This weekend, powerful winds blasting across Lake Superior created monster waves that exploded like bombs when they struck the shore. My daughter Katherine and I spent some time along the lake, leaning into the wind and watching nature have its way on this watery planet. Wind and water bonded dad and daughter in a shared appreciation of the big lake.
Astronomers are constantly on the lookout for planets orbiting within the habitable zones of their host suns. These are places at the right distance from a star where a rocky planet would be warmed enough for liquid water to pool on its surface. Water is quintessential to life on Earth, so if we’re going to start the search for alien life, a watery planet’s a good choice.
Earth orbits within the sun’s habitable zone. Water does everything here — drips, trickles, percolates, flows, bubbles, sloshes, pools, erodes, shoots, slams and even explodes. The latest tally on the Habitable Exoplanets Catalog lists 53 potential extrasolar planets where liquid water might exist. This is the optimistic number. If we look more conservatively, the tally drops to just 13. The closest watery world beyond the solar system is Proxima Centauri b at 4.2 light years. It circles the star Proxima Centauri, one of three that make up the Alpha Centauri system. Somewhere out there, waves beat a rhythm against the rocky shore under an alien sun.
While on the topic of orbs beyond Earth, the returning moon will engage with Venus Tuesday evening (April 17) during evening twilight. The two will be just 5.5° apart and low in the western sky. They’ll look beautiful together especially with the crescent filled out with ghostly earthshine, light reflected from our planet to the moon and back to our eyes. Add in the pretty Pleiades star cluster, the one with stars shaped like a tiny dipper, and you’ve got a great naked eye event.
Then on Wednesday (April 18), be sure to face west again in late twilight and early nightfall to catch a thicker crescent moon sitting smack in the middle of the Hyades star cluster. Binoculars will pull in many more stars and give the best view of this interesting alignment.