Star Trails: From Backyard Astronomy to Cosmic Wonder27 Sep

There Was a Planet That Swallowed a Moon

What if Venus once had a moon, and then destroyed it?

A new study suggests that under plausible conditions, an ancient Venusian moon could have slowly migrated inward, crossed the Roche limit and ultimately been torn apart or swallowed by the planet. And Venus may not be the only hungry object in our cosmic neighborhood: another recent study explores whether the young Sun could have consumed a super-Earth, leaving subtle chemical and structural fingerprints behind billions of years later.

This week on Star Trails, we're following a cosmic version of the old nursery rhyme "There Was an Old Lady Who Swallowed a Fly." Planets can swallow moons. Stars can swallow planets. Galaxies devour other galaxies. Along the way, we'll explore why orbits aren't permanent, why Earth's Moon is slowly escaping us while Mars's Phobos is falling inward, and how gravity can transform apparently stable systems over astronomical timescales.

Then in the Night Sky Report for September 27 through October 3, autumn has officially arrived. We'll look for Saturn near opposition, a Moon-and-Pleiades pairing, Jupiter and its Galilean moons, and the changing fall sky. We'll also visit a newly discovered crater on the Moon and check in on the fast-moving mystery of Webb's strange Little Red Dots.

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Episoder(127)

The Moon That Sends Us Its Ocean

Saturn has a moon with a hidden ocean, and that ocean is spraying samples of itself into space.Enceladus is only about 310 miles wide, but beneath its brilliant shell of ice lies a global saltwater oc...

11 Okt 34min

A Black Hole Is Pointing at Us

A black hole in our galaxy appears to be aiming a relativistic jet almost directly toward Earth. That sounds like a reasonably good opening line for October.The object, IRAS 18293−0941, is a binary sy...

4 Okt 29min

Dyson Spheres: The Heat Has to Go Somewhere

What if the first evidence of an advanced alien civilization isn’t a message, but a star whose energy books don’t quite balance?This week, we explore the strange history and surprisingly real science ...

13 Sep 23min

Rivers Through the Dark

Galaxies carry the evidence of their past. When the Milky Way captures a dwarf galaxy or tears apart a globular cluster, it leaves behind long, ghostly ribbons of stars called stellar streams. These s...

6 Sep 27min

Little Red Dots at Cosmic Dawn

The James Webb Space Telescope has uncovered hundreds of tiny red points in the early universe. They are extraordinarily compact, unexpectedly bright and strangely quiet in the X-ray and radio wavelen...

30 Aug 27min

Did the Milky Way Flip?

The Milky Way looks permanent from our place inside it, a great band of stars stretching across the night sky. But new research suggests our galaxy may once have been oriented in a completely differen...

16 Aug 35min

When Black Holes Twist Spacetime

What happens when a black hole spins? According to general relativity, it doesn't simply rotate in space, it actually drags spacetime around with it.This episode explores the strange phenomenon known ...

2 Aug 38min