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TechnologyWhy are planets all the same shape?

15:42  08 november  2018
15:42  08 november  2018 Source:   popsci.com

‘Trojan’ Asteroids Shed Light On Early Solar System’s Planetary Shake-Up

  ‘Trojan’ Asteroids Shed Light On Early Solar System’s Planetary Shake-Up The shake-up occurred much earlier than previously thought, according to findings of the latest work.Nearly 4.5 billion years ago, the sun formed at the center of a nebula, giving rise to what we know as the solar system. The birth of our star was followed by accretion of material and formation of planets, including gas-giants like Jupiter and rocky worlds like Earth.

But our planet ’s roundness is another story. From Mercury to distant Neptune, our neighbors are shaped like giant balls. To understand why , we have to go all the way back to the birth of a planet —about 4.5 billion years in Earth’s case. Planets form in clouds of dust around new stars.

I am no scientific genius but my first thought is that planets would not be able to stay in their orbit if they were not round. Although, they are not perfectly so. It was struck on its dark side by something that put a dent in it. Dwarf planets are often without a nice spherical shape because they lack the gravity.

Why are planets all the same shape?© NASA NASA earth from space Sometimes scientists like to describe Earth as a blue marble because it’s round and has so much water. Earth’s oceans are pretty special—other places in the solar system have no seas, or any trace of liquid water is locked up under miles of ice. But our planet’s roundness is another story. From Mercury to distant Neptune, our neighbors are shaped like giant balls. Even worlds beyond our solar system are pretty round.

To understand why, we have to go all the way back to the birth of a planet—about 4.5 billion years in Earth’s case. Planets form in clouds of dust around new stars. As specks of dust collide, they stick together, forming bigger and bigger clumps.

NASA telescope discovers two new planets five months after launch

  NASA telescope discovers two new planets five months after launch A planet-hunting orbital telescope designed to detect worlds beyond our solar system discovered two distant planets this week five months after its launch from Cape Canaveral, Florida, officials said on Thursday.NASA's Transiting Exoplanet Survey Satellite, better known as TESS, made an early discovery of "super-Earth" and "hot Earth" planets in solar systems at least 49 light-years away, marking the satellite's first discovery since its April launch. TESS is on a two-year, $337 million mission to expand astronomers' known catalog of so-called exoplanets, worlds circling distant stars.

Why are all planets round in shape ? Planets are round because they are bond together by gravity. Picture a planet as a bunch of rocks floating in They form this shape because the force of gravity wo…rks the same in all directions and it represents the lowest energy state of the body of matter.

If it was a different shape it wouldnt be a planet .

As a planet like Earth grows, its gravity becomes stronger. Earth’s gravity is why we don’t float off into space; when we jump into the air, it pulls us back to the ground. Every object in the universe—including you—tugs at everything else because of gravity. But only when an object becomes really huge (like the Moon or Earth) can we feel this tugging.

Eventually, a brand-new planet gets so big that its gravity is powerful enough to make its surface actually crumple. It’s like how a cardboard box will collapse if you sit on it, explains Mark Sykes, CEO and director of the Planetary Science Institute in Tucson, Arizona. On a new planet, this happens from all directions at once, so the planet is crushed into a round shape.

A lot of other things in space are also round because of their gravity, like the Sun and our Moon. An object has to be pretty big—around 600 miles wide—for this to happen. Smaller things like asteroids and comets, which have weaker gravity, can have pretty weird shapes. Saturn’s moon Prometheus looks like a potato. There’s a comet shaped like a rubber duck floating around our solar system, too.

Massive planets spotted near young star leave astronomers scratching their heads

Massive planets spotted near young star leave astronomers scratching their heads Astronomers have a pretty good handle on how stars and the planets around them form, and it's believed to be a process that takes many millions of years. Our own Solar System is thought to have taken some 500 million years just to get its feet under, but a recent discovery of a young planetary system is causing a bit of confusion among some scientists and challenging that assumption. require(["medianetNativeAdOnArticle"], function (medianetNativeAdOnArticle) { medianetNativeAdOnArticle.

If you look around in our solar system and any other planet around, you might notice that all plants are spheres. Why it is that planets are spheres?

Two questions if I may indulge ewe ? Why are they called Planetary Nebulae ? and why are they not all the same shape ? yes..there are lots of roundy Another possibility is that planets disrupt the flow of material away from the star as the nebula forms. In January 2005, astronomers announced the

But even Earth isn’t a perfect sphere. As the planet spins, land and water reaches off into space, similar to how you have to hold on more tightly to a merry-go-round to stay put the faster it spins. Earth’s gravity is strong enough to keep everything in place while it spins, but it does bulge out a tiny bit at the equator.

The Moon doesn't help, further distorting Earth’s shape. Tides on this blue marble are a result of the moon's gravity pulling at our oceans. But even solid land bulges just a teensy bit in the middle.

Every object in space experiences its own unique push and pull. Mars spins about as fast as Earth does but has less gravity, so it bulges out even more, says Mark Panning, a planetary scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. The dwarf-planet Haumea, which lies beyond Neptune, spins so quickly it’s shaped more like a football than a basketball.

Keep in mind, though, that in the grand scheme of a giant planet, these are really tiny imperfections. If you eyeball Earth or even Mars from space, they’ll look pretty round.

NASA: Kepler Space Telescope is dead, but search for alien life isn't.
The spacecraft, which revealed a universe full of planets that might be similar to our own, is now retired.

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