View of the Month: January 2018

Written in January 2018

One of the most common questions I get when I tell people about the gigantic telescope (it has a 28-inch mirror!) that will be housed as the JGAP observatory is:

"What will we be able to see?"

First and foremost, at this time next year we will be pointing our big scope (and many of the smaller ones, too) at one of the most spectacular objects in the heavens: The Great Orion Nebula (a.k.a "M42").

M42 is the illuminated portion of a an incomprehensibly vast cloud of gas and dust that fills much of the constellation of Orion. At its heart is a small, newborn, cluster of bright stars carving out, and illuminating, a flower-shaped notch.

Though it is over 1500 light-years away, it is visible to the naked eye as the fuzzy middle "star" in the sword of Orion.

The human eye does not easily detect the spectacular splash of color that is seen in photographs, but the blossom-shaped glow that is seen in telescopes is nonetheless ghostly and astonishing and unlike anything you've ever seen on Earth.

This illustration shows _approximately_ what it will look like.

The real thing is better.

M42 can be seen in the winter!

Brad Hoehne
The Anatomy of Jupiter's Clouds

The great planet Jupiter reaches opposition- that time when the planet is most directly opposite the sun in the sky- on May 9, giving observers their best chance of the year to observe the features on this giant planet.  The bands on Jupiter move in different directions around the body of Jupiter.  The lighter bands move in the direction of Jupiter’s rotation, circling the planet faster than the world as a whole.  The dark colored bands move opposite the motion, taking longer to make a complete circuit.   An patient observer with exceptional optics and seeing, would see features in the dark bands fall sluggishly behind those in the light bands as the planet turns on its axis.

Data from NASA’s JUNO spacecraft has, in recent months, given new insights into Jupiter’s makeup, weather, and the motion of these bands.   By measuring the slight changes in acceleration of the JUNO satellite as it swoops a few thousand km from the Jovian cloudtops, astronomers have determined that the motion of the cloudbands we see go far deeper into the body of the planet that had been previously thought- the swirling motion goes as far  as 3000km into the body of Jupiter.  Imagine a mass of air as deep as the continental USA  is tall.

Deeper down, the mass of Jupiter moves as if it were one solid body, much like the interior of the Earth.   It is, however, anything but.  It is a great sea of hydrogen and helium so compressed that the electrons in these elements are squeezed off their nuclei- turning the body of the world into a sphere of liquid metal. 

Brad Hoehne