Favorite numbers
Why does each cell in our body have 90 trillion atoms, roughly the same as the number of stars in our home galaxy cluster?
Posts Tagged 'night sky'
The worst time for clouds
On Saturday and Sunday nights, Dec. 15 and 16, Bob expects Comet Wirtanen to achieve naked-eye visibility – the first comet in years to do so.
Comet over the Hudson Valley and other cool stuff for December
Comet Wirtanen will soon pay Earth its closest-ever visit. It should be large and blobby-looking, appearing as a fuzzy glob the size of the full Moon.
Going to Mars…or at least gazing at it
The Martian surface air is 30 times thinner than the air atop Mount Everest. And if that weren’t bad enough, all that thin, barely-there gas is carbon dioxide: no oxygen. You can’t breathe there.
The consummate sky-speaker
One word is so consistently mispronounced that I’ve been repeatedly corrected when I say it the right way, which is why it drives me bonkers.
Find the black hole in the center of our galaxy this weekend
Friday-Saturday, Sept. 14-15: There’s probably a supermassive black hole in the core of every galaxy. Ours has the weight of four million Suns.
The astonishing CZA: How to find the upside-down rainbow
A rainbow requires a sunshower. It must be raining. But the CZA can appear against a blue sky.
How might extraterrestrials communicate with us?
We always assume aliens would know about circles and pi, and realize that hydrogen is the element that dominates the universe, even though most humans don’t know these things.
The year’s best stars
This week we face into the winter Milky Way, the spiral arm that’s opposite the galactic core. The Aztecs and Mayas regarded this luminescent band as the path taken by the newly departed en route to heaven. In medieval Europe it was called by its Latin name, Via Galactica, meaning “Milk Street.”
Starry, starry weekend – and a bloodless Blood Moon
Of the ten first-magnitude stars in the heavens, eight of them will surround the Moon. You’ll notice that the star directly below the Moon is also the very brightest. This blue gem is the famous Dog Star: Sirius. It also happens to be the very closest star we can ever see from New York State.