Wednesday, January 23, 2013

Take a Look at the Night Sky

What would it take to get you to look at the night sky, seriously look? A naked-eye supernova? Last time that occurred was 1987 and it was only visible from the Southern Hemisphere, and then it wasn’t really all that bright. The supernova of 1054 that created the Crab Nebula in Taurus the Bull was visible in the daylight for 2 weeks and visible at night whenever it was up for more than 2 years.

How about a major comet? We have one of those coming. Well, maybe, and that’s the problem with major comets. The brightest are first-time visitors to the inner solar system, or at the least one of the very few times they have come in this close. Young comets –ones that have made few, if any, previous visit to the inner solar system – have lots of fresh ices covering them. As these approach the sun, the tremendous heat vaporizes the ices (technically, the ices are sublimated, but the differences are subtle) and solar wind and magnetic field blow the gas dust off of the comet, creating a long, bright tail easily visible from Earth. They become brightest if they pass quite close to the sun to feel more of its tremendous heat.

And there’s the rub. The brightest young comets are those that pass closest to the sun, and therefore generate huge tails to reflect sunlight to create a dazzling display from Earth. But many comets are rather fragile, like a loosely-packed snowball. Passing close enough to the sun to create a brilliant display may also shatter them. On coming around the sun, to the anticipation of sky watchers on Earth, they instead become a major cometary dud. This is not uncommon in the astronomical world.

What if you woke up tomorrow and learned that a 50-mile-wide asteroid was streaking straight towards Earth. Remembering that an asteroid a “mere” 6 miles across wiped out the dinosaurs, do you becomes a sky watcher or do you bury yourself and your family as far underground as you can?

That’s not really a useful scenario for the purposes of this blog. I want to know what will make you become a lover of the night sky, not fearful of it.

How about a diamond bigger then our entire planet? That you can see in the night sky, right now? Would THAT pique your interest?

Then head outside tonight. Look to the east to find Cancer, the Crab. The shoulders of Orion point eastward more or less to it. See the main star chart. After locating Cancer in the east, go to the detailed star chart centered on Cancer. Using this chart, locate 55 Cancri. You’ll likely need binoculars, and you may need to go to a darker location then your backyard.

February 1, 2013, 10:00 pm.
55 Cancri has 5 known planets. The smallest one, designated 55 Cancri e, is abut twice as large and 8time more massive than Earth. Earth’s crust is dominated by oxygen, comprising 46.6% of the elemental composition, mostly in the form of oxides of silicon, aluminum, magnesium and other metals. Carbon makes up a mere 0.03% of Earth’s crust.

But 55 Cancri was born in a different environment than was Earth. Its crust contains a very high proportion of carbon, the stuff of life, of carbon dioxide, of graphite – and of diamond. Scientists estimate that one-third of this planet, as much as three Earth masses, may be solid diamond.

Would a diamond planet get you outside to look at the sky?

Close-up of Cancer and finder for 55 Cancri

1 comment:

  1. What gets me to look at the night sky? My excited four-year-old. He wants a "space telescope" for his birthday party--which he'd like to be "a space party on a live volcano." He pointed out Venus beside the moon the other night. I think he'll love to hunt for a diamond planet. Thanks, Wayne!