Wednesday, February 22, 2017

The Seven Daughters of Trappist-1

Trappist-1 is a red dwarf star, much smaller and cooler than the sun. It is about 39 light years from earth, very close as interstellar distances go, although unimaginably far in any other terms. Studies by earth-based telescopes have revealed that it probably has seven planets. All of them are rocky, with masses between 0.41 and 1.38 times that of the earth. They are very close to the sun, with orbital periods between 1.5 and 20 earth days, but because their star is so small and cool some of them probably have temperatures in the same range as the earth. NASA is planning to turn their new Webb Space Telescope on the system as soon as they can get the thing into orbit (2018, they say), and they hope they will be able to figure out if these worlds have atmospheres, and if any of those atmospheres contains free oxygen or other bizarre chemistries that might point to life.

The discovery of rocky planets around red dwarf star is also pretty cool, since they are the most common stars in the galaxy, especially our part; within 30 light years of the earth there are 250 red dwarf stars but only 20 in the same class as our sun. That's a lot of potential planets close enough for us to observe them directly.

It is amazing to me how quickly the discovery of planets around other stars has become routine. The first serious claim was not made until 1988, and that was very controversial; the first widely accepted claim was made in 1992. In the 25 years since the list has grown to more than 3,500 planets, and it gets longer every day.

1 comment:

G. Verloren said...

"It is amazing to me how quickly the discovery of planets around other stars has become routine. The first serious claim was not made until 1988, and that was very controversial; the first widely accepted claim was made in 1992. In the 25 years since the list has grown to more than 3,500 planets, and it gets longer every day."

Historical firsts are often like this. Consider organ transplants.

There had been a series of tissue grafts and replacements throughout the 19th century and into the 20th, but the first modern full organ transplant as we would think of it today occured in 1954, with the transplant of a kidney between two identical twins (thus preventing rejection due to genetic compatibility). Other major organ transplants remained elusive, with lung, heart, and liver transplants taking another decade or so to see any measure of success - and then only rarely.

It wasn't until 1968 with the discovery of Ciclosporin, an immunosupressant that could help prevent biological rejection, that the possibility of regular transplants became feasible. Within twenty years, organ transplants went from being incredibly risky surgeries performed very rarely chiefly for the sake of medical research, to being a reasonably safe, fairly common life-saving operation.

And in the decades since, they've become absolutely routine and utterly normal even to a person in the street, when before they were almost literally unthinkable, the stuff of gruesome fiction, the Frankensteinian dream of a madman.

Consider how quickly we adopted nuclear power in the wake of the Manhattan project. Consider how quickly the airplane became universally adopted. Consider how quickly the automobile supplanted all other forms of road transport. Consider how quickly the railroads killed off the steamboat, and before that how quickly the steamboat killed off the Mississippi's pole barges and rafts, and elevated the region from a sleepy backwater to a thriving commercial artery, only to then revert to being a sleepy backwater once again when the trains took trade further west.