Tag: planets

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You wouldn’t think that books about astronomy and archaeology would have a lot in common, but Four Lost Cities (Annalee Newitz) and Under Alien Skies (Phil Plait) pack some odd similarities.

Both are about places we (mostly) can’t visit in person: Faraway planets in one case, the distant past in the other.

We have to piece together parts of the experience from what has come to us through time or through space: Telescopic observations, space probes, spectral analysis, and our understanding of physics — ruins, artifacts, aerial surveys and
what we know about people (both contemporary and in general).

For some sites we have very detailed and solid information: Angkor’s stone temples are still standing. Pompeii was well-preserved under volcanic ash and we still have first-hand writings about the city and its destruction. Mars and the moon have been extensively surveyed, including multiple landers and photographs from the surface. (And, in the case of the moon, a handful of people!)

Others require a lot of speculation: There’s a solid core of what we’ve figured out about Cahokia, but a lot of unknowns that we can sorta-kinda extrapolate from the histories and tales of surviving tribes in the area — but only to a point. Similarly, we know the rough structure of the TRAPPIST-1 solar system and some of its planets, but we have to speculate: if one of the planets in the habitable zone actually is habitable, what conditions would that require?

Both include major discoveries made within the last decade: Pluto and Charon were just a pair of dots until the New Horizons mission flew past it in 2015, bringing us pictures and measurements and so much data it took months just to download it from the probe back to Earth. Lidar surveys at Angkor in 2012 revealed the foundations of a vast metropolitan area around the temple complexes, upending our sense of how big the city was and identifying new sites to investigate.

It’s kind of funny how I read them so close together. Synchronicity and all that. They’re also both good (see also my review of Four Lost Cities and review of Under Alien Skies), and I’d definitely recommend them!

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A photo of Venus and Jupiter close together in tonight's sky, and a close-up that appears to have very blurry images of Jupiter's moons.

Dark blue sky, blurry bushes off to the right. In the middle of the sky are two bright spots right next to each other, the right one noticeably brighter.

With rainstorms for the first half of the week, I figured the sky would be clouded over, and I completely forgot about the conjunction of Venus and Jupiter tonight.

Despite wind, rain and even hail today, it cleared up this afternoon. I happened to run out for groceries and looked up from the parking lot to see a blue sky with Venus and Jupiter right next to each other!

I snapped a quick shot with my phone. And then got out the good camera and tripod when I got home.

And…I think I may have caught some of Jupiter’s moons?!?

Closeup: two white circles against a dark blue background. The one on the right is bigger and has diffraction rays radiating from it. The one on the left doesn't, but there are two faint, blurry dots above it aligned with the disc.

The brighter planet to the right is Venus. The almost-as-bright one to the left is Jupiter. Venus shows diffraction rays, but Jupiter doesn’t…but those dots lined up on one side of it? They’re in the right location to be Callisto, Ganymede and (possibly) Io!

I’ve got to remember to use the telephoto after getting the wide shot the next time I’m taking night sky photos with planets. Just in case.

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I remember being bowled over when astronomers first detected planets around other stars. Now they’ve actually managed to get pictures!

Of course, they’re about as detailed as pictures of the stars at a science-fiction convention panel taken from the back of the room, or the band on stage from the upper-top-fifth-tier seating (see! that dot there is so-and-so!), but still…it’s a start.

There’s one photo from Hubble of the planetary debris disc around Fomalhaut, with a little dot that apparently has been tracked in other images, consistent with being in orbit around the star. It’s estimated at being about the size of Jupiter and about four times as far out from its star as Neptune is from the sun.

Meanwhile: consider that we can see something the size of Jupiter even though it’s 25 light years away!

Then there’s one from the Gemini North telescope that has actually caught two planets in orbit around a star called HR 8799 — a photo of a planetary system!

Update: Hubblesite has more on Fomalhaut including this image showing Fomalhaut B’s location in 2004 and 2006: