Easter sky over Austin, Texas.
Some stars could support as many as seven habitable planets
In recent decades, over 4,000 extrasolar planets have been confirmed beyond our Solar System. With so many planets available for study, astronomers have learned a great deal about the types of planets that exist out there and what kind of conditions are prevalent.
Planetary alignment August, 2020
Saturn, Jupiter, and the Moon in the eastern night sky.
A billion years as a day
My existential and cosmological ramblings with a little dab of Zen and science.
Stars are a good reminder of how the universe is all one and there is only now. This is a photograph of the star Betelgeuse, the 2nd brightest star in the constellation of Orion. It’s nearing the end of its life and has been showing signs that it’s ejecting matter from its surface. It’s a red supergiant nearly 12 times the mass of the Sun, and it is roughly 650ly from us. Light takes 650 years to reach us. Changes on its surface are that old. Astrophysicists are watching for evidence of a supernova.
So let’s forget all that for a moment and look at it from the perspective of 18th Century astronomy. We’re out at night looking at Orion. We’re tracing lines from the feet up to the belt, up the tunic to the shoulder of the arm that’s drawing the bow. And up at the left at the shoulder of the huntsman we see a star that can look pinkish at times.
And a minute later the star explodes.
We take out a notebook and make notes. We describe what we see in every way we can. We write about it for days until it stops being visible in daylight. From where we are in the 1700s the star just blew up. We don’t know about c, or concepts like light-years. We don’t understand that the actual explosion happened sometime in the 11th century during the crusades. This is all happening ‘now.’
And even today, with all our understanding of theoretical astrophysics, whatever we observe, in a sense, is happening in real time…because now is all there is.