That things don’t last forever, we all know it. After all, we witness cycles of life and death every day. But there are things we are used to think as eternal – like stars and galaxies – even though we’re aware they aren’t. Slightly unsettling is when we actually see things that don’t exist any longer.
A famous case is constituted by the so-called Pillars of Creation, a set of 4-light-year-tall columns located in the Eagle Nebula, 7,000 light years from the Solar System, without any doubt one of the most beautiful objects in our night skies. A new, enhanced photo of them has been recently released by NASA, while the original one was taken in 1995 by the Hubble telescope and used in all astronomy textbooks and websites.
The puzzling point about the Pillars of Creation is that they don’t exist. Not anymore.They were blasted away by a supernova around 6,000 years ago, but the images of that event have still to reach us, even though we can detect the shockwaves advancing toward them with our instruments.
An infrared image taken by the Spitzer Space Telescope has revealed in 2007 a previously unseen supernova (see on the left-end side of the photo) blasting wave heading for them. If estimates are correct, we are going to watch the destruction of the Pillars one thousand year from now, when reality will finally catch up with us. Better than any apocalyptic SF movie (in case you wonder how they look like now, the answer is: we have no idea, likewise the rest of the universe far away from us).
A thousand year from now will be an interesting time to be around. Maybe that will be also the moment Eta Carinae, a giant star mass over 100 times than the Sun and a luminosity a million times brighter, will burst again with another explosion at least as big as the one in the XIX century, when it became the second brightest star in the sky, and will create other spectacular nebulae.