![StarDate artwork](https://is2-ssl.mzstatic.com/image/thumb/Podcasts123/v4/6f/cf/48/6fcf484d-7f86-3a44-e116-c249e0f4760d/mza_6357709967657759596.png/100x100bb.jpg)
Sedna
StarDate
English - July 11, 2024 05:00 - 2 minutes - 1.06 MB - ★★★★★ - 205 ratingsNatural Sciences Science astronomy telescope mcdonald observatory npr sandy wood stargazing sky constellations meteor showers eclipses Homepage Download Apple Podcasts Google Podcasts Overcast Castro Pocket Casts RSS feed
A dwarf planet far from the Sun may spend most of its time outside the Sun’s influence. In fact, it might have come from interstellar space – from another star.
Sedna takes more than 11,000 years to orbit the Sun. It’s passing through the Kuiper Belt – a wide “doughnut” far beyond the orbit of Neptune, the Sun’s most distant major planet. Right now, Sedna’s almost eight billion miles from the Sun – about as close as it ever gets. At its most distant, it’s more than 10 times farther. That places it far beyond the Kuiper Belt – and well outside the “bubble” produced by the Sun’s magnetic field.
Scientists have speculated that Sedna started in the Oort Cloud – a big “shell” of rocky, icy bodies that surrounds the Sun. It could have been pushed into its elongated orbit by the gravity of a passing star. Or it could have been a member of another star system that was pulled away by the Sun.
There’s one other oddity about Sedna’s orbit: It seems to be influenced by the gravity of a much larger but unseen body far from the Sun – a possible “Planet Nine.”
Because Sedna’s so far away, we don’t know a lot about it. It’s probably about 600 miles in diameter. And it’s quite red – an indication that radiation has been zapping its surface for a long, long time. No one has found a moon yet, so it’s hard to measure Sedna’s mass. So we still have a lot to learn about this remote little world far, far from the Sun.
Script by Damond Benningfield