StarDate

Moon and Spica


Listen Later

When Earth was born, the Sun was fainter than it is today — by about 30 percent. That should have made the young Earth a snowball. But evidence shows that Earth had liquid water on its surface not long after it was formed. That leaves scientists wondering where the extra heat came from.

Some of it might have been provided by the Moon. It was born shortly after Earth itself. A planet as big as Mars slammed into Earth, blasting debris into space. Some of that material quickly coalesced to form one or more moons. Today, only one remains.

The newborn Moon was quite close to Earth — less than one-tenth of its current distance. At that range, its gravitational pull on Earth was much stronger than it is today. That created powerful tides in whatever water stood on the surface — and in the solid planet.

A recent study says those tides would have stretched and compressed rock at and below the surface. That would have generated heat, melting the rocks. That could have boosted the birth of volcanoes, which spewed carbon dioxide and other greenhouse gases into the atmosphere. Combined, that would have warmed the surface by several degrees — accounting for at least some of the heat needed to take up the slack of the weaker Sun.

The Moon is full tonight. It’s the Egg Moon or Grass Moon. And it has a bright companion: Spica, the leading light of Virgo. It rises below the Moon in early evening, and the Moon slides closer to it throughout the night.
 

Script by Damond Benningfield

Support McDonald Observatory

...more
View all episodesView all episodes
Download on the App Store

StarDateBy Billy Henry

  • 4.6
  • 4.6
  • 4.6
  • 4.6
  • 4.6

4.6

251 ratings


More shows like StarDate

View all
Science Friday by Science Friday and WNYC Studios

Science Friday

6,241 Listeners

BirdNote Daily by BirdNote

BirdNote Daily

1,187 Listeners

Planetary Radio: Space Exploration, Astronomy and Science by The Planetary Society

Planetary Radio: Space Exploration, Astronomy and Science

1,335 Listeners

Radiolab by WNYC Studios

Radiolab

44,008 Listeners

Astronomy Cast by Fraser Cain and Dr. Pamela Gay

Astronomy Cast

2,845 Listeners

The 365 Days of Astronomy by 365DaysOfAstronomy.org

The 365 Days of Astronomy

350 Listeners

Universe Today Podcast by Fraser Cain

Universe Today Podcast

549 Listeners

Ask a Spaceman! by Paul M. Sutter

Ask a Spaceman!

828 Listeners

Space Nuts: Astronomy Insights & Cosmic Discoveries by Professor Fred Watson and Andrew Dunkley

Space Nuts: Astronomy Insights & Cosmic Discoveries

228 Listeners

SpaceTime: Your Guide to Space & Astronomy by Stuart Gary

SpaceTime: Your Guide to Space & Astronomy

301 Listeners

Short Wave by NPR

Short Wave

6,236 Listeners

The Supermassive Podcast by The Royal Astronomical Society

The Supermassive Podcast

281 Listeners

NASA's Curious Universe by National Aeronautics and Space Administration (NASA)

NASA's Curious Universe

854 Listeners

Why This Universe? by Dan Hooper, Shalma Wegsman

Why This Universe?

360 Listeners

Crash Course Pods: The Universe by Crash Course Pods, Complexly

Crash Course Pods: The Universe

509 Listeners