Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Friday, July 24, 2020

Portrait of distant worlds

This week's news from astronomy is pretty amazing; we now have the first-ever photograph of an exoplanet system around a star very much like our Sun.

The star is the euphoniously-named TYC 8998-760-1, in the southern hemisphere constellation Musca (the Fly).  It's about three hundred light years away, so not exactly in our back yard, but still fairly close on the astronomical scale.  It, and two of its planets, were featured in a paper by a team led by Alexander Bohn of Leiden University, in the following photograph:

The two exoplanets are denoted with arrows; the other bright points of light near the star are distant stars lying behind the stellar system.

The photograph was taken by the Very Large Telescope array in Chile, which also has a fairly underwhelming name:
Astronomer 1: *takes swig of tequila* "So, what are we gonna name this thing, anyhow?" 
Astronomer 2: *also takes swig of tequila* "Got me.  Maybe name it after Edwin Hubble, or something?" 
Astronomer 1: "No, that's already taken." 
Astronomer 2: "Damn.  Well, okay, what's this telescope's outstanding feature?" 
Astronomer 1: "I dunno.  It's very large, I guess." 
Astronomer 1 and Astronomer 2, together:  "HEYYYYYY....."
Be that as it may, the photograph is stunning.  It bears keeping in mind, though, that the only reason it was possible is because the planets are so different than the ones in the Solar System, even if the star is similar to our Sun (although a lot younger; only an estimate seventeen million years old, so it was forming in the mid-Miocene Epoch, almost fifty million years after the extinction of the dinosaurs).  The two planets in the photograph are both enormous gas giants, the inner one fourteen times the mass of Jupiter, and the outer one six times; and they are very far away from their host star, with the inner one about 160 times further from its star than the Earth is from the Sun, and the outer one twice that far.  To put that in context -- the furthest human-made object, the Voyager 1 spacecraft, that flew out of the Sun's magnetic influence and into interstellar space in 2012, is still closer to the Sun than either of these planets are to its host star.

Nothing precludes this star having other planets, of course.  Multiple-planet systems seem to be the norm, the most famous of which is TRAPPIST-1, which has seven planets -- one of them of Earth-like size, and in the habitable zone, so a prime place to look for signs of life.  The likelihood is that TYC 8998-760-1 has other planets which were too small (or too close to the star) to show up in the photograph.  But as our ability to photograph astronomical objects continues to improve -- maybe with a Very Very Large Telescope -- we might well be able to see some of those, too.

In any case, the photograph released this week from Bohn et al. is breathtaking.  A portrait of two distant worlds in a planetary system very unlike our own in some respects, and startlingly similar in others.  It is a step toward beginning to comprehend the scale of what's out there, in a cosmos that seems to have planets everywhere we look, some of which almost certainly host life.  And maybe, on some planet around a distant star, there's an alien astronomer looking back at the Sun through their own Very Large Telescope, and thinking, "Look at that stellar system.  I wonder what it could be like?"


This week's Skeptophilia book recommendation of the week is about as cutting-edge as you can get, and is as scary as it is fascinating.  A Crack in Creation: Gene Editing and the Unthinkable Power to Control Evolution, by Jennifer Doudna and Samuel Sternberg, is a crash course in the new genetic technology called CRISPR-Cas9 -- the gene-editing protocol that Doudna herself discovered.  This technique allows increasingly precise cut-and-paste of DNA, offering promise in not just treating, but curing, deadly genetic diseases like cystic fibrosis and Huntington's disease.

But as with most new discoveries, it is not without its ethical impact.  The cautious are already warning us about "playing God," manipulating our genes not to eliminate disease, but to enhance intelligence or strength, to change personal appearance -- or personality.

A Crack in Creation is an unflinching look at the new science of gene editing, and tries to tease out the how much of what we're hearing is unwarranted fear-talk, and how much represents a genuine ethical minefield.  Doudna and Sternberg give the reader a clear understanding of what CRISPR-Cas9 is likely to be able to do, and what it won't, and maps out a direction for the discussion to take based on actual science -- neither panic and alarmism, nor a Panglossian optimism that everything will sort itself out.  It's a wonderful introduction to a topic that is sure to be much in the news over the next few years.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

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