- 3148 - PLANETS - in our Solar System? The order of the planets in the solar system, starting nearest the sun and working outward is the following: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and then the possible Planet Nine.
- ----------------------- 3148 - PLANETS - in our Solar System?
- Since the discovery of Pluto in 1930 in 2006 to designate Pluto as a "dwarf planet," reducing the list of the solar system's true planets to just eight.
-
- Astronomers, however, are still hunting for another possible planet in our solar system, a true ninth planet, after mathematical evidence of its existence was revealed on Jan. 20, 2016. The alleged "Planet Nine," also called "Planet X," is believed to be about 10 times the mass of Earth and 5,000 times the mass of Pluto.
-
-
- The inner four planets closest to the sun — Mercury, Venus, Earth and Mars — are often called the "terrestrial planets" because their surfaces are rocky. Pluto also has a rocky, albeit frozen, surface but has never been grouped with the four terrestrials.
-
- The four large outer worlds — Jupiter, Saturn, Uranus and Neptune — are sometimes called the Jovian or "Jupiter-like" planets because of their enormous size relative to the terrestrial planets. They're also mostly made of gases like hydrogen, helium and ammonia rather than of rocky surfaces, although astronomers believe some or all of them may have solid cores.
-
- Jupiter and Saturn are sometimes called the gas giants, whereas the more distant Uranus and Neptune have been nicknamed the ice giants. This is because Uranus and Neptune have more atmospheric water and other ice-forming molecules, such as methane, hydrogen sulfide and phosphene, that crystallize into clouds in the planets' frigid conditions. Methane crystallizes at minus 296 Fahrenheit.
-
- The IAU defines a true planet as a body that circles the sun without being some other object's satellite; is large enough to be rounded by its own gravity (but not so big that it begins to undergo nuclear fusion, like a star); and has "cleared its neighborhood" of most other orbiting bodies. Yeah, it's a mouthful.
-
- Pluto was among the bodies that didn't make the cut and was re-classified as a dwarf planet. The problem with Pluto, aside from its small size and offbeat orbit, is that it doesn't clear its neighborhood of debris — it shares its space with lots of other objects in the Kuiper Belt. Still, the demotion of Pluto remains controversial.
The IAU planet definition also put other small, round worlds into the dwarf planet category, including the Kuiper Belt objects Eris, Haumea and Makemake.
-
- Ceres, a round object in the Asteroid Belt between Mars and Jupiter, also got the boot. Ceres was considered a planet when it was discovered in 1801, but it was later deemed to be an asteroid. That still didn't quite fit because it was so much larger (and rounder) than the other asteroids. Astronomers instead deemed it a dwarf planet in 2006, although some astronomers like to consider Ceres as a 10th planet (not to be confused with Nibiru or Planet X).
-
- The planet Mercury is the innermost world of our solar system. Zipping around the sun in only 88 days, Mercury is the closest planet to the sun, and it's also the smallest, only a little bit larger than Earth's moon.
-
- Because it is close to the sun, about two-fifths the distance between Earth and the sun, Mercury experiences dramatic changes in its day and night temperatures: Day temperatures can reach a scorching 840 F, which is hot enough to melt lead. Meanwhile on the night side, temperatures drop to minus 290 F.
-
- Mercury has a very thin atmosphere of oxygen, sodium, hydrogen, helium and potassium and can't break-up incoming meteors, so its surface is pockmarked with craters, just like the moon.
-
- Over its four-year mission, NASA's MESSENGER spacecraft revealed incredible new discoveries that challenged astronomers' expectations. Among those findings was the discovery of water ice and frozen organic compounds at Mercury's north pole and that volcanism played a major role in shaping the planet's surface.
-
---------------------- Mercury diameter: 3,031 miles
---------------------- Orbit: 88 Earth days
---------------------- Day: 58.6 Earth days
-
- The second planet from the sun, Venus is Earth's twin in size. Radar images beneath its atmosphere reveal that its surface has various mountains and volcanoes. But beyond that, the two planets couldn't be more different.
-
- Because of its thick, toxic atmosphere that's made of sulfuric acid clouds, Venus is an extreme example of the greenhouse effect. It's scorching-hot, even hotter than Mercury. The average temperature on Venus' surface is 900 F. At 92 bar, the pressure at the surface would crush and kill you. And oddly, Venus spins slowly from east to west, the opposite direction of most of the other planets.
-
-
---------------------- Venus diameter: 7,521 miles
---------------------- Orbit: 225 Earth days
---------------------- Day: 241 Earth days
-
- The third planet from the sun, Earth is a water world, with two-thirds of the planet covered by ocean. It's the only world known to harbor life. Earth's atmosphere is rich in nitrogen and oxygen.
-
- Earth's surface rotates about its axis at 1,532 feet per second, slightly more than 1,000 mph at the equator. The planet zips around the sun at more than 18 miles per second .
-
---------------------- Earth diameter: 7,926 miles
---------------------- Orbit: 365.24 days
---------------------- Day: 23 hours, 56 minutes
-
- The fourth planet from the sun is Mars, and it's a cold, desert-like place covered in dust. This dust is made of iron oxides, giving the planet its iconic red hue. Mars shares similarities with Earth: It is rocky, has mountains, valleys and canyons, and storm systems ranging from localized tornado-like dust devils to planet-engulfing dust storms.
-
- Substantial scientific evidence suggests that Mars at one point billions of years ago was a much warmer, wetter world. Rivers and maybe even oceans existed. Although Mars' atmosphere is too thin for liquid water to exist on the surface for any length of time, remnants of that wetter Mars still exist today. Sheets of water ice the size of California lie beneath Mars' surface, and at both poles are ice caps made in part of frozen water.
-
- In July 2018, scientists revealed that they had found evidence of a liquid lake beneath the surface of the southern pole's ice cap. It's the first example of a persistent body of water on the Red Planet.
-
- Scientists also think ancient Mars would have had the conditions to support life like bacteria and other microbes. Hope that signs of this past life and the possibility of even current lifeforms may exist on the Red Planet has driven numerous space exploration missions and Mars is now one of the most explored planets in the solar system.
-
---------------------- Mars diameter: 4,217 miles
---------------------- Orbit: 687 Earth days
---------------------- Day: Just more than one Earth day (24 hours, 37 minutes)
-
- The fifth planet from the sun, Jupiter is a giant gas world that is the most massive planet in our solar system, more than twice as massive as all the other planets combined. Its swirling clouds are colorful due to different types of trace gases.
-
- And a major feature in its swirling clouds is the Great Red Spot, a giant storm more than 10,000 miles wide. It has raged at more than 400 mph for the last 150 years, at least. Jupiter has a strong magnetic field, and with 75 moons, it looks a bit like a miniature solar system.
-
---------------------- Jupiter diameter: 86,881 miles
---------------------- Orbit: 11.9 Earth years
---------------------- Day: 9.8 Earth hours
-
- The sixth planet from the sun, Saturn is known most for its rings. When polymath Galileo Galilei first studied Saturn in the early 1600s, he thought it was an object with three parts: a planet and two large moons on either side.
-
- Not knowing he was seeing a planet with rings, the stumped astronomer entered a small drawing, a symbol with one large circle and two smaller ones, in his notebook, as a noun in a sentence describing his discovery. More than 40 years later, Christiaan Huygens proposed that they were rings.
-
- The rings are made of ice and rock and scientists are not yet sure how they formed. The gaseous planet is mostly hydrogen and helium and has numerous moons.
-
---------------------- Saturn diameter: 74,900 miles
---------------------- Orbit: 29.5 Earth years
---------------------- Day: About 10.5 Earth hours
-
- The seventh planet from the sun, Uranus is an oddball. It has clouds made of hydrogen sulfide, the same chemical that makes rotten eggs smell so foul. It rotates from east to west like Venus. But unlike Venus or any other planet, its equator is nearly at right angles to its orbit, it basically orbits on its side.
-
- Astronomers believe an object twice the size of Earth collided with Uranus roughly 4 billion years ago, causing Uranus to tilt. That tilt causes extreme seasons that last 20-plus years, and the sun beats down on one pole or the other for 84 Earth-years at a time.
-
- The collision is also thought to have knocked rock and ice into Uranus' orbit. These later became some of the planet's 27 moons. Methane in the atmosphere gives Uranus its blue-green tint. It also has 13 sets of faint rings.
---------------------- Uranus discovery: 1781 by William Herschel
---------------------- Diameter: 31,763 miles
---------------------- Orbit: 84 Earth years
---------------------- Day: 18 Earth hours
-
- The eighth planet from the sun, Neptune is about the size of Uranus and is known for supersonic strong winds. Neptune is far out and cold. The planet is more than 30 times as far from the sun as Earth.
-
- Neptune was the first planet predicted to exist by using math, before it was visually detected. Irregularities in the orbit of Uranus led French astronomer Alexis Bouvard to suggest some other planet might be exerting a gravitational tug. German astronomer Johann Galle used calculations to help find Neptune in a telescope. Neptune is about 17 times as massive as Earth and has a rocky core.
