High in the air of WASP-17b are cloud of tiny quartz particles , like minuscule grain of sand . The find is proof of the content of the JWST to dig into the composition of distant planets – in this case , one 1,300 easy years away . It ’s also a great monitor of how expert we have it on Earth .
One of the JWST ’s priority is probing the atmospheres ofplanets revolve other stars . Gas giants make sluttish prey than jumpy planets like our own . For one thing , they have a quite a little more atmosphere to interpolate the incoming starlight . favour fair game are loosely so - called “ red-hot Jupiters ” that orbit so closely to their wizard we can see them crossing oftentimes .
WASP-17b , also known as Ditsö̀ , certainly fits the bill . It has a spate just over half that of Jupiter , but a radius almost doubled , a consequence of the expanding upon grow by its 1,550 K ( 2,800 ° fluorine ) temperature . Ever since its discovery in 2009 as one of the earlyexoplanetdiscoveries , we ’ve known WASP-17b is truly extreme , but had to wait ( andwaitandwait ) for the JWST to know more .
The spectrum from WASP-17, subtracting what is detected when it passes through the planet’s atmosphere to identify the molecules presentImage Credit: NASA, ESA, CSA, Ralf Crawford (STScI)
“ We were tickle ! ” say Dr David Grant of the University of Bristol in astatement . “ We knew from Hubble Observations that there must be aerosols – tiny particles make up cloud or haze – in WASP-17 b ’s standard pressure , but we did n’t expect them to be made of quartz . ”
Quartz is atomic number 14 dioxide , made up of the two most coarse element in Earth ’s freshness , so their mien on other creation is to be require . However , previous passing spicy satellite have been found to have silicates high-pitched in magnesium such asolivine , not quartz as vestal as the okay beach .
Nevertheless , when Grant and colleaguescompared the lightfiltered by WASP-17b ’s standard pressure with that direct from WASP-17 , the major difference was at a wavelength of 8.6 micrometer , ordered with perfect vitreous silica .
“ We fully expect to see magnesium silicates , ” said Dr Hannah Wakeford . “ But what we ’re seeing rather are likely the building blocking of those , the tiny ‘ germ ’ particle needed to form the larger silicate grain we detect in cooler exoplanets and browned dwarfs . ”
base on dot observation previously made using Hubble , the grain are thought to be about 10 nm ( 0.0000004 inch ) across , build them too minor to inspire even the most devoted believer in the power of vitreous silica .
Although primarily hydrogen and atomic number 2 , WASP-17b is so raging it carry atomic number 14 dioxide gas , which condense to microscopic quartz at high altitudes where the atmosphere is thin . However , the planet is almost certainlytidally locked , with one for good star - facing and one Nox - facing side . The crystals are forming crowds at the twilight boundary , the region we can study , and we ca n’t separate how far they stretch forth beyond this region . Grant noted ; “ The wind could be move these tiny glassy particles around at thousands of miles per 60 minutes . ”
The uncovering of a satellite with less than half the density of Saturn revolve a red-faced dwarf stunned astronomers , whocompared it to a marshmallow – WASP-17b ’s density is 2 - 3 times low still , maybe just 8 percent that of water , but it orbits an F6 star topology some 20 percentage more monolithic than the Sun . therefore , in this case , we have a right reason of why this is the typeface . WASP-17b has a quite elongated orbit which , given how close it gets to its star , causes immensetidal flexing . It is think this puffs up its interior while radiotherapy expand its outer layers .
WASP-17b is one of the very few known planet orbiting in the opposite way to its champion ’s spin , indicating something very unmated about its chronicle .
The find is undefended accession inThe Astrophysical Journal Letters .
