggling what caused
03:12such an extreme tilt scientists reckon uranus suffered a massive collision long ago that knocked
03:18its rotation axis sideways based on calculations the impacting object would need to be about earth size
03:23to create uranus's current state but that's just theory we don't have solid proof yet still this
03:29quirky orientation definitely makes uranus stand out now let's check out uranus's ring system many
03:36people think only saturn has beautiful rings but uranus has them too it was the second planet discovered
03:42to have rings after saturn in 1977 scientists were observing a star when uranus blocked their view
03:49and they accidentally discovered the rings so far we've found 13 rings around around uranus mainly
03:56composed of rocks and ice particles unlike saturn's bright dazzling rings uranus's rings are more
04:03subtle only visible under specific lighting conditions uranus also has plenty of moons 27 known so far
04:10their names mostly come from shakespeare and pope's literary works miranda ariel umbriel titania and oberon
04:18titania and oberon are uranus's largest moons with surfaces covered in thick ice layers
04:23actually among these five major moons four have varying degrees of ice layers and subsurface
04:29oceans all except miranda even miranda with just a 472 kilometer diameter and weak heat retention
04:37might still have ice layers or underground water thanks to orbital resonance and tidal stretching
04:43uranus's magnetic field is completely different from earth's or jupiter's instead of originating from
04:48from the planet's center it's offset by about one-third of the planet's radius this creates a
04:53highly asymmetric magnetic field with magnetic poles tilted 59 degrees from the rotation axis
04:59this magnetic structure is absolutely unique in our solar system it's got scientists fascinated
05:04about uranus's internal structure the magnetic field strength is about 75 percent of earth's
05:10but because of this weird structure uranus's auroras are unlike anything else they appear at different
05:16latitudes creating strange light bands speaking of internal structure uranus is classified as an ice
05:22giant different from gas giants like jupiter and saturn let me explain traditionally uranus gets lumped
05:28with saturn jupiter and neptune as gas giants because they all lack solid surfaces and have outer layers
05:34mainly of hydrogen and helium but modern astronomy classifies uranus as an ice giant based on compositional
05:40differences the key difference gas giants have caused mainly of liquid metallic hydrogen and helium
05:46with higher gas ratios ice giants lack clear solid surfaces but have high density ice mantles
05:52models suggest uranus has a dense rocky metallic core but most of its mass concentrates in an ice rock
05:58mixed mantle the ice giant classification comes from this ice mantle's dominant role this isn't everyday
06:04ice though it's high density matter formed under extreme pressure and low temperatures mainly water ice
06:10ammonia ice and methane ice scientists think uranus might experience diamond rain under high pressure
06:17methane breaks down and carbon atoms cluster into diamond particles that slowly sink toward the planet's
06:23depths like raindrops while unconfirmed theoretical models and lab simulations support this fascinating
06:29possibility uranus is absolutely freezing the coldest planet in our solar system hands down its upper
06:37atmosphere can drop to minus 224 degrees celsius nearly absolute zero although uranus is far from the sun
06:45it cools faster than even more distant neptune this puzzles scientists the rapid cooling might relate to
06:52its unique axial tilt and internal structure or perhaps early violent impacts caused massive internal heat loss
06:59human observation of uranus has been limited since herschel's discovery we've never stopped studying it
07:05but only nasa's voyager 2 has actually visited uranus flying past in 1986 it sent back loads of
07:12precious data and photos giving us our first close look at uranus's rings moons and atmosphere though
07:19voyager 2's flyby was brief it discovered two new rings 11 new moons and confirmed uranus's extremely low
07:26temperatures but this information barely scratches the surface there's so much more to explore uranus's
07:33discovery gave humanity new understanding about planets its unique rotation extreme climate complex
07:39magnetic field and mysterious internal structure open new doors for scientific research maybe someday
07:45when humans can visit uranus we might harness its extreme cold and diamond rain for our benefit
07:51finally starweaver will teach you how to spot uranus yourself you'll need a telescope with at least an
07:5780 millimeter refractor this will show a tiny blue green disc if your budget allows a 150 millimeter
08:04reflector works even better paired with 200 by magnification eyepieces the best viewing time is
08:11around november each year during uranus's opposition in 2025 opposition occurs on november 21st
08:18that's when uranus is brightest and closest to earth during opposition when the sun sets in the west
08:24uranus rises in the east reaches its highest point at midnight then sets at dawn taking sydney as an
08:31example about an hour after sunset point your telescope toward the northeastern horizon looking
08:37about 30 to 40 degrees above the horizon that's where you'll find it uranus will be in the constellation
08:44taurus sitting just south of the famous pleiades star cluster if you can't locate it just ask an ai app
08:51for uranus's real-time position if you're feeling energetic midnight is ideal because the atmosphere
08:56is most stable with minimal interference giving the clearest views oh and don't try this from the city
09:03light pollution will seriously mess with your viewing experience choose somewhere high and open a
09:09mountaintop or open farmland works brilliantly best of luck spotting this beautiful planet mates
09:15this is cosmic canvas i'm star weaver if you love space exploration and cosmic mysteries hit that like
09:22button and subscribe next up neptune the windiest stormiest world you've never imagined
09:28you won't want to miss it see you next time love you all bye
成為第一個評論的人
新增評論

推薦