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More Trappist-1

October 3, 2017

The almost-full Moon is near the eastern edge of the constellation Aquarius tonight. That puts it just a few degrees from the most populous planetary system other than our own: Trappist-1. Unfortunately, the star at the center of the system is tiny and feeble, so it’s far too faint to see with the eye alone.

The system consists of seven known planets. All of them are rocky worlds, like Earth. The smallest is a small fraction the size and mass of Earth, while the largest is more than half-again Earth’s mass. They orbit the star at ranges of one million to six million miles. And they probably are locked so that the same hemisphere of each world always faces the star.

This configuration means that you’d see quite a show in the night sky of any of these planets. The other planets would all pass quite close, so they’d be big targets. In fact, you’d be able to make out surface features on at least some of the other worlds.

No one knows what the planets might look like. But some of them are at the right temperature for liquid water, so they could have lakes or oceans. The inner planets might be covered by volcanoes — perhaps shooting out plumes that are tall enough to see from the other worlds.

And all of the planets would have great views of the star. Although small and faint, the star might produce magnetic storms that would blast out great streamers of hot gas. That’s a danger to anything that might live on these planets — but an amazing sight.


Script by Damond Benningfield


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