-
---------------------- Neptune discovery: 1846
---------------------- Diameter: 30,775 miles
---------------------- Orbit: 165 Earth years
---------------------- Day: 19 Earth hours
-
- Once the ninth planet from the sun, Pluto is unlike other planets in many respects. It is smaller than Earth's moon; its orbit is highly elliptical, falling inside Neptune's orbit at some points and far beyond it at others; and Pluto's orbit doesn't fall on the same plane as all the other planets, instead, it orbits 17.1 degrees above or below.
-
- From 1979 until early 1999, Pluto had actually been the eighth planet from the sun. Then, on Feb. 11, 1999, it crossed Neptune's path and once again became the solar system's most distant planet, until it was redefined as a dwarf planet. It's a cold, rocky world with a tenuous atmosphere.
-
- Scientists thought it might be nothing more than a hunk of rock on the outskirts of the solar system. But when NASA's New Horizons mission performed history's first flyby of the Pluto system on July 14, 2015, it transformed scientists' view of Pluto.
-
- Pluto is a very active ice world that's covered in glaciers, mountains of ice water, icy dunes and possibly even cryo-volcanoes that erupt icy lava made of water, methane or ammonia.
-
---------------------- Discovery: 1930 by Clyde Tombaugh
---------------------- Diameter: 1,430 miles
---------------------- Orbit: 248 Earth years
---------------------- Day: 6.4 Earth day
-
- Orbits of distant Kuiper Belt objects and the hypothesized Planet Nine. Updated orbital calculations suggest that Planet Nine is an approximately 5-Earth-mass planet that resides on a mildly eccentric orbit with a period of about 10,000 years.
-
- In 2016, researchers proposed the possible existence of a ninth planet, for now dubbed "Planet Nine" or Planet X. The planet is estimated to be about 10 times the mass of Earth and to orbit the sun between 300 and 1,000 times farther than the orbit of the Earth.
-
- Scientists have not actually seen Planet Nine. They inferred its existence by its gravitational effects on other objects in the Kuiper Belt, a region at the fringe of the solar system that is home to icy rocks left over from the birth of the solar system. Also called trans-Neptunian objects, these Kuiper Belt objects have highly elliptical or oval orbits that align in the same direction.
-
- A recent hypothesis proposed September 2019 suggests Planet Nine might not be a planet at all. Instead, it could be a primordial blackhole that formed soon after the Big Bang and that our solar system later captured, according to Newsweek.
-
- Unlike blackholes that form from the collapse of giant stars, primordial black holes are thought to have formed from gravitational perturbations less than a second after the Big Bang, and this one would be so small (5 centimeters in diameter) that it would be challenging to detect. -------------- (Other reviews about planets available):
-
- 3043 - PLANETS - how many are out there? We are content in thinking we have discovered the planets in our solar system. We have eight planets circling he Sun. Nine if you count Pluto. Then more planetoids are being discovered orbiting farther from the Sun than Pluto.
-
- 2666 - PLANET NINE . I always thought that Pluto was Planet Nine. Then Pluto got demoted to a “ Dwarf Planet”. Now astronomers are telling us there are many more dwarf planet out there, and also one “real planet nine“. We still have more to discover in our own Solar System.
-
- 2647 - PLANET NINE - may be a blackhole? One theory is that it is a “blackhole“. Maybe there is an ancient, grapefruit-size blackhole hiding out in our solar system. This tiny, heavy object might in fact take the place of a theoretical planet that might be tugging on other objects in our solar system. This so-called “Planet 9” could explain the math calculations and why we cannot find it.
-
- 2448 - PLANET NINE - could it be a blackhole? Maybe there is an ancient, grapefruit-size blackhole hiding out in our solar system. This tiny, heavy object might in fact take the place of a theoretical planet that might be tugging on other objects in our solar system.
-
- 965 - The chemistry of planet formation. . Astronomers are using 2 different methods to find these planets. The “Transit Method” and the “Radial Velocity Method”. With both of these methods we have to be lucky and happen to be viewing the planet orbits edge-on. If we are viewing the orbits face-on we can never discover planets with these methods.
-
- 935 - Planet temperatures.
-
- 928 - Planet formation. . Astronomers have found more than 4,000 planets in other solar systems. How they formed and how they contain such wide diversity is a new mystery. We thought we had a design for planet formation that matched our Solar System. In contrast, other solar systems are so diverse and supposedly formed out of chaos.
-
- May 4, 2021 PLANETS - in our Solar System? 3148
----------------------------------------------------------------------------------------
----- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
----------------------- --- Tuesday, May 4, 2021 --------------------------------
No comments:
Post a Comment