Welcome to brain Stuff production of I Heart Radio. Hi brain Stuff. I'm Lauren vogel Bom and this is another classic episode. In this one, we dip into the everyday science of why the stars and our skies, most of which emit fairly constant light, appear to twinkle. Hey, brain Stuff, Lauren Vogel bomb Here. All things considered, our atmosphere is
pretty great. This blanket of nitrogen, oxygen, and other gases keeps the world's temperature nice and habitable while protecting us from harmful U V radiation, to say nothing of this space debris it vaporizes for us. Oh yeah, and without all that oxygen in our atmosphere, animal life couldn't survive on planet Earth. Not a bad resume. But despite its many good qualities, the atmosphere can be a nuisance to
astronomy buffs. That's because it distorts light. At night, the atmosphere makes some heavenly bodies appear to flicker and shimmer. The technical term for this phenomenon is astronomical scintillation. You probably know it by a different name, twinkling like an onion. The atmosphere is made up of layers. At the bottom is the troposphere, which starts right here at ground level on the planet's surface, standing about five to nine miles that's eight to four point five kilometers tall. It's where
most of Earth's weather events take place. The other layers are in ascending order, the stratosphere, mesosphere, thermosphere, and exosphere. There's also a region called the ionosphere, which encompasses parts of both the mesosphere and the thermosphere. These layers have different temperatures. In addition, the air's density varies from level to level. When starlight enters our atmosphere, it runs into
pockets of cool and warm air. The pockets act as big lenses, causing the light to change direction or refract as it passes through them. Yet the lenses are not fixed in place. They move around in a shape as they shift. So does starlight refraction. That's why the stars appear to twinkle. Scintillation affects planets to Mercury, Venus, Mars, and the other planets in our Solar system do twinkle when viewed from Earth on a clear night. So does
our moon. However, the planets twinkled to a barely noticeable degree distance is the main reason stars twinkle. More conspicuously than the planets in our Solar system. Because the former are so far away, each star looks like a single pinpoint of light, a single pixel. You might say. It's a different story for Earth's moon and our neighboring planets, being a lot closer, they are less affected by the atmosphere. Planets and moons appear as tiny disks up in the sky.
The light they emanate comes not from a single point, but from many individual points, all clustered together. These rarely scintillate in unison, which is why planets and moons don't twinkle as dramatically as the stars. So twinkling can only happen an atmosphere is present. It's for this reason that photos taken by the Hubble telescope looks so clear. There
aren't any atmospheric air pockets to refract the starlight. Earthbound astronomers use telescopes with adaptive optics systems to compensate for twinkling, making the stars look more stable. Today's episode is based on the article why do stars Twinkle? On how stuff works dot com, written by Mark Mancini. Brain Stuff is production of by Heart Radio in partnership with how Stuff Works. Dot com and it is produced by Tyler Clang with
assistance from Ramsey Young. For more podcasts from My Heart Radio, visit the air heart Radio app, Apple Podcasts, or wherever you listen into your favorite shows.